Quan (Donny) V. Hoang, MD, PhD

All Publications

• Shorter Viewing Distance Reduces Contrast in Man-Made Environments. Ophthalmology science Myles, W. E., McFadden, S. A., Hoang, Q. V. 2026; 6 (1): 100962

  Abstract

  Myopia is associated with increased near-work, time spent indoors, and urban environments. This may in part stem from the spatial frequency (SF) composition of the visual environment in such scenarios compared to nature. We investigated the SF content of natural and man-made environments and how the relative contrast experienced may be affected by viewing distance.Experimental study of environmental contrast.Digital images (n = 594) from natural, mixed-urban, urban, and indoor environments across Singapore.The fast Fourier transform was computed and radially averaged, and the slope of the amplitude spectra with SF was determined. The total contrast energy within each SF octave (f-2f) was measured to determine exposure deficits between environments and whether environmental contrast was scale invariant (unaffected by changes in viewing distance).Environment differences in SF gradient, total contrast, and scale invariance.As expected, indoor environments displayed the steepest SF gradients at -1.36 ± 0.1, more than urban (-1.22 ± 0.1, P < 0.01), mixed-urban (-1.09 ± 0.1, P < 0.01), and natural (-1.00 ± 0.1, P < 0.01) environments. Specifically, mixed-urban, urban, and indoor environments all lacked contrast at middle and higher SFs compared with natural scenes (P < 0.01 each). Contrast energy/octave was approximately equal for natural environments, signifying the relative SF composition was scale invariant. This was not true for man-made environments. Contrast energy/octave decreased as a function of SF in mixed-urban, urban, and most rapidly in indoor environments (P < 0.001 each), meaning the total contrast experienced in such environments is directly dependent on viewing distance. Consequently, halving viewing distance when indoors would reduce total perceived middle SF contrast by 35%, despite indoor environments already being deficient compared to nature.The SF content of natural environments is consistent regardless of viewing distance, signifying scale invariance. This does not apply in man-made environments where contrast at all SFs directly depends on viewing distance. This implies that shorter viewing distances in man-made environments further exacerbate inherent deficits in middle and higher SF contrast, and thus these environments may fail to stimulate the eye with sufficient contrast compared to natural environments, possibly explaining why such environments induce myopia.The authors have no proprietary or commercial interest in any materials discussed in this article.

  View details for DOI 10.1016/j.xops.2025.100962

  View details for PubMedID 41321842

  View details for PubMedCentralID PMC12661147

• Association Between Pigmentation Heritage and Susceptibility to Experimentally Induced Myopia: Crossbreeding Insights From Albino and Pigmented Guinea Pigs. Investigative ophthalmology & visual science Jiang, L., Dan, Y. S., Myles, W. E., Seah, S. H., Koh, J. H., Khine, M. T., Schmetterer, L., Barathi, V. A., Hoang, Q. V. 2025; 66 (12): 47

  Abstract

  To investigate how pigmentation heritage affects susceptibility to form deprivation myopia (FDM) through crossbreeding myopia-susceptible albino and myopia-resistant pigmented guinea pigs (GPs).Ninety GPs (albino: n = 29, pigmented: n = 29, F1 crossbred: n = 32) were studied. Eye parameters were measured using retinoscopy and A-scan ultrasound. Scotopic electroretinograms were recorded by full-field electroretinography in 36 naive GPs at 1 and 5 weeks of age. Monocular form deprivation (FD) was applied from 1 to 5 weeks of age in 27 GPs, with 27 littermates as controls. The retina, choroid, and sclera were imaged using optical coherence tomography. From control GPs at 5 weeks, scleral melanin was assessed histologically; choroidal melanin and tyrosinase activity in the choroid and sclera were quantified biochemically.Crossbreds had a pigmented appearance, and choroidal thickness (ChT, 100 ± 19 µm) was thicker than in albino GPs (69 ± 12 µm, P < 0.001) but thinner than in pigmented GPs (124 ± 19 µm, P = 0.004). Choroidal melanin content and tyrosinase activity followed similar patterns and were significantly different (one-way ANOVA): highest in pigmented GPs, intermediate in crossbreds, and undetectable in albinos. Albinos exhibited the largest a-wave amplitudes across the intensity-response functions among the three breeds. Crossbreds displayed a monotonic b-wave intensity-response function, similar to but with higher amplitudes than pigmented GPs, whereas albinos showed a bell-shaped response pattern before the second rise. FD induced significant myopic shift and axial elongation in albinos (spherical equivalent [SE]: -7.83 ± 4.74 D, P = 0.001; axial length [AL]: 0.20 ± 0.14 mm, P = 0.003) and crossbreds (SE: -5.42 ± 2.90 D, P < 0.001; AL: 0.17 ± 0.09 mm, P = 0.001). Pigmented GPs showed a mild myopic shift (-2.08 ± 1.93 D, P = 0.01) with no significant AL changes (0.03 ± 0.08 mm, P = 0.357). FDM severity differed across breeds (SE: P = 0.006, AL: P = 0.004); thicker baseline ChT was associated with less FDM in crossbreds (P = 0.027) and reduced axial elongation in albinos (P = 0.004); retinal and scleral thicknesses were nonpredictive.Crossbreeding improved retinal function and choroidal morphology, while preserving susceptibility to FDM, suggesting a partial restoration of myopia-inducible mechanisms inherited from the albino lineage. These findings support the value of the crossbred model for investigating retinal and choroidal regulation in myopia.

  View details for DOI 10.1167/iovs.66.12.47

  View details for PubMedID 40970666

  View details for PubMedCentralID PMC12453062

• The Distribution of Spatial Contrast in Manmade Environments Produces Regional Visual Form Deprivation. Investigative ophthalmology & visual science Myles, W. E., McFadden, S. A., Hoang, Q. V. 2025; 66 (11): 42

  Abstract

  Children who spend less time outdoors or who live in urban areas are more likely to develop myopia (short-sightedness). This may stem from the altered spatial distribution of contrast in manmade environments, which contain large featureless surfaces that may potentially produce regional environmental form deprivation (eFD).Images (n = 590) from natural, mixed-urban, urban, and indoor environments, were subdivided into 36 × 36 zones (1.6° × 1.2° visual angle). The weighted contrast energy (CEw) of each zone was calculated by filtering the fast Fourier transform with a filter describing the contrast sensitivity of the human retina at that eccentricity. Zones with less CEw than in images taken through white Perspex ocular diffusers that induce form-deprivation myopia in guinea pigs were classified as eFD. The spatial complexity of CEw signals across the visual field were compared among the environments.Featureless manmade structures such as blank walls, ceilings, and roads contain low CEw and thus cause regional eFD, particularly when present in the peripheral retina where spatial resolution is low. Based on the images analyzed from indoor environments, 29.5% of the human visual field would potentially experience eFD, a percentage greater than that likely experienced in outdoor urban (15.2%, P < 0.001), mixed-urban (6.7%, P < 0.001), and natural (2.8%, P < 0.001) environments. The complexity of the contrast energies perceived across the visual field were also significantly less in indoor environments than in all other settings, meaning eye movements are less likely to result in a change in contrast, thus regional eFD is more likely to be temporally maintained. Furthermore, this effect was exaggerated in the visual periphery during gaze-limiting tasks such as reading or using a mobile phone.Widespread eFD is potentially experienced across the visual field in manmade environments. The extensive peripheral eFD and diminished contrast complexity of manmade environments suggest that gaze-limiting activities such as reading or using a mobile phone result in extended periods of peripheral eFD, which may contribute to myopia development. Therefore, enhancing the distribution of contrast in artificial environments to limit regional eFD may serve to prevent myopia onset.

  View details for DOI 10.1167/iovs.66.11.42

  View details for PubMedID 40824242

  View details for PubMedCentralID PMC12366869

• Can we predict which high myopes will develop pathological myopia? Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Hoang, Q. V., Flitcroft, I., Rizzieri, N. 2025; 45 (4): 906-910

  View details for DOI 10.1111/opo.13462

  View details for PubMedID 40062507

  View details for PubMedCentralID PMC12087808

• Comparing IOP-Induced Scleral Deformations in the Myopic and Myopic Glaucoma Spectrums. Investigative ophthalmology & visual science Chuangsuwanich, T., Tun, T. A., Braeu, F. A., Chong, R. S., Wang, X., Ho, C. L., Aung, T., Girard, M. J., Hoang, Q. V. 2024; 65 (13): 54

  Abstract

  To compare changes in macular curvature following acute IOP elevation across a range of myopic conditions.We studied 328 eyes from 184 subjects, comprising 32 emmetropic controls (between +2.75 and -2.75 diopters), 50 eyes with high myopia (<-5 diopters; HM), 108 highly myopic with glaucoma (HMG) and 105 pathologic myopia (PM) eyes, and 33 PM with staphyloma (PM+S) eyes. For each eye, we imaged the macula using optical coherence tomography (OCT) under the baseline condition and under acute IOP elevation (to ∼40 mm Hg) achieved through ophthalmodynamometry. We manually aligned the scans (baseline and IOP elevation) using three vascular landmarks in the macula tissue. We then automatically segmented the sclera and the choroid tissues using a deep learning algorithm and extracted the sclera-choroid interface. We calculated the macula curvatures, determined by the radius of curvature of the sclera-choroid interface in the nasal-temporal and superior-inferior direction. Differences in macula curvatures between baseline and elevated IOP scans were calculated at corresponding locations, and the mean curvature difference was reported for each eye.IOP elevation resulted in a significantly higher macula curvature change along the nasal-temporal direction in the PM+S (13.5 ± 8.2 × 10-5 µm-1), PM (9.0 ± 7.9 × 10-5 µm-1), and HMG (5.2 ± 5.1 × 10-5 µm-1) eyes as compared to HM (3.1 ± 2.7 × 10-5 µm-1) eyes (all P < 0.05). Interestingly, HM and HMG eyes had the same curvature change in the nasal-temporal direction as emmetropic control eyes (4.2 ± 4.3 × 10-5 µm-1).Our findings indicate that the macula in HMG, PM, and PM+S eyes showed greater curvature changes under IOP elevation compared to HM and emmetropic eyes. These preliminary results suggest that HM eyes with conditions such as glaucoma or staphyloma are more sensitive to acute IOP elevation.

  View details for DOI 10.1167/iovs.65.13.54

  View details for PubMedID 39585674

  View details for PubMedCentralID PMC11601134

• Distortion-Corrected Posterior Ocular Shape in Myopic Eyes Assessed by Ultrawide OCT Detects Deformations Associated With Vision-Threatening Changes. Investigative ophthalmology & visual science Tan, B., Shah, J. N., McNabb, R. P., Jayaraman, S., Wong, D., Chua, J., Ang, M., Saw, S. M., Jonas, J. B., Kuo, A. N., Hoang, Q. V., Schmetterer, L. 2024; 65 (13): 22

  Abstract

  To develop a quantitative tool for assessing the posterior ocular shape using widefield, volumetric optical coherence tomography (OCT) in eyes with myopia.This observational, cross-sectional study included 178 eyes from 113 participants. Participants underwent a standardized eye examination, including ocular biometry and a custom ultrawide OCT. True ocular shape was reconstructed by tracing the beam propagation from the system to the posterior eye. Gaussian curvature quantified the localized ocular shape, which was further categorized into five distinct categories. An ocular shape irregularity (OSI) was calculated using principal component analysis. Linear regression with breakpoints analyzed the relationship between ocular shape parameters and axial length (AL).Increased curvature mean and variance were associated with more severe myopia (P < 0.001). Curvature categories (convex, normal, concave, and highly concave) differed significantly between the groups (all P < 0.001). Their correlations with AL revealed significant breakpoints between 27.1 and 27.2 mm. OSI, as a single metric for quantifying ocular shape distortion, was associated with more severe myopia (P < 0.001), and its correlation with AL revealed a breakpoint at 27.2 mm with a fourfold increase in slope steepness beyond this pivot. Determination of OSI was highly reproducible and could also be obtained with fewer scans.Eyes exceeding 27.2 mm in length exhibit pronounced shape changes. Our framework can be seamlessly integrated into commercial OCTs for ocular shape deformation detection, which could aid in identifying eyes with pathologic myopia.

  View details for DOI 10.1167/iovs.65.13.22

  View details for PubMedID 39535789

  View details for PubMedCentralID PMC11572758

• In-vivo high-frequency quantitative ultrasound-derived parameters of the anterior sclera correlated with level of myopia and presence of staphyloma. Clinical & experimental ophthalmology Hoerig, C., Hoang, Q. V., Mamou, J. 2024; 52 (8): 840-852

  Abstract

  A high-frequency point-of-care (POC) ultrasound instrument was used to evaluate the microstructural and biomechanical properties of the anterior sclera in vivo using parameters computed from quantitative ultrasound (QUS) methods.In this cross-sectional study, both eyes of 85 enrolled patients were scanned with the POC instrument and ultrasound data were processed to obtain QUS parameters. Pearson correlation and multi-linear regression were used to identify relationships between QUS parameters and refractive error (RE) or axial length. After categorising eyes based on RE, binary support vector machine (SVM) classifiers were trained using the QUS or ophthalmic parameters (anterior chamber depth, central corneal thickness, corneal power, and intraocular pressure) to classify each eye. Classifier performance was evaluated by computing the area under the receiver-operating characteristic curve (AUC).Individual QUS parameters correlated with RE and axial length (p < 0.05). Multi-linear regression revealed significant correlation between the set of QUS parameters and both RE (R = 0.49, p < 0.001) and axial length (R = 0.46, p = 0.001). Classifiers trained with QUS parameters achieved higher AUC (𝑝 = 0.06) for identifying myopic eyes (AUC = 0.71) compared to classifiers trained with ophthalmic parameters (AUC = 0.63). QUS-based classifiers attained the highest AUC when identifying highly myopic eyes (AUC = 0.77).QUS parameters correlate with progressing myopia and may be indicative of myopia-induced microstructural and biomechanical changes in the anterior sclera. These methods may provide critical clinical information complementary to standard ophthalmic measurements for predicting myopia progression and risk assessment for posterior staphyloma formation.

  View details for DOI 10.1111/ceo.14415

  View details for PubMedID 38964827

  View details for PubMedCentralID PMC11560725

• Biomechanical changes occur in myopic choroidal stroma and mirror those in the adjacent sclera. Communications engineering Ito, K., Hoerig, C., Dan, Y. S., McFadden, S. A., Mamou, J., Hoang, Q. V. 2024; 3 (1): 139

  Abstract

  Retina-derived growth signals relayed from the choroid to the sclera cause remodeling of the extracellular scleral matrix, resulting in myopic ocular elongation. However, to the best of our knowledge, no studies have assessed changes in choroidal stromal biomechanical properties during myopia progression. Here we utilized 7 µm-resolution scanning acoustic microscopy (SAM) to assess biomechanical properties (bulk modulus (K) and mass density (rho)) of choroidal stroma from guinea pig eyes with form-deprivation (FD) induced myopia. The choroidal stroma had considerable intrinsic strength arising from its biomechanical properties and these were differentially affected by myopia in central and peripheral regions. Choroidal stromal biomechanical values were also highly correlated with those in adjacent scleral regions, and the choroidal stromal-scleral association was stronger in myopic eyes. Biomechanical changes observed in the choroidal stroma of myopic eyes were mirrored to those observed in the adjacent sclera. These findings suggest that choroidal stromal remodeling may accompany myopia and open the door to the source of the signals that cause scleral remodeling in myopia.

  View details for DOI 10.1038/s44172-024-00280-7

  View details for PubMedID 39384899

  View details for PubMedCentralID PMC11464896

• Key role for inflammation-related signaling in the pathogenesis of myopia based on evidence from proteomics analysis. Scientific reports Jiang, L., Koh, J. H., Seah, S. H., Dan, Y. S., Wang, Z., Chan, X., Zhou, L., Barathi, V. A., Hoang, Q. V. 2024; 14 (1): 23486

  Abstract

  The mechanisms underlying myopia pathogenesis are not well understood. Using publicly-available human and animal datasets, we expound on the roles of known, implicated proteins, and new myopia-related signaling pathways were hypothesized. Proteins identified from human serum or ocular fluids, and from ocular tissues in myopic animal models, were uploaded and analyzed with the QIAGEN Ingenuity Pathway Analysis (IPA) software (March 2023). With each IPA database update, more potentially-relevant proteins and signaling pathways previously unavailable during data acquisition are added, allowing extraction of novel conclusions from existing data. Canonical pathway analysis was used to analyze these data and calculate an IPA activation z-score-which indicates not only whether an association is significant, but also whether the pathway is likely activated or inhibited. Cellular immune response and cytokine signaling were frequently found to be affected in both human and animal myopia studies. Analysis of two publicly-available proteomic datasets highlighted a potential role of the innate immune system and inflammation in myopia development, detailing specific signaling pathways involved such as Granzyme A (GzmA) and S100 family signaling in the retina, and activation of myofibroblast trans-differentiation in the sclera. This perspective in myopia research may facilitate development of more effective and targeted therapeutic agents.

  View details for DOI 10.1038/s41598-024-67337-7

  View details for PubMedID 39379387

  View details for PubMedCentralID PMC11461836

• Posterior scleral birefringence measured by triple-input polarization-sensitive imaging as a biomarker of myopia progression. Nature biomedical engineering Liu, X., Jiang, L., Ke, M., Sigal, I. A., Chua, J., Hoang, Q. V., Chia, A. W., Najjar, R. P., Tan, B., Cheong, J., Bellemo, V., Chong, R. S., Girard, M. J., Ang, M., Liu, M., Garhöfer, G., Barathi, V. A., Saw, S. M., Villiger, M., Schmetterer, L. 2023; 7 (8): 986-1000

  Abstract

  In myopic eyes, pathological remodelling of collagen in the posterior sclera has mostly been observed ex vivo. Here we report the development of triple-input polarization-sensitive optical coherence tomography (OCT) for measuring posterior scleral birefringence. In guinea pigs and humans, the technique offers superior imaging sensitivities and accuracies than dual-input polarization-sensitive OCT. In 8-week-long studies with young guinea pigs, scleral birefringence was positively correlated with spherical equivalent refractive errors and predicted the onset of myopia. In a cross-sectional study involving adult individuals, scleral birefringence was associated with myopia status and negatively correlated with refractive errors. Triple-input polarization-sensitive OCT may help establish posterior scleral birefringence as a non-invasive biomarker for assessing the progression of myopia.

  View details for DOI 10.1038/s41551-023-01062-w

  View details for PubMedID 37365268

  View details for PubMedCentralID PMC10427432

• Scleral growth stunting via sub-Tenon injection of cross-linking solutions in live rabbits. The British journal of ophthalmology Hoang, Q. V., Wen, Q., Paik, D. C., Chun, Y. Y., Silverman, R., Nagasaki, T., Trokel, S. L., Zyablitskaya, M. 2023; 107 (6): 889-894

  Abstract

  Scleral cross-linking is a potential method to inhibit axial elongation of the eye, preventing the progression of pathological myopia. Formaldehyde releasers, which are common preservatives found in cosmetics and ophthalmic solutions, have been shown to be not only effective in cross-linking corneal collagen in vitro and in vivo, but also have minimal toxicity effects on the eye. The present study aims to evaluate the efficacy of scleral cross-linking using sodium hydroxymethylglycinate (SMG) to inhibit eye growth using an in vivo rabbit model.A cross-linking solution containing 40 mM SMG was delivered to the sub-Tenon's space behind the equator. The application regimen included a two-quadrant injection performed five times over 2 weeks on New Zealand White rabbits (n=5, group 1), and one-time injection followed for up to 5 days on Dutch-Belted rabbits (n=6, group 2). Group 1 was monitored serially for axial length changes using B-scan ultrasound for 5-6 weeks. Group 2 was injected with a higher viscosity solution formulation. Both groups were evaluated for thermal denaturation temperature changes of the sclera postmortem.Axial growth was limited by 10%-20% following SMG treatment as compared with the untreated eye. Thermal denaturation analysis showed increased heat resistance of the treated eyes in the areas of injection. Overall, the SMG treatment inhibited eye growth with few side effects from the injections.Cross-linking solutions delivered via sub-Tenon injection provide a potential method for limiting axial length growth in progressive myopia and could be used as a potential treatment for myopia.

  View details for DOI 10.1136/bjophthalmol-2021-319427

  View details for PubMedID 34670748

  View details for PubMedCentralID PMC9018885

• High-frequency ultrasound point-of-care device to quantify myopia-induced microstructural changes in the anterior sclera. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Hoerig, C., Hoang, Q. V., Aichele, J., Catheline, S., Mamou, J. 2023; 43 (3): 544-557

  Abstract

  To develop a point-of-care (POC) device using high-frequency ultrasound (US) for evaluating microstructural changes in the anterior sclera associated with myopia.The proposed POC device must satisfy four primary requirements for effective clinical use: the measurement component is handheld; the software must be simple and provide real-time feedback; patient safety and health data security requirements set forth by relevant governing bodies must be satisfied and the measurement data must have sufficient signal-to-noise ratio (SNR) and repeatability. Radiofrequency (RF) echo data acquired by the POC device will be processed using our quantitative US methods to characterise tissue microstructure and biomechanical properties.All stated requirements have been met in the developed POC device. The high-frequency transducer is housed in a custom, 3D-printed, pen-like holder that allows for easy measurements of the anterior sclera. Custom software provides a simple interface for data acquisition, real-time data display and secure data storage. Exposimetry measurements of the US pressure field indicate device compliance with United States Food and Drug Administration limits for ophthalmic US. In vivo measurements on a volunteer suggest the RF data SNR and acquisition consistency are suitable for quantitative analysis.A fully functioning POC device using high-frequency US has been created for evaluating the microstructure of the anterior sclera. Planned studies using the POC device to scan the eyes of myopia patients will help clarify how the anterior sclera microstructure may be affected by myopia. If effective, this portable, inexpensive and user-friendly system could be an important part of routine eye examinations.

  View details for DOI 10.1111/opo.13122

  View details for PubMedID 36943177

  View details for PubMedCentralID PMC10183215

• Biomechanical changes in myopic sclera correlate with underlying changes in microstructure. Experimental eye research Hoerig, C., McFadden, S., Hoang, Q. V., Mamou, J. 2022; 224: 109165

  Abstract

  Myopia alters the microstructural and biomechanical properties of the posterior sclera, which is characterized as a layered structure with potentially different inter-layer collagen fibril characteristics. Scanning acoustic microscopy (SAM) has been used to investigate how the micron-scale bulk mechanical properties of the posterior sclera are affected by myopia. Other investigators have employed second harmonic generation (SHG) imaging to characterize the collagen microstructure of tissues. In the present study, SAM and SHG imaging were used to investigate the existence of biomechanically-distinct scleral layers and identify relationships between mechanical properties and tissue microstructure in myopic guinea pig (GP) eyes. Diffusers were worn over the right eyes of six, 1-week-old GPs for one week to induce unilateral form-deprivation myopia. GPs were euthanized, enucleated, and eyes were cryosectioned. Twelve-micron-thick adjacent vertical cryosections were scanned with SAM or SHG. SAM maps of bulk modulus, mass density, and acoustic attenuation were estimated. A fiber-extraction algorithm applied to SHG images estimated collagen fiber length, width, straightness, alignment, and number density. Results revealed that the posterior sclera may exhibit biomechanically distinct layers that are affected differently in myopia. Specifically, a layered structure was observed in the mechanical-parameter maps of control eyes that was less apparent in myopic eyes. Collagen fibers in myopic eyes had smaller diameters and were more aligned. Myopia-associated biomechanical changes were most significant in the outermost and innermost scleral layers. SAM-measured mechanical parameters were correlated with collagen fiber microstructure, particularly fiber length, alignment, and number density, which may imply the biomechanical parameters estimated from SAM measurements are related to tissue microstructure. Interestingly, some changes were greatest in more-peripheral regions, suggesting interventions to strengthen the sclera may be effective away from the optic nerve and efficacy may be achieved best when intervention is applied to the outermost layer.

  View details for DOI 10.1016/j.exer.2022.109165

  View details for PubMedID 35810771

• Choroidal Thickness in Early Postnatal Guinea Pigs Predicts Subsequent Naturally Occurring and Form-Deprivation Myopia. Investigative ophthalmology & visual science Jiang, L., Liu, X., Zhou, L., Busoy, J. M., Khine, M. T., Dan, Y. S., Ke, M., Brennan, N. A., Catbagan, K. J., Schmetterer, L., Barathi, V. A., Hoang, Q. V. 2022; 63 (11): 10

  Abstract

  To identify choroidal characteristics associated with susceptibility to development of naturally occurring and experimentally induced myopia.We compared choroidal properties between pigmented and albino guinea pig (GP) strains. Biometry, cycloplegic refractive error (RE), and eye wall sublayer thickness were measured from 171 GPs at postnatal day (P)6, 14, and 28. Forty-three P14 GPs underwent two-week monocular form-deprivation myopia (FDM). En face images of choroidal vasculature were obtained with a customized swept-source optical coherence tomography. Multivariate regression analyses were performed, with P28 RE as the outcome and P14 choroidal thickness (ChT) as the main predictor variable. Proteomic analysis was performed on choroidal tissue from P14 albino and pigmented GPs.At P14, RE was correlated with thickness of the choroid (β = 0.06), sclera (β = 0.12), and retina (β = 0.27; all P < 0.001). P14 ChT was correlated with P28 RE both with (β = 0.06, P = 0.0007) and without FDM (β = 0.05, P = 0.008). Multivariate regression analysis, taking into account FDM (versus physiological growth) and strain, revealed that for every 10-µm greater ChT at P14, P28 RE was 0.50D more positive (P = 0.005, n = 70). En face images of choroidal sublayers showed that albino choroids were relatively underdeveloped, with frequent avascular regions. Consistent with this finding, proteomic analysis suggested abnormalities of the nitric oxide system in the albino GP choroid.Current results are consistent with the notion that greater ChT could protect from or delay the onset of myopia, while lower ChT is associated with greater susceptibility to myopia development. The underlying mechanism could be related to dysfunction of the choroidal vascular system.

  View details for DOI 10.1167/iovs.63.11.10

  View details for PubMedID 36239975

  View details for PubMedCentralID PMC9586133

• 3-D assessment of gaze-induced eye shape deformations and downgaze-induced vitreous chamber volume increase in highly myopic eyes with staphyloma. The British journal of ophthalmology Hoang, Q. V., Chang, S., Yu, D. J., Yannuzzi, L. A., Freund, K. B., Grinband, J. 2021; 105 (8): 1149-1154

  Abstract

  To determine if the stress of normal eye movements results in gaze-induced globe deformations, vitreous chamber axial length and vitreous chamber axial volume (VCAV) change in highly myopic eyes.A prospective imaging study was performed on 82 eyes of 43 patients with high myopia (>27 mm of axial length) with a clinical diagnosis of staphyloma. Three-dimensional MRI scans were acquired while subjects gazed in five directions (primary, nasal, temporal, superior and inferior). Surface renderings were generated, and a processing pipeline was created to automate alignment of the eye and to measure VCAV within 5.5 mm of the visual axis for each eye in every gaze. The degree of gaze-induced globe deformation was determined by calculating the Dice coefficient to assess the degree of overlap of the sclera at each eccentric gaze with that found in primary gaze. Each eccentric gaze VCAV was compared to VCAV in primary gaze using a fixed-effects regression allowing for subject-specific and eye-specific effects.The Dice coefficient showed significant gaze-induced eye shape changes in all gazes (all p<0.0001). There were no statistically significant gaze-induced VCAV changes when comparing primary gaze to nasal, temporal or upgaze. However, when changing from primary to downgaze, VCAV was increased by +4.79 mm3 (p=0.002, 95% CI 1.71 to 7.86).Significant gaze-induced globe deformation was noted in all gazes, but a reversible, instantaneous VCAV increase occurred only in downgaze, which is consistent with studies supporting the association of environmental factors such as near work with myopia development and progression.

  View details for DOI 10.1136/bjophthalmol-2020-316084

  View details for PubMedID 32830122

• Multimodal imaging in subretinal hypopyon endogenous endophthalmitis: Early detection of retinal tear and detachment. Retinal cases & brief reports Tan, S. S., Loo, Y., Hoang, Q. V., Yee Chan, A. S. 2026

  View details for DOI 10.1097/ICB.0000000000001864

  View details for PubMedID 41512223

• 3D Structural Phenotype of the Optic Nerve Head in Glaucoma and Myopia-A Key to Improving Glaucoma Diagnosis in Myopic Populations. American journal of ophthalmology Sharma, S., Braeu, F. A., Chuangsuwanich, T., Tun, T. A., Hoang, Q. V., Chong, R., Perera, S. A., Ho, C. L., Husain, R., Buist, M. L., Aung, T., Girard, M. J. 2026; 281: 138-150

  Abstract

  To characterize the three-dimensional (3D) structural phenotypes of the optic nerve head (ONH) in patients with glaucoma, high myopia, and concurrent high myopia and glaucoma, and to evaluate their variations across these conditions.Retrospective cross-sectional study.A total of 685 optical coherence tomography (OCT) scans from 754 subjects of Singapore-Chinese ethnicity, including 256 healthy (H), 94 highly myopic (HM), 227 glaucomatous (G), and 108 highly myopic with glaucoma (HMG) cases.We segmented the retinal and connective tissue layers from OCT volumes, and their boundary edges were converted into 3D point clouds. To classify the 3D point clouds into four ONH conditions, ie, H, HM, G, and HMG, a specialized ensemble network was developed, consisting of an encoder to transform high-dimensional input data into a compressed latent vector, a decoder to reconstruct point clouds from the latent vector, and a classifier to categorize the point clouds into the four ONH conditions. In addition, the network included an extension to reduce the latent vector to two dimensions for enhanced visualization.Structural variation in the ONH in H, HM, G, and HMG conditions.The classification network achieved high accuracy, distinguishing H, HM, G, and HMG classes with a microaverage area under the receiver operating characteristic curve of 0.92 ± 0.03 on an independent test set. The decoder effectively reconstructed point clouds, achieving a Chamfer loss of 0.013 ± 0.002. Dimensionality reduction clustered ONHs into four distinct groups, revealing structural variations such as changes in retinal and connective tissue thickness, tilting and stretching of the disc and scleral canal opening, and alterations in optic cup morphology, including shallow or deep excavation, across the four conditions.This study demonstrated that ONHs exhibit distinct structural signatures across H, HM, G, and HMG conditions. The findings further indicate that ONH morphology provides sufficient information for classification into distinct clusters, with principal components capturing unique structural patterns within each group. Future studies should seek to establish a connection between these structural patterns with the functional changes to enhance glaucoma diagnosis in myopic eyes.

  View details for DOI 10.1016/j.ajo.2025.09.004

  View details for PubMedID 40921348

  View details for PubMedCentralID PMC12687752

• An integrated language-vision foundation model for conversational diagnostics and triaging in primary eye care. Cell reports. Medicine Soh, Z. D., Bai, Y., Yu, K., Zhou, Y., Lei, X., Thakur, S., Lee, Z., Phang, L. C., Peng, Q., Xue, C. C., Chong, R. S., Hoang, Q. V., Raghavan, L., Tham, Y. C., Sabanayagam, C., Wu, W. C., Ho, M. C., He, J., Gupta, P., Lamoureux, E., Saw, S. M., Nangia, V., Panda-Jonas, S., Xu, J., Wang, Y. X., Xu, X., Jonas, J. B., Wong, T. Y., Goh, R. S., Liu, Y., Cheng, C. Y. 2025; 6 (12): 102476

  Abstract

  We present Meta-EyeFM, an integrated language-vision foundation model designed for conversational diagnostics and triaging in primary eye care. By combining a large language model (LLM) with eight task-specific vision foundation models (VFMs), Meta-EyeFM dynamically routes user queries and fundus photographs to the most appropriate VFMs (accuracy 96.8%). It demonstrates high performance in detecting ocular diseases (area under the receiver operating curve [AUC] ≥91.2%), differentiating disease severity (AUC ≥82%), identifying ocular signs (AUC ≥77.9%), and predicting systemic conditions like diabetes (AUC ≥79.8%). Meta-EyeFM is 11%-43% more accurate than Gemini-1.5-flash and GPT-4o LLM and generally outperforms junior ophthalmologist and optometrist graders in detecting different eye diseases. Its conversational interface and robust generalizability support its role as a diagnostic decision support tool in community settings. Through self-supervised learning and a user-friendly platform, Meta-EyeFM addresses the scarcity of skilled eye care professionals, offering scalable, explainable AI for enhancing vision screening and disease triage globally.

  View details for DOI 10.1016/j.xcrm.2025.102476

  View details for PubMedID 41349528

  View details for PubMedCentralID PMC12765825

• Diet and myopic macular degeneration in the Aier-SERI high myopia adult cohort study. Acta ophthalmologica Cheong, K. X., Chi, M., Pan, W., Lee, Y. Q., Zhang, Y., Hu, Z., Htoon, H. M., Hoang, Q. V., Chong, M. F., Lan, W., Saw, S. M., Lamoureux, E. L. 2025; 103 (8): 891-899

  Abstract

  We investigated relationships between two dietary composite scores and myopic macular degeneration (MMD) in a high myopia adult cohort, as there is a knowledge gap regarding the role of diet in MMD.This is a cross-sectional analysis of a population-based prospective cohort, the Aier-Singapore Eye Research Institute (SERI) high myopia cohort study of Chinese adults, in Changsha, central China. Systemic and ocular (including cycloplegic spherical equivalent [SE] and axial length [AL]) assessments were carried out. A self-administered food frequency questionnaire was used to assess the dietary intake. Dietary intake was categorised into 13 food groups (refined grains, whole grains, meat, fish, processed/unhealthy meat, plant-based protein, fruits, vegetables, fast food and savoury snacks, dairy products, desserts and sweet snacks, sugar-sweetened beverages, and alcohol). Using exploratory factor analysis, two dietary patterns (Dietary Pattern 1 [less healthy] and 2 [healthier]) were identified. Multivariable logistic regression analyses with Bonferroni corrections were performed to assess associations between diet and MMD.Of 445 participants, 71 (16.0%) had MMD. The participants had an overall mean age of 42.3 ± 7.3 years, SE of -9.5 ± 4.3 dioptres (D) and AL of 27.3 ± 11.86 mm. In the multivariable analyses, none of the 13 food groups (p > 0.004 for all) or 2 dietary patterns (p > 0.05 for both) were associated with MMD, after adjusting for age, sex, education, SE and AL.We did not find associations between diet and MMD in a cohort of highly myopic adults. There is currently no dietary advice to prevent MMD. Larger and prospective studies conducted over multiple time points are required.

  View details for DOI 10.1111/aos.17528

  View details for PubMedID 40386979

• The prevalence, progression, and visual loss associated with myopic macular degeneration in Asia TAIWAN JOURNAL OF OPHTHALMOLOGY Cheong, K., Lan, W., Hoang, Q. V., Saw, S. 2025

  View details for DOI 10.4103/tjo.TJO-D-25-00095

  View details for Web of Science ID 001594792000001

• A psychometric evaluation of the Chinese Impact of Vision Impairment (C-IVI) questionnaire in an adult cohort with high myopia using Rasch analysis. PloS one Pan, W., Man, R. E., Fenwick, E. K., Hu, Z., Jiang, Y., Tan, H., Chen, Z., Hoang, Q. V., Saw, S. M., Lamoureux, E. L., Lan, W., Yang, Z. 2025; 20 (10): e0327708

  Abstract

  A psychometric evaluation of the Chinese Impact of Vision Impairment (C-IVI) questionnaire in an adult cohort with high myopia using Rasch Analysis and determination of the relationship between vision-related quality-of-life (VRQoL) and myopia macular degeneration (MMD).We used the baseline visit data of the AIER-Singapore Eye Research Institute (SERI) High Myopia Adult Cohort Study. VRQoL was assessed using the 28-item C-IVI. Rasch analysis was conducted to evaluate the overall C-IVI and domain scores ('Mobility and independence'-MB, 'Reading and accessing information'-RD, and 'Emotional well-being'-EWB), including response category functioning, precision, unidimensionality, targeting, and differential item functioning (DIF). The criterion validity, C-IVI's ability to distinguish participants based on severity of vision impairment (VI), spherical equivalent (SER), and the presence of MMD were analyzed using ANOVA and pairwise t-tests.There were 431 participants, with mean (SD) age of 42.2 (7.1) years, SER of -8.3 (3.8) D, and visual acuity of 0.1 (0.2) LogMAR. Of these, 15.8% presented MMD, 79.4%, 13.5%, 7.0%, and 0.2% had no, mild, moderate, and severe VI, respectively. Response thresholds were ordered for the overall and three domains. The overall range-based precision was 0.94, and 0.80 for each domain. The three domains demonstrated unidimensionality. DIF was uniform in overall and EWB, but not the MB and RD domains. Person estimates decreased with increasing VI severity, worsening SER, and presenting MMD (all p < 0.05) for the overall and domain scores.The C-IVI questionnaire is a valid and reliable tool for assessing VRQoL in adults with high myopia in China.

  View details for DOI 10.1371/journal.pone.0327708

  View details for PubMedID 41066402

  View details for PubMedCentralID PMC12510582

• Independent Effects of Axial Length and Intraocular Pressure on the Highly Myopic Optic Nerve Head. Investigative ophthalmology & visual science Wong, M. W., Chong, C., Sharma, S., Phang, L. C., Lor, S., Hoang, Q. V., Girard, M., Cheng, C. Y., Schmetterer, L., Jonas, J. B., Yang, H., Wang, Y. X., Jeoung, J. W., Chong, R. S. 2025; 66 (12): 49

  Abstract

  The purpose of this study was to investigate associations among intraocular pressure (IOP), axial length (AXL), and optic nerve head (ONH) characteristics in highly myopic eyes.This retrospective cross-sectional study included highly myopic eyes with a refractive error of ≤-6.0 diopters (D) or an AXL of ≥26 mm, without glaucomatous optic neuropathy. Using IOP profiles, obtained retrospectively over a 5-year period, we assessed maximum, median, and range of IOP readings. We performed cross-sectional measurements of morphometric ONH parameters on fundus photographs and optical coherence tomographic (OCT) images.The study included 201 eyes (134 individuals) with a mean AXL of 27.6 ± 1.4 mm and a mean maximum IOP of 16.6 ± 3.7 millimeters of mercury (mm Hg; median = 14.9 ± 2.5 mm Hg, range = 3.14 ± 3.13 mm Hg obtained in 5.25 ± 2.76 measurements). Longer AXL was associated (multivariable analysis) with higher disc ovality (β = 0.05, P < 0.001), longer disc-fovea distance (β = 0.22, P < 0.001), shallower lamina cribrosa depth (β = -20.5, P = 0.02), and thicker ganglion cell layer and retinal nerve fiber layer in the temporal/inferotemporal sectors (all P < 0.05) with adjustments for age and gender. Higher mean maximum IOP readings were linked to deeper lamina cribrosa depth (β = 6.03, P = 0.006) and reduced disc rotation angle (β = -0.31, P = 0.04); higher mean median IOP was associated with smaller Bruch's membrane opening area (β = -0.06, P = 0.02). AXL was inversely associated with mean median IOP (β = -0.19, P = 0.02).Higher IOP and longer AXL are associated with distinct structural changes of the ONH in highly myopic eyes, particularly involving the lamina cribrosa. Elevated IOP but not AXL was associated with ONH features characteristic of glaucoma.

  View details for DOI 10.1167/iovs.66.12.49

  View details for PubMedID 40980969

  View details for PubMedCentralID PMC12462529

• Structure-Function Associations of Choroidal Thickness With Retinal Sensitivity in Myopia. Investigative ophthalmology & visual science Sreng, S., Chung, J., Toh, A., Zhen, Y. N., Eppenberger, L. S., Chua, J., Hoang, Q. V., Chong, R. S., Tan, A. C., Schmetterer, L., Ang, M., Wong, D. 2025; 66 (12): 21

  Abstract

  The purpose of this study was to investigate the focal relationship between choroidal thickness and retinal sensitivity in myopic eyes.Participants underwent swept-source optical coherence tomography (SS-OCT) imaging and microperimetry testing. Choroidal thicknesses were obtained by segmenting the SS-OCT scans using a deep-learning approach. Retinal sensitivity was measured at 33 locations using scotopic microperimetry, and corresponding focal choroidal thickness at these locations were computed. Focal structure-function associations between retinal sensitivity and choroidal thickness across 15 retinal eccentricities were evaluated, and adjusted for retinal thickness, signal strength, age, axial length, and gender.The analysis included 280 eyes from 155 participants (mean age = 25.8 ± 3.0 years) with myopia with a mean axial length of 26.56 ± 0.99 mm and refractive error of -6.87 ± 2.05 diopters (D). Mean retinal sensitivity was 27.68 ± 1.28 decibels (dB). Mean choroid thickness was 217.85 ± 66.66 µm, with choroidal thickness in the nasal quadrant significantly thinner than in the other quadrants. Choroidal thicknesses were correlated with retinal sensitivity in 14 of 15 retinal regions, including the global eccentricity zone (r = 0.261, P < 0.001). Significant associations were similarly found with retinal thickness (r = 0.305, P < 0.001), age (r = 0.182, P < 0.05), and axial length (r = -0.402, P < 0.001). Focal structure-function models further substantiated these relationships, demonstrating a significant effect size (β = 0.78, 95% confidence interval [CI] = 0.39-1.16, P < 0.001) after adjusting for retinal thickness and other demographic factors.Significant associations between choroidal thickness measurements and microperimetry were observed in a cross-sectional cohort of myopic eyes, suggesting a structure-function relationship with retinal sensitivity at the choroid. Further studies will be required to evaluate this in other cohorts and in progression.

  View details for DOI 10.1167/iovs.66.12.21

  View details for PubMedID 40923694

  View details for PubMedCentralID PMC12425144

• Psychometric Evaluation and Computerized Adaptive Testing Simulations of Myopic Refractive Intervention Quality of Life Item Banks. Translational vision science & technology Man, R. E., Fenwick, E. K., Goh, K. J., Teo, P. R., Ang, M., Hoang, Q. V., Wong, C. W., Rosman, M., Saw, S. M., Lamoureux, E. L. 2025; 14 (8): 4

  Abstract

  To optimize the psychometric properties of myopia refractive intervention quality of life (QoL) item banks (IBs), and evaluate their performance using computerized adaptive testing (CAT) simulations.In this clinical study, adults utilizing myopic refractive intervention modalities answered 204 items within seven IBs: Activity Limitation (AL); Comfort (CM); Concerns (CN); Convenience (CV); Emotional (EM); Mobility (MB); and Work (WK), referred to collectively as "MyoRICAT". The psychometric properties of each IB were assessed with Rasch analysis, and CAT simulations with 1000 respondents determined the average number of items needed to achieve moderate (standard error of measurement [SEM] = 0.387) and high (SEM = 0.30) precision levels.Of the 291 participants (mean age 34.02 ± 11.04 years; 65.64% female), 61 (20.96%) wore spectacles only, 123 (42.27%) used both spectacles and contact lenses, and 107 (36.76%) underwent laser refractive surgery. AL, CM, CN, CV, and EM showed satisfactory psychometric properties after minor amendments. WK lacked measurement precision owing to certain items being applicable only to specific subsets of refractive modalities. This IB was therefore retained as a fixed length rather than a CAT operationalized scale. Conversely, MB demonstrated such poor targeting that it was not considered further. In CAT simulations, the mean number of items required per IB ranged from 10 (CV) to 12 (AL) for moderate, and 15 (CV) to 19 (AL) for high measurement precision.Five IBs demonstrated strong psychometric properties and potential CAT efficiency.MyoRICAT can provide a comprehensive measurement of the QoL impact of myopic refractive intervention modalities.

  View details for DOI 10.1167/tvst.14.8.4

  View details for PubMedID 40747989

  View details for PubMedCentralID PMC12320898

• Sensitivity of ophthalmologists, residents, and optometrists in identifying peripheral retinal tears on ultra-widefield imaging. Canadian journal of ophthalmology. Journal canadien d'ophtalmologie Jung, J. J., Chan, X., Cheong, K. X., Dan, Y. S., Cheng, J. Y., Lai, E. W., Li, H., Hoang, Q. V. 2025; 60 (4): 222-229

  Abstract

  To compare the sensitivity of 3 groups of masked graders with varying levels of ophthalmic training to identify peripheral retinal breaks utilizing ultra-widefield orthogonal, directed peripheral steering, and auto-montaged images.Retrospective observational cohort study.155 patients from a single vitreoretinal specialist's practice.221 eyes with pretreatment orthogonal, directed-peripheral steering, and auto-montage that underwent laser retinopexy for retinal tears between 2015 and 2021 were divided into 2 groups: treatment-naïve and control. Combined sensitivity and specificity of identifying all retinal breaks on orthogonal, directed-peripheral steering, and auto-montaged imaging were calculated compared with the gold standard of mydriatic, scleral depression examination. Linear probability modeling was performed to calculate the required surface area from auto-montage images to identify breaks that were missed initially on orthogonal images.For orthogonal images, combined sensitivity was highest for ophthalmologists (67.53%), residents (62.34%), and then optometrists (55.84%). The sensitivity increased for orthogonal/steering (ophthalmologists [85.71%], residents [77.92%], and optometrists [67.53%]) and auto-montage (ophthalmologists [85.51%], residents (80.28%), and optometrists [75.00%]). To ensure identification of all tears with auto-montage that was initially missed on grading the orthogonal image, for every 10% increase in montage surface area, there was a 4.8 percentage point (%p) increase in the likelihood of detecting a retinal tear on montage image grading (p = 0.023).Masked graders had moderate sensitivity in identifying retinal breaks with ultra-widefield images. Even with directed-peripheral steering and auto-montage, optometrists had the lowest sensitivity compared to ophthalmology residents and general ophthalmologists and required increased surface area to identify all retinal breaks.

  View details for DOI 10.1016/j.jcjo.2025.02.002

  View details for PubMedID 39993440

• Characteristics of Myopic Traction Maculopathy in the Aier-SERI High Myopia Adult Cohort Study. Ophthalmology science Cheong, K. X., Jiang, Y., Htoon, H. M., Pan, W., Foo, L. L., Hu, Z., Chen, L., Ang, S., Lamoureux, E. L., Hoang, Q. V., Saw, S. M., Lan, W. 2025; 5 (6): 100894

  Abstract

  To describe the prevalence, clinical characteristics, associations, and visual outcomes of myopic traction maculopathy (MTM), which was defined by the presence of retinoschisis (RS), macular holes (MHs), or foveal retinal detachment (RD), in an adult high myope cohort in Changsha, China.A cross-sectional study.Chinese adults with high myopia (defined as spherical equivalent [SE] less than or equal to -5 diopters [D]) in the Aier-Singapore Eye Research Institute High Myopia Adult Cohort Study, which is a prospective population-based study.Swept-source OCT was performed to detect RS, MH, and foveal RD. Multivariable generalized estimating equation analyses were performed to assess associations of MTM and the impact of MTM on best-corrected visual acuity (BCVA).Prevalence, clinical characteristics, associations, and visual outcomes of MTM.Of 437 participants (839 eyes), MTM was observed in 20 participants with a prevalence of 4.6% (by participants) or in 24 eyes (with a prevalence of 2.9%; by eyes). Overall, the whole cohort (64.7% female) had a mean age of 42.9 ± 7.2 years, an SE of -9.5 ± 4.4 D, and an axial length (AL) of 27.3 ± 1.9 mm. Retinoschisis was the most common lesion (91.7%; 22/24 eyes with MTM). In the multivariable analysis, the prevalence of MTM was associated with a more myopic SE (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.01-1.18; P = 0.03), longer AL (OR: 1.30; 95% CI: 1.03-1.65; P = 0.03), myopic macular degeneration (MMD) (OR: 12.77; 95% CI: 3.18-51.24; P < 0.001), and older age (OR: 1.06; 95% CI: 1.01-1.11; P = 0.01). In the multivariable analysis, the prevalence of MTM was also associated with poorer BCVA (beta coefficient: -0.07; 95% CI: -0.13 to -0.01; P < 0.01).The prevalence of MTM was 4.6% in an adult high myope cohort. Associations with MTM include more myopic SE, longer AL, MMD, and older age. Myopic traction maculopathy is associated with poorer vision.The authors have no proprietary or commercial interest in any materials discussed in this article.

  View details for DOI 10.1016/j.xops.2025.100894

  View details for PubMedID 41000209

  View details for PubMedCentralID PMC12459344

• Gaze-Induced Optic Nerve Head Deformations Are Greater in High Myopia and Strains Increase With Axial Length. Investigative ophthalmology & visual science Liu, T., Wang, Y. X., Jonas, J. B., Hoang, Q. V., Girard, M. J., Wang, X. 2025; 66 (9): 21

  Abstract

  To investigate optic nerve head (ONH) deformations caused by horizontal eye movements in high myopia (HM) using in vivo optical coherence tomography (OCT) imaging and finite-element (FE) modeling, and to identify factors influencing these deformations.A total of 28 HM eyes and 28 non-HM eyes were imaged at baseline, 20° adduction, and 20° abduction positions using OCT. Lamina cribrosa (LC) effective strains were quantified using a three-dimensional tracking algorithm. A baseline FE model of an emmetropic eye with an axial length of 23.5 mm and normal tissues structures and a HM model with elongated axial length and thinner sclera were developed. The effects of varying scleral stiffness and the eye movement center on gaze-induced ONH deformations were explored.In vivo measurement showed that LC strains were significantly greater in HM eyes than in non-HM eyes during adduction (5.95% ± 3.52% vs. 3.65% ± 1.85%; P = 0.002) and abduction (3.35% ± 1.94% vs. 2.29% ± 1.65%; P = 0.016). Strains correlated positively with axial length. FE modeling demonstrated greater gaze-induced LC strains in the HM model compared to the emmetropic model, in both adduction and abduction. A softer sclera reduced LC strains in the HM model, whereas a forward shift in the eye movement center (relative to the geometric center, as seen in HM eyes) increased strain.This study demonstrates that gaze-induced ONH deformations increase with axial elongation. The findings highlight the role of scleral stiffness and eye movement center position in modulating ONH biomechanics, contributing to the understanding of glaucomatous, glaucoma-like, and non-glaucomatous optic neuropathy in HM.

  View details for DOI 10.1167/iovs.66.9.21

  View details for PubMedID 40626805

  View details for PubMedCentralID PMC12249009

• Spectral-domain optical coherence tomography imaging findings in patients receiving teprotumumab for thyroid eye disease. American journal of ophthalmology case reports Truong, T., Silkiss, R. Z., Amoroso, J. R., Li, H., Hoang, Q. V., Eliasieh, K., Jung, J. J. 2025; 38: 102282

  Abstract

  Prior studies have demonstrated the potential side effects of insulin-like growth factor-1 (IGF-1) inhibition for thyroid eye disease (TED) including hearing loss. In this study, we assessed changes in functional vision including visual field testing and best-corrected visual acuity (BCVA), clinical examination parameters, and spectral-domain optical coherence tomography (SD-OCT) biomarkers in patients who received insulin growth factor receptor-1 (IGF-R1) inhibition with teprotumumab for TED.Retrospective, noncomparative cohort.22 eyes of 12 TED patients.Retrospective chart review was conducted, with demographics, clinical examination, BCVA, Humphrey visual field (HVF), and SD-OCT data: central foveal thickness (CFT), sub-foveal choroidal thickness (SFCT), choroidal vascular index (CVI), retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (mGCIPL) thickness compared between before and after an 8-infusion course of teprotumumab. Linear regression modeling with clustering was used for statistical analysis. Statistical significance was set at p < 0.05.Proptosis, clinical activity scores, and intraocular pressure improved. SFCT -35.7μm (p = 0.038), RNFL -5.41μm (p = 0.001), and mGCIPL -7.35μm (p = 0.010) decreased after six months. CFT and CVI did not statistically differ. BCVA and HVF mean deviation remained stable.There were statistically significant decreases in SFCT, RNFL, and mGCIPL in TED patients treated with teprotumumab, but no differences in CFT and CVI. Functional testing, with HVF and BCVA, was not affected, but there were significant systemic side effects including hearing loss noted in several patients. Further research is needed to understand the potential effects of IGF-1R blockade on the retina and optic nerve.

  View details for DOI 10.1016/j.ajoc.2025.102282

  View details for PubMedID 40083365

  View details for PubMedCentralID PMC11903837

• Prevalence and risk factors of myopic macular degeneration: the Aier-SERI high myopia adult cohort. The British journal of ophthalmology Foo, L. L., Jiang, Y., Hoang, Q. V., Htoon, H. M., Hu, Z., Pan, W., Cheong, K. X., Lamoureux, E. L., Yang, Z., Lan, W., Saw, S. M. 2025; 109 (6): 721-726

  Abstract

  To assess the prevalence and risk factors of myopic macular degeneration (MMD) in young and middle-aged individuals with high myopia in Changsha, central China.A total of 445 adults with high myopia (worse than or equal to -5.0 D) were examined between 2021 and 2023. Autorefraction and biometry using IOLMaster were conducted, and fundus photos were graded for MMD using Meta-PM criteria. MMD was diagnosed if category 2, 3, 4 or any plus lesion was present. Risk factors such as age, gender, spherical equivalent (SE)/axial length (AL), body mass index, education and residence were analysed via logistic regression.Participants had an average age of 42.3±7.3 years. MMD prevalence was 21.8% (71 adults) with a mean SE of -9.5±4.7 D and AL of 27.3±1.9 mm. Significant risk factors included greater myopic SE (OR=1.7 per 1 D decrease) and longer AL (OR=3.6 per 1 mm increase). MMD prevalence rose sharply with myopia worse than -10.00 D and AL >27.00 mm, reaching up to 100% for myopia worse than -14.00 D or AL ≥29.00 mm.MMD affects about one in five young to middle-aged adults with high myopia. Those exceeding critical myopia and AL thresholds are at higher risk and should be closely monitored. Further research on interventions to prevent axial elongation is needed, particularly for those with high genetic risk.

  View details for DOI 10.1136/bjo-2024-326116

  View details for PubMedID 39779283

• Association of macular sensitivity with posterior staphyloma in highly myopic eyes: Aier-SERI high myopia adult cohort study. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Jiang, Y., Foo, L. L., Hu, Z., Pan, W., Cheong, K. X., Tan, H., Saw, S. M., Hoang, Q. V., Yang, Z., Lan, W. 2025; 45 (3): 845-853

  Abstract

  The purpose of this study was to determine the relationship between macular sensitivity (MS) and posterior staphyloma (PS) in highly myopic eyes.This cross-sectional, observational study included 646 highly myopic eyes (spherical equivalent (SE) ≤-5.00D and the international meta-analysis for pathologic myopia classification grade of <2) from 362 participants. MS was measured using microperimetry and evaluated between eyes with and without PS. Correlations between MS and PS were determined in multivariate regression models.Although there was no significant difference in best-corrected visual acuity (BCVA) (p = 0.07), the MS of the PS group was significantly lower than the no PS group at the central 2°, 4°, 6°, 8° and 10° (all p < 0.001). After controlling age, axial length (AL) and SE, the MS in the PS group was still lower than the no PS group from 2° to 10° (all p < 0.05). In a multivariable analysis adjusting for age, AL, SE and BCVA, the presence of PS was significantly associated with lower MS in the central 2°-10° (all p < 0.05).Lower MS was independently associated with the presence of PS in highly myopic eyes. Even when BCVA was not significantly different, MS still could reveal subtle changes in visual function in highly myopic eyes with PS.

  View details for DOI 10.1111/opo.13467

  View details for PubMedID 39976340

• THE SPECTRUM OF RELENTLESS PLACOID AND ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY: A MULTIMODAL IMAGING ANALYSIS. Retinal cases & brief reports Chan, X., Amoroso, J. R., Hoang, Q. V., Jung, J. J. 2025; 19 (2): 148-151

  Abstract

  The objective of this study was to showcase the spectrum between acute posterior multifocal placoid pigment epitheliopathy and relentless placoid utilizing ultra-widefield imaging findings of a case of acute posterior multifocal placoid pigment epitheliopathy progressing to relentless placoid chorioretinitis.A 23-year-old White woman presented with worsening vision in both eyes. Clinical examination and multimodal imaging modalities including fundus photographs, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, and spectral domain optical coherence tomography and angiography were utilized to diagnose acute posterior multifocal placoid pigment epitheliopathy and clinically follow the patient.Clinical examination of the patient initially revealed posterior lesions consistent with acute posterior multifocal placoid pigment epitheliopathy, but subsequent multimodal images including ultra-widefield fluorescein angiography and indocyanine green angiography revealed newer, more peripheral lesions more typical of relentless placoid chorioretinitis.When compared with standard multimodal imaging, ultra-widefield imaging is an effective tool to delineate nuances between acute posterior multifocal placoid pigment epitheliopathy and relentless placoid chorioretinitis through identification of peripheral lesions, which may be of clinical importance when determining management and therapeutics for patients.

  View details for DOI 10.1097/ICB.0000000000001555

  View details for PubMedID 38437794

• Bruch's Membrane Opening Changes in Eyes With Myopic Macular Degeneration: AIER-SERI Adult High Myopia Study. Investigative ophthalmology & visual science Wu, L., Foo, L. L., Hu, Z., Pan, W., Jiang, Y., Saw, S. M., Hoang, Q. V., Lan, W. 2024; 65 (8): 36

  Abstract

  The purpose of this study was to assess the choroidal thickness and the Bruch's membrane opening size and their relationship to visual acuity in eyes with myopic macular degeneration (MMD).This was a population-based, cross-sectional study. Patients over the age of 30 years with high myopia (spherical equivalent ≤-5 diopters [D]) were recruited. The eyes were grouped according to the International Meta-Analysis for Pathologic Myopia (META-PM) classification based on fundus photographs and diffuse atrophy was subdivided into peripapillary diffuse choroidal atrophy (PDCA) or macular diffuse choroidal atrophy (MDCA). Swept-source optical coherence tomography imaging was performed and then the subfoveal choroidal thickness (SFCT) and Bruch's membrane opening diameter (BMOD) were measured.Of the 470 study participants recruited, 373 patients (691 eyes), with a mean age of 42.8 ± 7.2 years, were eligible for the study and included in the analysis. There was no significant difference in SFCT between MDCA and patchy atrophy (M3) groups (P = 1.000), and the BMOD enlarged significantly from no myopic macular lesions to M3 (the P values of multiple comparison tests were all <0.005). Simple linear regression analysis showed that BMOD correlated positively with age (P < 0.001) and axial length (P < 0.001). Multiple linear regression analysis showed that best corrected visual acuity (BCVA) was significantly correlated with age (P = 0.041), axial length (P = 0.001), and BMOD (P = 0.017), but not with SFCT (P = 0.231).The significant variation of BMOD among MMD groups and the correlation between BMOD and BCVA in MMD eyes suggest that BMOD may be an imaging biomarker for monitoring MMD.

  View details for DOI 10.1167/iovs.65.8.36

  View details for PubMedID 39028975

  View details for PubMedCentralID PMC11262543

• Comparison of manual and artificial intelligence-automated choroidal thickness segmentation of optical coherence tomography imaging in myopic adults. Eye and vision (London, England) Lim, Z. W., Li, J., Wong, D., Chung, J., Toh, A., Lee, J. L., Lam, C., Balakrishnan, M., Chia, A., Chua, J., Girard, M., Hoang, Q. V., Chong, R., Wong, C. W., Saw, S. M., Schmetterer, L., Brennan, N., Ang, M. 2024; 11 (1): 21

  Abstract

  Myopia affects 1.4 billion individuals worldwide. Notably, there is increasing evidence that choroidal thickness plays an important role in myopia and risk of developing myopia-related conditions. With the advancements in artificial intelligence (AI), choroidal thickness segmentation can now be automated, offering inherent advantages such as better repeatability, reduced grader variability, and less reliance for manpower. Hence, we aimed to evaluate the agreement between AI-automated and manual segmented measurements of subfoveal choroidal thickness (SFCT) using two swept-source optical coherence tomography (OCT) systems.Subjects aged ≥ 16 years, with myopia of ≥ 0.50 diopters in both eyes, were recruited from the Prospective Myopia Cohort Study in Singapore (PROMYSE). OCT scans were acquired using Triton DRI-OCT and PLEX Elite 9000. OCT images were segmented both automatically with an established SA-Net architecture and manually using a standard technique with adjudication by two independent graders. SFCT was subsequently determined based on the segmentation. The Bland-Altman plot and intraclass correlation coefficient (ICC) were used to evaluate the agreement.A total of 229 subjects (456 eyes) with mean [± standard deviation (SD)] age of 34.1 (10.4) years were included. The overall SFCT (mean ± SD) based on manual segmentation was 216.9 ± 82.7 µm with Triton DRI-OCT and 239.3 ± 84.3 µm with PLEX Elite 9000. ICC values demonstrated excellent agreement between AI-automated and manual segmented SFCT measurements (PLEX Elite 9000: ICC = 0.937, 95% CI: 0.922 to 0.949, P < 0.001; Triton DRI-OCT: ICC = 0.887, 95% CI: 0.608 to 0.950, P < 0.001). For PLEX Elite 9000, manual segmented measurements were generally thicker when compared to AI-automated segmented measurements, with a fixed bias of 6.3 µm (95% CI: 3.8 to 8.9, P < 0.001) and proportional bias of 0.120 (P < 0.001). On the other hand, manual segmented measurements were comparatively thinner than AI-automated segmented measurements for Triton DRI-OCT, with a fixed bias of - 26.7 µm (95% CI: - 29.7 to - 23.7, P < 0.001) and proportional bias of - 0.090 (P < 0.001).We observed an excellent agreement in choroidal segmentation measurements when comparing manual with AI-automated techniques, using images from two SS-OCT systems. Given its edge over manual segmentation, automated segmentation may potentially emerge as the primary method of choroidal thickness measurement in the future.

  View details for DOI 10.1186/s40662-024-00385-2

  View details for PubMedID 38831465

  View details for PubMedCentralID PMC11145894

• Gaze-dependent alterations in posterior eyewall morphology in highly myopic eyes Cheong, K., Lim, S., Dan, Y., Silverman, R. H., Chang, S., Yannuzzi, L. A., Freund, K., Ito, K., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024

  View details for Web of Science ID 001312227703182

• Comparison of Quadrant Asymmetry of OCTA Metrics Across 3 Different Spectral-Domain and Swept-Source OCTA Machines Jung, J. J., Li, H., Madrid, J., Sha, P., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024

  View details for Web of Science ID 001313316200192

• ULTRA-WIDEFIELD IMAGING DETECTION RATE IN IDENTIFYING PERIPHERAL RETINAL TEARS IN SINGLE VERSUS MONTAGE OF PERIPHERAL STEERING. Retina (Philadelphia, Pa.) Jung, J. J., Lim, S. Y., Chan, X., Yee Yeoh, C. H., Smolyar, K., Oribello, A., Dizon, A. G., Hoang, Q. V. 2024; 44 (3): 406-413

  Abstract

  To compare the detection rate of orthogonal, directed peripheral steering, and automontaged images with ultra-widefield imaging and the factors influencing the ability to identify retinal breaks.Retrospective cohort study.Three hundred and seventy-six treatment-naive eyes (349 patients) that underwent laser retinopexy for retinal breaks between 2015 and 2021 were included. Pretreatment ultra-widefield orthogonal, peripheral steering, and automontage were cross-referenced to scleral-depressed examination to determine whether images successfully visualized all retinal breaks. Total relative retinal area (RRA) visualized was divided by its optic disk area (pixels) to calculate relative retinal area. Potential associations were assessed by linear regression analysis.One hundred and sixty two eyes (154 patients) met inclusion criteria. Orthogonal, peripheral steering, and automontage images showed detection rates of 47.5%, 90.7%, and 80.0%, respectively. Relative retinal area increased from orthogonal versus montage by 34.7% ± 26.5% (mean ± SD), which increased the detection rate by 90.8% ( P = 0.006). In linear probability models, vertical meridian tears decreased probability of identification in orthogonal, peripheral steering, and automontage by -26.6%, -86.2%, and -68.7%, respectively ( P < 0.001), and horizontal meridian tears increased the probability by 62.2%, 92.9%, and 85.5%, respectively, ( P < 0.001). Tears posterior to the equator in orthogonal images increased the probability (91.4%, P < 0.001). Artifacts such as lids/lashes, reflection, and face guard decreased the probability in directed peripheral steering by -28.6%, -50.0%, and -66.7%, respectively, ( P = 0.020, P = 0.049, and P = 0.016).Using directed peripheral steering and automontage increases RRA and detection rate of identifying peripheral retinal breaks. Tears in horizontal meridians or posterior to the equator increase the probability of identification. Common ultra-widefield imaging artifacts can significantly limit the probability of identifying retinal tears.

  View details for DOI 10.1097/IAE.0000000000003979

  View details for PubMedID 37976437

• Pathologic myopia in highly myopic patients with high axial anisomyopia. The British journal of ophthalmology Li, J., Dan, Y. S., Chua, S. Q., Wong, Q. Y., Chong, R. S., Ang, M., Wong, C. W., Hoang, Q. V. 2024; 108 (3): 411-416

  Abstract

  To determine prevalence of anisomyopia (axial length (AL) difference ≥2.5 mm) among high myopes ((HMs), defined by spherical equivalent of ≤6.0 diopters or AL ≥ 26.5 mm). To characterise the shorter anisomyopic eye (SAE) and evaluate if pathologic myopia (PM) in the longer anisomyopic eye (LAE) was associated with increased risk of PM in the SAE.1168 HMs were recruited from Singapore National Eye Centre clinic for this cross-sectional study. Biometry, fundus photography and swept-source optical coherence tomography were performed. Patients with high axial anisomyopia were identified. Structural characteristics and presence of PM were described. Stepwise multivariate regression explored associations between PM in the LAE and pathology in the SAE, controlling for confounding variables.Prevalence of anisomyopia was 15.8% (184 of 1168 patients). Anisomyopic patients (age 65.8±13.5 years) had mean AL of 30.6±2.0 mm and 26.2±2.3 mm in the LAE and SAE, respectively. 52.7% of SAEs had AL < 26.5 mm. Prevalence of myopic macular degeneration, macula-involving posterior staphyloma (PS), myopic traction maculopathy (MTM) and myopic choroidal neovascularisation (mCNV) in the SAE was 52.2%, 36.5%, 13.0% and 8.2%, respectively. Macular hole in the LAE was associated with increased risk of MTM in the SAE (OR=4.88, p=0.01). mCNV in the LAE was associated with mCNV in the SAE (OR=3.57, p=0.02). PS in the LAE was associated with PS in the SAE (OR=4.03, p<0.001).Even when controlled for AL, PM complications in the LAE predict similar PM complications in the SAE. Patients with high axial anisometropia with PM in the LAE should be monitored carefully for complications in the SAE.

  View details for DOI 10.1136/bjo-2022-322285

  View details for PubMedID 36690422

• NODULAR EPIRETINAL MÜLLER CELL GLIOSIS IN THE FOVEA. Retinal cases & brief reports Jung, J. J., Zeng, A., Komati, R., Mackin, A. G., Skondra, D., Yonekawa, Y., Fineman, M. S., Ezon, I., Rofagha, S., Hoang, Q. V. 2023; 17 (6): 779-784

  Abstract

  The purpose of this study was to report the findings of a hyperreflective nodular epiretinal gliosis observed with optical coherence tomography presumed to be due to subclinical hyaloidal traction causing Mϋller cell cone gliosis.Retrospective, observational case series.Six eyes of six patients (mean age: 57 years, range 35-81 years) presented with a nodular epiretinal gliosis and had an average follow-up interval of 26 months (range 1-82 months). The mean baseline best-corrected visual acuity was 0.25 ± 0.17 (Snellen equivalent 20/38.3 ± 16.9). Fundus photography demonstrated a yellowish lesion overlying the fovea. Optical coherence tomography imaging revealed a hyperreflective preretinal lesion with a mean vertical length of 267 μ m (range 185-497) and a mean greatest linear diameter of 312 µ m (range 124-640). There was no vitreoretinal abnormality including vitreomacular traction or epiretinal membrane noted in any eye, and two of six eyes displayed a definitive posterior vitreous detachment. These nodules may have occurred before and persisted even after a posterior vitreous detachment or may have been acquired after the posterior vitreous detachment. The nodules typically remained stable with minimal change although in one eye, a posterior vitreous detachment occurred 6 months after initial presentation and lifted the gliosis off of the retinal surface where it remained attached to the posterior hyaloid.Foveal nodular epiretinal gliosis may occur due to subclinical hyaloidal traction on the Müller cell cone even without obvious vitreoretinal interface abnormality on optical coherence tomography.

  View details for DOI 10.1097/ICB.0000000000001298

  View details for PubMedID 35972829

  View details for PubMedCentralID PMC10597442

• Ultrasound Assessment of Gaze-induced Posterior Eyewall Deformation in Highly Myopic Eyes. Investigative ophthalmology & visual science Cheong, K. X., Lim, S. Y., Dan, Y. S., Silverman, R. H., Chang, S., Yannuzzi, L. A., Freund, K. B., Ito, K., Hoang, Q. V. 2023; 64 (13): 38

  Abstract

  To establish a quantitative metric of posterior eyewall deformability in different directions of gaze in highly myopic eyes with and without posterior staphyloma.A prospective study was performed on 53 highly myopic patients (106 eyes). Ultrasound scans were acquired in primary, up, downward, nasal, and temporal gazes. A validated intensity-based segmentation algorithm was used to quantify the posterior eyewall geometry on digitalized B-scan images. Posterior eyewall local curvature (K) and distance (L) to the transducer were calculated. The associations between directions of gaze, axial length (AL), and presence of staphyloma with the K and L parameters were assessed.A total of 53 participants (106 eyes) were studied. Multivariate regression analysis demonstrated that, after accounting for longer AL, and presence of staphyloma, eccentric gaze was often independently associated with various K and L parameters. Specifically, downward gaze was associated with increased posterior eyewall concavity as reflected in the maximum of K (KMax) (β = 0.050, P < 0.001) and absolute value of KMax (β = 0.041, P = 0.011). Both downward gaze and upgaze were independently associated with increase in the derivative of absolute KMax (which is consistent with more apparent, steeper staphyloma ridges), local KMax (which detects KMax at smaller intervals), and Kstd (which represents likelihood of staphyloma presence) and decrease in maximum of L (which represents movement of the staphyloma apex) with all P < 0.05. The β coefficients for downward gaze were consistently greater in magnitude compared with those in upgaze. After accounting for AL and presence of staphyloma, horizontal gazes were independently associated only with decrease in the standard deviation of L (which also represents likelihood of staphyloma presence) and maximum of L.Downward gaze results in a significant increase in posterior eyewall concavity in highly myopic eyes after accounting for AL and staphyloma presence. In comparison with downward gaze, upgaze resulted in a lower magnitude, but significant changes in staphyloma ridge steepness and the likelihood of staphyloma presence. Horizontal gazes seemed to be associated with less posterior eyewall geometric parameters. Studies are required to further assess the association between downward gaze during near work on posterior eyewall concavity and possible effects on myopia development and progression.

  View details for DOI 10.1167/iovs.64.13.38

  View details for PubMedID 37878303

  View details for PubMedCentralID PMC10615140

• Predictors of myopic macular degeneration in a 12-year longitudinal study of Singapore adults with myopia. The British journal of ophthalmology Foo, L. L., Xu, L., Sabanayagam, C., Htoon, H. M., Ang, M., Zhang, J., Ohno-Matsui, K., Cheng, C. Y., Hoang, Q. V., Tan, C. S., Saw, S. M., Wong, C. W. 2023; 107 (9): 1363-1368

  Abstract

  To investigate the predictive factors for myopic macular degeneration (MMD) and progression in adults with myopia.We examined 828 Malay and Indian adults (1579 myopic eyes) with myopia (spherical equivalent (SE) ≤-0.5 dioptres) at baseline who participated in both baseline and 12-year follow-up visits of the Singapore Malay Eye Study and the Singapore Indian Eye Study. Eye examinations, including subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the Meta-Analysis for Pathologic Myopia classification. The predictive factors for MMD development and progression were assessed in adults without and with MMD at baseline, respectively as risk ratios (RR) using multivariable modified Poisson regression models. The receiver operating characteristic curve was used to visualise the performance of the predictive models for the development of MMD, with performance quantified by the area under the curve (AUC).The 12-year cumulative MMD incidence was 10.3% (95% CI 8.9% to 12.0%) among 1504 myopic eyes without MMD at baseline. Tessellated fundus was a major predictor of MMD (RR=2.50, p<0.001), among other factors including age, worse SE and longer AL (all p<0.001). The AUC for prediction of MMD development was found to be 0.78 (95% CI 0.76 to 0.80) for tessellated fundus and increased significantly to an AUC of 0.86 (95% CI 0.84 to 0.88) with the combination of tessellated fundus with age, race, gender and SE (p<0.001). Older age (p=0.02), worse SE (p<0.001) and longer AL (p<0.001) were found to be predictors of MMD progression.In adults with myopia without MMD, tessellated fundus, age, SE and AL had good predictive value for incident MMD. In adults with MMD, 1 in 10 eyes experienced progression over the same period. Older age, more severe myopia and longer AL were independent risk factors for progression.

  View details for DOI 10.1136/bjophthalmol-2021-321046

  View details for PubMedID 35534177

• How Myopia and Glaucoma Influence the Biomechanical Susceptibility of the Optic Nerve Head. Investigative ophthalmology & visual science Chuangsuwanich, T., Tun, T. A., Braeu, F. A., Yeoh, C. H., Chong, R. S., Wang, X., Aung, T., Hoang, Q. V., Girard, M. J. 2023; 64 (11): 12

  Abstract

  The purpose of this study was to assess optic nerve head (ONH) deformations following acute intraocular pressure (IOP) elevations and horizontal eye movements in control eyes, highly myopic (HM) eyes, HM eyes with glaucoma (HMG), and eyes with pathologic myopia (PM) alone or PM with staphyloma (PM + S).We studied 282 eyes, comprising of 99 controls (between +2.75 and -2.75 diopters), 51 HM (< -5 diopters), 35 HMG, 21 PM, and 75 PM + S eyes. For each eye, we imaged the ONH using spectral-domain optical coherence tomography (OCT) under the following conditions: (1) primary gaze, (2) 20 degrees adduction, (3) 20 degrees abduction, and (4) primary gaze with acute IOP elevation (to ∼35 mm Hg) achieved through ophthalmodynamometry. We then computed IOP- and gaze-induced ONH displacements and effective strains. Effective strains were compared across groups.Under IOP elevation, we found that HM eyes exhibited significantly lower strains (3.9 ± 2.4%) than PM eyes (6.9 ± 5.0%, P < 0.001), HMG eyes (4.7 ± 1.8%, P = 0.04), and PM + S eyes (7.0 ± 5.2%, P < 0.001). Under adduction, we found that HM eyes exhibited significantly lower strains (4.8% ± 2.7%) than PM + S eyes (6.0 ± 3.1%, P = 0.02). We also found that eyes with higher axial length were associated with higher strains.Our study revealed that eyes with HMG experienced significantly greater strains under IOP compared to eyes with HM. Furthermore, eyes with PM + S had the highest strains on the ONH of all groups.

  View details for DOI 10.1167/iovs.64.11.12

  View details for PubMedID 37552032

  View details for PubMedCentralID PMC10411647

• Quantitative assessment of the choroidal vasculature in myopic macular degeneration with optical coherence tomographic angiography. Frontiers in ophthalmology Dan, Y. S., Cheong, K. X., Lim, S. Y., Wong, Q. Y., Chong, R. S., Wong, C. W., Hoang, Q. V. 2023; 3: 1202445

  Abstract

  To assess and compare choroidal morphometric vascular parameters, using optical coherence tomographic angiography (OCTA), in highly myopic adults with and without myopic macular degeneration (MMD).This is a clinic-based observational study of 148 eyes with axial length (AL) ≥25mm, enrolled from the high myopia clinic of the Singapore National Eye Centre. MMD was graded from fundus photographs. Swept source OCT (SS-OCT) and OCTA were performed and assessed for choroidal layer thickness (CT) and choroidal vasculature (choroidal vessel density (CVD), choroidal branch area (CBA) and mean choroidal vessel width (MCVW)) in the different choroidal layers (overall choroidal layer (CL), medium-vessel choroidal layer (MVCL), large-vessel choroidal layer (LVCL)).CTCL (r=-0.58, p<0.001), CTMVCL (r=-0.22, p=0.04), MCVWCL (r=-0.58, p<0.001), and CVDCL (r=-0.19, p=0.02) were negatively correlated with AL, while CBACL (r=0.61, p<0.001) was positively correlated. Compared to eyes with no MMD, eyes with MMD2 had lower CTCL (120.37±47.18µm vs 218.33±92.70µm, p<0.001), CTMVCL (70.57±15.28µm vs 85.32±23.71µm, p=0.04), CTLVCL (101.65±25.36µm vs 154.55±68.41µm, p=0.001) and greater CVDCL (71.10±3.97% vs 66.97±3.63%, p<0.001), CVDMVCL (66.96±2.35% vs 65.06±2.69%, p=0.002), CVDLVCL (68.36±2.56% vs 66.58±2.88%, p=0.012), MCVWMVCL (6.14±0.34µm vs 5.90±0.35µm, p=0.007), and CBACL (12.69±1.38% vs 11.34±1.18%, p<0.001). After adjusting for age, thicker CTCL (odds ratio (OR) 0.98, 95% confidence interval (CI) 0.97-0.99, p<0.001), CTMVCL (OR 0.97 (0.94-0.99), p=0.002) and CTLVCL (OR 0.97 (0.96-0.98, p<0.001) were significantly associated with lower odds of MMD2, while increased CVDCL (OR 1.37 (1.20-1.55), p<0.001), CVDMVCL (OR 1.39 (1.12-1.73), p=0.003), CVDLVCL (OR 1.31 (1.07-1.60), p=0.009), CBACL (OR 2.19 (1.55-3.08), p<0.001) and MCVWMVCL (OR 6.97 (1.59-30.51), p=0.01) was significantly associated with higher odds of MMD2.Decrease in choroidal vessel width, density and thickness, and an increase in vascular branching were observed in eyes with long AL. A thinner and denser choroid with greater branching area and vessel width, which may all be signs of hypoxia, were associated with greater odds of MMD2.

  View details for DOI 10.3389/fopht.2023.1202445

  View details for PubMedID 38983085

  View details for PubMedCentralID PMC11182253

• Myopia-induced changes in the choroid mirror the microscopic biomechanical changes in the adjacent sclera Ito, K., Mamou, J., Hoerig, C., Dan, Y., McFadden, S., Hoang, Q. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023

  View details for Web of Science ID 001053795600150

• Macula Deformability as a Potential Biomarker for High Myopia Eyes at Risk of Developing Glaucoma and Pathologic Myopia Hoang, Q., Chuangsuwanich, T., Tun, T., Aung, T., Girard, M. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023

  View details for Web of Science ID 001053795606225

• Identifying Content for an Item Bank to Measure the Quality-of-Life Impact of Myopia Refractive Interventions. Translational vision science & technology Man, R. E., Goh, K. J., Lee, E. P., Lim, J. H., Ang, M., Hoang, Q. V., Wong, C. W., Saw, S. M., Fenwick, E. K., Lamoureux, E. L. 2023; 12 (5): 27

  Abstract

  To report on the content generation and item refinement phases for a myopia refractive intervention-specific quality-of-life (QoL) item bank that will be operationalized using computerized adaptive testing.Myopia refractive intervention-specific QoL domains and items were generated from (1) a literature search of existing refractive-intervention QoL questionnaires; (2) semistructured interviews with myopic patients corrected using spectacles, contact lenses and/or refractive surgery (n = 32); (3) and myopia experts (n = 9) recruited from the Singapore National Eye Centre. After a thematic analysis, items were systematically refined and tested using cognitive interviews with 24 additional patients with corrected myopia.Of the 32 participants with myopia interviewed (mean ± standard deviation age, 35.6 ± 9.0 years; 71.9% female; 78.1% Chinese), 12 (37.5%) wore spectacles, 7 (21.9%) used contact lenses, and 20 (62.5%) had undergone laser refractive surgery. Initially, 912 items within 7 independent QoL domains were identified. After refinement, 204 items were retained, including those relating to mobility challenges and work-related difficulties that are not well-represented in current refractive intervention-specific questionnaires.Through a rigorous item generation and selection process, we have developed a 204-item and 7-domain myopia refractive intervention-specific item bank that will now undergo rigorous psychometric testing to generate item calibrations for the validation of a novel computerized adaptive testing instrument designed for use in research and routine clinical practice.Once psychometrically validated and operationalized using computerized adaptive testing, this myopia refractive intervention-specific instrument will enable researchers and clinicians to quickly and comprehensively assess the impact of myopic refractive interventions across seven QoL domains.

  View details for DOI 10.1167/tvst.12.5.27

  View details for PubMedID 37227748

  View details for PubMedCentralID PMC10214877

• Pathologic myopia: advances in imaging and the potential role of artificial intelligence. The British journal of ophthalmology Li, Y., Foo, L. L., Wong, C. W., Li, J., Hoang, Q. V., Schmetterer, L., Ting, D. S., Ang, M. 2023; 107 (5): 600-606

  Abstract

  Pathologic myopia is a severe form of myopia that can lead to permanent visual impairment. The recent global increase in the prevalence of myopia has been projected to lead to a higher incidence of pathologic myopia in the future. Thus, imaging myopic eyes to detect early pathological changes, or predict myopia progression to allow for early intervention, has become a key priority. Recent advances in optical coherence tomography (OCT) have contributed to the new grading system for myopic maculopathy and myopic traction maculopathy, which may improve phenotyping and thus, clinical management. Widefield fundus and OCT imaging has improved the detection of posterior staphyloma. Non-invasive OCT angiography has enabled depth-resolved imaging for myopic choroidal neovascularisation. Artificial intelligence (AI) has shown great performance in detecting pathologic myopia and the identification of myopia-associated complications. These advances in imaging with adjunctive AI analysis may lead to improvements in monitoring disease progression or guiding treatments. In this review, we provide an update on the classification of pathologic myopia, how imaging has improved clinical evaluation and management of myopia-associated complications, and the recent development of AI algorithms to aid the detection and classification of pathologic myopia.

  View details for DOI 10.1136/bjophthalmol-2021-320926

  View details for PubMedID 35288438

• Applications of Genomics and Transcriptomics in Precision Medicine for Myopia Control or Prevention. Biomolecules Jiang, L., Goh, D. X., Koh, J. H., Chan, X., Brennan, N. A., Barathi, V. A., Hoang, Q. V. 2023; 13 (3)

  Abstract

  Myopia is a globally emerging concern accompanied by multiple medical and socio-economic burdens with no well-established causal treatment to control thus far. The study of the genomics and transcriptomics of myopia treatment is crucial to delineate disease pathways and provide valuable insights for the design of precise and effective therapeutics. A strong understanding of altered biochemical pathways and underlying pathogenesis leading to myopia may facilitate early diagnosis and treatment of myopia, ultimately leading to the development of more effective preventive and therapeutic measures. In this review, we summarize current data about the genomics and transcriptomics of myopia in human and animal models. We also discuss the potential applicability of these findings to precision medicine for myopia treatment.

  View details for DOI 10.3390/biom13030494

  View details for PubMedID 36979429

  View details for PubMedCentralID PMC10046175

• Quadrant Asymmetry in Optical Coherence Tomography Angiography Metrics in Ischemic Versus Non-Ischemic Central Retinal Vein Occlusion Eyes. Translational vision science & technology Jung, J. J., Chan, X., Lim, S. Y., Lee, S. S., Rofagha, S., Hoang, Q. V. 2023; 12 (3): 30

  Abstract

  To determine whether quadrant asymmetry (QA) of optical coherence tomography angiography (OCTA) metrics differs between non-ischemic versus ischemic central retinal vein occlusion (CRVO).Fifty-eight eyes (21 non-ischemic, 10 ischemic CRVO, and 27 contralateral control eyes) underwent 3 × 3 mm spectral-domain OCTA scans with quantification of the superficial retinal layer vessel length density (VLD) and perfusion density (PD). QA, defined as the maximum-minus-minimum value among four parafoveal Early Treatment Diabetic Retinopathy Study (ETDRS) quadrants, was compared by linear regression including fixed effects for each eye.Mean age was 73.6 ± 11.4 (range 39-88), 73.8 ± 12.4 (range 39-91) and 77.2 ± 9.83, (range 60-88); and QA was 3.46 ± 1.76, 3.14 ± 1.57, and 4.88 ± 2.42 for VLD and 0.072 ± 0.038, 0.062 ± 0.036, and 0.11 ± 0.056 for PD for control, non-ischemic, and ischemic, respectively. QA was significantly higher in ischemic (0.109 ± 0.056) than non-ischemic CRVO eyes (0.062 ± 0.036; P = 0.02) and control eyes for PD (0.072 ± 0.038; P = 0.03). QA was also greater in ischemic (4.875 ± 2.418) than non-ischemic CRVO (3.141 ± 1.572) for VLD (P = 0.04). In terms of identifying which particular quadrant is most affected by ischemia, multivariate regression analysis comparing intra-quadrant effect on the presence of ischemia versus non-ischemia showed no quadrant was significantly affected (P > 0.05 for all quadrants).Ischemic CRVO increases intraeye QA of OCTA metrics when compared to non-ischemic CRVO and control eyes. No specific ETDRS quadrant appears to be more affected.This work uses an intraeye method to delineate between ischemic and non-ischemic CRVO by OCTA imaging, overcoming inter-eye variables encountered in clinical care.

  View details for DOI 10.1167/tvst.12.3.30

  View details for PubMedID 36988945

  View details for PubMedCentralID PMC10064914

• Deep learning system to predict the 5-year risk of high myopia using fundus imaging in children. NPJ digital medicine Foo, L. L., Lim, G. Y., Lanca, C., Wong, C. W., Hoang, Q. V., Zhang, X. J., Yam, J. C., Schmetterer, L., Chia, A., Wong, T. Y., Ting, D. S., Saw, S. M., Ang, M. 2023; 6 (1): 10

  Abstract

  Our study aims to identify children at risk of developing high myopia for timely assessment and intervention, preventing myopia progression and complications in adulthood through the development of a deep learning system (DLS). Using a school-based cohort in Singapore comprising of 998 children (aged 6-12 years old), we train and perform primary validation of the DLS using 7456 baseline fundus images of 1878 eyes; with external validation using an independent test dataset of 821 baseline fundus images of 189 eyes together with clinical data (age, gender, race, parental myopia, and baseline spherical equivalent (SE)). We derive three distinct algorithms - image, clinical and mix (image + clinical) models to predict high myopia development (SE ≤ -6.00 diopter) during teenage years (5 years later, age 11-17). Model performance is evaluated using area under the receiver operating curve (AUC). Our image models (Primary dataset AUC 0.93-0.95; Test dataset 0.91-0.93), clinical models (Primary dataset AUC 0.90-0.97; Test dataset 0.93-0.94) and mixed (image + clinical) models (Primary dataset AUC 0.97; Test dataset 0.97-0.98) achieve clinically acceptable performance. The addition of 1 year SE progression variable has minimal impact on the DLS performance (clinical model AUC 0.98 versus 0.97 in primary dataset, 0.97 versus 0.94 in test dataset; mixed model AUC 0.99 versus 0.97 in primary dataset, 0.95 versus 0.98 in test dataset). Thus, our DLS allows prediction of the development of high myopia by teenage years amongst school-going children. This has potential utility as a clinical-decision support tool to identify "at-risk" children for early intervention.

  View details for DOI 10.1038/s41746-023-00752-8

  View details for PubMedID 36702878

  View details for PubMedCentralID PMC9879938

• Rare variant analyses across multiethnic cohorts identify novel genes for refractive error. Communications biology Musolf, A. M., Haarman, A. E., Luben, R. N., Ong, J. S., Patasova, K., Trapero, R. H., Marsh, J., Jain, I., Jain, R., Wang, P. Z., Lewis, D. D., Tedja, M. S., Iglesias, A. I., Li, H., Cowan, C. S., Biino, G., Klein, A. P., Duggal, P., Mackey, D. A., Hayward, C., Haller, T., Metspalu, A., Wedenoja, J., Pärssinen, O., Cheng, C. Y., Saw, S. M., Stambolian, D., Hysi, P. G., Khawaja, A. P., Vitart, V., Hammond, C. J., van Duijn, C. M., Verhoeven, V. J., Klaver, C. C., Bailey-Wilson, J. E. 2023; 6 (1): 6

  Abstract

  Refractive error, measured here as mean spherical equivalent (SER), is a complex eye condition caused by both genetic and environmental factors. Individuals with strong positive or negative values of SER require spectacles or other approaches for vision correction. Common genetic risk factors have been identified by genome-wide association studies (GWAS), but a great part of the refractive error heritability is still missing. Some of this heritability may be explained by rare variants (minor allele frequency [MAF] ≤ 0.01.). We performed multiple gene-based association tests of mean Spherical Equivalent with rare variants in exome array data from the Consortium for Refractive Error and Myopia (CREAM). The dataset consisted of over 27,000 total subjects from five cohorts of Indo-European and Eastern Asian ethnicity. We identified 129 unique genes associated with refractive error, many of which were replicated in multiple cohorts. Our best novel candidates included the retina expressed PDCD6IP, the circadian rhythm gene PER3, and P4HTM, which affects eye morphology. Future work will include functional studies and validation. Identification of genes contributing to refractive error and future understanding of their function may lead to better treatment and prevention of refractive errors, which themselves are important risk factors for various blinding conditions.

  View details for DOI 10.1038/s42003-022-04323-7

  View details for PubMedID 36596879

  View details for PubMedCentralID PMC9810640

• Automated Classification and Detection of Staphyloma with Ultrasound Images in Pathologic Myopia Eyes. Ultrasound in medicine & biology Ito, K., Lye, T. H., Dan, Y. S., Yu, J. D., Silverman, R. H., Mamou, J., Hoang, Q. V. 2022; 48 (12): 2430-2441

  Abstract

  The aim of this study was to develop an eyewall curvature- and axial length (AxL)-based algorithm to automate detection (clinician-free) of staphyloma ridge and apex locations using ultrasound (US). Forty-six individuals (with emmetropia, high myopia or pathologic myopia) were enrolled in this study (AxL range: 22.3-39.3 mm), yielding 130 images in total. An intensity-based segmentation algorithm automatically tracked the posterior eyewall, calculating the posterior eyewall local curvature (K) and distance (L) to the transducer and the location of the staphyloma apex. By use of the area under the receiver operator characteristic (AUROC) curve to evaluate the diagnostic ability of eight local statistics derived from K, L and AxL, the algorithm successfully quantified non-uniformity of eye shape with an AUROC > 0.70 for most K-based parameters. The performance of binary classification (staphyloma absence vs. presence) was assessed with the best classifier (the combination of AxL, standard deviation of K and standard deviation of L) yielding a diagnostic validation performance of 0.897, which was comparable to the diagnostic performance of junior clinicians. The staphyloma apex was localized with an average error of 1.35 ± 1.34 mm. Combined with the real-time data acquisition capabilities of US, this method can be employed as a screening tool for clinician-free in vivo staphyloma detection.

  View details for DOI 10.1016/j.ultrasmedbio.2022.06.010

  View details for PubMedID 36096896

  View details for PubMedCentralID PMC12360850

• Optic nerve tortuosity and displacements during horizontal eye movements in healthy and highly myopic subjects. The British journal of ophthalmology Wang, X., Chang, S., Grinband, J., Yannuzzi, L. A., Freund, K. B., Hoang, Q. V., Girard, M. J. 2022; 106 (11): 1596-1602

  Abstract

  (1) To assess the morphology and 3-dimensional (3D) displacements of the eye globe and optic nerve (ON) in adduction/abduction using MRI. (2) To assess differences between healthy emmetropic and highly myopic (HM) subjects.MRI volumes of both eyes from 18 controls and 20 HM subjects in primary gaze, abduction and adduction (15°) were postprocessed. All ONs were manually segmented and fitted to a 3D curve to assess ON tortuosity. ON displacements were evaluated in four quasicoronal planes which were perpendicular to the ON in primary gaze and were 3 mm apart.Axial length was higher in the HM group (28.62±2.60 vs 22.84±0.89 mm; p<0.0001). Adjusted ON tortuosities (ie, ON tortuosities estimated before myopia onset) were lower in HM eyes (0.9063±0.0591) versus controls (1.0152±0.02981) in primary gaze, adduction (0.9023±0.05538 vs 1.0137±0.0299) and abduction (0.9100±0.0594 vs 1.0182±0.0316); p<0.0001 for all cases. In all eyes, ON displacements in adduction were significantly different from those in abduction in the naso-temporal direction (p<0.0001 in all planes) but not in the supero-inferior direction. ON displacements in the posterior segments of the ON were smaller in the HM group in both gaze directions and were larger in the anterior-most ON segment in adduction only.The adjusted tortuosity of the ON was significantly lower in HM eyes, suggesting that eyes destined towards HM exhibited higher ON traction forces during eye movements before the onset of myopia. Our ON metrics may be valuable to explore a potential link between eye movements and axial elongation.

  View details for DOI 10.1136/bjophthalmol-2021-318968

  View details for PubMedID 34039559

• Visual field defects and myopic macular degeneration in Singapore adults with high myopia. The British journal of ophthalmology Lanca, C., Sun, C. H., Chong, R., Wong, Y. L., Nongpiur, M. E., Htoon, H. M., Thakur, S., Quek, D. Q., Cheng, C. Y., Hoang, Q. V., Sabanayagam, C., Saw, S. M., Wong, C. W. 2022; 106 (10): 1423-1428

  Abstract

  To characterise the association between visual field (VF) defects and myopic macular degeneration (MMD) in highly myopic adults without glaucoma.Participants (n=106; 181 eyes) with high myopia (HM; spherical equivalent ≤-5.0 D or axial length (AL) ≥26 mm), after excluding glaucoma and glaucoma suspects, from the Singapore Epidemiology of Eye Diseases-HM study were included in this cross-sectional study. Humphrey VF (central 24-2 threshold), cup-disc ratio (CDR) and intraocular pressure (IOP) measurements were performed. Mean deviation (MD) and pattern SD (PSD), VF defects (normal or abnormal; p<0.05 in ≥3 non-edge contiguous locations) and pattern (eg, generalised sensitivity loss) were analysed. MMD presence was diagnosed from fundus photographs. Generalised estimating equations were used for analysing factors (MD, PSD, VF defects, CDR and IOP) associated with MMD.Mean age was 55.4±9.9 years and 51.9% were women (AL=26.7±1.1 mm). MMD eyes had lower MD (-3.8±2.9 dB vs -1.1±1.4 dB) and higher PSD (2.8±1.7 dB vs 1.7±0.6 dB). A higher percentage of MMD eyes (n=48) had abnormal VF (62.5% vs 28.6%; p<0.001) compared with no MMD (n=133 eyes). VF pattern in MMD eyes was significantly different from eyes without MMD (p=0.001) with greater generalised sensitivity loss (53.3% vs 10.5%) and arcuate defects (16.7% vs 10.5%). In multivariate analyses, MD (OR=1.52) and PSD (OR=1.67) were significantly (p=0.003) associated with MMD, but VF defects were not associated with MMD.Highly myopic adults with MMD may have VF loss when compared with highly myopic patients without MMD even in adults without glaucoma.

  View details for DOI 10.1136/bjophthalmol-2020-318674

  View details for PubMedID 33888462

• Correlation of Diabetic Disease Severity to Degree of Quadrant Asymmetry in En Face OCTA Metrics. Investigative ophthalmology & visual science Jung, J. J., Lim, S. Y., Chan, X., Sadda, S. R., Hoang, Q. V. 2022; 63 (9): 12

  Abstract

  To determine if diabetic retinopathy (DR) severity affects quadrant asymmetry (QA) of optical coherence tomography angiography (OCTA) metrics differentially.Ninety eyes (60 patients) with no diabetes mellitus (DM) (n = 39) or varying levels of DR (n = 51) had OCTA images (3 × 3 mm, Cirrus5000) acquired five times and averaged. The vessel length density (VLD) and perfusion density (PD) of the superficial retinal layer (SRL) and deep retinal layer (DRL) were measured. QA was defined as the maximum minus minimum value among four parafoveal Early Treatment Diabetic Retinopathy quadrants, and compared with DR severity by linear regression including fixed effects for each individual and eye.The mean patient age was 55.5 years (range, 24-88 years) and 60% were male. Comparing severe nonproliferative DR or proliferative DR versus no DM/DR eyes, QA was significantly higher for SRL VLD, and PD (+0.67 ± 0.16 and +0.014 ± 0.003; P < 0.001) and DRL VLD, and PD (+1.25 ± 0.16 and +0.032 ± 0.003; P < 0.001). When comparing mild or moderate nonproliferative DR versus no DM/DR, the DRL VLD, and PD were significantly higher (+0.51 ± 0.13 and +0.015 ± 0.003; P < 0.001). For every step increase in DR severity, there was a +0.20 QA for SRL VLD, +0.004 SRL PD, +0.33 DRL VLD and +0.009 DRL PD (P < 0.001). Regression analysis comparing intraquadrant effect on DR severity demonstrated that the superior quadrant was most affected for all OCTA metrics.DR severity affects VLD and PD more asymmetrically across Early Treatment Diabetic Retinopathy quadrants with a linear increase in QA for each worsening level of DR. Individual intraeye metrics such as QA can accurately quantify DR severity without concerns for intereye variabilities that could affect the reproducibility and reliability of OCTA quantification.

  View details for DOI 10.1167/iovs.63.9.12

  View details for PubMedID 35943732

  View details for PubMedCentralID PMC9379327

• The Potential of Current Polygenic Risk Scores to Predict High Myopia and Myopic Macular Degeneration in Multiethnic Singapore Adults. Ophthalmology Kassam, I., Foo, L. L., Lanca, C., Xu, L., Hoang, Q. V., Cheng, C. Y., Hysi, P., Saw, S. M. 2022; 129 (8): 890-902

  Abstract

  To evaluate the transancestry portability of current myopia polygenic risk scores (PRSs) to predict high myopia (HM) and myopic macular degeneration (MMD) in an Asian population.Population-based study.A total of 5894 adults (2141 Chinese, 1913 Indian, and 1840 Malay) from the Singapore Epidemiology of Eye Diseases study were included in the analysis. The mean ± standard deviation age was 57.05 ± 9.31 years. A total of 361 adults had a diagnosis of HM (spherical equivalent [SE] < -5.00 diopters [D]) from refraction measurements, 240 individuals had a diagnosis of MMD graded by the International Photographic Classification and Grading System for Myopic Maculopathy criteria from fundus photographs, and 3774 individuals were control participants without myopia (SE > -0.5 D).The PRS, derived from 687 289 HapMap3 single nucleotide polymorphisms (SNPs) from the largest genome-wide association study of myopia in Europeans to date (n = 260 974), was assessed on its ability to predict patients with HM and MMD versus control participants.The primary outcomes were the area under the receiver operating characteristic curve (AUC) to predict HM and MMD.The PRS had an AUC of 0.73 (95% confidence interval [CI], 0.70-0.75) for HM and 0.66 (95% CI, 0.63-0.70) for MMD versus no myopia. The inclusion of the PRS with other predictors (age, sex, educational attainment [EA], and ancestry; age-by-ancestry, sex-by-ancestry, and EA-by-ancestry interactions; and 20 genotypic principal components) increased the AUC to 0.84 (95% CI, 0.82-0.86) for HM and 0.79 (95% CI, 0.76-0.82) for MMD. Individuals with a PRS in the top 5% showed up to a 4.66 (95% CI, 3.34-6.42) times higher risk of HM developing and up to a 3.43 (95% CI, 2.27-5.05) times higher risk of MMD developing compared with the remaining 95% of individuals.The PRS is a good predictor for HM and facilitates the identification of high-risk children to prevent myopia progression to HM. In addition, the PRS also predicts MMD and helps to identify high-risk adults with myopia who require closer monitoring for myopia-related complications.

  View details for DOI 10.1016/j.ophtha.2022.03.022

  View details for PubMedID 35358591

• Impact of Coronavirus Disease 2019 Restrictions on Retinal Detachment: A Multicenter Experience. Ophthalmology. Retina Jung, J. J., Chang, J. S., Oellers, P. R., Ali, M. H., Do, B. K., Tseng, J. J., Roizenblatt, R., Muni, R. H., Weng, C. Y., Oakey, Z. B., Tsao, S. W., Rofagha, S., Chan, X., Hoang, Q. V. 2022; 6 (7): 638-641

  Abstract

  In this retrospective, multicenter study of 261 eyes (259 patients), patients who underwent rhegmatogenous retinal detachment repair during the coronavirus disease 2019 (COVID-19) post-lockdown period experienced an additional 22-day delay, leading to significantly more epiretinal membrane and proliferative vitreoretinopathy and lower single-surgery anatomic success rates. During lockdown, perfluoropropane gas was used more commonly, and pneumatic retinopexy was used more commonly in COVID-19-positive patients.

  View details for DOI 10.1016/j.oret.2022.02.001

  View details for PubMedID 35144021

  View details for PubMedCentralID PMC8820022

• Advances in OCT Imaging in Myopia and Pathologic Myopia. Diagnostics (Basel, Switzerland) Li, Y., Zheng, F., Foo, L. L., Wong, Q. Y., Ting, D., Hoang, Q. V., Chong, R., Ang, M., Wong, C. W. 2022; 12 (6)

  Abstract

  Advances in imaging with optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) technology, including the development of swept source OCT/OCTA, widefield or ultra-widefield systems, have greatly improved the understanding, diagnosis, and treatment of myopia and myopia-related complications. Anterior segment OCT is useful for imaging the anterior segment of myopes, providing the basis for implantable collamer lens optimization, or detecting intraocular lens decentration in high myopic patients. OCT has enhanced imaging of vitreous properties, and measurement of choroidal thickness in myopic eyes. Widefield OCT systems have greatly improved the visualization of peripheral retinal lesions and have enabled the evaluation of wide staphyloma and ocular curvature. Based on OCT imaging, a new classification system and guidelines for the management of myopic traction maculopathy have been proposed; different dome-shaped macula morphologies have been described; and myopia-related abnormalities in the optic nerve and peripapillary region have been demonstrated. OCTA can quantitatively evaluate the retinal microvasculature and choriocapillaris, which is useful for the early detection of myopic choroidal neovascularization and the evaluation of anti-vascular endothelial growth factor therapy in these patients. In addition, the application of artificial intelligence in OCT/OCTA imaging in myopia has achieved promising results.

  View details for DOI 10.3390/diagnostics12061418

  View details for PubMedID 35741230

  View details for PubMedCentralID PMC9221645

• Assessment of stiffness of posterior eye wall in myopic eyes with an ultrasound-based algorithm using strain elastography Lim, S., Ito, K., Dan, Y., Yu, J. G., Silverman, R. H., Mamou, J., Saw, S., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437004232

• Identifying Content for an Item Bank to Measure the Quality-of-Life Impact of Myopia Man, R., Goh, K., Lee, E., Aranvindhan, A., Gan, A. T. L., Ang, M., Hoang, Q. V., Wong, C., Saw, S., Fenwick, E. K., Lamoureux, E. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437006017

• Novel Super Resolution Magnetic Resonance Imaging Processing Pipeline for Whole Eye Imaging with Short Scan Times in High Myopic Eyes Hoang, Q. V., Chang, S., Najjar, R., Milea, D., Yannuzzi, L., Freund, K., Grinband, J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437006100

• Level of Diabetic Retinopathy Severity Correlates to Degree of Quadrant Asymmetry in OCTA Metrics Jung, J. J., Lim, S., Chan, X., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437001275

• Effect of Axial Length on the Quality of ONH Scans Acquired from SS-OCT and SD-OCT in Highly Myopic Eyes Loh, I., Chong, R., Dan, Y., Wong, Q., Yu, J. G., Chua, C. S. Q., Wong, C., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437006099

• Real-Time, Clinician-Free Detection of Staphyloma Presence and Apex Location in a Cohort of Highly Myopic Eyes With an Ultrasound-Based Algorithm Ito, K., Lye, T. H., Dan, Y., Yu, J. G., Silverman, R. H., Mamou, J., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437006098

• Changes in visual function in eyes with myopic traction maculopathy over 1 year Wong, Q., Dan, Y., Chua, C. S. Q., Ang, M., Hoang, Q. V., Wong, C. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844401301072

• Evaluating chemical-crosslinking induced microstructural changes in the posterior sclera with high-frequency quantitative ultrasound Hoerig, C., Aichele, J., Catheline, S., Hoang, Q. V., Mamou, J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437006173

• Quantitative OCT angiography of the retinal microvasculature and choriocapillaris in highly myopic eyes with myopic macular degeneration. The British journal of ophthalmology Zheng, F., Chua, J., Ke, M., Tan, B., Yu, M., Hu, Q., Cheung, C. M., Ang, M., Lee, S. Y., Wong, T. Y., Schmetterer, L., Wong, C. W., Hoang, Q. V. 2022; 106 (5): 681-688

  Abstract

  To quantify retinal and choriocapillaris (CC) microvasculature in highly myopic (HM) eyes with myopic macular degeneration (MMD) using swept-source optical coherence tomography angiography (SS-OCTA).162 HM eyes (spherical equivalent ≤ -6.0 dioptres or axial length (AL) ≥26.5 mm) from 98 participants were enrolled, including 60 eyes (37.0%) with tessellated fundus, 54 eyes (33.3%) with peripapillary diffuse chorioretinal atrophy (PDCA), 27 eyes (16.7%) with macular diffuse chorioretinal atrophy (MDCA) and 21 eyes (13.0%) with patchy or macular atrophy. PLEX Elite 9000 SS-OCTA was performed to obtain perfusion densities (PD) of the superficial and deep retinal capillary plexus, and CC signal voids (number, area and density).Retinal PD decreased with increasing severity of MMD. Multivariable analysis showed that after adjustment of age and other factors, retinal PD decreased significantly in eyes with longer AL (β≤-0.51, p<0.001) and with an MMD severity of MDCA or worse (β≤-1.63, p<0.001). Reduced retinal PD were significantly associated with worse vision (β≤-0.01, p≤0.04). In terms of CC signal voids, multivariable analysis showed that longer AL (p<0.001), but not MMD severity (p≥0.12) was significantly associated with CC signal void changes in the earliest stage of MMD.We demonstrate significant OCTA alterations in the retina and CC in HM eyes with varying severities of MMD. In eyes with early-stage PDCA, lower retinal PD and more extensive CC signal voids are predominantly associated with increasing AL. In contrast, in eyes with MDCA or worse, MMD itself was associated with sparser retinal and CC circulation.

  View details for DOI 10.1136/bjophthalmol-2020-317632

  View details for PubMedID 33397658

• An evidence-based review of the epidemiology of myopic traction maculopathy. Survey of ophthalmology Cheong, K. X., Xu, L., Ohno-Matsui, K., Sabanayagam, C., Saw, S. M., Hoang, Q. V. 2022; 67 (6): 1603-1630

  Abstract

  Myopic traction maculopathy (MTM), one of the complications of pathologic myopia, is a spectrum of pathological conditions that are attributed to tractional changes in the eye characterized by retinoschisis, lamellar or full thickness macular hole, and foveal retinal detachment. Considering the global public health burden of MTM and pathologic myopia, it is important to understand these sight-threatening complications and their associations. We conducted an evidence-based review of the prevalence and natural history of MTM and associated risk factors. The prevalence of MTM in the general population is low, but is increased among high myopes. MTM is associated with preretinal tractional structures, myopic refractive error and axial elongation, posterior staphyloma, dome-shaped macula, chorioretinal atrophy, and myopic macular degeneration. The clinical course of MTM tends to be stable; however, MTM may progress, resulting in visual acuity deterioration, although spontaneous improvement also occurs. The associations of MTM progression include vitreous traction, location, and extent of MTM, and lamellar macular hole-specific factors. More high-quality population-based studies that assess MTM prevalence and natural history are needed.

  View details for DOI 10.1016/j.survophthal.2022.03.007

  View details for PubMedID 35367479

• Editorial: Advances in Management and Treatment of High Myopia and Its Complications. Frontiers in medicine Hoang, Q. V., Chan, X., Zhu, X., Zhou, X., Shentu, X., Lu, Y. 2022; 9: 846540

  View details for DOI 10.3389/fmed.2022.846540

  View details for PubMedID 35360711

  View details for PubMedCentralID PMC8960236

• MACULAR SENSITIVITY AND CAPILLARY PERFUSION IN HIGHLY MYOPIC EYES WITH MYOPIC MACULAR DEGENERATION. Retina (Philadelphia, Pa.) Zheng, F., Chua, J., Sim, Y. C., Tan, B., Yu, M., Wong, Q. Y., Dan, Y. S., Chong, R. S., Gemmy Cheung, C. M., Ang, M., Lee, S. Y., Wong, T. Y., Schmetterer, L., Wai Wong, C., Hoang, Q. V. 2022; 42 (3): 529-539

  Abstract

  To evaluate the interrelationship between macular sensitivity and retinal perfusion density (PD) in eyes with myopic macular degeneration (MMD).One hundred and thirty-eight highly myopic eyes from 82 adult participants were recruited. Macular sensitivity was evaluated using the Microperimeter MP-3. Retinal PD was measured using the PLEX Elite 9000 swept source optical coherence tomography angiography. Macular sensitivity values between different categories of MMD and its relationship with optical coherence tomography angiography measurements were evaluated using multivariable linear mixed models, adjusting for age and axial length.Macular sensitivity reduced with increasing severity of MMD (β ≤ -0.95, P < 0.001), whereas the best-corrected visual acuity was not associated with MMD severity (P > 0.04). Persons who were older (β = -0.08, P < 0.001), with longer axial length (β = -0.32, P = 0.005), presence of macular diffuse choroidal atrophy (β = -2.16, P < 0.001) or worse MMD (β = -5.70, P < 0.001), and presence of macular posterior staphyloma (β ≤ -2.98, P < 0.001) or Fuchs spot (β = -1.58, P = 0.04) were associated with reduced macular sensitivity. Macular sensitivity was significantly associated with deep retinal PD in MMD (β = 0.15, P = 0.004) but not with superficial retinal PD (P = 0.62).There was a strong correlation between reduced macular sensitivity and increasing MMD severity, even in mild MMD independent of the best-corrected visual acuity. Furthermore, macular sensitivity was correlated with deep retinal PD, suggesting a vasculature-function relationship in MMD.

  View details for DOI 10.1097/IAE.0000000000003333

  View details for PubMedID 35188491

• Untitled Reply RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Soh, Y., Hoang, Q. V., Freund, K., Jung, J. J. 2022; 42 (1): E1-E3

  Abstract

  Response to the Letter to the Editor regarding “Bacillary layer detachment due to macular neovascularization” and identification of the distinct differences between bacillary layer detachment associated with Type 2 subretinal macular neovascularization (MNV) and subretinal hemorrhage versus bridge arch-shaped serous retinal detachment associated with Type 2 MNV and subretinal fibrosis.

  View details for Web of Science ID 000732829100002

  View details for PubMedID 34173360

  View details for PubMedCentralID PMC8692482

• Reply. Retina (Philadelphia, Pa.) Soh, Y. Q., Hoang, Q. V., Freund, K. B., Jung, J. J. 2022; 42 (1): e1-e3

  Abstract

  Response to the Letter to the Editor regarding “Bacillary layer detachment due to macular neovascularization” and identification of the distinct differences between bacillary layer detachment associated with Type 2 subretinal macular neovascularization (MNV) and subretinal hemorrhage versus bridge arch-shaped serous retinal detachment associated with Type 2 MNV and subretinal fibrosis.

  View details for DOI 10.1097/IAE.0000000000003240

  View details for PubMedID 34173360

  View details for PubMedCentralID PMC8692482

• Steady-State Pattern Electroretinography in Eyes with Glaucoma and High Myopia. Clinical ophthalmology (Auckland, N.Z.) Lim, X. H., Nongpiur, M. E., Najjar, R. P., Hoang, Q. V., Milea, D., Wong, C. W., Husain, R., Htoon, H. M., Aung, T., Perera, S., Wong, T. T. 2021; 15: 4455-4465

  Abstract

  To investigate features of the steady-state pattern electroretinogram (ssPERG) in subjects with glaucoma (G), high myopia (HM; spherical equivalent ≤-6D) and glaucoma with high myopia (GHM).Our study included 48 participants divided into 3 groups (G, HM, and GHM) who each underwent monocular ssPERG testing with Diopsys NOVA PERG protocols. The ConStim protocol detects distinct topographic patterns of dysfunction 16° and 24° around the central macula. MagD is the amplitude of the average signal and MagD/Mag ratio indicates the consistency of the response. ssPERG indices were compared between groups and correlated with functional (ie, visual field mean deviation (VFMD)) and structural (ie, average retinal nerve fibre layer (RNFL) thickness; Cirrus optical coherence tomography) features.Participants had an average age of 59.4±7.6 years. Mean Humphrey VFMD was -14.22 ± 2.88dB, -2.62 ± 1.18dB and -12.80 ± 2.60dB for G, HM and GHM groups, respectively. Mean RNFL thickness was 63.0 ± 8.20μm, 69.5 ± 15.7μm and 60.6 ± 5.0μm for G, HM and GHM groups, respectively. For the 24° setting, no significant differences were noted for any of the parameters. For the 16° setting, MagD was lower in the GHM group compared to the HM group (0.29µV vs 0.52µV; p = 0.02). Significant differences were noted for the MagD/Mag ratio between HM and G groups (0.58 vs 0.40; p = 0.02) and between HM and GHM groups (0.58 vs 0.35; p = 0.002). There were positive correlations between both MagD 16° and MagD/Mag ratio 16° with VFMD (correlation coefficient [r]=0.37, p = 0.009; and r = 0.44, p = 0.002, respectively) and RNFL (r = 0.43, p = 0.002; and r = 0.48, p = 0.001, respectively).MagD/Mag ratio at 16° was significantly lower in glaucomatous eyes (with or without high myopia) compared to those with high myopia without glaucoma, suggesting that glaucoma has a distinct impact on MagD/Mag ratio at 16° irrespective of the presence of myopia.

  View details for DOI 10.2147/OPTH.S336903

  View details for PubMedID 34819717

  View details for PubMedCentralID PMC8607345

• BACILLARY LAYER DETACHMENT BECAUSE OF MACULAR NEOVASCULARIZATION. Retina (Philadelphia, Pa.) Jung, J. J., Soh, Y. Q., Yu, D. J., Rofagha, S., Lee, S. S., Freund, K. B., Hoang, Q. V. 2021; 41 (10): 2106-2114

  Abstract

  To describe the clinical and multimodal imaging features of bacillary layer detachment (BD), and its response to intravitreal anti-vascular endothelial growth factor therapy, in eyes with macular neovascularization.Retrospective, observational case series of 14 eyes (14 patients, 7 men) imaged with eyes (14 patients, 7 men) were imaged with spectral-domain optical coherence tomography, and either fluorescein angiography or optical coherence tomography angiography. Therapeutic response was monitored with serial imaging and best-corrected visual acuity assessments.The mean age was 75 ± 13 (range: 45-96) years, with mean follow-up duration of 27 ± 21 (range: 1-56) months. Neovascular age-related macular degeneration was found in 71% (10/14) eyes. Type 2 macular neovascularization lesions were associated with BD in all 14 eyes. Subretinal hemorrhage was noted in 79% (11/14) eyes. BD promptly resolved after intravitreal antivascular endothelial growth factor therapy in all eyes. The baseline best-corrected visual acuity improved from logarithm of the minimum angle of resolution 0.84 ± 0.32 (Snellen equivalent 20/138) to logarithm of the minimum angle of resolution 0.48 ± 0.31 (Snellen equivalent 20/60) at the last follow-up, with treatment of the macular neovascularization.Type 2 macular neovascularization and subretinal hemorrhage are associated with BDs, which may be due to a rapid influx of exudative fluid into the potential space between the external limiting membrane and ellipsoid zone. Intravitreal antivascular endothelial growth factor therapy results in rapid resolution of BDs and visual improvement in most eyes.

  View details for DOI 10.1097/IAE.0000000000003153

  View details for PubMedID 33625111

  View details for PubMedCentralID PMC8371094

• Ultrawide field, distortion-corrected ocular shape estimation with MHz optical coherence tomography (OCT). Biomedical optics express Tan, B., McNabb, R. P., Zheng, F., Sim, Y. C., Yao, X., Chua, J., Ang, M., Hoang, Q. V., Kuo, A. N., Schmetterer, L. 2021; 12 (9): 5770-5781

  Abstract

  Ocular deformation may be associated with biomechanical alterations in the structures of the eye, especially the cornea and sclera in conditions such as keratoconus, congenital glaucoma, and pathological myopia. Here, we propose a method to estimate ocular shape using an ultra-wide field MHz swept-source optical coherence tomography (SS-OCT) with a Fourier Domain Mode-Locked (FDML) laser and distortion correction of the images. The ocular biometrics for distortion correction was collected by an IOLMaster 700, and localized Gaussian curvature was proposed to quantify the ocular curvature covering a field-of-view up to 65°×62°. We achieved repeatable curvature shape measurements (intraclass coefficient = 0.88 ± 0.06) and demonstrated its applicability in a pilot study with individuals (N = 11) with various degrees of myopia.

  View details for DOI 10.1364/BOE.428430

  View details for PubMedID 34692214

  View details for PubMedCentralID PMC8515957

• Highlights from the 2019 International Myopia Summit on 'controversies in myopia'. The British journal of ophthalmology Wong, C. W., Foo, L. L., Morjaria, P., Morgan, I., Mueller, A., Davis, A., Keys, D., He, M., Sankaridurg, P., Zhu, J. F., Hendicott, P., Tan, D., Saw, S. M., Cheng, C. Y., Lamoureux, E. L., Crowston, J. G., Gemmy Cheung, C. M., Sng, C., Chan, C., Wong, D., Lee, S. Y., Agrawal, R., Hoang, Q. V., Su, X., Koh, A., Ngo, C., Chen, H., Wu, P. C., Chia, A., Jonas, J. B., Wong, T. Y., Ang, M. 2021; 105 (9): 1196-1202

  Abstract

  Myopia is an emerging public health issue with potentially significant economic and social impact, especially in East Asia. However, many uncertainties about myopia and its clinical management remain. The International Myopia Summit workgroup was convened by the Singapore Eye Research Institute, the WHO Regional Office for the Western Pacific and the International Agency for the Prevention of Blindness in 2019. The aim of this workgroup was to summarise available evidence, identify gaps or unmet needs and provide consensus on future directions for clinical research in myopia. In this review, among the many 'controversies in myopia' discussed, we highlight three main areas of consensus. First, development of interventions for the prevention of axial elongation and pathologic myopia is needed, which may require a multifaceted approach targeting the Bruch's membrane, choroid and/or sclera. Second, clinical myopia management requires co-operation between optometrists and ophthalmologists to provide patients with holistic care and a tailored approach that balances risks and benefits of treatment by using optical and pharmacological interventions. Third, current diagnostic technologies to detect myopic complications may be improved through collaboration between clinicians, researchers and industry. There is an unmet need to develop new imaging modalities for both structural and functional analyses and to establish normative databases for myopic eyes. In conclusion, the workgroup's call to action advocated for a paradigm shift towards a collaborative approach in the holistic clinical management of myopia.

  View details for DOI 10.1136/bjophthalmol-2020-316475

  View details for PubMedID 32816799

• Correspondence. Retina (Philadelphia, Pa.) Soh, Y. Q., Hoang, Q. V., Jung, J. J. 2021; 41 (9): e71-e72

  View details for DOI 10.1097/IAE.0000000000003269

  View details for PubMedID 34310546

• Framework for quantitative three-dimensional choroidal vasculature analysis using optical coherence tomography. Biomedical optics express Saxena, A., Yao, X., Wong, D., Chua, J., Ang, M., Hoang, Q. V., Agrawal, R., Girard, M., Cheung, G., Schmetterer, L., Tan, B. 2021; 12 (8): 4982-4996

  Abstract

  Choroidal vasculature plays an important role in the pathogenesis of retinal diseases, such as myopic maculopathy, age-related macular degeneration, diabetic retinopathy, central serous chorioretinopathy, and ocular inflammatory diseases. Current optical coherence tomography (OCT) technology provides three-dimensional visualization of the choroidal angioarchitecture; however, quantitative measures remain challenging. Here, we propose and validate a framework to segment and quantify the choroidal vasculature from a prototype swept-source OCT (PLEX Elite 9000, Carl Zeiss Meditec, USA) using a 3×3 mm scan protocol centered on the macula. Enface images referenced from the retinal pigment epithelium were reconstructed from the volumetric data. The boundaries of the choroidal volume were automatically identified by tracking the choroidal vessel feature structure over the depth, and a selective sliding window was applied for segmenting the vessels adaptively from attenuation-corrected enface images. We achieved a segmentation accuracy of 96% ± 1% as compared with manual annotation, and a dice coefficient of 0.83 ± 0.04 for repeatability. Using this framework on both control (0.00 D to -2.00 D) and highly myopic (-8.00 D to -11.00 D) eyes, we report a decrease in choroidal vessel volume (p<0.001) in eyes with high myopia.

  View details for DOI 10.1364/BOE.426093

  View details for PubMedID 34513237

  View details for PubMedCentralID PMC8407849

• Anti-retinal autoantibodies in myopic macular degeneration: a pilot study. Eye (London, England) Sim, S. S., Wong, C. W., Hoang, Q. V., Lee, S. Y., Wong, T. Y., Cheung, C. M. 2021; 35 (8): 2254-2259

  Abstract

  The aim of this study is to evaluate the frequency and types of anti-retinal autoantibodies (ARAs) in highly myopic patients and to explore any association between ARAs and the severity of myopic macular degeneration (MMD).This was a clinic-based study of 16 patients with high myopia (spherical equivalent worse than -6 dioptres or axial length (AL) ≥ 26.5 mm) recruited from the High Myopia clinic of the Singapore National Eye Centre. MMD was graded from fundus photographs according to the Meta-analysis for Pathologic Myopia (META-PM) classification. Severe MMD was defined as META-PM category 3 or 4. AL and logarithm of the minimal angle of resolution (logMAR) best corrected visual acuity (BCVA) were measured. Sera were obtained from subjects and analysed for the presence of ARAs with the western blot technique.The mean AL was significantly longer in patients with severe MMD (n = 8) than those without severe MMD (n = 8) (31.50 vs. 28.51, p = 0.005). There was at least one ARA identified in all patients. The most common ARA was anti-carbonic anhydrase II (anti-CAII), present in nine patients (56.3%). Anti-CAII was detected in more patients with severe MMD than those without (75 vs. 37.5%, p = 0.32). LogMar BCVA was also worse in subjects with anti-CAII (0.5 ± 0.38 vs. 0.22 ± 0.08, p = 0.06). The number of ARAs significantly correlated with increasing AL (r = 0.61, p = 0.012).ARAs are prevalent in patients with high myopia, and this increases with increasing AL. In particular, anti-CAII antibodies were highly prevalent in patients with severe MMD, suggesting that ARAs may be associated with MMD. Further studies are necessary to confirm these observations in larger cohorts.

  View details for DOI 10.1038/s41433-020-01241-y

  View details for PubMedID 33116263

  View details for PubMedCentralID PMC8302687

• New Polygenic Risk Score to Predict High Myopia in Singapore Chinese Children. Translational vision science & technology Lanca, C., Kassam, I., Patasova, K., Foo, L. L., Li, J., Ang, M., Hoang, Q. V., Teo, Y. Y., Hysi, P. G., Saw, S. M. 2021; 10 (8): 26

  Abstract

  The purpose of this study was to develop an Asian polygenic risk score (PRS) to predict high myopia (HM) in Chinese children in the Singapore Cohort of Risk factors for Myopia (SCORM) cohort.We included children followed from 6 to 11 years old until teenage years (12-18 years old). Cycloplegic autorefraction, ultrasound biometry, Illumina HumanHap 550, or 550 Duo Beadarrays, demographics, and environmental factors data were obtained. The PRS was generated from the Consortium for Refractive Error and Myopia genomewide association study (n = 542,934) and the Strabismus, Amblyopia, and Refractive Error in Singapore children Study (n = 500). The Growing Up in Singapore Towards healthy Outcomes Cohort study (n = 339) was the replication cohort. The outcome was teenage HM (≤ -5.00 D) with predictive performance assessed using the area under the curve (AUC).Mean baseline age ± SD was 7.85 ± 0.84 (n = 1004) and 571 attended the teenage visit; 23.3% had HM. In multivariate analysis, the PRS was associated with a myopic spherical equivalent with an incremental R2 of 0.041 (95% confidence interval [CI] = 0.010, 0.073; P < 0.001). AUC for HM (0.77 [95% CI = 0.71-0.83]) performed better (P = 0.02) with the PRS compared with a model without (0.72 [95% CI = 0.65, 0.78]). Children at the top 25% PRS risk had a 2.34-fold-greater risk of HM (95% CI = 1.53, 3.55; P < 0.001).The new Asian PRS improved the predictive performance to detect children at risk of HM.Clinicians may use the PRS with other predictive factors to identify high risk children and guide interventions to reduce the risk of HM later in life.

  View details for DOI 10.1167/tvst.10.8.26

  View details for PubMedID 34319387

  View details for PubMedCentralID PMC8322707

• Microscopic Regional Changes in the Elastic Properties of Myopic Guinea Pig Choroid Lee, R., Ito, K., Jiang Liqin, Yu, D., McFadden, S. A., Mamou, J., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761600513

• Association of Aberrant Posterior Vitreous Detachment and Pathologic Tractional Forces With Myopic Macular Degeneration. Investigative ophthalmology & visual science Tey, K. Y., Wong, Q. Y., Dan, Y. S., Tsai, A. S., Ting, D. S., Ang, M., Cheung, G. C., Lee, S. Y., Wong, T. Y., Hoang, Q. V., Wong, C. W. 2021; 62 (7): 7

  Abstract

  The purpose of this study was to assess whether the tractional elements of pathologic myopia (PM; e.g. myopic traction maculopathy [MTM], posterior staphyloma [PS], and aberrant posterior vitreous detachment [PVD]) are associated with myopic macular degeneration (MMD) independent of age and axial length, among highly myopic (HM) eyes.One hundred twenty-nine individuals with 239 HM eyes from the Myopic and Pathologic Eyes in Singapore (MyoPES) cohort underwent ocular biometry, fundus photography, swept-source optical coherence tomography, and ocular B-scan ultrasound. Images were analyzed for PVD grade, and presence of MTM, PS, and MMD. The χ² test was done to determine the difference in prevalence of MMD between eyes with and without PVD, PS, and MTM. Multivariate probit regression analyses were performed to ascertain the relationship between the potential predictors (PVD, PS, and MTM) and outcome variable (MMD), after accounting for possible confounders (e.g. age and axial length). Marginal effects were reported.Controlling for potential confounders, eyes with MTM have a 29.92 percentage point higher likelihood of having MMD (P = 0.003), and eyes with PS have a 25.72 percentage point higher likelihood of having MMD (P = 0.002). The likelihood of MMD increases by 10.61 percentage points per 1 mm increase in axial length (P < 0.001). Subanalysis revealed that eyes with incomplete PVD have a 22.54 percentage point higher likelihood of having MMD than eyes with early PVD (P = 0.04).Our study demonstrated an association between tractional (MTM, PS, and persistently incomplete PVD) and degenerative elements of PM independent of age and axial length. These data provide further insights into the pathogenesis of MMD.

  View details for DOI 10.1167/iovs.62.7.7

  View details for PubMedID 34096974

  View details for PubMedCentralID PMC8185394

• Thicker Choroidal Layers are Protective against Myopia Development in both Myopia-Resistant and Spontaneous Myopia Guinea Pig Strains Jiang, L., Hoang, Q. V., Catbagan, K. J. V., Busoy, J., Barathi, V. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761400427

• Ultrasonic Assessment of Gaze-Induced Deformation of Posterior Staphyloma in Highly Myopic Eyes by Means of a Semi-Automated Assessment of Local Radius of Curvature Hoang, Q. V., Silverman, R. H., Yu, D., Dan, Y., Loh, I., Lye, T. H., Tey, K., Mamou, J., Ito, K. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761400433

• Effect of Axial Length on the Difference Between SS-OCT and SD-OCT Retinal Nerve Fiber Layer Thickness Measurements in Highly Myopic Eyes Loh, I., Chong, R. S., Tan, B., Yu, D., Wong, Q., Dan, Y., Wong, C., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761400431

• Quantitative Analysis of Quadrant Asymmetry of OCTA Metrics in Central Retinal Vein Occlusion Eyes Jung, J. J., Sha, P., Ito, K., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761600439

• Fine Resolution Quantitative Ultrasound Assessment of Posterior Scleral Microstructural Change in Form-Deprived Myopic Guinea Pig Eyes Ito, K., Mamou, J., Hoerig, C., Lee, D., McFadden, S. A., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761600511

• Relationships between mechanical and microstructural tissue properties in the posterior sclera Hoerig, C., Ito, K., Lee, D., McFadden, S. A., Hoang, Q. V., Mamou, J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021

  View details for Web of Science ID 000690761600510

• Retinal photograph-based deep learning algorithms for myopia and a blockchain platform to facilitate artificial intelligence medical research: a retrospective multicohort study LANCET DIGITAL HEALTH Tan, T., Anees, A., Chen, C., Li, S., Xu, X., Li, Z., Xiao, Z., Yang, Y., Lei, X., Ang, M., Chia, A., Lee, S., Wong, E., Yeo, I., Wong, Y., Hoang, Q., Wang, Y., Bikbov, M. M., Nangia, V., Jonas, J. B., Chen, Y., Wu, W., Ohno-Matsui, K., Rim, T., Tham, Y., Goh, R., Lin, H., Liu, H., Wang, N., Yu, W., Tan, D., Schmetterer, L., Cheng, C., Chen, Y., Wong, C., Cheung, G., Saw, S., Wong, T., Liu, Y., Ting, D. 2021; 3 (5): E317-E329

  Abstract

  By 2050, almost 5 billion people globally are projected to have myopia, of whom 20% are likely to have high myopia with clinically significant risk of sight-threatening complications such as myopic macular degeneration. These are diagnoses that typically require specialist assessment or measurement with multiple unconnected pieces of equipment. Artificial intelligence (AI) approaches might be effective for risk stratification and to identify individuals at highest risk of visual loss. However, unresolved challenges for AI medical studies remain, including paucity of transparency, auditability, and traceability.In this retrospective multicohort study, we developed and tested retinal photograph-based deep learning algorithms for detection of myopic macular degeneration and high myopia, using a total of 226 686 retinal images. First we trained and internally validated the algorithms on datasets from Singapore, and then externally tested them on datasets from China, Taiwan, India, Russia, and the UK. We also compared the performance of the deep learning algorithms against six human experts in the grading of a randomly selected dataset of 400 images from the external datasets. As proof of concept, we used a blockchain-based AI platform to demonstrate the real-world application of secure data transfer, model transfer, and model testing across three sites in Singapore and China.The deep learning algorithms showed robust diagnostic performance with areas under the receiver operating characteristic curves [AUC] of 0·969 (95% CI 0·959-0·977) or higher for myopic macular degeneration and 0·913 (0·906-0·920) or higher for high myopia across the external testing datasets with available data. In the randomly selected dataset, the deep learning algorithms outperformed all six expert graders in detection of each condition (AUC of 0·978 [0·957-0·994] for myopic macular degeneration and 0·973 [0·941-0·995] for high myopia). We also successfully used blockchain technology for data transfer, model transfer, and model testing between sites and across two countries.Deep learning algorithms can be effective tools for risk stratification and screening of myopic macular degeneration and high myopia among the large global population with myopia. The blockchain platform developed here could potentially serve as a trusted platform for performance testing of future AI models in medicine.None.

  View details for Web of Science ID 000642286500011

  View details for PubMedID 33890579

• Retinal photograph-based deep learning algorithms for myopia and a blockchain platform to facilitate artificial intelligence medical research: a retrospective multicohort study. The Lancet. Digital health Tan, T. E., Anees, A., Chen, C., Li, S., Xu, X., Li, Z., Xiao, Z., Yang, Y., Lei, X., Ang, M., Chia, A., Lee, S. Y., Wong, E. Y., Yeo, I. Y., Wong, Y. L., Hoang, Q. V., Wang, Y. X., Bikbov, M. M., Nangia, V., Jonas, J. B., Chen, Y. P., Wu, W. C., Ohno-Matsui, K., Rim, T. H., Tham, Y. C., Goh, R. S., Lin, H., Liu, H., Wang, N., Yu, W., Tan, D. T., Schmetterer, L., Cheng, C. Y., Chen, Y., Wong, C. W., Cheung, G. C., Saw, S. M., Wong, T. Y., Liu, Y., Ting, D. S. 2021; 3 (5): e317-e329

  Abstract

  By 2050, almost 5 billion people globally are projected to have myopia, of whom 20% are likely to have high myopia with clinically significant risk of sight-threatening complications such as myopic macular degeneration. These are diagnoses that typically require specialist assessment or measurement with multiple unconnected pieces of equipment. Artificial intelligence (AI) approaches might be effective for risk stratification and to identify individuals at highest risk of visual loss. However, unresolved challenges for AI medical studies remain, including paucity of transparency, auditability, and traceability.In this retrospective multicohort study, we developed and tested retinal photograph-based deep learning algorithms for detection of myopic macular degeneration and high myopia, using a total of 226 686 retinal images. First we trained and internally validated the algorithms on datasets from Singapore, and then externally tested them on datasets from China, Taiwan, India, Russia, and the UK. We also compared the performance of the deep learning algorithms against six human experts in the grading of a randomly selected dataset of 400 images from the external datasets. As proof of concept, we used a blockchain-based AI platform to demonstrate the real-world application of secure data transfer, model transfer, and model testing across three sites in Singapore and China.The deep learning algorithms showed robust diagnostic performance with areas under the receiver operating characteristic curves [AUC] of 0·969 (95% CI 0·959-0·977) or higher for myopic macular degeneration and 0·913 (0·906-0·920) or higher for high myopia across the external testing datasets with available data. In the randomly selected dataset, the deep learning algorithms outperformed all six expert graders in detection of each condition (AUC of 0·978 [0·957-0·994] for myopic macular degeneration and 0·973 [0·941-0·995] for high myopia). We also successfully used blockchain technology for data transfer, model transfer, and model testing between sites and across two countries.Deep learning algorithms can be effective tools for risk stratification and screening of myopic macular degeneration and high myopia among the large global population with myopia. The blockchain platform developed here could potentially serve as a trusted platform for performance testing of future AI models in medicine.None.

  View details for DOI 10.1016/S2589-7500(21)00055-8

  View details for PubMedID 33890579

• Rapid Myopic Progression in Childhood Is Associated With Teenage High Myopia. Investigative ophthalmology & visual science Lanca, C., Foo, L. L., Ang, M., Tan, C. S., Kathrani, B., Htoon, H. M., Tan, D., Hoang, Q. V., Brennan, N., Saw, S. M., Sabanayagam, C. 2021; 62 (4): 17

  Abstract

  The purpose of this study was to evaluate the association of childhood progression of spherical equivalent (SE) with high myopia (HM) in teenagers in the Singapore Cohort of Risk factors for Myopia (SCORM).We included 928 SCORM children followed over a mean follow-up of 6.9 ± 1.0 years from baseline (6-11 years old) until their teenage years (12-19 years old). Cycloplegic autorefraction and axial length (AL) measurements were performed yearly. The outcomes in teenagers were HM (SE ≤ -5 diopter [D)], AL ≥ 25 mm, SE and AL. Three-year SE and AL progression in childhood and baseline SE and AL with outcomes were evaluated using multivariable logistic or linear regression models, with predictive performance of risk factors assessed using the area under the curve (AUC).At the last visit, 9.8% of teenagers developed HM and 22.7% developed AL ≥ 25 mm. In multivariate regression analyses, every -0.3 D/year increase in 3-year SE progression and every 0.2 mm/year increase in 3-year AL progression were associated with a -1.14 D greater teenage SE and 0.52 mm greater teenage AL (P values < 0.001). The AUC (95% confidence interval [CI]) of a combination of 3-year SE progression and baseline SE for teenage HM was 0.97 (95% CI = 0.95 - 0.98). The AUC of 3-year AL progression and baseline AL for teenage AL ≥ 25 mm was 0.91 (95% CI = 0.89 - 0.94).Three-year myopia progression in childhood combined with baseline SE or AL were good predictors of teenage HM. Clinicians may use this combination of factors to guide timing of interventions, potentially reducing the risk of HM later in life.

  View details for DOI 10.1167/iovs.62.4.17

  View details for PubMedID 33851974

  View details for PubMedCentralID PMC8054625

• Characteristics of myopic traction maculopathy in myopic Singaporean adults. The British journal of ophthalmology Matsumura, S., Sabanayagam, C., Wong, C. W., Tan, C. S., Kuo, A., Wong, Y. L., Ohno-Matsui, K., Wong, T. Y., Cheng, C. Y., Hoang, Q. V., Saw, S. M. 2021; 105 (4): 531-537

  Abstract

  To investigate the characteristics, risk factors and visual impact of myopic traction maculopathy (MTM) among adults with myopia in Singapore.We analysed 3316 myopic eyes of adults aged over 40 years who participated in the Singapore Epidemiology of Eye Diseases-2 study. Detailed questionnaires and ophthalmic examinations were conducted. A total of 2913 myopic eyes of 1639 subjects were graded for MTM by spectral-domain optical coherence tomography. MTM is defined as the presence of retinoschisis, lamellar or full-thickness macula hole and foveal retinal detachment. Fundus photographs were graded for myopic macular degeneration (MMD).Of these 2913 myopic eyes, the mean and SD of age was 60.1±8.0 years; the spherical equivalent (SE) was -2.5±2.3 D; and the axial length (AL) was 24.6±1.3 mm. MTM was found in 0.9% of myopic eyes and 7.3% of highly myopic eyes. In the multivariate analysis, myopic SE (p<0.001), longer AL (p<0.001), MMD (p=0.01) and epiretinal traction (p<0.001) were independent risk factors for MTM. MTM was not associated with age (p=0.38). MTM was significantly associated with poorer best-corrected visual acuity (BCVA) (p<0.01).Our population-based study revealed that MTM was present in 0.9% of myopic eyes and 7.3% of highly myopic eyes. While greater myopic SE, longer AL, MMD and epiretinal traction are risk factors of MTM, age was not related to MTM. MTM has a negative effect on BCVA.

  View details for DOI 10.1136/bjophthalmol-2020-316182

  View details for PubMedID 32447325

• Prevalence, risk factors and impact of posterior staphyloma diagnosed from wide-field optical coherence tomography in Singapore adults with high myopia. Acta ophthalmologica Zheng, F., Wong, C. W., Sabanayagam, C., Cheung, Y. B., Matsumura, S., Chua, J., Man, R. E., Ohno-Matsui, K., Wong, T. Y., Cheng, C. Y., Tai, E. S., Lamoureux, E. L., Schmetterer, L., Kuo, A., Hoang, Q. V., Saw, S. M. 2021; 99 (2): e144-e153

  Abstract

  To investigate the prevalence and risk factors of posterior staphyloma using wide-field optical coherence tomography (WF-OCT) in adults with high myopia in Singapore.Population-based cross-sectional study.Adults with spherical equivalent (SE) ≤ -5D in either eye at the first visit of Singapore Epidemiology of Eye Diseases study and Singapore Prospective Study Program study were recruited. Posterior staphyloma was diagnosed using WF-OCT (PLEX® Elite9000, Carl Zeiss Meditec). Myopic macular degeneration (MMD), myopic traction maculopathy (MTM) and vision-related quality of life (VRQoL) were assessed using fundus photographs, DRI-Triton OCT (Topcon) and the Impact of Vision Impairment (IVI) questionnaire, respectively. Factors associated with posterior staphyloma were identified with multilevel, multivariable logistic regression. Impact of posterior staphyloma on MMD, MTM and visual function was analysed with multilevel, multivariable logistic regression and linear mixed model, respectively.Among the 225 eyes [mean SE = -6.5 ± 2.2 D, mean axial length (AL) = 26.2 ± 1.5 mm] of 117 participants (mean age = 60.3 ± 7.1 years), posterior staphyloma was detected in 47 (20.9%) eyes of 38 (32.5%) participants. Older age [odds ratio (OR), 1.18; 95% confidence interval (CI), 1.10-1.26], more myopic SE (0.63; 0.51-0.77) and increased AL (2.51; 1.69-3.73) were associated with higher prevalence of posterior staphyloma (all p < 0.001). Adults with posterior staphyloma had higher odds of MMD (2.67; 1.23-5.82; p = 0.013), MTM (3.79; 1.13-12.68; p = 0.031) and worse IVI Reading (β = -1.44; -2.31 to 0.58; p = 0.001) scores.About one in three adults with high myopia had posterior staphyloma, which was associated with increased odds of having myopic maculopathy and a detrimental impact on VRQoL.

  View details for DOI 10.1111/aos.14527

  View details for PubMedID 32602252

• Multimodal Imaging-Based Phenotyping of a Singaporean Hospital-Based Cohort of High Myopia Patients. Frontiers in medicine Tey, K. Y., Hoang, Q. V., Loh, I. Q., Dan, Y. S., Wong, Q. Y., Yu, D. J., Yandri, V. R., Ang, M., Cheung, G. C., Lee, S. Y., Wong, T. Y., Chong, R. S., Wong, C. W. 2021; 8: 670229

  Abstract

  Purpose: To assess the effect of axial length (AL) on the prevalence of pathologic myopia (PM) and associated myopic features in a Singaporean hospital-based cohort of patient with high myopia (HM). Methods: In total, 923 HM eyes from 495 individuals were recruited from the Myopic and Pathologic Eyes in Singapore (MyoPES) cohort and underwent ocular biometry, fundus photography, fundus autofluorescence, and swept-source optical coherence tomography (SS-OCT). Images were analyzed for the presence of myopic macular degeneration (MMD), myopic choroidal neovascularization (mCNV), myopic traction maculopathy (MTM), peripapillary atrophy (PPA), myopic tilted disc, posterior staphyloma (PS), dome-shaped macula (DSM), vitremacular adhesions (VMA), and the epiretinal membrane (ERM). Eyes were stratified into quartiles based on ALs to determine cut-off values to perform comparisons between shorter-length and longer-length groups. A χ2-test was done to determine the difference in the prevalence of pathologies between groups. Results: Overall, mean AL was 29.2 ± 2.2 mm (range 25.0-36.7 mm). Myopic macular degeneration, PPA, myopic tilted disc, and ERM have AL threshold of ≥27.5 mm, whereas MTM has an AL threshold of ≥29.0 mm. We found that there was a significantly higher prevalence of MMD (88.2 vs. 49.4%; p < 0.001), PPA (98.1 vs. 80.1%; p < 0.001), myopic tilted disc (72.7 vs. 50.2%; p < 0.001), and ERM (81.4 vs. 17.3%; p = 0.003) in eyes with AL ≥ 27.5 mm vs. eyes without AL <27.5 mm. Prevalence of MTM (34.7 vs. 32.1%; p < 0.001), mCNV (17.4 vs. 12.1%; p = 0.03), PS (43.4 vs. 34.7%; p = 0.012), DSM (21.3 vs. 13.2%; p = 0.002), and VMA (5.9 vs. 2.6%; p = 0.014) in eyes with AL ≥ 29.0 mm compared with AL < 29.0 mm. Conclusion: Our study describes the overall prevalence of PM and related pathologies among patients with HM in our hospital-based cohort. Longer eyes even among HM eyes had a significantly higher prevalence of PM-associated pathologies studied. This supports the premise that eyes with longer AL, even among HM eyes may be at greater risk of vision-threatening changes and therefore merit regular follow-up.

  View details for DOI 10.3389/fmed.2021.670229

  View details for PubMedID 35059405

  View details for PubMedCentralID PMC8764286

• Effects of Induced Astigmatism on Spectral Domain-OCT Angiography Quantitative Metrics. American journal of ophthalmology Jung, J. J., Soh, Y. Q., Sha, P., Yu, S., Durbin, M. K., Hoang, Q. V. 2020; 219: 49-58

  Abstract

  To analyze the effect of induced astigmatism on en-face spectral-domain optical coherence tomography angiography quantitative metrics.Prospective crossover study.Normal eyes without astigmatism and with 0.75, 1.75, and 2.75 diopters (D) of with-the-rule (WTR) astigmatism were imaged using a 3 × 3-mm scan pattern SD-OCTA CIRRUS 5000 HD-OCT with AngioPlex (Carl Zeiss Meditec, Dublin, CA, USA). Quantitative parameters, including foveal avascular zone metrics, parafoveal vessel length density (VD), and perfusion density (PD) were corrected for magnification secondary to axial length and analyzed. Univariate linear regressions were performed within each eye to correlate quantitative metrics to the level of an induced astigmatic cylinder.Fifteen eyes from 15 patients were imaged. Every 1-D increase in induced WTR astigmatism was associated with a statistically significant decrease in VD and PD within all Early Treatment Diabetic Retinopathy Study inner ring quadrants; however, especially more so nasally (VD: 0.63; P < .001; PD: 0.0089; P = .001). For every 1-D increase in induced astigmatism, the resulting decrease in the inner ring superior quadrant was 12% greater for VD and 16% greater for PD versus that in the inferior quadrant. The resulting decrease in the inner ring nasal quadrant was 40% greater for VD and 48% greater for PD versus that in the temporal quadrant.Increasing levels of induced WTR astigmatism correlated with globally diminishing VD and PD, was more symmetrical for vertical than horizontal quadrants, and was most pronounced nasally. This may be due to a high prevalence of horizontally oriented vessels nasally and the horizontal optical defocus induced by WTR astigmatism.

  View details for DOI 10.1016/j.ajo.2020.07.005

  View details for PubMedID 32681911

  View details for PubMedCentralID PMC7606665

• Correlation of Quantitative Measurements with Diabetic Disease Severity Using Multiple En Face OCT Angiography Image Averaging. Ophthalmology. Retina Jung, J. J., Yu, D. J., Zeng, A., Chen, M. H., Shi, Y., Nassisi, M., Marion, K. M., Sadda, S. R., Hoang, Q. V. 2020; 4 (11): 1069-1082

  Abstract

  To evaluate the effect of averaging en face OCT angiography (OCTA) images on quantitative measurements of the retinal microvasculature and their correlation to diabetic retinopathy (DR) disease severity.Cross-sectional cohort study.One hundred five eyes (65 patients) comprising 28 eyes from 19 healthy, aged-matched control participants, 14 eyes from 9 diabetics without DR, and 63 eyes from 37 diabetics with varying levels of DR.Spectral-domain CIRRUS 5000 (Carl Zeiss Meditec, Dublin, CA) OCTA images with no macular edema or significant motion artifact were acquired 5 times with the 3 × 3-mm scan pattern. En face images of the superficial retinal layer (SRL) and deep retinal layer were registered and averaged. Vessel length density (VLD), perfusion density (PD), and foveal avascular zone (FAZ) parameters were measured on averaged versus single OCTA images.Univariate and multivariate linear regression correlated quantitative metrics to DR severity and best-corrected visual acuity (BCVA).Eighty-four eyes (55 patients) met the inclusion criteria. Almost uniformly, lower VLD and PD parameters were associated significantly with worse DR severity and BCVA. Multivariate linear regression for DR severity resulted in an R2 value of 0.82 and 0.77 for single and averaged groups, respectively. No variables remained associated significantly with DR severity in multivariate analysis with single images, but in averaged images, increased superior SRL PD significantly predicted worse DR severity (coefficient, 52.7; P = 0.026). Multivariate linear regression for BCVA had an R2 value of 0.42 and 0.47 for single and averaged groups, respectively. Foveal avascular zone size was not associated with DR severity when single OCTA images (P = 0.98) were considered, but was highly associated when using averaged images (coefficient, 6.18; P < 0.001). Foveal avascular zone size was predictive for logarithm of the minimum angle of resolution BCVA with averaged images (0.21; P = 0.004), but not with single images (P = 0.31).Averaging of en face OCTA images improves the visualization of capillaries, particularly increasing the clarity of the FAZ borders, and therefore improves the correlation of vessel density and FAZ-specific parameters to DR severity and BCVA.

  View details for DOI 10.1016/j.oret.2020.04.029

  View details for PubMedID 32389888

  View details for PubMedCentralID PMC7609623

• Quantitative Assessment of Asymmetric Choroidal Outflow in Pachychoroid Eyes on Ultra-Widefield Indocyanine Green Angiography. Investigative ophthalmology & visual science Jung, J. J., Yu, D. J., Ito, K., Rofagha, S., Lee, S. S., Hoang, Q. V. 2020; 61 (8): 50

  Abstract

  To quantitatively demonstrate asymmetric choroidal outflow in pachychoroid (central serous chorioretinopathy [CSC]/pachychoroid pigment epitheliopathy [PPE]) eyes using mid-phase, ultra-widefield indocyanine green angiography (UWF ICGA) images.Eyes with a clinical diagnosis of CSC/PPE were imaged with multimodal imaging including UWF ICGA (Optos California). Quadrant brightness was measured by manually segmenting based on vortex vein location, calculating the brightness "max-min" value to assess nonuniformity between quadrants, and comparing between CSC/PPE and control eyes. A multivariate linear regression was performed to determine, across individual eyes, which specific quadrants have the greatest brightness in pachychoroid eyes, after taking into account patient-eye-specific variability.Thirty-three eyes (18 patients) with CSC/PPE along with 16 eyes of 9 controls had a mean age of 51.94 ± 9.72 vs. 53.78 ± 17.92 years (P = 0.731), respectively. Max-min analysis showed significantly increased likelihood of nonuniform drainage between vortex veins in both CSC/PPE and control eyes. Multivariate linear regression in control eyes showed that on average, the inferotemporal quadrant was significantly brighter than the superonasal quadrant (9.72 units, P < 0.001). Among CSC/PPE eyes, adjusting for the preferential, nonuniform drainage in control eyes, the inferonasal and inferotemporal quadrants in CSC/PPE eyes remained significantly brighter than the reference quadrant by 5.36 units (P = 0.034) and 7.51 units (P = 0.008), respectively.Asymmetric choroidal venous outflow occurs in both control and CSC/PPE eyes based on UWF ICGA quantitative brightness levels in each quadrant. Increased brightness levels along inferior quadrants in mid-phase ICGA images suggest venous outflow congestion among eyes with CSC or PPE.

  View details for DOI 10.1167/iovs.61.8.50

  View details for PubMedID 32735325

  View details for PubMedCentralID PMC7425745

• Complications of pathologic myopia in extremely long eyes ≥30.0mm and their impact on vision Dan, Y., Wong, Q., Yu, D., Hoang, Q. V., Wong, C. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2020

  View details for Web of Science ID 000554495705217

• Quantitative ultrasound-based assessment of microstructural change in guinea pig sclera after crosslinking Mamou, J., Ito, K., McFadden, S. A., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2020

  View details for Web of Science ID 000554528301156

• Influence of Greater Axial Length on Prevalence of Myopic Maculopathy in a Cohort of Highly Myopic Eyes Yu, D., Wong, C., Ow, J., Dan, Y., Wong, Q., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2020

  View details for Web of Science ID 000554495705211

• Differing Optic Nerve Head Strains Comparing Low, High and Pathologic Myopia Eyes Hoang, Q. V., Chuangsuwanich, T., Yu, D., Tun, T. A., Wong, C., Wang, X., Chin, Z., Devalla, S., Milea, D., Aung, T., Girard, M. J. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2020

  View details for Web of Science ID 000554495705213

• A microperimetric evaluation of macular function in highly myopic eyes with myopic macular degeneration Wong, Q., Dan, Y., Yu, D., Hoang, Q. V., Wong, C. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2020

  View details for Web of Science ID 000554495705216

• Six-Year Changes in Myopic Macular Degeneration in Adults of the Singapore Epidemiology of Eye Diseases Study. Investigative ophthalmology & visual science Wong, Y. L., Sabanayagam, C., Wong, C. W., Cheung, Y. B., Man, R. E., Yeo, A. C., Cheung, G., Chia, A., Kuo, A., Ang, M., Ohno-Matsui, K., Wong, T. Y., Wang, J. J., Cheng, C. Y., Hoang, Q. V., Lamoureux, E., Saw, S. M. 2020; 61 (4): 14

  Abstract

  To examine the 6-year incidence, progression, associated risk factors, and impact of myopic macular degeneration (MMD) in a myopic population in Singapore.We examined myopic (spherical equivalent ≤-0.5 diopters) adults (N = 2157 persons and 3661 eyes) who were phakic at baseline and participated in both baseline and 6-year follow-up visits of the Singapore Epidemiology of Eye Diseases study. Eye examinations, including visual acuity, subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the META-PM classification. Vision-related quality of life was assessed with Rasch-transformed scores from reading, mobility, and emotional domains of the Impact of Vision Impairment questionnaire.The 6-year eye-specific incidence of MMD among myopic eyes was 1.2% (95% CI, 0.9%-1.6%). Older age, worse spherical equivalent, and longer AL at baseline were associated with MMD incidence (all P < 0.001). The 6-year eye-specific progression of MMD in 288 eyes with baseline MMD was 17.0% (95% CI, 12.6%-21.4%). More severe MMD at baseline, worse spherical equivalent, and longer AL (all P < 0.05) were associated with MMD progression. Patients with Meta-PM categories 3 and 4 had worse best-corrected visual acuity and poorer vision-related quality of life outcomes than those without MMD (all P < 0.05).Over a 6-year period, one in 80 myopic eyes developed MMD and one in six with existing MMD had MMD progression. Myopia severity and AL were strong predictors of MMD development and progression. Eyes with severe MMD were at higher risk of MMD progression than those with less severe MMD, and were associated with poorer visual acuity and vision-related quality of life.

  View details for DOI 10.1167/iovs.61.4.14

  View details for PubMedID 32298432

  View details for PubMedCentralID PMC7401489

• CORRELATION OF EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AVERAGING VERSUS SINGLE-IMAGE QUANTITATIVE MEASUREMENTS WITH RETINAL VEIN OCCLUSION VISUAL OUTCOMES. Retina (Philadelphia, Pa.) Jung, J. J., Chen, M. H., Shi, Y., Nassisi, M., Marion, K., Sadda, S. R., Hoang, Q. V. 2020; 40 (4): 786-794

  Abstract

  To demonstrate the effect of averaging multiple en face optical coherence tomography angiography images on the correlation between retinal microvasculature quantitative metrics and best-corrected visual acuity (BCVA) in eyes with retinal vein occlusion.A cross-sectional cohort with unilateral retinal vein occlusion was imaged in both eyes. Five 3 mm × 3-mm spectral domain optical coherence tomography angiography images were averaged, and quantitative parameters from averaged versus single images were correlated with logMAR BCVA. Regression analyses were performed to correlate quantitative metrics with BCVA.Ten patients (5 male, average age 64.3 years) were included. Among retinal vein occlusion eyes, vessel length density was significantly less in averaged versus a single image for both the superficial retinal layer (15.5 ± 2.5 vs. 17.8 ± 2.4/mm, P = 0.05) and deep retinal layer (16.2 ± 1.4 vs. 18.5 ± 1.6/mm, P = 0.003). Multivariate linear regression showed an increased R value with averaging (0.93 to 0.95, for single and averaged groups, respectively). Foveal avascular zone circularity was associated with BCVA on single images (coefficient = -0.96, P = 0.002), but not with averaged images (P = 0.063).Scan averaging of en face optical coherence tomography angiography images improves the clarity of vessels and may allow for more accurate quantification of vessel metrics. Quantitative metrics are significantly associated with BCVA, and averaging does not further improve this association compared with single-scan analysis.

  View details for DOI 10.1097/IAE.0000000000002453

  View details for PubMedID 30676529

  View details for PubMedCentralID PMC6646103

• Imaging in Myopia UPDATES ON MYOPIA: A CLINICAL PERSPECTIVE Hoang, Q. V., Chua, J., Ang, M., Schmetterer, L. edited by Ang, M., Wong, T. Y. 2020: 219-239

  View details for DOI 10.1007/978-981-13-8491-2_10

  View details for Web of Science ID 000620417800011

• Correction: Genetic variants linked to myopic macular degeneration in persons with high myopia: CREAM Consortium. PloS one Wong, Y. L., Hysi, P., Cheung, G., Tedja, M., Hoang, Q. V., Tompson, S. W., Whisenhunt, K. N., Verhoeven, V. J., Zhao, W., Hess, M., Wong, C. W., Kifley, A., Hosoda, Y., Haarman, A. E., Hopf, S., Laspas, P., Sensaki, S., Sim, X., Miyake, M., Tsujikawa, A., Lamoureux, E., Ohno-Matsui, K., Nickels, S., Mitchell, P., Wong, T. Y., Wang, J. J., Hammond, C. J., Barathi, V. A., Cheng, C. Y., Yamashiro, K., Young, T. L., Klaver, C. C., Saw, S. M. 2019; 14 (10): e0223942

  Abstract

  [This corrects the article DOI: 10.1371/journal.pone.0220143.].

  View details for DOI 10.1371/journal.pone.0223942

  View details for PubMedID 31600355

  View details for PubMedCentralID PMC6786527

• Regional changes in the elastic properties of myopic Guinea pig sclera. Experimental eye research Hoang, Q. V., Rohrbach, D., McFadden, S. A., Mamou, J. 2019; 186: 107739

  Abstract

  Biomechanical changes in the sclera likely underlie the excessive eye elongation of axial myopia. We studied the biomechanical characteristics of myopic sclera at the microscopic level using scanning acoustic microscopy (SAM) with 7-μm in-plane resolution. Guinea pigs underwent form-deprivation (FD) in one eye from 4 to 12 days of age to induce myopia, and 12-μm-thick scleral cryosections were scanned using a custom-made SAM. Two-dimensional maps of the bulk modulus (K) and mass density (ρ) were derived from the SAM data using a frequency-domain approach. We assessed the effect on K and ρ exerted by: 1) level of induced myopia, 2) region (superior, inferior, nasal or temporal) and 3) eccentricity from the nerve using univariate and multivariate regression analyses. Induced myopia ranged between -3D and -9.3D (Mean intraocular difference of -6.2 ± 1.7D, N = 11). K decreased by 0.036 GPa for every 1.0 D increase in induced myopia across vertical sections (p < 0.001). Among induced myopia right eyes, K values in the inherently more myopic superior region were 0.088 GPa less than the inferior region (p = 0.002) and K in the proximal nasal region containing the central axis were 0.10 GPa less than temporal K (p = 0.036). K also increased 0.12 GPa for every 1 mm increase in superior vertical distance (p < 0.001), an effect that was blunted after 1 week of FD. Overall, trends for ρ were less apparent than for K. ρ values increased by 20.7 mg/cm3 for every 1.00 D increase in induced myopia across horizontal sections (p < 0.001), and were greatest in the region containing the central posterior pole. ρ values in the inherently more myopic superior region were 13.1 mg/cm3 greater than that found in inferior regions among control eyes (p = 0.002), and increased by 11.2 mg/cm3 for every 1 mm increase in vertical distance (p = 0.001). This peripheral increase in ρ was blunted after 1 week of FD. Scleral material properties vary depending on the location in the sclera and the level of induced myopia. Bulk modulus was most reduced in the most myopic regions (both induced myopia and inherent regional myopia), and suggests that FD causes microscopic local decreases in sclera stiffness, while scleral mass density was most increased in the most myopic regions.

  View details for DOI 10.1016/j.exer.2019.107739

  View details for PubMedID 31330141

  View details for PubMedCentralID PMC6712578

• Genetic variants linked to myopic macular degeneration in persons with high myopia: CREAM Consortium. PloS one Wong, Y. L., Hysi, P., Cheung, G., Tedja, M., Hoang, Q. V., Tompson, S. W., Whisenhunt, K. N., Verhoeven, V., Zhao, W., Hess, M., Wong, C. W., Kifley, A., Hosoda, Y., Haarman, A. E., Hopf, S., Laspas, P., Sensaki, S., Sim, X., Miyake, M., Tsujikawa, A., Lamoureux, E., Ohno-Matsui, K., Nickels, S., Mitchell, P., Wong, T. Y., Wang, J. J., Hammond, C. J., Barathi, V. A., Cheng, C. Y., Yamashiro, K., Young, T. L., Klaver, C. C., Saw, S. M. 2019; 14 (8): e0220143

  Abstract

  To evaluate the roles of known myopia-associated genetic variants for development of myopic macular degeneration (MMD) in individuals with high myopia (HM), using case-control studies from the Consortium of Refractive Error and Myopia (CREAM).A candidate gene approach tested 50 myopia-associated loci for association with HM and MMD, using meta-analyses of case-control studies comprising subjects of European and Asian ancestry aged 30 to 80 years from 10 studies. Fifty loci with the strongest associations with myopia were chosen from a previous published GWAS study. Highly myopic (spherical equivalent [SE] ≤ -5.0 diopters [D]) cases with MMD (N = 348), and two sets of controls were enrolled: (1) the first set included 16,275 emmetropes (SE ≤ -0.5 D); and (2) second set included 898 highly myopic subjects (SE ≤ -5.0 D) without MMD. MMD was classified based on the International photographic classification for pathologic myopia (META-PM).In the first analysis, comprising highly myopic cases with MMD (N = 348) versus emmetropic controls without MMD (N = 16,275), two SNPs were significantly associated with high myopia in adults with HM and MMD: (1) rs10824518 (P = 6.20E-07) in KCNMA1, which is highly expressed in human retinal and scleral tissues; and (2) rs524952 (P = 2.32E-16) near GJD2. In the second analysis, comprising highly myopic cases with MMD (N = 348) versus highly myopic controls without MMD (N = 898), none of the SNPs studied reached Bonferroni-corrected significance.Of the 50 myopia-associated loci, we did not find any variant specifically associated with MMD, but the KCNMA1 and GJD2 loci were significantly associated with HM in highly myopic subjects with MMD, compared to emmetropes.

  View details for DOI 10.1371/journal.pone.0220143

  View details for PubMedID 31415580

  View details for PubMedCentralID PMC6695159

• Quantitative OCTA Change Analysis after 6 month Anti-VEGF Treatments for Proliferative Diabetic Retinopathy in the Real World Jung, J. J., Chen, M. H., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019

  View details for Web of Science ID 000488628107137

• Optic nerve displacements during horizontal eye movements in healthy and high myopic subjects Wang, X., Hoang, Q. V., Chang, S., Yannuzzi, L. A., Freund, K., Milea, D., Girard, M. J. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019

  View details for Web of Science ID 000488800702131

• Curvature Differences in Myopic Eyes With and Without Staphyloma using OCT Kuo, A. N., Liu, A., Wong, C., McNabb, R. P., Lee, S., Cheung, G., Saw, S., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019

  View details for Web of Science ID 000488800702130

• Imaging in myopia: potential biomarkers, current challenges and future developments. The British journal of ophthalmology Ang, M., Wong, C. W., Hoang, Q. V., Cheung, G. C., Lee, S. Y., Chia, A., Saw, S. M., Ohno-Matsui, K., Schmetterer, L. 2019; 103 (6): 855-862

  Abstract

  Myopia is rapidly increasing in Asia and around the world, while it is recognised that complications from high myopia may cause significant visual impairment. Thus, imaging the myopic eye is important for the diagnosis of sight-threatening complications, monitoring of disease progression and evaluation of treatments. For example, recent advances in high-resolution imaging using optical coherence tomography may delineate early myopic macula pathology, optical coherence tomography angiography may aid early choroidal neovascularisation detection, while multimodal imaging is important for monitoring treatment response. However, imaging the eye with high myopia accurately has its challenges and limitations, which are important for clinicians to understand in order to choose the best imaging modality and interpret the images accurately. In this review, we present the current imaging modalities available from the anterior to posterior segment of the myopic eye, including the optic nerve. We summarise the clinical indications, image interpretation and future developments that may overcome current technological limitations. We also discuss potential biomarkers for myopic progression or development of complications, including basement membrane defects, and choroidal atrophy or choroidal thickness measurements. Finally, we present future developments in the field of myopia imaging, such as photoacoustic imaging and corneal or scleral biomechanics, which may lead to innovative treatment modalities for myopia.

  View details for DOI 10.1136/bjophthalmol-2018-312866

  View details for PubMedID 30636210

• Anatomic, Visual, and Financial Outcomes for Traditional and Nontraditional Primary Pneumatic Retinopexy for Retinal Detachment. American journal of ophthalmology Jung, J. J., Cheng, J., Pan, J. Y., Brinton, D. A., Hoang, Q. V. 2019; 200: 187-200

  Abstract

  To determine factors predictive of anatomic, visual, and financial outcomes after traditional and nontraditional primary pneumatic retinopexy (PR) for rhegmatogenous retinal detachment (RD).Retrospective interventional case series and cost comparison.Participants: Total of 178 eyes (156 patients) with PR-repaired primary RD by a single surgeon at a clinical practice from January 2001 to December 2013 and followed for ≥1 year. The cohort had 2 subgroups: traditional (TPR) and nontraditional (NTPR) PR.Characteristics associated with best-corrected visual acuity (BCVA) and anatomic outcomes. Cost analysis and potential cost savings comparing PR to scleral buckle and vitrectomy.One hundred thirty-one of 178 eyes (73.5%) were successfully treated at 1 year (postoperative year 1): 72.8% (75/103) in TPR and 74.6% (56/75) in NTPR. Macula-off detachment (-0.44 logMAR, P < .001) and clock hours of RD (-0.84 logMAR, P < .001) correlated with improved BCVA; pseudophakia (0.26 logMAR, P = .002) and inferior retinal tears (0.62 logMAR, P = .009) correlated with worsening BCVA. Pseudophakia (-0.15, P = .03), inferior quadrant RD (-0.27, P < .001), and proliferative vitreoretinopathy (-0.68, P < .001) correlated with anatomic failure. Total average cost for TPR and NTPR was $1248.37 ± $882.11 and $1471.91 ± $942.84, respectively (P = .10). PR had a potential cost savings of 62% and 60.8% when compared to scleral buckle and vitrectomy, respectively.PR results in successful anatomic and visual outcomes in both TPR and NTPR repair of primary RD. Preoperative pseudophakia is associated with worse visual outcomes and less anatomic success. The cost of primary PR and subsequent procedures to achieve final anatomic success was not significantly different between TPR and NTPR, and supports the possible cost-effectiveness of expanded indications for PR.

  View details for DOI 10.1016/j.ajo.2019.01.008

  View details for PubMedID 30684455

  View details for PubMedCentralID PMC6445687

• IMI - Myopia Genetics Report INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE Tedja, M. S., Haarman, A. E. G., Meester-Smoor, M. A., Kaprio, J., Mackey, D. A., Guggenheim, J. A., Hammond, C. J., Verhoeven, V. J. M., Klaver, C. C. W., Bailey-Wilson, J. E., Baird, P., Veluchamy, A., Biino, G., Burdon, K. P., Campbell, H., Chen, L., Cheng, C., Chew, E. Y., Craig, J. E., Cumberland, P. M., Deangelis, M. M., Delcourt, C., Ding, X., van Duijn, C. M., Evans, D. M., Fan, Q., Fossarello, M., Foster, P. J., Gharahkhani, P., Iglesias, A. I., Guol, X., Haller, T., Han, X., Hayward, C., He, M., Hewitt, A. W., Hoang, Q., Hysi, P. G., Igo, R. P., Iyengar, S. K., Jonas, J. B., Kahonen, M., Khawaja, A. P., Klein, B. E., Klein, R., Lass, J. H., Lee, K., Lehtimaki, T., Lewis, D., Li, Q., Li, S., Lyytikainen, L., MacGregor, S., Martin, N. G., Meguro, A., Metspalu, A., Middlebrooks, C., Miyake, M., Mizuki, N., Musolf, A., Nickels, S., Oexle, K., Pang, C., Parssinen, O., Paterson, A. D., Pfeiffer, N., Polasek, O., Rahi, J. S., Raitakari, O., Rudan, I., Sahebjada, S., Saw, S., Stambolian, D., Simpson, C. L., Tai, E., Tideman, J. L., Tsujikawa, A., Verhoeven, V. J. M., Vitart, V., Wang, N., Wedenoja, J., Wei, W., Williams, C., Williams, K. M., Wilson, J. F., Wojciechowski, R., Wang, Y., Yamashiro, K., Yam, J. C. S., Yap, M. K. H., Yazar, S., Yip, S., Young, T. L., Zhou, X., CREAM Consortium 2019; 60 (3): M89-M105

  Abstract

  The knowledge on the genetic background of refractive error and myopia has expanded dramatically in the past few years. This white paper aims to provide a concise summary of current genetic findings and defines the direction where development is needed. We performed an extensive literature search and conducted informal discussions with key stakeholders. Specific topics reviewed included common refractive error, any and high myopia, and myopia related to syndromes. To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk variants mostly carry low risk but are highly prevalent in the general population. Several genes for secondary syndromic myopia overlap with those for common myopia. Polygenic risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated genes have a wide variety of functions, and all retinal layers appear to be sites of expression. The current genetic findings offer a world of new molecules involved in myopiagenesis. As the missing heritability is still large, further genetic advances are needed. This Committee recommends expanding large-scale, in-depth genetic studies using complementary big data analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial occurrence. Functional characterization of associated variants is simultaneously needed to bridge the knowledge gap between sequence variance and consequence for eye growth.

  View details for DOI 10.1167/iovs.18-25965

  View details for Web of Science ID 000460128100005

  View details for PubMedID 30817828

  View details for PubMedCentralID PMC6892384

• Prevention and Management of Myopia and Myopic Pathology. Investigative ophthalmology & visual science Saw, S. M., Matsumura, S., Hoang, Q. V. 2019; 60 (2): 488-499

  Abstract

  Myopia is fast becoming a global public health burden with its increasing prevalence, particularly in developed countries. Globally, the prevalence of myopia and high myopia (HM) is 28.3% and 4.0%, respectively, and these numbers are estimated to increase to 49.8% for myopia and 9.8% for HM by 2050 (myopia defined as -0.50 diopter [D] or less, and HM defined as -5.00 D or less). The burden of myopia is tremendous, as adults with HM are more likely to develop pathologic myopia (PM) changes that can lead to blindness. Accordingly, preventive measures are necessary for each step of myopia progression toward vision loss. Approaches to prevent myopia-related blindness should therefore attempt to prevent or delay the onset of myopia among children by increased outdoor time; retard progression from low/mild myopia to HM, through optical (e.g., defocus incorporated soft contact lens, orthokeratology, and progressive-additional lenses) and pharmacological (e.g., low dose of atropine) interventions; and/or retard progression from HM to PM through medical/surgical treatments (e.g., anti-VEGF therapies, macula buckling, and scleral crosslinking). Recent clinical trials aiming for retarding myopia progression have shown encouraging results. In this article, we highlight recent findings on preventive and early interventional measures to retard myopia, and current and novel treatments for PM.

  View details for DOI 10.1167/iovs.18-25221

  View details for PubMedID 30707221

• Prevalence, Risk Factors, and Impact of Myopic Macular Degeneration on Visual Impairment and Functioning Among Adults in Singapore. Investigative ophthalmology & visual science Wong, Y. L., Sabanayagam, C., Ding, Y., Wong, C. W., Yeo, A. C., Cheung, Y. B., Cheung, G., Chia, A., Ohno-Matsui, K., Wong, T. Y., Wang, J. J., Cheng, C. Y., Hoang, Q. V., Lamoureux, E., Saw, S. M. 2018; 59 (11): 4603-4613

  Abstract

  To determine the prevalence, risk factors, and impact of myopic macular degeneration (MMD) on visual impairment and functioning among adults in Singapore.A comprehensive eye examination, including subjective refraction, axial length, and visual acuity (VA) measurements, was performed in adults aged ≥40 years in the Singapore Epidemiology of Eye Diseases (SEED) study. From fundus photographs, MMD was graded using the International META-PM classification. Vision-specific functioning (VSF) was assessed with a validated visual-functioning questionnaire (VF-11) using Rasch analysis.A total of 8716 phakic subjects were included in this analysis. The mean age (± SD) was 57.2 ± 9.5 years (33.5% Malays, 33.2% Indians, and 33.3% Chinese). The prevalence of myopia (spherical equivalent [SE] ≤ -0.5 diopters [D]) and high myopia (SE ≤ -5.0 D) was 35.7% and 6.0%, respectively. The age-standardized prevalence of MMD was 3.8% (95% confidence interval [CI], 3.4-4.3%). The prevalence of MMD was 7.7% among low to moderate myopes, and 28.7% among high myopes. The prevalence of MMD increased nonlinearly with SE and age. MMD was associated with older age, more myopic SE, and lower education. Subjects with Meta-PM categories 3 or 4 in the better-seeing eye had worse best-corrected VA (β, 0.19; 95%CI, 0.16-0.23) and poorer VSF (β, -9.7; 95%CI, -17.6 to -1.8) than those without MMD after multivariate adjustments.Approximately 1 in 26 phakic adults in Singapore has MMD. Older age and myopic SE are major risk factors of MMD. Severe MMD has a substantial impact on visual impairment and functioning.

  View details for DOI 10.1167/iovs.18-24032

  View details for PubMedID 30242361

• Longitudinal Changes in Disc and Retinal Lesions Among Highly Myopic Adolescents in Singapore Over a 10-Year Period. Eye & contact lens Wong, Y. L., Ding, Y., Sabanayagam, C., Wong, C. W., Verkicharla, P., Ohno-Matsui, K., Tan, D., Yeo, A. C., Hoang, Q. V., Lamoureux, E., Saw, S. M. 2018; 44 (5): 286-291

  Abstract

  To examine the progression pattern of disc and retinal lesions in highly myopic Chinese adolescents over a 10-year period in Singapore.This longitudinal study included Chinese participants who showed high myopia (spherical equivalent [SE] worse than or equal to -5 diopters [D]), no history of refractive surgery, and available fundus photographs at both 2006 (baseline) and 2016 (10-year follow-up) visits. Forty-four adolescents (aged 12-16 years at baseline) who were re-examined later at follow-up were included. Cycloplegic refraction, biometry, and fundus photography were performed at both visits. A trained grader classified myopic macular degeneration (MMD) based on the Meta-pathologic myopia classification and disc lesions from fundus photographs. Choroidal thickness (CT) measurements were performed at 10-year follow-up using swept-source optical coherence tomography. The ocular parameters and lesions were compared between baseline and follow-up.There was a significant worsening of high myopia at follow-up to -7.5±1.8 D (mean SE±SD) in 2016 versus -6.2±1.3 D in 2006; (P<0.001). The 10-year changes included increased degree of tessellation (26 eyes, 29.5%), development of new tessellated fundus (19 eyes, 21.6%), disc tilt (7 eyes, 8.0%), and expansion of peripapillary atrophy size (33 eyes, 37.5%). Eyes with early-onset tessellation (present at baseline, 48 eyes) showed significantly thinner CT (P<0.05), compared with eyes with late-onset tessellation (incident at 10-year follow-up, 19 eyes). No cases of MMD were recorded at baseline or 10-year follow-up.Although there was no incident MMD, the retinal and disc lesions worsened over the follow-up period. Early-onset fundus tessellation was associated with thinner CT.

  View details for DOI 10.1097/ICL.0000000000000466

  View details for PubMedID 29369230

• PROPHYLACTIC PREOPERATIVE LASER RETINOPEXY DOES NOT REDUCE THE OCCURRENCE OF RHEGMATOGENOUS RETINAL COMPLICATIONS IN MACULAR SURGERY. Retina (Philadelphia, Pa.) Garg, A., Chang, J. S., Tosi, G. M., Esposti, P., Chen, R. W., Horowitz, J., Hoang, Q. V., Schiff, W. M., Barile, G. R., Chang, S. 2018; 38 (9): 1707-1712

  Abstract

  Knowledge on the utility of prophylactic 360° laser retinopexy before pars plana vitrectomy in the absence of peripheral retinal pathology is limited. This study compares the occurrence of rhegmatogenous events in the setting of small-gauge pars plana vitrectomy with and without prophylactic preoperative laser.Our multicenter, retrospective case-control analysis reviewed patients who underwent epiretinal membrane removal or macular hole repair through 23- or 25-gauge pars plana vitrectomy: 205 controls who did not receive prophylactic laser and 176 cases who received preoperative prophylactic laser retinopexy anterior to the equator. Main outcome measures were the rate and characteristics of postoperative retinal tears and detachments. Patients with previous pars plana vitrectomy or significant retinal disease were excluded.Of those patients with prophylactic laser and those without, there was no significant difference in the number of retinal breaks (1.7% vs. 0.49%, respectively; P = 0.339) or retinal detachments (0% vs. 0.49%, respectively; P = 1.00). Of the lasered group, there was one sclerotomy-related retinal break and two non-sclerotomy-related retinal breaks. Of the nonlasered group, there was one non-sclerotomy-related retinal break and one sclerotomy-related retinal detachment.Preoperative prophylactic peripheral laser retinopexy does not seem to offer an added benefit in the prevention of intraoperative and postoperative rhegmatogenous events.

  View details for DOI 10.1097/IAE.0000000000001780

  View details for PubMedID 28737533

• Characterization of the Shorter Eye in Highly Myopic Patients with more than 3 mm of Axial Anisometropia Hoang, Q. V., Wong, C., Yeo, I., Tan, G. S., Lee, S., Cheung, G. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018

  View details for Web of Science ID 000442932804212

• Correlation of En Face OCTA Averaging versus Single Image Quantitative Measurements with Retinal Vein Occlusion Visual Outcomes Jung, J. J., Chen, M. H., Shi, Y., Nassisi, M., Marion, K., Shemonski, N., Sadda, S. R., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018

  View details for Web of Science ID 000442912508128

• Correlation of Quantitative Measurements with Diabetic Disease Severity utilizing Multiple En Face OCTA Image Averaging Chen, M. H., Hoang, Q. V., Nassisi, M., Shi, Y., Marion, K., Shemonski, N., Sadda, S. R., Jung, J. J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018

  View details for Web of Science ID 000442912508179

• An ultrasound-based biomarker of myopia in the guinea pig sclera Mamou, J., McFadden, S. A., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018

  View details for Web of Science ID 000442912501330

• Inter-Layer Differences in Elastic Properties of Guinea Pig Sclera at the Micrometer Scale with Acoustic Microscopy Hoang, Q. V., Rohrbach, D., McFadden, S. A., Silverman, R. H., Mamou, J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2017

  View details for Web of Science ID 000432176306074

• Downgaze-Induced Vitreous Chamber Elongation in Highly Myopic Eyes with Staphyloma as Gauged by Magnetic Resonance Imaging Chun, D., Grinband, J., Chang, S., Yannuzzi, L. A., Freund, K., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2017

  View details for Web of Science ID 000432170305008

• Quantitative-ultrasound assessment of the myopic sclera in the guinea pig Mamou, J., Silverman, R. H., McFadden, S. A., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2017

  View details for Web of Science ID 000432176303178

• Clinical Characteristics, Choroidal Neovascularization, and Predictors of Visual Outcomes in Acquired Vitelliform Lesions. American journal of ophthalmology Balaratnasingam, C., Hoang, Q. V., Inoue, M., Curcio, C. A., Dolz-Marco, R., Yannuzzi, N. A., Dhrami-Gavazi, E., Yannuzzi, L. A., Freund, K. B. 2016; 172: 28-38

  Abstract

  To quantify the temporal properties of the acquired vitelliform lesion (AVL) life cycle, define the clinical characteristics of choroidal neovascularization (NV) in this setting, and determine the predictors of long-term visual outcomes.Retrospective cohort study.Clinical and imaging data from 199 eyes of 124 consecutive patients with AVLs associated with age-related macular degeneration (AMD) and adult-onset foveomacular vitelliform dystrophy (AOFVD) were analyzed. Volumetric calculations of vitelliform material were determined using spectral-domain optical coherence tomography and the temporal properties of the AVL life cycle were quantified. The clinical characteristics of NV were assessed, as were the predictors of final best-corrected visual acuity (BCVA) and change in BCVA.Mean age was 79.2 ± 12.1 years. AVLs grew and collapsed at approximately the same rate (P = .275). Fifteen eyes (7.5%) developed NV, of which all were type 1. In 13 of these eyes, NV occurred during the collapse phase of the AVL life cycle, after the peak AVL volume was reached. The risk of NV (P = .006) and the decline in BCVA (P = .001) were both significantly greater among eyes with AMD. Foveal atrophy was the characteristic most significantly associated with final BCVA and change in BCVA from baseline (both P < .0005). The development of NV was not predictive of long-term visual outcomes (all P = .216).Complications associated with AVLs typically occur during the collapse phase of the AVL life cycle. Visual outcomes and risk of NV are related to the underlying disease associated with AVLs.

  View details for DOI 10.1016/j.ajo.2016.09.008

  View details for PubMedID 27640006

• LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES. Retina (Philadelphia, Pa.) Jung, J. J., Hoang, Q. V., Ridley-Lane, M. L., Sebrow, D. B., Dhrami-Gavazi, E., Chang, S. 2016; 36 (11): 2101-2109

  Abstract

  To determine the long-term effect of internal limiting membrane with associated epiretinal membrane (ERM) peeling versus single peeling alone in terms of best-corrected visual acuity and anatomical outcomes on spectral-domain optical coherence tomography.This retrospective comparative cohort study of patients who had follow-up of >1 year and underwent surgery for ERM by a single surgeon (S.C.) from January 1, 2008 to December 31, 2012 compared cases in which the internal limiting membrane was stained with brilliant blue G to facilitate double peeling (n = 42) and single peeling (n = 43) of the ERM alone for up to 3 years of follow-up. For continuous variables, an independent two-tailed t-test was performed. For binary variables, the Fisher's exact test was performed. Statistical significance was defined as P < 0.05.Eighty-five of 142 patients fit the inclusion criteria. At the last follow-up, the single-peeling group were more likely to have ERM remaining in the central fovea postoperatively (P = 0.0020, becoming significant by postoperative Year 1, P = 0.022) and less likely to develop inner retinal dimpling (P = 0.000, becoming significant by postoperative Month 3, P = 0.015). At 3 years, central foveal thickness had decreased in the single-peeling group by -136.9 µm and by -84.1 μm in the double-peeling group, which was not significantly different (P = 0.08). Mean best-corrected visual acuity improved in both the groups at all time points. There was no statistically significant difference between the 2 groups at 3 years (P = 0.44; single-peeling group, 0.32 ± 0.42, Snellen 20/42; double-peeling group, 0.23 ± 0.27, Snellen 20/34).Brilliant blue G-assisted internal limiting membrane peeling for ERM results in a more thorough removal of residual ERM around the paracentral fovea. However, there is no difference in long-term best-corrected visual acuity at 3 years and a greater likelihood of inner retinal dimpling.

  View details for DOI 10.1097/IAE.0000000000001055

  View details for PubMedID 27124883

  View details for PubMedCentralID PMC5077635

• No Evidence for Association of SCO2 Heterozygosity with High-Grade Myopia or Other Diseases with Possible Mitochondrial Dysfunction. JIMD reports Piekutowska-Abramczuk, D., Kocyła-Karczmarewicz, B., Małkowska, M., Łuczak, S., Iwanicka-Pronicka, K., Siegmund, S., Yang, H., Wen, Q., Hoang, Q. V., Silverman, R. H., Kowalski, P., Szczypińska, O., Czornak, K., Zimowski, J., Płoski, R., Pilch, J., Ciara, E., Zaremba, J., Krajewska-Walasek, M., Schon, E. A., Pronicka, E. 2016; 27: 63-8

  Abstract

  SCO2 mutations cause recessively inherited cytochrome c oxidase deficiency. Recently Tran-Viet et al. proposed that heterozygosity for pathogenic SCO2 variants, including the common E140K variant, causes high-grade myopia. To investigate the association of SCO2 mutations with myopia, ophthalmic examinations were performed on 35 E140K carriers, one homozygous infant, and on a mouse model of Sco2 deficiency. Additionally, a screen for other putative effects of SCO2 heterozygosity was carried out by comparing the prevalence of the common E140K variant in a population of patients with undiagnosed diseases compatible with SCO2-related pathogenesis to that in a general population sample. High-grade myopia was not identified in any of the studied individuals. Of the carriers, 17 were emmetropic, and 18 possessed refractive errors. Additionally, no significant axial elongation indicative of high-grade myopia was found in mice carrying E129K (corresponding to E140K in humans) knock-in mutations. The prevalence of E140K carriers in the symptomatic cohort was evaluated as 1:103 (CI: 0.44-2.09) and did not differ significantly from the population prevalence (1:147, CI: 0.45-1.04).Our study demonstrates that heterozygosity for pathogenic SCO2 variants is not associated with high-grade myopia in either human patients or in mice.

  View details for DOI 10.1007/8904_2015_468

  View details for PubMedID 26427993

  View details for PubMedCentralID PMC4864719

• Reply. Retina (Philadelphia, Pa.) Hoang, Q. V., Freund, K. B. 2016; 36 (10): e100-1

  View details for DOI 10.1097/IAE.0000000000001291

  View details for PubMedID 27617548

• Comparison of OCT Angiography and Conventional Fluorescein Angiography in the Evaluation of Collateralization in Acute versus Chronic Branch or Hemi Retinal Vein Occlusion Jones, B., Chen, M. H., Jung, J. J., Hoang, Q. V., Inoue, M., Bala, C., Freund, K., Yannuzzi, L. A., Rofagha, S., Lee, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210601149

• Small-Gauge Pars Plana Vitrectomy Without Prophylactic Endolaser: Rate Of Retinal Tear Or Detachment Garg, A., Lin, J., Chang, J. S., Chen, R. W. S., Horowitz, J., Hoang, Q. V., Mogil, R., Schiff, W. M., Barile, G. R., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210204250

• Novel MRI Algorithm Pipeline Suggests Overestimation of Axial Length on IOLMaster Compared to Measurement on MRI Vu, A. H., Grinband, L., Xing, A., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210205227

• Association between Axial Length and Subfoveal Scleral Thickness in Highly Myopic Eyes with Staphyloma Xing, A., Vu, A. H., Girard, M. J. A., Mari, J., Chang, S., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210601017

• Ultra-widefield Indocyanine Green Angiography in Central Serous Chorioretinopathy and Pachychoroid Pigment Epitheliopathy Jung, J. J., Hoang, Q. V., Rofagha, S., Sarraf, D., Freund, K. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210601032

• Characterization of the Elastic Properties of Lower Field Myopia in Guinea Pig Eyes at the Micrometer Scale with Acoustic Microscopy Hoang, Q. V., Rohrbach, D., Wen, Q., McFadden, S. A., Silverman, R. H., Mamou, J. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394210601205

• Acoustic microscopy: an imaging tool to assess elastic properties of ocular tissues at the micrometer scale Mamou, J., Rohrbach, D., Hoang, Q. V., Lloyd, H., McFadden, S. A., Silverman, R. H. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394174004113

• Improved detection of vitreous inhomogeneities using a 20-MHz, ultrasound annular array Ketterling, J. A., Gross, D., Mamou, J., Hoang, Q. V., Silverman, R. H. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394174004086

• Aflibercept anti-vascular endothelial growth factor therapy in vitrectomized eyes with neovascular age-related macular degeneration. Acta ophthalmologica Jung, J. J., Hoang, Q. V., Arain, M. Z., Chang, S. 2016; 94 (3): e249-50

  View details for DOI 10.1111/aos.12840

  View details for PubMedID 26401896

  View details for PubMedCentralID PMC4808506

• ASSESSMENT OF THE SIGNIFICANCE OF CYSTIC CHANGES AFTER EPIRETINAL MEMBRANE SURGERY WITH INTERNAL LIMITING MEMBRANE REMOVAL. Retina (Philadelphia, Pa.) Dolz-Marco, R., Hoang, Q. V., Gallego-Pinazo, R., Chang, S. 2016; 36 (4): 727-32

  Abstract

  To assess the prevalence and significance of cystic changes after internal limiting membrane peeling during epiretinal membrane surgery.A retrospective review was performed on 64 patients who underwent pars plana vitrectomy with membranectomy for idiopathic epiretinal membrane between January 2010 and January 2012 by a single physician. Pars plana vitrectomy alone (Group 1, n = 32) or in combination with phacoemulsification (Group 2, n = 32) was performed. Peeling of the epiretinal membrane was assisted by triamcinolone, and internal limiting membrane was peeled up to the vascular arcades with the aid of brilliant blue dye.In Group 1, best-corrected visual acuity in logMAR (Snellen) improved from 0.53 ± 0.29 (20/68) at baseline to 0.23 ± 0.22 (20/34) at 6-month follow-up (P < 0.001). Two cases (6.3%) developed new cystic changes within the inner nuclear layer; however, there was no significant difference in best-corrected visual acuity at 6 months (P = 0.475). In Group 2, best-corrected visual acuity improved from 0.41 ± 0.17 (20/51) at baseline to 0.18 ± 0.15 (20/30) at 6 months (P < 0.001). Eight cases (25%) developed new inner nuclear layer cystic changes; however, there was no significant difference in best-corrected visual acuity at 6 months (P = 0.894).Development of new inner nuclear layer cystic changes after epiretinal membrane surgery may be a frequent finding, but in contrast to cystoid macular edema, it does not seem to affect visual recovery and should be observed. The combination of pars plana vitrectomy with cataract extraction may increase the risk of inner nuclear layer cystic changes.

  View details for DOI 10.1097/IAE.0000000000000780

  View details for PubMedID 26447395

  View details for PubMedCentralID PMC5548381

• Radius of curvature changes in spontaneous improvement of foveoschisis in highly myopic eyes. The British journal of ophthalmology Hoang, Q. V., Chen, C. L., Garcia-Arumi, J., Sherwood, P. R., Chang, S. 2016; 100 (2): 222-6

  Abstract

  Myopic foveoschisis is the splitting of retinal layers overlying staphyloma in highly myopic patients that can lead to vision loss. We assess possible contributing mechanisms to the formation of foveoschisis by examining two cases of spontaneous improvement of myopic foveoschisis and employ a radius of curvature (ROC) measure to track posterior scleral curvature over time.A retrospective, non-comparative case series was performed and optical coherence tomography images were analysed. Retinal pigment epithelial layer ROC was calculated from manually segmented images through the posterior scleral curvature apex.Two cases of myopic foveoschisis with foveal detachments in the left eye (OS) were studied. Both patients had high myopia (either <-10 D or >30 mm in axial length). One case occurred in a treatment-naive patient who improved after 4 months of observation. On initial presentation, OS posterior scleral ROC was 12.35 mm and decreased to 12.15 mm at the time of resolution. The other case occurred in a patient who was followed for 7 years, had previously underwent pars plana vitrectomy and removal of epiretinal membrane, experienced recurrence of foveoschisis and then spontaneously improved without further posterior segment surgery. There was an uncomplicated cataract extraction in the interim. Posterior scleral ROC was 4.05 mm on presentation, 4.10 during recurrence, 3.55 mm after cataract extraction and 3.75 mm at resolution.Spontaneous improvement of myopic foveoschisis may be due to changes in tractional forces from the internal limiting membrane, cortical vitreous or staphyloma or, alternatively, from a delayed or fluctuant recovery course after intervention.

  View details for DOI 10.1136/bjophthalmol-2015-306628

  View details for PubMedID 26130673

  View details for PubMedCentralID PMC4795994

• Microstructural Assessment of the Guinea Pig Sclera Using Quantitative Acoustic Microscopy Rohrbach, D., Reisner, A. S., Wen, Q., McFadden, S. A., Silverman, R. H., Hoang, Q. V., Mamou, J., IEEE IEEE. 2016

  View details for Web of Science ID 000387497400421

• Intraocular Pressure in Patients with Neovascular Age-Related Macular Degeneration Receiving Intravitreal Aflibercept or Ranibizumab. Ophthalmology Freund, K. B., Hoang, Q. V., Saroj, N., Thompson, D. 2015; 122 (9): 1802-10

  Abstract

  To assess change in intraocular pressure (IOP) in patients with neovascular age-related macular degeneration (NVAMD) receiving intravitreal aflibercept injection (IAI) or ranibizumab in VEGF Trap-Eye: Investigation of Efficacy and Safety in Wet AMD (VIEW) 1 and 2 studies.Analyses from 2 randomized, active-controlled, phase III trials.A total of 2457 patients with NVAMD.Patients received IAI 2 mg every (q) 4 weeks (2q4), 0.5 mg q4 weeks (0.5q4), 2 mg q8 weeks (after 3 monthly doses; 2q8), or ranibizumab 0.5 mg q4 weeks (Rq4) for 52 weeks. At week 52, patients were switched to a variable regimen requiring at least quarterly dosing and allowing interim injections based on anatomic and visual assessment.Pre-injection IOP was analyzed in study and uninjected fellow eyes from baseline to week 96. Prespecified end points included mean change in IOP from baseline and prevalence of a >21 mmHg and >10 mmHg increase in IOP from baseline. Cumulative incidence of sustained (at 2 consecutive visits) IOP >21 mmHg, a single event of IOP >25 mmHg, and sustained IOP increase from baseline (≥5 mmHg) was also evaluated.Mean IOP change from baseline over 96 weeks in all IAI groups was consistently lower than in the Rq4 group, and this finding was replicated in both trials. In an analysis integrating both studies, the proportion of study eyes with IOP >21 mmHg at week 96 was 20.2%, 14.2%, 12.1%, and 12.5% in Rq4, 2q4, 2q8, and 0.5q4, respectively. Reduction in risk, relative to Rq4, of having sustained IOP >21 mmHg over 96 weeks was 62% (95% confidence interval [CI], 36%-78%), 50% (95% CI, 19%-70%), and 69% (95% CI, 45%-84%) for 2q4, 2q8, and 0.5q4, respectively. Risk reduction in the IAI groups for a sustained IOP increase ≥5 mmHg was 31% (95% CI, 8%-48%), 38% (95% CI, 17%-54%), and 47% (95% CI, 27%-61%), respectively. In uninjected fellow eyes, only sustained IOP >21 mmHg events were higher in the Rq4 group compared with all IAI groups.Incidence of elevated IOP in eyes with NVAMD was lower in all IAI groups than in the ranibizumab group.

  View details for DOI 10.1016/j.ophtha.2015.04.018

  View details for PubMedID 26025097

• ASSOCIATION BETWEEN NEEDLE SIZE, POSTINJECTION REFLUX, AND INTRAOCULAR PRESSURE SPIKES AFTER INTRAVITREAL INJECTIONS. Retina (Philadelphia, Pa.) Pang, C. E., Mrejen, S., Hoang, Q. V., Sorenson, J. A., Freund, K. B. 2015; 35 (7): 1401-6

  Abstract

  To compare the effect of 30-gauge versus 32-gauge needle size on postinjection reflux and immediate postinjection intraocular pressure (IOP(immed_post)) spikes in eyes injected with anti-vascular endothelial growth factor agents.This was a prospective interventional case series of 65 eyes of 54 consecutive patients in a clinical practice setting who received intravitreal anti-vascular endothelial growth factor therapy. All eyes had preinjection IOP, IOP(immed_post), postinjection reflux, and axial lengths recorded.There was a higher incidence of postinjection reflux in eyes injected with 30-gauge (53%) compared with those injected with 32-gauge (13%, P = 0.0007). Among 34 eyes injected with 30-gauge, 16 eyes without appreciable postinjection reflux had mean IOP(immed_post) of 44.3 ± 7.48 mmHg and mean IOP(immed_post) elevation of 29.6 ± 2.10 mmHg, which was significantly higher than the 18 eyes with reflux (mean IOP(immed_post) of 18.8 ± 7.15 mmHg and mean IOP(immed_post) elevation of 4.5 ± 1.74 mmHg, P < 0.0001). Among 31 eyes injected with 32-gauge, 27 eyes without appreciable postinjection reflux had mean IOP(immed_post) of 44.4 ± 10.82 mmHg and mean IOP(immed_post) elevation of 29.5 ± 1.99 mmHg, which was significantly higher than the 4 eyes with reflux (mean IOP(immed_post) of 21.3 ± 8.54 mmHg and mean IOP(immed_post) elevation of 9.5 ± 4.05 mmHg, P < 0.001). The differences in reflux and IOP between the two groups were unrelated to axial lengths (P = 0.451).Eyes receiving injections with 32-gauge needles had a lower incidence of postinjection reflux and higher mean IOP immediately after injection.

  View details for DOI 10.1097/IAE.0000000000000476

  View details for PubMedID 25650712

• Assessment of the Influence of Greater Axial Length on the Accuracy of Partial Coherence Interferometry in Emmetropic and Highly Myopic Patients Chi, A., Vu, A., Nguyen, J., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2015

  View details for Web of Science ID 000362891107010

• Effect of Primary Gaze Axial Length on Gaze-Induced Eye Shape Changes in High Myopia Patients Hoang, Q. V., Freund, K., Yannuzzi, L. A., Sherman, J., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2015

  View details for Web of Science ID 000362882207125

• Characteristics of Early versus Late Inner Retinal Dimpling Following Internal Limiting Membrane Peeling Sebrow, D. B., Jung, J. J., Hoang, Q. V., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2015

  View details for Web of Science ID 000362891104406

• Long-term analysis of visual acuity and optical coherence topographic changes after single versus double peeling during vitrectomy for macular pucker Ridley-Lane, M., Jung, J. J., Hoang, Q. V., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2015

  View details for Web of Science ID 000362891104409

• Gaze-Induced Axial Length Changes in Emmetropic Eyes as Gauged by Magnetic Resonance Imaging Vu, A., Chi, A., Nguyen, J., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2015

  View details for Web of Science ID 000362891106410

• Reply: To PMID 23514797. Retina (Philadelphia, Pa.) Hoang, Q. V., Freund, K. B. 2015; 35 (3): e24

  View details for DOI 10.1097/IAE.0000000000000566

  View details for PubMedID 25699508

• Fine-resolution elastic-property maps of myopic sclera by means of acoustic microscopy Rohrbach, D., Hoang, Q. V., Wen, Q., McFadden, S. A., Silverman, R. H., Mamou, J., IEEE IEEE. 2015

  View details for DOI 10.1109/ULTSYM.2015.0169

  View details for Web of Science ID 000366045700505

• Intravitreal anti-vascular endothelial growth factor for choroidal neovascularization in ocular histoplasmosis. Retinal cases & brief reports Hu, J., Hoang, Q. V., Chau, F. Y., Blair, M. P., Lim, J. I. 2014; 8 (1): 24-9

  Abstract

  To report eight cases of long-term successful treatment of choroidal neovascularization because of ocular histoplasmosis syndrome with intravitreal anti-vascular endothelial growth factor agents.Retrospective case series. This article reviewed the course of eight eyes in seven patients who underwent intravitreal injection of bevacizumab and/or ranibizumab for treatment of choroidal neovascularization secondary to ocular histoplasmosis syndrome. Outcomes were assessed using pre- and post-anti-vascular endothelial growth factor visual acuities.Eight eyes in seven patients were found to have new ocular histoplasmosis syndrome-associated subfoveal choroidal neovascularization lesions, as evidenced on clinical examination, fluorescein angiography, and optical coherence tomography. Intravitreal anti-vascular endothelial growth factor injections were used as initial or early treatment with successful resolution of the choroidal neovascularization lesions in most cases. Mean visual acuity improved from 20/60 to 20/47 over an average of 121.4 weeks. Either bevacizumab or ranibizumab was administered with an average of 2.6 injections per year of follow-up. Three eyes (37.5%) experienced a gain in visual acuity with a mean increase of 7.7 lines, 1 eye (12.5%) experienced no change, and 2 eyes (25%) experienced a loss of visual acuity of 2 or more lines. Six eyes (75%) were able to avoid mild visual loss (2 lines or less).Intravitreal anti-vascular endothelial growth factor agents may successfully treat or at least stabilize neovascular complications of ocular histoplasmosis syndrome when used as a first-line treatment.

  View details for DOI 10.1097/ICB.0b013e3182a48bcc

  View details for PubMedID 25372202

• Gene therapy in patient-specific stem cell lines and a preclinical model of retinitis pigmentosa with membrane frizzled-related protein defects. Molecular therapy : the journal of the American Society of Gene Therapy Li, Y., Wu, W. H., Hsu, C. W., Nguyen, H. V., Tsai, Y. T., Chan, L., Nagasaki, T., Maumenee, I. H., Yannuzzi, L. A., Hoang, Q. V., Hua, H., Egli, D., Tsang, S. H. 2014; 22 (9): 1688-97

  Abstract

  Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naïve human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrp(rd6)/Mfrp(rd6) mice--an established preclinical model of RP--and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrp(rd6)/Mfrp(rd6) preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials.

  View details for DOI 10.1038/mt.2014.100

  View details for PubMedID 24895994

  View details for PubMedCentralID PMC4435479

• Late recurrence of myopic foveoschisis after successful repair with primary vitrectomy and incomplete membrane peeling. Retina (Philadelphia, Pa.) Sepúlveda, G., Chang, S., Freund, K. B., Park, S., Hoang, Q. V. 2014; 34 (9): 1841-7

  Abstract

  To report three cases of late recurrence of myopic foveoschisis (MF) after initial successful repair with pars plana vitrectomy and membrane peeling to assess the importance of internal limiting membrane peeling.A retrospective noncomparative case series was performed of patients who underwent a primary pars plana vitrectomy by a single surgeon with successful resolution of MF, but eventually underwent repeat pars plana vitrectomy for recurrent MF. Best-corrected visual acuity, fundus photography, and optical coherence tomography were obtained at each examination.Three eyes of three patients underwent pars plana vitrectomy for recurrent MF. Myopic foveoschisis recurrence occurred 6, 3.5, and 12 years after the primary vitrectomy, respectively. Repeat vitrectomy with staining and additional peeling of the internal limiting membrane resulted in good anatomical outcome and stabilization of visual acuity in all cases.Late recurrence of MF after successful primary vitrectomy is described. Fibrocellular proliferation on residual cortical vitreous or incomplete internal limiting membrane peeling during the initial vitrectomy may underlie recurrence.

  View details for DOI 10.1097/IAE.0000000000000156

  View details for PubMedID 24743643

  View details for PubMedCentralID PMC4145023

• Multilayered pigment epithelial detachment in neovascular age-related macular degeneration. Retina (Philadelphia, Pa.) Rahimy, E., Freund, K. B., Larsen, M., Spaide, R. F., Costa, R. A., Hoang, Q., Christakopoulos, C., Munch, I. C., Sarraf, D. 2014; 34 (7): 1289-95

  Abstract

  To describe the spectral domain optical coherence tomography findings in eyes with chronic fibrovascular pigment epithelial detachment (PED) receiving intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy.Retrospective observational case series of patients with chronic fibrovascular PEDs receiving serial intravitreal anti-VEGF therapy. Corresponding spectral domain optical coherence tomography scans of chronic PEDs were studied in detail over multiple visits. The internal structure within the sub-PED compartment was analyzed, characteristic features were identified, and then correlated with visual outcome.Thirty-eight eyes of 34 patients with fibrovascular PEDs were included. Mean and median Snellen visual acuity was 20/50 (range, 20/20-20/400). Eyes received a mean of 28.2 intravitreal anti-VEGF injections (median, 23.0; range, 3-70) administered over a mean of 36.9 months (median, 37.5; range, 6-84). A fusiform, or spindle-shaped, complex of highly organized layered hyperreflective bands was noted within each PED. Nineteen eyes demonstrated heterogenous, dilated, irregular neovascular tissue adherent to the undersurface of the retinal pigment epithelium. Additionally, 25 eyes demonstrated a hyporeflective cavity separating the choroidal neovascularization complex from the underlying choroid.Chronic fibrovascular PEDs receiving serial anti-VEGF therapy demonstrate a characteristic fusiform complex of highly organized, layered, hyperreflective bands, termed a "multilayered PED," which is often seen in conjunction with neovascular tissue adherent to the undersurface of the retinal pigment epithelium monolayer. On the basis of previous histopathologic correlations, these bands may represent a fibrous tissue complex with contractile properties. An associated hyporeflective space, termed a "pre-choroidal cleft," separates the fusiform complex from the underlying choroid and may be due to contraction, the exudation of fluid, or both. Many of these eyes maintain good visual acuity, presumably because the neovascular and cicatricial process is suppressed within the sub-retinal pigment epithelium space by chronic anti-VEGF therapy, thus permitting the viability of the photoreceptor population through preservation of the retinal pigment epithelium.

  View details for DOI 10.1097/IAE.0000000000000130

  View details for PubMedID 24675391

• Pharmacologic alternatives to riboflavin photochemical corneal cross-linking: a comparison study of cell toxicity thresholds. Investigative ophthalmology & visual science Kim, M., Takaoka, A., Hoang, Q. V., Trokel, S. L., Paik, D. C. 2014; 55 (5): 3247-57

  Abstract

  The efficacy of therapeutic cross-linking of the cornea using riboflavin photochemistry (commonly abbreviated as CXL) has caused its use to become widespread. Because there are known chemical agents that cross-link collagenous tissues, it may be possible to cross-link tissue pharmacologically. The present study was undertaken to compare the cell toxicity of such agents.Nine topical cross-linking agents (five nitroalcohols, glyceraldehyde [GLYC], genipin [GP], paraformaldehyde [FA], and glutaraldehyde [GLUT]) were tested with four different cell lines (immortalized human corneal epithelial cells, human skin fibroblasts, primary bovine corneal endothelial cells, and immortalized human retinal pigment epithelial cells [ARPE-19]). The cells were grown in planar culture and exposed to each agent in a range of concentrations (0.001 mM to 10 mM) for 24 hours followed by a 48-hour recovery phase. Toxicity thresholds were determined by using the trypan blue exclusion method.A semiquantitative analysis using five categories of toxicity/fixation was carried out, based on plate attachment, uptake of trypan blue stain, and cellular fixation. The toxicity levels varied by a factor of 10(3) with the least toxic being mononitroalcohols and GLYC, intermediate toxicity for a nitrodiol and nitrotriol, and the most toxic being GLUT, FA, GP, and bronopol, a brominated nitrodiol. When comparing toxicity between different cell lines, the levels were generally in agreement.There are significant differences in cell toxicity among potential topical cross-linking compounds. The balance between cross-linking of tissue and cell toxicity should be borne in mind as compounds and strategies to improve mechanical tissue properties through therapeutic tissue cross-linking continue to develop.

  View details for DOI 10.1167/iovs.13-13703

  View details for PubMedID 24722697

  View details for PubMedCentralID PMC4037937

• Gaze-Induced Axial Length Changes in Highly Myopic Eyes as Gauged by Magnetic Resonance Imaging Hoang, Q. V., Tang, J., Goldman, J., Pan, J. Y., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433203503281

• Fovea-Sparing ILM peeling for myopic traction maculopathy Arain, M., Hoang, Q. V., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433199702280

• Clinical Significance Of Inner Nuclear Layer Cystic Changes After Internal Limiting Membrane Peeling For Epiretinal Membrane Gavazi, E., Dolz-Marco, R., Hoang, Q. V., Gallego-Pinazo, R., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433199702260

• Gene therapy on patient-specific stem cell lines with MFRP defect Li, Y., Wu, W., Tsai, Y., Hua, H., Nagasaki, T., Maumenee, I. H., Yannuzzi, L. A., Hoang, Q. V., Egli, D., Tsang, S. H. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433199701378

• Transgenic Mouse Models of Marfan Syndrome (<i>Fibrillin</i>-<i>1</i>) Exhibit Elongated Ocular Axial Length Garg, A., Gavazi, E., Lee, W., Hoang, Q. V., Silverman, R. H., Flynn, E. E., Lloyd, H. O., Tsang, S. H. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433205505332

• Comparison of Ocular Axial Length Measurements with MRI and Partial Coherence Interferometry in Highly Myopic Patients with Posterior Staphyloma Tang, J., Pan, J. Y., Chang, S., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433205504315

• Longterm Follow up and Role of Staphyloma Radius of Curvature in Cases of Spontaneous Improvement of Myopic Foveoschisis Chen, K., Chen, C., Garcia-Arumi, J., Chang, S., Hoang, Q. V. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2014

  View details for Web of Science ID 000433205504314

• Influence of axial length and postinjection reflux on sustained intraocular pressure elevation as a result of intravitreal anti-vascular endothelial growth factor therapy. Retina (Philadelphia, Pa.) Hoang, Q. V., Jung, J. J., Mrejen, S., Freund, K. B. 2014; 34 (3): 519-24

  Abstract

  To assess an association of axial length (AL) or postinjection reflux with transient or sustained intraocular pressure (IOP) elevation in patients with neovascular age-related macular degeneration receiving anti-vascular endothelial growth factor injections.One hundred and forty-seven eyes from 74 consecutive patients with neovascular age-related macular degeneration who presented to a single physician over a 2-month period had ALs measured by IOLMaster. Twenty-one patients had preinjection and immediate postinjection IOP measured and immediate reflux assessed.Overall, 9.5% of eyes had been identified with sustained IOP elevation in our previous study. Axial length did not significantly differ between eyes that had (AL, 23.96 ± 0.66 mm; n = 14) and had not experienced sustained IOP elevation (AL, 23.44 ± 1.24 mm; n = 133; P = 0.12, t-test). By linear regression analysis, the relationship between experiencing sustained IOP elevation and AL was not statistically significant (R² = 0.0165; P = 0.121). The relationship between AL and immediate postinjection IOP elevation was also not statistically significant (R² = 0.0001; P = 0.97). Immediate postinjection IOP increase did differ between eyes without reflux (30.2 ± 9.3 mmHg; n = 12) and those with reflux (1.1 ± 7.2; n = 9; P < 0.001).Axial length does not seem to be a predictor of transient or sustained IOP elevation. Repeated trabecular meshwork trauma related to the absence or presence of reflux and immediate postinjection IOP elevation may be a contributing factor.

  View details for DOI 10.1097/IAE.0000000000000039

  View details for PubMedID 24240557

• Pachychoroid pigment epitheliopathy. Retina (Philadelphia, Pa.) Warrow, D. J., Hoang, Q. V., Freund, K. B. 2013; 33 (8): 1659-72

  Abstract

  To report nine cases of pachychoroid pigment epitheliopathy.An observational case series of nine patients who underwent comprehensive ophthalmic examination, fundus photography, fundus autofluorescence, spectral-domain optical coherence tomography, and enhanced depth imaging optical coherence tomography.Eighteen eyes of 9 patients, aged 27 years to 89 years, were diagnosed with pachychoroid pigment epitheliopathy based on the characteristic funduscopic appearance of reduced fundus tessellation with overlying retinal pigment epithelial changes in one or both eyes, fundus autofluorescence abnormalities, and increased subfoveal choroidal thickness confirmed by enhanced depth imaging optical coherence tomography (mean, 460.2 μm). The five older patients had been previously diagnosed with age-related macular degeneration, while the four younger subjects were referred for possible inflammatory chorioretinitis, pattern dystrophy, or nonspecific drusen. No subjects had a history of or subsequently developed subretinal fluid.Pachychoroid pigment epitheliopathy falls within a spectrum of diseases associated with choroidal thickening that includes central serous chorioretinopathy and polypoidal choroidal vasculopathy, and it should be suspected in eyes with a characteristic fundus appearance related to choroidal thickening and associated retinal pigment epithelial abnormalities but no history of subretinal fluid. Enhanced depth imaging optical coherence tomography confirming an abnormally thick choroid and characteristic retinal pigment epithelial changes on fundus autofluorescence support the diagnosis. Because these patients are frequently misdiagnosed, the recognition of pachychoroid pigment epitheliopathy may avoid unnecessary diagnostic testing and interventions.

  View details for DOI 10.1097/IAE.0b013e3182953df4

  View details for PubMedID 23751942

• In Vivo Crosslinking of Scleral Collagen in the Rabbit Using Sub-Tenon Injection of Nitroalcohol Hoang, Q., Wen, Q., Chang, S., Trokel, S., Silverman, R., Paik, D. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2013

  View details for Web of Science ID 000436232902259

• Approach to Previously Vitrectomized Patients with Neovascular Age-Related Macular Degeneration with Reduced Response to Anti-vascular Endothelial Growth Factor Treatment Arain, M., Hoang, Q., Slakter, J., Chang, S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2013

  View details for Web of Science ID 000436232900038

• Influence of Axial Length and Degree of Injection Reflux on Sustained Intraocular Pressure Elevation Due to Intravitreal Anti-Vascular Endothelial Growth Factor Therapy Mendonca, L., Hoang, Q., Jung, J., Mrejen, S., Freund, K. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2013

  View details for Web of Science ID 000436232902030

• THE "PITCHFORK SIGN" A Distinctive Optical Coherence Tomography Finding in Inflammatory Choroidal Neovascularization RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Hoang, Q. V., Cunningham, E. T., Sorenson, J. A., Freund, K. B. 2013; 33 (5): 1049-1055

  Abstract

  To report four examples of a novel optical coherence tomography finding, which appears to be characteristic of inflammatory choroidal neovascularization.Retrospective observational case series.Four eyes of four patients were diagnosed clinically with inflammatory choroidal neovascularization and underwent optical coherence tomography. In each case, imaging revealed multiple, distinctive finger-like projections extending from the area of active choroidal neovascularization into the outer retina-the "pitchfork sign"--a finding not typically seen in Type 2 neovascularization due to other etiologies.The pitchfork sign may help distinguish inflammatory choroidal neovascularization from other causes of Type 2 neovascularization.

  View details for DOI 10.1097/IAE.0b013e31827e25b8

  View details for Web of Science ID 000318011100023

  View details for PubMedID 23514797

• Long-term follow-up of acute zonal occult outer retinopathy. Retina (Philadelphia, Pa.) Hoang, Q. V., Gallego-Pinazo, R., Yannuzzi, L. A. 2013; 33 (7): 1325-7

  Abstract

  Acute zonal occult outer retinopathy (AZOOR) was described by Gass in 1992 as an independent posterior uveitis characterized by photopsias and rapid visual field zonal loss, with 70% of cases stabilizing within 6 months, although there is a paucity of long-term documentation of AZOOR cases.The authors reported the case of a 55-year-old woman diagnosed with AZOOR and followed for 13 years.Best-corrected visual acuity at baseline was 20/60 in her right eye and 20/25 in her left eye, with an annular peripapillary area of irregular retinal thickening and temporal visual field loss in both eyes. Over her 13-year follow-up, best-corrected visual acuity dropped to 20/60 in both eyes and visual field loss because of chorioretinal atrophy progressed significantly. Antiviral and immunomodulatory drugs did not halt this progression.The prognosis of cases with AZOOR should be cautiously considered. The authors showed that in the long term, chorioretinal atrophy may lead to severe visual field loss in patients with AZOOR.

  View details for DOI 10.1097/IAE.0b013e318286cc57

  View details for PubMedID 23591538

• Double peeling during vitrectomy for macular pucker: the Charles L. Schepens lecture. JAMA ophthalmology Chang, S., Gregory-Roberts, E. M., Park, S., Laud, K., Smith, S. D., Hoang, Q. V. 2013; 131 (4): 525-530

  Abstract

  Epiretinal membranes are commonly encountered in retinal practice, and they result in decreased vision. The present work addresses whether peeling of the internal limiting membrane is necessary during vitrectomy for macular pucker. We performed a retrospective analysis to investigate the effects of "single peeling," in which only the epiretinal membrane was peeled, and "double peeling," in which the internal limiting membrane was also stained and peeled. Although significantly more patients in the single-peeling group had an epiretinal membrane remaining in the central fovea postoperatively, visual acuity was not found to differ between the 2 groups in the short term. Patients who had an epiretinal membrane for more than 18 months had significantly worse visual acuity outcomes. Unexpectedly, there was a greater proportional decrease in central macular thickness in the single-peeling group than in the double peeling group, a finding that deserves further study.

  View details for DOI 10.1001/jamaophthalmol.2013.2176

  View details for PubMedID 23579603

• Role of fluorescein angiography in the treatment of age-related macular degeneration AGE-RELATED MACULAR DEGENERATION, 3RD EDITION Jung, J. J., Hoang, Q. V., Barbazetto, I. A., Slakter, J. S. edited by Lim, J. I. 2013: 163-172

  View details for Web of Science ID 000351467800014

• Clinical predictors of sustained intraocular pressure elevation due to intravitreal anti-vascular endothelial growth factor therapy. Retina (Philadelphia, Pa.) Hoang, Q. V., Tsuang, A. J., Gelman, R., Mendonca, L. S., Della Torre, K. E., Jung, J. J., Freund, K. B. 2013; 33 (1): 179-87

  Abstract

  We assess for frequency and predictive factors related to sustained intraocular pressure (IOP) elevation in eyes with neovascular age-related macular degeneration receiving intravitreal injections of ranibizumab and/or bevacizumab.A total of 328 patients with neovascular age-related macular degeneration (449 eyes) who presented to a single physician over a 6-month period were retrospectively assessed for baseline demographic/clinical information, total number of bevacizumab and/or ranibizumab injections, and sustained IOP elevation on 2 or more consecutive visits (absolute IOP >25 mmHg, increase above baseline >10 mmHg, or IOP of >21 mmHg and increase of >5 mmHg). Cox regression survival analysis and multivariate logistic regression were performed to assess the influence of intravitreal injections on experiencing sustained IOP elevation.Overall, 32 eyes (7.1%) experienced sustained IOP elevation. Survival analysis showed a significant effect of the number of anti-vascular endothelial growth factor injections on sustained IOP elevation (hazard ratio, 1.085; 95% confidence interval: 1.06-1.11, P < 0.001). Also, there was an increased odds ratio (16.1, P = 0.008) of sustained IOP elevation in eyes receiving ≥29 injections compared with ≤12 injections. After controlling for the confounder (prior intravitreal steroid injection), total number of injections still showed a statistically significant association (P = 0.002).A greater number of intravitreal anti-vascular endothelial growth factor injections is associated with an increased risk for sustained IOP elevation in eyes with neovascular age-related macular degeneration receiving intravitreal ranbizumab and/or bevacizumab.

  View details for DOI 10.1097/IAE.0b013e318261a6f7

  View details for PubMedID 22990314

• Imaging in the diagnosis and management of acute idiopathic maculopathy. International ophthalmology clinics Hoang, Q. V., Strauss, D. S., Pappas, A., Freund, K. B. 2012; 52 (4): 263-8

  View details for DOI 10.1097/IIO.0b013e31826861db

  View details for PubMedID 22954949

• Effect on intraocular pressure in patients receiving unilateral intravitreal anti-vascular endothelial growth factor injections. Ophthalmology Hoang, Q. V., Mendonca, L. S., Della Torre, K. E., Jung, J. J., Tsuang, A. J., Freund, K. B. 2012; 119 (2): 321-6

  Abstract

  We assessed the frequency and predictive factors related to intraocular pressure (IOP) elevation in neovascular age-related macular degeneration (AMD) patients undergoing unilateral intravitreal ranibizumab and/or bevacizumab injections.Retrospective cohort study.Charts of 207 patients with neovascular AMD who presented to a single physician at a retinal referral practice over a 6-month period were retrospectively reviewed.Data recorded included demographic information, clinical findings, total number of bevacizumab and ranibizumab injections received and IOP at each visit. Increases above baseline IOP of >5, >10, or >15 mmHg on ≥2 consecutive visits while under treatment were noted.The frequency of IOP elevation was compared between treated and untreated eyes. In addition, among treated eyes, frequency and odds ratio of experiencing IOP elevation >5 mmHg above baseline on ≥2 consecutive visits was stratified by number of injections. For the main regression analysis, the outcome variable was IOP elevation >5 mmHg on ≥2 consecutive visits and the main independent variable was total number of injections.On ≥2 consecutive visits, 11.6% of treated versus 5.3% of untreated/control eyes experienced IOP elevation of >5 mmHg. The mean number of injections was higher in those with (24.4; 95% confidence interval [CI], 20.9-28.0; range, 9-39) than without IOP elevation of >5 mmHg (20.4; 95% CI, 18.9-21.8; range, 3-48) on ≥2 consecutive visits. There was an increased odds ratio (5.75; 95% CI, 1.19-27.8; P = 0.03) of experiencing IOP elevation >5 mmHg on ≥2 consecutive visits in patients receiving ≥29 injections compared with ≤12 injections. Of the factors considered, only the total number of injections showed a statistically significant association with IOP elevation >5 mmHg above baseline on ≥2 consecutive visits in treated eyes (P = 0.05).A greater number of intravitreal anti-vasular endothelial growth factor injections is associated with an increased risk for IOP elevation >5 mmHg on ≥2 consecutive visits in eyes with neovascular AMD receiving intravitreal ranbizumab and/or bevacizumab.

  View details for DOI 10.1016/j.ophtha.2011.08.011

  View details for PubMedID 22054994

• FOCAL RETINAL PHLEBITIS RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Hoang, Q. V., Freund, K. B., Klancnik, J. M., Sorenson, J. A., Cunningham, E. T., Yannuzzi, L. A. 2012; 32 (1): 120-126

  Abstract

  To report three cases of solitary, focal retinal phlebitis.An observational case series.Three eyes in three patients were noted to have unilateral decreased vision, macular edema, and a focal retinal phlebitis, which was not at an arteriovenous crossing. All three patients developed a branch retinal vein occlusion at the site of inflammation. These patients had no other evidence of intraocular inflammation, including vitritis, retinitis, retinal vasculitis, or choroiditis, nor was there any systemic disorder associated with inflammation, infection, or coagulation identified.Focal retinal phlebitis appears to be an uncommon and unique entity that produces macular edema and ultimately branch retinal vein occlusion. In our patients, the focal phlebitis and venous occlusion did not occur at an arteriovenous crossing, which is the typical site for branch retinal venous occlusive disease. This suggests that our cases represent a distinct clinical entity, which starts with a focal abnormality in the wall of a retinal venule, resulting in surrounding exudation and, ultimately, ends with branch retinal vein occlusion.

  View details for DOI 10.1097/IAE.0b013e31821504c1

  View details for Web of Science ID 000298661800017

  View details for PubMedID 21691257

• Central macular splaying and outer retinal thinning in asymptomatic sickle cell patients by spectral-domain optical coherence tomography. American journal of ophthalmology Hoang, Q. V., Chau, F. Y., Shahidi, M., Lim, J. I. 2011; 151 (6): 990-994.e1

  Abstract

  To investigate the prevalence and degree of macular thinning on optical coherence tomography (SDOCT) in African-American female patients with asymptomatic sickle cell disease.Prospective comparative case series.Twenty-one sickle cell patients (42 eyes) without other systemic or ocular diseases and 18 healthy control patients (33 eyes) underwent SD-OCT. Images were manually segmented to measure inner retinal thickness (IRT) and outer retinal thickness (ORT). Central macular (central 1 mm), parafoveal (0.5-1.5 mm eccentricity), and perifoveal (1.5-3 mm eccentricity) thickness measurements were obtained in sickle cell patients and age/gender/race-matched healthy control subjects.Central macular total thickness (CMT) in sickle cell patients was 220 ± 3 μm (mean ± SEM), which was significantly lower (P < .05) than controls (228 ± 3 μm). Parafoveal regions had thickness measurements of 314 ± 5 μm (nasal) and 304 ± 2 μm (temporal), which were significantly lower than controls (327 ± 2 μm and 311 ± 2 μm nasally and temporally, respectively) (P < .03, P < .043). There was also no significant difference in IRT in central macula, parafoveal, and perifoveal regions. Central macular ORT was 175 ± 2 μm vs 185 ± 1 μm in controls (P < .0002). ORT in temporal parafoveal and perifoveal regions was 142 ± 2 μm and 120 ± 1 μm, respectively, vs 150 ± 1 μm and 122 ± 1 μm in controls (P < .001 and P = .16, respectively).Manual segmentation of SD-OCT images revealed significant total retinal thinning in the central macula and splaying in asymptomatic sickle cell patients. Retinal thinning was predominately in outer retinal layers in central macula and parafoveal regions.

  View details for DOI 10.1016/j.ajo.2010.12.010

  View details for PubMedID 21457923

  View details for PubMedCentralID PMC3697103

• Optical coherence tomography of nasal sliding of the retina and temporal arcades in retinopathy of prematurity. Retinal cases & brief reports Hoang, Q. V., Chau, F. Y., Blair, M. P., Shapiro, M. J. 2011; 5 (2): 165-6

  Abstract

  The purpose of this study was to report a case of nasal dragging and sliding of retina over the optic disk, as documented by spectral-domain optical coherence tomography.Case report.We present the case of a 22-year-old woman with a history of retinopathy of prematurity noted to have nasal dragging of the retina, stable at least since the patient was 21 months old. Spectral domain optical coherence tomography showed folding of the temporal retina over the disk and the adjacent nasal retina, contributing to the nasal diversion of the vessels within the fold.Despite retinal anchoring at the optic nerve, the disk does not appear to serve as a barrier to retinal movement. Spectral domain optical coherence tomography showed in vivo a mechanism through which nasal dragging can occur, namely through the sliding and folding of temporal retina over the disk and the adjacent nasal retina.

  View details for DOI 10.1097/ICB.0b013e3181d4271b

  View details for PubMedID 25389892

• Multiple retinal holes and peripheral nonperfusion in muscle-eye-brain disease. Archives of ophthalmology (Chicago, Ill. : 1960) Hoang, Q. V., Blair, M. P., Rahmani, B., Galasso, J. M., Shapiro, M. J. 2011; 129 (3): 373-5

  View details for DOI 10.1001/archophthalmol.2011.37

  View details for PubMedID 21403000

• Macular thinning associated with unilateral optic nerve hypoplasia. Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye Hoang, Q. V., Chau, F. Y., Shahidi, M., Miller, M. T., Blair, M. P. 2011; 42 Online: e6-9

  Abstract

  The authors present the case of an 8-year-old boy with a long-term diagnosis of unilateral optic nerve hypoplasia (ONH) of unknown cause in the right eye. Spectral-domain optical coherence tomography (SD-OCT) of the central macula was consistent with hypoplasia greatest in the inner retinal layers, but also involving the outer retinal layers when compared with the unaffected contralateral eye. Although ONH is commonly associated with hypoplasia of the nerve fiber and ganglion cell layers, it can also be associated with hypoplasia of other layers in the inner and outer retina, including the outer nuclear and photoreceptor inner/outer segment layers, as evidenced by SD-OCT.

  View details for DOI 10.3928/15428877-20110125-08

  View details for PubMedID 21323261

  View details for PubMedCentralID PMC3690277

• Anomalous retinal vasculature in a patient with a history of aortic coarctation. Retinal cases & brief reports Hoang, Q. V., Blair, M. P., Shapiro, M. J. 2011; 5 (1): 79-81

  Abstract

  The purpose of this study was to report a case of anomalous retinal vasculature in a patient with a history of aortic coarctation.This is a case report.We present the case of a 4-month-old male infant with a history of juxtaductal aortic coarctation diagnosed on prenatal ultrasound, repaired at 2 weeks of life, who was referred for possible retinal detachment of the right eye. Examination under anesthesia and fluorescein angiography showed persistent fetal vasculature and tractional retinal detachment of the right eye and anomalous retinal vasculature of the left eye.Although aortic coarctation has been associated with arteriole corkscrew tortuosity and serpentine pulsation of arterioles, it can also be associated with an anomalous retinal vascular pattern.

  View details for DOI 10.1097/ICB.0b013e3181cc211e

  View details for PubMedID 25389689

• Fluorescein angiography of recurrent retinopathy of prematurity after initial intravitreous bevacizumab treatment. Archives of ophthalmology (Chicago, Ill. : 1960) Hoang, Q. V., Kiernan, D. F., Chau, F. Y., Shapiro, M. J., Blair, M. P. 2010; 128 (8): 1080-1

  View details for DOI 10.1001/archophthalmol.2010.145

  View details for PubMedID 20697016

• Functional analysis of hemichannels and gap-junctional channels formed by connexins 43 and 46. Molecular vision Hoang, Q. V., Qian, H., Ripps, H. 2010; 16: 1343-52

  Abstract

  The gap junctions (GJs) mediating direct cell-cell interaction are formed by clusters of membrane-spanning proteins known as connexins (Cxs). These channels play a key role in signal transmission, and their permeability, time-, and voltage-dependence are governed by the properties of the specific Cxs forming the gap junctions. Retinal pigment epithelium (RPE) cells express Cx43 and Cx46. Here, we employed a heterologous expression system to explore the functional properties of the hemichannels and GJs that could be formed by different combinations of these Cxs. Specifically, we examined the response kinetics of GJs formed by pairing cells expressing Cx43 or Cx46, or those expressing both, i.e., designated as Cx43*Cx46.The Xenopus oocyte expression system and a two-electrode voltage clamp technique were used to study the properties of hemichannels and GJs formed in oocytes transfected with Cx43 and/or Cx46 mRNA.Depolarizing voltages activated hemicurrents of similar amplitude from single oocytes transfected with Cx46 or Cx43*Cx46, but not in oocytes expressing Cx43 alone. Incorporating Cx43 with Cx46 altered the gating charge, but not the voltage sensitivity of the hemichannels. In addition, Cx43*Cx46 hemichannel currents exhibited faster activation kinetics than homomeric Cx46 hemichannels. Both homotypic GJs formed by Cx43 and Cx46, and heteromeric Cx43*Cx46 GJs exhibited large junctional conductances with amplitudes of 6.5+/-3.0 microS (Cx43), 8.9+/-3.4 microS (Cx46), and 8.5+/-1.8 microS (Cx43*46); a significantly lower conductance (1.8+/-0.7 microS) was observed for heterotypic GJs formed by Cx43 and Cx46. There were also differences in their gating kinetics. Whereas the kinetics of homotypic Cx46 could be described by a single exponential function (tau=0.91 s), double exponential functions were required for homotypic Cx43 (tau(1)=0.24, tau(2)=3.4 s), heterotypic Cx43/Cx46 (tau(1)=0.29, tau(2)=3.6 s), and heteromeric Cx43*Cx46/Cx43*Cx46 (tau(1)=1.2, tau(2)=8.1 s) junctions.The failure of oocytes expressing Cx43 to exhibit hemichannel activity is an intrinsic membrane property of this Cx, and cannot be attributed to a lack of expression; western blot analysis showed clearly that Cx43 was expressed in oocytes in which it was injected. Our results provide further evidence that Cx43 and Cx46 form both heterotypic and heteromeric channels when co-expressed, an indication that various combinations of Cxs may participate in gap-junctional communication between RPE cells.

  View details for PubMedID 20664797

  View details for PubMedCentralID PMC2905638

• Recurrent CMV retinitis in a non-HIV patient with drug-resistant CMV. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie Hoang, Q. V., Simon, D. M., Kumar, G. N., Oh, F., Goldstein, D. A. 2010; 248 (5): 737-40

  Abstract

  We report a case of recurrent cytomegalovirus (CMV) retinitis in an HIV-negative patient with CD4+ T lymphocytopenia.Case report.A 41-year-old HIV-negative woman with a history of systemic lupus erythematosus, idiopathic thrombocytopenic purpura requiring splenectomy, and diabetes presented with primary CMV infection, high-grade viremia, CMV pneumonia followed by CMV retinitis (CMVR) and a CD4+ T lymphocyte (CD4) count of 12 cells/mm(3) after therapy with rituximab, prednisone, and methotrexate. Persistent CMV viremia led to genotypic analysis of the circulating virus, which revealed UL97 and UL54 mutations known to be associated with resistance to ganciclovir (GCV) and cidofovir. CMV clearance from the bloodstream followed systemic antiviral therapy and recovery of CD4 cell count. However, CMVR recurred multiple times despite GCV implants, systemic valganciclovir, intravitreal GCV injections, and persistent CD4 counts greater than 100 cells/mm(3). Recurrent episodes of CMVR responded to multiple high dose intravitreal GCV injections (5000-6000 micrograms) and recovery of CD4 cell counts to greater than 200 cells/mm(3).This case demonstrates that recurrent CMVR occurs in HIV-negative patients at CD4 cell counts thought to be protective in HIV patients, and suggests that an ineffective local immune response to retinal infection combined with CMV drug resistance may have been important factors leading to recurrent disease in this patient. Treatment producing high local concentrations of GCV may be effective therapy for CMV retinitis due to GCV-resistant virus.

  View details for DOI 10.1007/s00417-009-1283-3

  View details for PubMedID 20094728

• Orexin (hypocretin) effects on constitutively active inward rectifier K+ channels in cultured nucleus basalis neurons. Journal of neurophysiology Hoang, Q. V., Zhao, P., Nakajima, S., Nakajima, Y. 2004; 92 (6): 3183-91

  Abstract

  Orexins are excitatory transmitters implicated in sleep disorders. Because orexins were discovered only recently, their ionic and signal transduction mechanisms have not been well clarified. We recently reported that orexin A (OXA) inhibits G protein-coupled inward rectifier K+ (GIRK) channels in cultured locus coeruleus and nucleus tuberomammillaris neurons. Other work in our laboratory revealed the existence of a novel inward rectifier K+ channel (KirNB), which is located in cholinergic neurons of the nucleus basalis (NB) and possesses unique single-channel characteristics. The mean open time is considerably shorter in KirNB than in Kir2.0 channels. Constitutive activity and a smaller unitary conductance set KirNB apart from cloned Kir3.0 channels. Previously, we found that substance P excites NB neurons by inhibiting KirNB channels. Here we show that orexins suppress KirNB channel activity, likely leading to neuronal excitation. Electrophysiological studies were performed on cultured NB neurons from the basal forebrain. OXA application decreased whole cell conductance through a pertussis toxin (PTX)-insensitive G protein. The OXA-suppressed current was inwardly rectifying with a reversal potential around E(K). Single-channel recordings of NB neurons revealed that constitutively active KirNB channels were transiently inhibited by OXA. Okadaic acid pretreatment abolished the recovery. The results suggest that OXA inhibition of KirNB is mediated by a PTX-insensitive G protein (i.e., G(q/11)), which eventually results in channel phosphorylation. Recovery from this inhibition is by dephosphorylation. These results, taken together with our previous study, suggest that orexin receptors can elicit neuronal excitation through at least two families of inward rectifier K+ channels: GIRK and KirNB channels.

  View details for DOI 10.1152/jn.01222.2003

  View details for PubMedID 15269229

• Dissociated histaminergic neuron cultures from the tuberomammillary nucleus of rats: culture methods and ghrelin effects. Journal of neuroscience methods Bajic, D., Hoang, Q. V., Nakajima, S., Nakajima, Y. 2004; 132 (2): 177-84

  Abstract

  The tuberomammillary nucleus (TMN) in the hypothalamus is the sole source of histamine in the brain. This nucleus, by innervating various brain regions, plays an important role for vital functions such as arousal and appetite. We have developed dissociated primary histaminergic neuron cultures from TMN of postnatal (3 and 10-day-old) rats. More than 50% of our cultured neurons from the TMN were histaminergic as revealed by adenosine deaminase (AD) as well as histamine immunocytochemistry. Among large neurons (diameter, >22 microm), more than 88% were histaminergic. Such large neurons (mean diameter, 26.5 microm) were used for electrophysiology. Using about 2-month-old TMN cultures, we investigated the effects of ghrelin, a recently discovered appetite-stimulating endogenous peptide. In GTPgammaS-loaded neurons, ghrelin (3 microM) suppressed currents that had previously been activated by an inhibitory neuropeptide, nociceptin. The mean current suppression by ghrelin was 471+/-128 pA (S.E.M., n=7). The I-V relationship revealed that the ghrelin-suppressed current was inwardly rectifying with a reversal potential around E(K). These results suggest that ghrelin inhibits G protein-coupled inward rectifier K+ channels (Kir3, GIRK) of TMN neurons and that our TMN cultures are useful for investigating physiological properties of brain histaminergic neurons.

  View details for DOI 10.1016/j.jneumeth.2003.09.008

  View details for PubMedID 14706715

• Effects of orexin (hypocretin) on GIRK channels. Journal of neurophysiology Hoang, Q. V., Bajic, D., Yanagisawa, M., Nakajima, S., Nakajima, Y. 2003; 90 (2): 693-702

  Abstract

  Orexins (hypocretins) are recently discovered excitatory transmitters implicated in arousal and sleep. Yet, their ionic and signal transduction mechanisms have not been fully clarified. Here we show that orexins suppress G-protein-coupled inward rectifier (GIRK) channel activity, and this suppression is likely to lead to neuronal excitation. Cultured neurons from the locus coeruleus (LC) and the nucleus tuberomammillaris (TM) were used, as well as HEK293A cells transfected with GIRK1 and 2, either human orexin receptor type 1 (OX1R) or type 2 (OX2R), mu opioid receptor and GFP cDNAs. In GTPgammaS-loaded cells, orexin A (OXA, 3 microM) inhibited GIRK currents that had previously been activated by somatostatin (in LC cells), nociceptin (TM cells), or the mu opioid agonist DAMGO (HEK cells). In guanosine triphosphate (GTP)-loaded HEK cells, in which GIRK currents were not preactivated, OXA induced a biphasic response through both types of orexin receptors: an initial current increase and a subsequent decrease to below resting levels. Current-voltage (I-V) relationships revealed that both the OXA-induced and suppressed currents are inwardly rectifying with reversal potentials around EK. The OXA-induced initial current was partially pertussis toxin (PTX) sensitive and partially PTX insensitive, whereas the OXA-suppressed current was PTX insensitive. These data suggest that orexin receptors couple with more than one type of G-protein, including PTX-sensitive (such as Gi/o) and PTX-insensitive (such as Gq/11) G-proteins. The modulation of GIRK channels by orexins may be one of the cellular mechanisms for the regulation of brain nuclei (e.g., LC and TM) that are crucial for arousal, sleep, and appetite.

  View details for DOI 10.1152/jn.00001.2003

  View details for PubMedID 12702704

• Photoreceptor inner segments in monkey and human retina: mitochondrial density, optics, and regional variation. Visual neuroscience Hoang, Q. V., Linsenmeier, R. A., Chung, C. K., Curcio, C. A. 2002; 19 (4): 395-407

  Abstract

  The present work quantifies aspects of photoreceptor structure related to mitochondria, inner segment dimensions, and optical properties, as a basis for furthering our understanding of rod and cone function. Electron-microscopic analyses were performed on the retina of one stumptail macaque (Macaca arctoides) to obtain stereological measurements of ellipsoid mitochondrial density, and sizes and shapes of outer and inner segments. In addition, the distribution of mitochondria and the optical properties of human foveal cones were examined with electron microscopy and Nomarski differential interference contrast (NDIC) imaging. Mitochondria comprised 74-85% of cone ellipsoids and 54-66% of rod ellipsoids in macaque. Ellipsoid volume increased with eccentricity by 2.4-fold for rods and more than 6-fold for cones over eccentricities to 12.75 mm, while the volume of the outer segment supported by the ellipsoid was essentially constant for both rods and cones. Per unit volume of outer segment, cones contained ten times as much mitochondria as rods. In human fovea, as in the rest of the retina, most cone mitochondria were located in the distal inner segment. In the foveal center, however, there are also mitochondria in the myoid, as well as in the outer fiber, proximal to the external limiting membrane (ELM). Analyses of the optical aperture of human foveal cones, the point at which their refractive index clearly differs from the extrareceptoral space, showed that it correlated well with the location of mitochondria, except in the foveal center, where the aperture appeared proximal to the ELM. While mitochondria have an important metabolic function, we suggest that the striking differences between rods and cones in mitochondrial content are unlikely to be determined by metabolic demand alone. The numerous cone mitochondria may enhance the waveguide properties of cones, particularly in the periphery.

  View details for DOI 10.1017/s0952523802194028

  View details for PubMedID 12511073