Clinical Focus
- Ophthalmology
- Glaucoma and cataract surgery
- Drug development and clinical trials
- Epidemiology
Honors & Awards
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Delta Omega, Johns Hopkins University (2009)
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Heed fellow, Heed Foundation (2018)
Boards, Advisory Committees, Professional Organizations
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Scientific Advisory Board, Mary Tyler Moore Vision Initiative (2023 - Present)
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Chief Scientific Officer, Kodiak Sciences (2024 - Present)
Professional Education
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Residency: Wilmer Eye Institute of Ophthalmology (2018) MD
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Fellowship: Stanford University Ophthalmology Fellowships (2020) CA
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Board Certification: American Board of Ophthalmology, Ophthalmology (2019)
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Internship: Greater Baltimore Medical Center Internal Medicine Residency (2015) MD
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Medical Education: National Taiwan University College of Medicine (2008) Taiwan
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PhD, Bloomberg School of Public Health, Johns Hopkins University, Epidemiology (2013)
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MPH, Bloomberg School of Public Health, Johns Hopkins University (2009)
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MD, National Taiwan University (2008)
All Publications
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Report of the 2023 Mary Tyler Moore Vision Initiative Workshop.
Translational vision science & technology
2025; 14 (7): 11
Abstract
The Mary Tyler Moore Vision Initiative (MTM Vision) Diabetic Retinal Disease (DRD) Clinical Endpoints Workshop was held on November 14, 2023. More than 130 clinicians, scientists, and representatives from funding and regulatory agencies, diagnostic, therapeutic, and biotech industry and patient advocates discussed the needs for new diagnostic and therapeutic approaches to preserve and restore retinal neurovascular unit integrity in people with diabetes. MTM Vision projects, notably updating the DRD staging system and severity scale, establishing a human ocular biorepository and resource, and validating useful clinical endpoints and biomarkers to accelerate development of new drugs and improve patient care were emphasized. A public-private consortium is essential to fulfill the objectives of MTM Vision for the benefit of persons with diabetes.
View details for DOI 10.1167/tvst.14.7.11
View details for PubMedID 40679331
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Development of Potent Bispecific Inhibitors Targeting Complement Pathways and Cytokines for the Treatment of Geographic Atrophy
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2025
View details for Web of Science ID 001558421400032
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Flavoprotein Fluorescence as a Biomarker for Retinal Metabolism in Diabetic Macular Edema Undergoing Anti-VEGF Therapy
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2025
View details for Web of Science ID 001559838700030
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Aqueous Humor Neurofilament Light Chain Level as a Candidate Biomarker for Glaucoma Disease Staging
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2025
View details for Web of Science ID 001561888100044
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Comparison of structure-function correlation among IMO visual function analyser and Humphrey field analyser.
The British journal of ophthalmology
2025
Abstract
To compare the structure-function correlations between optical coherence tomography (OCT) thickness parameters and the corresponding sectorial mean sensitivity (MS) values obtained with IMO visual function analyser (IMOvifa) and Humphrey field analyser (HFA) perimeters.Prospective cross-sectional study.Glaucoma suspect, glaucoma and ocular hypertension patients underwent IMOvifa 24-2 Ambient Interactive Zippy Estimated Sequential Testing, HFA 24-2 Swedish Interactive Threshold Algorithm-Standard and OCT tests within 12 weeks. Based on the Garway-Heath map, the sensitivity points were divided in corresponding OCT peripapillary retinal nerve fibre layer (pRNFL) sectors, and also the central 10° points in corresponding ganglion cell-inner plexiform layer thickness over the macula. The structure-function correlations were analysed by Spearman's rank coefficient and compared by Steiger's test.57 eyes of 57 patients (mean age 59.2 years, 61.4% female) with reliable field and adequate OCT strength were included in this analysis. IMOvifa had significantly shorter testing time (3.7 vs 5.3 mins), lower mean deviation (difference -0.6 dB) and greater visual field index (difference +1.0%) compared with HFA (p<0.001 for all). There was moderate to strong correlation between IMOvifa and HFA MS sectors (p<0.001 for all). IMOvifa had significant correlations in the inferior (I, r=0.46), superior (S, r=0.45), temporal (T, r=0.28) pRNFL sectors and in the I (r=0.63) and S (r=0.53) mGCPIPL hemispheres (p≤0.03 for all). There was no significant difference in the strength of the correlation of IMOvifa versus HFA results with OCT parameters (p≥0.06).The IMOvifa test took less time and resulted in slightly less severe defects than HFA. MS in all sectors was moderately to strongly correlated. Function-structure correlations were similar when using either perimeter.
View details for DOI 10.1136/bjo-2023-324846
View details for PubMedID 40086867
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Macular Sensitivity Endpoints in Geographic Atrophy: Exploratory Analysis of Chroma and Spectri Clinical Trials.
Ophthalmology science
2024; 4 (1): 100351
Abstract
To assess different microperimetry (MP) macular sensitivity outcome measures capturing functional deterioration in eyes with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).Patients were included from 2 identically designed, phase III, double-masked, randomized controlled clinical trials, Chroma (NCT02247479) and Spectri (NCT02247531).Patients enrolled were aged ≥ 50 years with bilateral GA and no evidence of previous or active neovascular AMD.Patients were randomized 2:1:2:1 to receive through 96 weeks intravitreal lampalizumab 10 mg every 4 weeks (LQ4W), every 6 weeks (LQ6W), or corresponding sham procedures. For this study, mesopic macular sensitivity of the central 20° was assessed using MP-1 microperimeter at selected sites.Two exploratory endpoints were developed, namely perilesional sensitivity (average of points adjacent to absolute scotomatous points) and responding sensitivity (average of all nonscotomatous points; > 0 dB at baseline) by using customized masks for each patient. These were compared with conventional MP endpoints (mean macular sensitivity and number of absolute scotomatous points).Of 1881 Chroma and Spectri participants, 277 agreed to participate in the present study. Of these, 197 (LQ4W, n = 63; LQ6W, n = 68; pooled sham, n = 66) had reliable MP results. Enlargement of GA lesion area by approximately 2 mm2/year across treatment groups was accompanied by deterioration in all MP parameters. There was no difference in worsening of macular sensitivity or absolute scotomatous points among treatment groups. Perilesional and responding sensitivities showed greater decline over time than mean macular sensitivity. Change in GA lesion area at week 48 showed better correlation with perilesional sensitivity (r = -0.17) and responding sensitivity (r = -0.20) than mean macular sensitivity (r = -0.03), while the correlation was highest with the number of absolute scotomatous points (r = 0.37).Perilesional or responding macular sensitivity measured by MP should be considered more sensitive endpoints than mean macular sensitivity for monitoring functional decline over time in GA. Although perilesional, responding, and mean macular sensitivity had weak correlation with GA lesion area, the number of absolute scotomatous points may provide additional information on the anatomic/functional correlation.Proprietary or commercial disclosure may be found after the references.
View details for DOI 10.1016/j.xops.2023.100351
View details for PubMedID 37869030
View details for PubMedCentralID PMC10587617
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Faricimab for neovascular age-related macular degeneration and diabetic macular edema: from preclinical studies to phase 3 outcomes.
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie
2024
Abstract
Intravitreal anti-vascular endothelial growth factor (VEGF) therapy is the standard of care for diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD); however, vision gains and anatomical improvements are not sustained over longer periods of treatment, suggesting other relevant targets may be needed to optimize treatments. Additionally, frequent intravitreal injections can prove a burden for patients and caregivers. Angiopoietin-2 (Ang-2) has been explored as an additional therapeutic target, due to the involvement of Ang-2 in DME and nAMD pathogenesis. Recent evidence supports the hypothesis that targeting both VEGF and Ang-2 may improve clinical outcomes in DME and nAMD compared with targeting VEGF alone by enhancing vascular stability, resulting in reduced macular leakage, prevention of neovascularization, and diminished inflammation. Faricimab, a novel bispecific antibody that targets VEGF-A and Ang-2, has been evaluated in clinical trials for DME (YOSEMITE/RHINE) and nAMD (TENAYA/LUCERNE). These trials evaluated faricimab against the anti-VEGFA/B and anti-placental growth factor fusion protein aflibercept, both administered by intravitreal injection. In addition to faricimab efficacy, safety, and pharmacokinetics, durability was evaluated during the trials using a treat-and-extend regimen. At 1 year, faricimab demonstrated non-inferior vision gains versus aflibercept across YOSEMITE/RHINE and TENAYA/LUCERNE. In YOSEMITE/RHINE, faricimab improved anatomic parameters versus aflibercept. Reduction of central subfield thickness (CST), and absence of both DME and intraretinal fluid were greater in faricimab- versus aflibercept-treated eyes. In TENAYA/LUCERNE, CST reductions were greater for faricimab than aflibercept at the end of the head-to-head phase (0-12 weeks), and were comparable with aflibercept at year 1, but with less frequent dosing. CST and vision gains were maintained during year 2 of both YOSEMITE/RHINE and TENAYA/LUCERNE. These findings suggest that dual Ang-2/VEGF-A pathway inhibition may result in greater disease control versus anti-VEGF alone, potentially addressing the unmet needs and reducing treatment burden, and improving real-world outcomes and compliance in retinal vascular diseases. Long-term extension studies (RHONE-X, AVONELLE-X) are ongoing. Current evidence suggests that dual inhibition with faricimab heralds the beginning of multitargeted treatment strategies inhibiting multiple, independent components of retinal pathology, with faricimab providing opportunities to reduce treatment burden and improve outcomes compared with anti-VEGF monotherapy.
View details for DOI 10.1007/s00417-024-06531-9
View details for PubMedID 38847896
View details for PubMedCentralID 10408259
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Repeatability of a Virtual Reality Headset Perimeter in Glaucoma and Ocular Hypertensive Patients.
Translational vision science & technology
2024; 13 (6): 14
Abstract
The VisuALL S is an automated, static threshold, virtual reality-based perimeter for mobile evaluation of the visual field. We examined same-day and 3-month repeatability.Adult participants with a diagnosis of glaucoma or ocular hypertension underwent two VisuALL 24-2 Normal T- Full threshold strategy tests at baseline and one additional exam at 3 months for each eligible eye. Spearman, intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to assess the correlation of individual point sensitivities and mean deviation (MD) among three tests.Eighty-eight eyes (44 participants) were included. Average age was 68.1 ± 14.3 years, and 60.7% were male. VisuALL MD was highly correlated between tests (intravisit: r = 0.89, intervisit: r = 0.82; P < 0.001 for both). Bland-Altman analysis showed an average difference in intravisit MD of -0.67 dB (95% confidence interval [CI], -6.04 to 4.71 dB) and -0.15 dB (95% CI, -8.04 to 7.73 dB) for intervisit exams. Eight-five percent of pointwise intravisit ICCs were above 0.75 (range, 0.63 to 0.93), and 65% of pointwise intervisit ICCs were above 0.75 (range, 0.55 to 0.91).VisuALL demonstrated high correlation of MD between tests and good repeatability for individual point sensitivities among three tests in 3 months, except at the points around the blind spot and superiorly.The preliminary reproducibility results for VisuALL are encouraging. Its portable design makes it a potentially useful tool for patients with glaucoma, enabling more frequent assessments both at home and in clinical settings.
View details for DOI 10.1167/tvst.13.6.14
View details for PubMedID 38899952
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Artificial Intelligence Quantified Outer Retinal Disruption On Optical Coherence Tomography As Clinical Endpoints For Geographic Atrophy
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024
View details for Web of Science ID 001312227706305
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Participant Experience Using Novel Perimetry Tests to Monitor Glaucoma Progression.
Journal of glaucoma
2023
Abstract
Participant surveys taken after using tablet-based and smart visual function analyzer perimetry tests suggest that patients may prefer novel perimetry tests over traditional visual-field machines.Compare patient experience using the IMOvifa smart visual function analyzer and the tablet-based Melbourne Rapid Fields visual field tests to the Humphrey Field 24-2 Swedish Interactive Threshold Algorithm Standard.Prospective observational cohort study on adult participants with diagnoses of glaucoma suspect, ocular hypertension, or glaucoma. Participants attended two study visits approximately three months apart. During the first visit, participants were trained to use the two novel perimeters, took one test on both new devices and the Humphrey Field Analyzer, then were surveyed. Participants received tablets and performed weekly tablet visual field tests at home between study visits. At the final study visit, participants re-took the visual field tests and completed the same surveys.Eighty-one participants were surveyed twice. At the baseline survey, participants preferred the smart visual function analyzer (71.7%) and tablet tests (69.2%) over the Humphrey visual field. Most were willing to perform weekly monitoring at home on the smart visual function analyzer (69.1%) and tablet (75.4%). Participants generally had a "very good" overall experience when testing on the smart visual function analyzer (71.6%) and tablet (90.1%). At the final visit, participants were not willing to test as frequently on the tablet (P = 0.03).Users reported a preference for the novel visual field devices. Overall participant experience using these devices was positive, supporting the feasibility of home monitoring of visual fields from an experience perspective.
View details for DOI 10.1097/IJG.0000000000002296
View details for PubMedID 37671465
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Reproducibility of retinal mitochondrial imaging using flavoprotein fluorescence in glaucoma patients and suspects
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023
View details for Web of Science ID 001053795606156
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Structure-Function correlation between sectorial OCT parameters and corresponding mean sensitivity values obtained with IMOvifa and Humphrey Field Analyzer perimeters
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023
View details for Web of Science ID 001053758305281
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Stability of recorded sensitivities with the tablet-based Melbourne Rapid Fields (MRF) perimeter across eleven at-home weekly tests
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023
View details for Web of Science ID 001053795607241
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Comparison of Perimetric Outcomes From a Tablet Perimeter, Smart Visual Function Analyzer, and Humphrey Field Analyzer.
Ophthalmology. Glaucoma
2023
Abstract
The tablet-based Melbourne Rapid Fields (MRF) visual field (VF) test and the IMOvifa Smart Visual Function Analyzer (SVFA) are portable perimeters that may allow for at-home monitoring and more frequent testing. We compared tablet and SVFA results to outputs from the Humphrey Field Analyzer (HFA) 24-2 Swedish Interactive Threshold Algorithm (SITA) Standard program.Observational cross-sectional study.Adult participants with a diagnosis of glaucoma, suspected glaucoma, or ocular hypertension seen in the Massachusetts Eye and Ear glaucoma clinic were enrolled. All participants were reliable, experienced HFA testers.Participants were tested with the SVFA and HFA. Study staff also trained participants on the MRF tablet with instructions to take weekly tests at home for three months. VF results from the three devices were compared.Mean deviation (MD), pattern standard deviation (PSD), reliability parameters, point sensitivity.79 participants (133 eyes) with a mean age of 61 ± 13 years (range 26-79) were included; 59% of the participants were female, and the mean HFA MD was -2.7 ± 3.9 decibels (dB). The global indices of MD and PSD did not significantly vary between HFA and the two novel devices, except that the tablet VF reported a 0.6 dB higher PSD compared to HFA (95% CI for difference between HFA and tablet = [0.27 dB to 1.02 dB], P < 0.001). However, tablet and SVFA sensitivities significantly differed from those of the HFA at 36 and 39 locations, respectively, out of 52 locations. Relative to HFA, the tablet overestimated light sensitivity in the nasal field while underestimating the temporal field. The SVFA generally underestimated light sensitivity, but its results were more similar to HFA results compared to the tablet.While average MD values from the two novel devices suggest that they provide similar results to the HFA, point-by-point comparisons highlight notable deviations. Differences in specific point sensitivity values were significant, especially between the tablet and the other two devices. These differences may in part be explained by differences in the normative databases of each device as well as how MD is calculated. However, the tablet had substantial differences based on location, indicating that the tablet design itself may be responsible for the differences in local sensitivities.
View details for DOI 10.1016/j.ogla.2023.03.001
View details for PubMedID 36918066
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Lens extraction versus laser peripheral iridotomy for acute primary angle closure.
The Cochrane database of systematic reviews
2023; 3: CD015116
Abstract
Acute primary angle closure (APAC) is a potentially blinding condition. It is one of the few ophthalmic emergencies and carries high rates of visual morbidity in the absence of timely intervention. Laser peripheral iridotomy (LPI) has been the standard of care thus far. However, LPI does not eliminate the long-term risk of chronic angle closure glaucoma and other associated sequelae. There has been increasing interest in lens extraction as the primary treatment for the spectrum of primary angle closure disease, and it is as yet unclear whether these results can be extrapolated to APAC, and whether lens extraction provides better long-term outcomes. We therefore sought to evaluate the effectiveness of lens extraction in APAC to help inform the decision-making process. OBJECTIVES: To assess the effect of lens extraction compared to LPI in the treatment of APAC.We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 1), Ovid MEDLINE, Ovid MEDLINE E-pub Ahead of Print, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to 10 January 2022), Embase (January 1947 to 10 January 2022), PubMed (1946 to 10 January 2022), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to 10 January 2022), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 10 January 2022.We included randomized controlled clinical trials comparing lens extraction against LPI in adult participants ( ≥ 35 years) with APAC in one or both eyes.We used standard Cochrane methodology and assessed the certainty of the body of evidence for prespecified outcomes using the GRADE approach.We included two studies conducted in Hong Kong and Singapore, comprising 99 eyes (99 participants) of predominantly Chinese origin. The two studies compared LPI with phacoemulsification performed by experienced surgeons. We assessed that both studies were at high risk of bias. There were no studies evaluating other types of lens extraction procedures. Phacoemulsification may result in an increased proportion of participants with intraocular pressure (IOP) control compared with LPI at 18 to 24 months (risk ratio (RR) 1.66, 95% confidence interval (CI) 1.28 to 2.15; 2 studies, n = 97; low certainty evidence) and may reduce the need for further IOP-lowering surgery within 24 months (RR 0.07, 96% CI 0.01 to 0.51; 2 studies, n = 99; very low certainty evidence). Phacoemulsification may result in a lower mean IOP at 12 months compared to LPI (mean difference (MD) -3.20, 95% CI -4.79 to -1.61; 1 study, n = 62; low certainty evidence) and a slightly lower mean number of IOP-lowering medications at 18 months (MD -0.87, 95% CI -1.28 to -0.46; 1 study, n = 60; low certainty evidence), but this may not be clinically significant. Phacoemulsification may have little to no effect on the proportion of participants with one or more recurrent APAC episodes in the same eye (RR 0.32, 95% CI 0.01 to 7.30; 1 study, n = 37; very low certainty evidence). Phacoemulsification may result in a wider iridocorneal angle assessed by Shaffer grading at six months (MD 1.15, 95% CI 0.83 to 1.47; 1 study, n = 62; very low certainty evidence). Phacoemulsification may have little to no effect on logMAR best-corrected visual acuity (BCVA) at six months (MD -0.09, 95% CI -0.20 to 0.02; 2 studies, n = 94; very low certainty evidence). There was no evidence of a difference in the extent of peripheral anterior synechiae (PAS) (clock hours) between intervention arms at 6 months (MD -1.86, 95% CI -7.03 to 3.32; 2 studies, n = 94; very low certainty evidence), although the phacoemulsification group may have less PAS (degrees) at 12 months (MD -94.20, 95% CI -140.37 to -48.03; 1 study, n = 62) and 18 months (MD -127.30, 95% CI -168.91 to -85.69; 1 study, n = 60). In one study, there were 26 adverse events in the phacoemulsification group: intraoperative corneal edema (n = 12), posterior capsular rupture (n = 1), intraoperative bleeding from iris root (n = 1), postoperative fibrinous anterior chamber reaction (n = 7), and visually significant posterior capsular opacification (n = 5), and no cases of suprachoroidal hemorrhage or endophthalmitis. There were four adverse events in the LPI group: closed iridotomy (n = 1) and small iridotomies that required supplementary laser (n = 3). In the other study, there was one adverse event in the phacoemulsification group (IOP > 30 mmHg on day 1 postoperatively (n = 1)), and no intraoperative complications. There were five adverse events in the LPI group: transient hemorrhage (n = 1), corneal burn (n = 1), and repeated LPI because of non-patency (n = 3). Neither study reported health- or vision-related quality of life measures.Low certainty evidence suggests that early lens extraction may produce more favorable outcomes compared to initial LPI in terms of IOP control. Evidence for other outcomes is less clear. Future high-quality and longer-term studies evaluating the effects of either intervention on the development of glaucomatous damage and visual field changes as well as health-related quality of life measures would be helpful.
View details for DOI 10.1002/14651858.CD015116.pub2
View details for PubMedID 36884304
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Visual Field Prediction: Evaluating the Clinical Relevance of Deep Learning Models.
Ophthalmology science
2023; 3 (1): 100222
Abstract
Two novel deep learning methods using a convolutional neural network (CNN) and a recurrent neural network (RNN) have recently been developed to forecast future visual fields (VFs). Although the original evaluations of these models focused on overall accuracy, it was not assessed whether they can accurately identify patients with progressive glaucomatous vision loss to aid clinicians in preventing further decline. We evaluated these 2 prediction models for potential biases in overestimating or underestimating VF changes over time.Retrospective observational cohort study.All available and reliable Swedish Interactive Thresholding Algorithm Standard 24-2 VFs from Massachusetts Eye and Ear Glaucoma Service collected between 1999 and 2020 were extracted. Because of the methods' respective needs, the CNN data set included 54 373 samples from 7472 patients, and the RNN data set included 24 430 samples from 1809 patients.The CNN and RNN methods were reimplemented. A fivefold cross-validation procedure was performed on each model, and pointwise mean absolute error (PMAE) was used to measure prediction accuracy. Test data were stratified into categories based on the severity of VF progression to investigate the models' performances on predicting worsening cases. The models were additionally compared with a no-change model that uses the baseline VF (for the CNN) and the last-observed VF (for the RNN) for its prediction.PMAE in predictions.The overall PMAE 95% confidence intervals were 2.21 to 2.24 decibels (dB) for the CNN and 2.56 to 2.61 dB for the RNN, which were close to the original studies' reported values. However, both models exhibited large errors in identifying patients with worsening VFs and often failed to outperform the no-change model. Pointwise mean absolute error values were higher in patients with greater changes in mean sensitivity (for the CNN) and mean total deviation (for the RNN) between baseline and follow-up VFs.Although our evaluation confirms the low overall PMAEs reported in the original studies, our findings also reveal that both models severely underpredict worsening of VF loss. Because the accurate detection and projection of glaucomatous VF decline is crucial in ophthalmic clinical practice, we recommend that this consideration is explicitly taken into account when developing and evaluating future deep learning models.
View details for DOI 10.1016/j.xops.2022.100222
View details for PubMedID 36325476
View details for PubMedCentralID PMC9619031
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Functional imaging of mitochondria using flavoprotein fluorescence and its correlation with intraocular pressure in treated glaucoma patients
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844437003227
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Learning curve on tablet-based visual field tests during one week of daily testing
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844437002153
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Relationship between contrast sensitivity and visual field mean deviation
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401303245
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Participant experience using novel perimetry tests to monitor glaucoma progression
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401303246
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Repeatability and correlation of a virtual reality perimeter with standard automated perimetry in glaucoma patients
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401303262
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Comparison of portable perimetry tests with the Humphrey Field Analyzer
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022
View details for Web of Science ID 000844401303261
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Acute Angle Closure Attacks Are Uncommon in Primary Angle-Closure Suspects: The Zhongshan Angle Closure Prevention Trial.
Ophthalmology. Glaucoma
2022
Abstract
PURPOSE: Angle-closure glaucoma is a major cause of blindness worldwide that carries an excess risk of severe, bilateral visual impairment. A common concern among clinicians is precipitating acute angle closure (AAC) attacks by mydriasis. We evaluated the risk of AAC after pharmacologic dilation in Chinese individuals classified as bilateral primary angle-closure suspects (PACS).DESIGN: Randomized interventional controlled trial.PARTICIPANTS: A total of 889 bilateral PACS aged between 50 and 70 years were identified through community screening in Guangzhou, China and enrolled in the study.METHODS: In the Zhongshan Angle Closure Prevention (ZAP) Trial, bilateral PACS were treated by laser peripheral iridotomy (LPI) in one randomly selected eye, with the fellow eye serving as an untreated control. Over 72 months of follow-up, participants had their pupils pharmacologically dilated six times with 5% phenylephrine and 0.5% tropicamide.MAIN OUTCOME MEASURES: Incidence and risk of post-mydriasis AAC in LPI-treated and untreated control PACS eyes.RESULTS: One bilateral AAC attack occurred after mydriasis at the two-week post-LPI visit. No other AAC events occurred in LPI-treated eyes. In untreated eyes, four additional attacks occurred: two after dilation (one at 54- and one at 72-months follow-up) and two spontaneously. The risk of post-mydriasis AAC in untreated eyes was one attack in 1,587 dilations. The risk of spontaneous AAC in untreated eyes was 0.44 per 1000 eye-years (95% CI: 0.11-1.77 per 1000 eye-years).CONCLUSIONS: The risk of an incident AAC attack in PACS eyes was extremely low, even in a higher-risk group with repeated pharmacologic pupillary dilation over six years of follow-up. Prophylactic LPI reduced this small but real risk.
View details for DOI 10.1016/j.ogla.2022.04.003
View details for PubMedID 35568336
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Deep Learning for Glaucoma Detection and Identification of Novel Diagnostic Areas in Diverse Real-World Datasets.
Translational vision science & technology
2022; 11 (5): 11
Abstract
To develop a three-dimensional (3D) deep learning algorithm to detect glaucoma using spectral-domain optical coherence tomography (SD-OCT) optic nerve head (ONH) cube scans and validate its performance on ethnically diverse real-world datasets and on cropped ONH scans.In total, 2461 Cirrus SD-OCT ONH scans of 1012 eyes were obtained from the Glaucoma Clinic Imaging Database at the Byers Eye Institute, Stanford University, from March 2010 to December 2017. A 3D deep neural network was trained and tested on this unique raw OCT cube dataset to identify a multimodal definition of glaucoma excluding other concomitant retinal disease and optic neuropathies. A total of 1022 scans of 363 glaucomatous eyes (207 patients) and 542 scans of 291 normal eyes (167 patients) from Stanford were included in training, and 142 scans of 48 glaucomatous eyes (27 patients) and 61 scans of 39 normal eyes (23 patients) were included in the validation set. A total of 3371 scans (Cirrus SD-OCT) from four different countries were used for evaluation of the model: the non overlapping test dataset from Stanford (USA) consisted of 694 scans: 241 scans from 113 normal eyes of 66 patients and 453 scans of 157 glaucomatous eyes of 89 patients. The datasets from Hong Kong (total of 1625 scans; 666 OCT scans from 196 normal eyes of 99 patients and 959 scans of 277 glaucomatous eyes of 155 patients), India (total of 672 scans; 211 scans from 147 normal eyes of 98 patients and 461 scans from 171 glaucomatous eyes of 101 patients), and Nepal (total of 380 scans; 158 scans from 143 normal eyes of 89 patients and 222 scans from 174 glaucomatous eyes of 109 patients) were used for external evaluation. The performance of the model was then evaluated on manually cropped scans from Stanford using a new algorithm called DiagFind. The ONH region was cropped by identifying the appropriate zone of the image in the expected location relative to Bruch's Membrane Opening (BMO) using a commercially available imaging software. Subgroup analyses were performed in groups stratified by eyes, myopia severity of glaucoma, and on a set of glaucoma cases without field defects. Saliency maps were generated to highlight the areas the model used to make a prediction. The model's performance was compared to that of a glaucoma specialist using all available information on a subset of cases.The 3D deep learning system achieved area under the curve (AUC) values of 0.91 (95% CI, 0.90-0.92), 0.80 (95% CI, 0.78-0.82), 0.94 (95% CI, 0.93-0.96), and 0.87 (95% CI, 0.85-0.90) on Stanford, Hong Kong, India, and Nepal datasets, respectively, to detect perimetric glaucoma and AUC values of 0.99 (95% CI, 0.97-1.00), 0.96 (95% CI, 0.93-1.00), and 0.92 (95% CI, 0.89-0.95) on severe, moderate, and mild myopia cases, respectively, and an AUC of 0.77 on cropped scans. The model achieved an AUC value of 0.92 (95% CI, 0.90-0.93) versus that of the human grader with an AUC value of 0.91 on the same subset of scans (\(P=0.99\)). The performance of the model in terms of recall on glaucoma cases without field defects was found to be 0.76 (0.68-0.85). Saliency maps highlighted the lamina cribrosa in glaucomatous eyes versus superficial retina in normal eyes as the regions associated with classification.A 3D convolutional neural network (CNN) trained on SD-OCT ONH cubes can distinguish glaucoma from normal cases in diverse datasets obtained from four different countries. The model trained on additional random cropping data augmentation performed reasonably on manually cropped scans, indicating the importance of lamina cribrosa in glaucoma detection.A 3D CNN trained on SD-OCT ONH cubes was developed to detect glaucoma in diverse datasets obtained from four different countries and on cropped scans. The model identified lamina cribrosa as the region associated with glaucoma detection.
View details for DOI 10.1167/tvst.11.5.11
View details for PubMedID 35551345
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Cataract progression after Nd:YAG laser iridotomy in primary angle-closure suspect eyes.
The British journal of ophthalmology
2022
Abstract
BACKGROUND/AIMS: Prophylactic laser peripheral iridotomy (LPI) is performed in primary angle-closure suspect (PACS) eyes to prevent acute angle-closure attacks. However, accelerated cataractogenesis is a potential risk of the procedure that may result in decreased visual acuity. We aimed to assess the long-term impact of LPI on cataract formation in Chinese PACS.METHODS: In the Zhongshan Angle Closure Prevention Trial, eligible bilateral PACS participants received LPI in one randomly selected eye, while the fellow eye remained untreated. Cataract was graded using the Lens Opacity Classification System III, and progression was defined as an increase in grade by at least two units in any category or cataract surgery.RESULTS: In total, 889 participants were randomly assigned to LPI in one eye only (mean age 59±5 years, 83% female). At 72 months, treated eyes had slightly higher average nuclear grades (p<0.001). However, there were no differences between eyes for predefined cataract progression (cumulative probability at 72 months: 21.2% in LPI vs 19.4% in control, p=0.401) or cataract surgery (1% for both). While LPI-treated eyes had a 10% higher risk of progression over 6years (HR=1.10 (95% CI 0.88 to 1.36)), this was not statistically significant. Visual acuity at 72 months was similar in treated and untreated eyes (p=0.43).CONCLUSION: Although lenses were graded on average as slightly more opaque in laser-treated eyes, prophylactic neodymium:yttrium-aluminum-garnet LPI did not cause significant cataract progression. Our results suggest that LPI treatment of asymptomatic narrow angles does not increase the risk of developing clinically meaningful cataract worsening over time.TRIAL REGISTRATION NUMBER: ISRCTN45213099.
View details for DOI 10.1136/bjophthalmol-2021-320929
View details for PubMedID 35501120
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Predictors of long-term intraocular pressure control after clear lens extraction in primary angle closure glaucoma: results from the EAGLE
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2021
View details for Web of Science ID 000690760500631
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Baseline vision results from the Baltimore Reading and Eye Disease Study.
Canadian journal of ophthalmology. Journal canadien d'ophtalmologie
2021
Abstract
OBJECTIVE: We describe the Baltimore Reading and Eye Disease Study, report baseline ocular findings, and explore the feasibility of eye examinations in the school setting.DESIGN: Prospective, school-based cohort study.METHODS: Setting: 12 Baltimore public schools.PARTICIPANTS: Students in second and third grades.METHOD: Baseline eye examinations, including near and distance presenting visual acuity (VA), stereopsis, ocular alignment, dilated retinal examination, and cycloplegic refraction, were performed during the school year 2014-15.MAIN OUTCOMES: Presenting VA, prevalence of refractive error, and other ocular findings.RESULTS: Among the 1054 eligible students, 321 participated. There were 271 (84.4%) African American and 186 (57.9%) female students; mean age was 7.9 ± 0.8 years. Cycloplegia was achieved in 308. The mean presenting distance and near VA was 0.1 ± 0.2 logMAR (range -0.1 to 1.5) and 0.1 ± 0.2 logMAR (range 0.0-1.6) in the better-seeing eye, respectively. The most common ocular findings were +1.00 diopter (D) or greater hyperopia (34.7%), -0.50 D or greater myopia (29.5%), 1.00 D or greater astigmatism (23.4%), and convergence insufficiency (7.2%). Thirty-seven (11.5%) children needed referral to an eye care provider; 10% of students required glasses full-time.CONCLUSIONS: Whereas the majority of second and third grade students in this study have good VA and minimal refractive error, 1 in 9 have an ocular finding necessitating further evaluation. It was feasible to conduct cycloplegic eye examinations in the school setting.
View details for DOI 10.1016/j.jcjo.2021.02.014
View details for PubMedID 33745870
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Lens extraction versus laser peripheral iridotomy for acute primary angle closure (Protocol)
COCHRANE DATABASE OF SYSTEMATIC REVIEWS
2021
View details for DOI 10.1002/14651858.CD015116
View details for Web of Science ID 000756038600032
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A 3D Deep Learning System for Detecting Referable Glaucoma Using Full OCT Macular Cube Scans.
Translational vision science & technology
2020; 9 (2): 12
Abstract
The purpose of this study was to develop a 3D deep learning system from spectral domain optical coherence tomography (SD-OCT) macular cubes to differentiate between referable and nonreferable cases for glaucoma applied to real-world datasets to understand how this would affect the performance.There were 2805 Cirrus optical coherence tomography (OCT) macula volumes (Macula protocol 512 × 128) of 1095 eyes from 586 patients at a single site that were used to train a fully 3D convolutional neural network (CNN). Referable glaucoma included true glaucoma, pre-perimetric glaucoma, and high-risk suspects, based on qualitative fundus photographs, visual fields, OCT reports, and clinical examinations, including intraocular pressure (IOP) and treatment history as the binary (two class) ground truth. The curated real-world dataset did not include eyes with retinal disease or nonglaucomatous optic neuropathies. The cubes were first homogenized using layer segmentation with the Orion Software (Voxeleron) to achieve standardization. The algorithm was tested on two separate external validation sets from different glaucoma studies, comprised of Cirrus macular cube scans of 505 and 336 eyes, respectively.The area under the receiver operating characteristic (AUROC) curve for the development dataset for distinguishing referable glaucoma was 0.88 for our CNN using homogenization, 0.82 without homogenization, and 0.81 for a CNN architecture from the existing literature. For the external validation datasets, which had different glaucoma definitions, the AUCs were 0.78 and 0.95, respectively. The performance of the model across myopia severity distribution has been assessed in the dataset from the United States and was found to have an AUC of 0.85, 0.92, and 0.95 in the severe, moderate, and mild myopia, respectively.A 3D deep learning algorithm trained on macular OCT volumes without retinal disease to detect referable glaucoma performs better with retinal segmentation preprocessing and performs reasonably well across all levels of myopia.Interpretation of OCT macula volumes based on normative data color distributions is highly influenced by population demographics and characteristics, such as refractive error, as well as the size of the normative database. Referable glaucoma, in this study, was chosen to include cases that should be seen by a specialist. This study is unique because it uses multimodal patient data for the glaucoma definition, and includes all severities of myopia as well as validates the algorithm with international data to understand generalizability potential.
View details for DOI 10.1167/tvst.9.2.12
View details for PubMedID 32704418
View details for PubMedCentralID PMC7347026
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A 3D Deep Learning System for Detecting Referable Glaucoma Using Full OCT Macular Cube Scans
TRANSLATIONAL VISION SCIENCE & TECHNOLOGY
2020; 9 (2)
View details for DOI 10.1167/tvst.9.2.12
View details for Web of Science ID 000517757300008
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Efficacy of Laser Peripheral Iridotomy for the Prevention of Angle Closure: A Randomized Controlled Trial
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019
View details for Web of Science ID 000488628104164
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Macular sensitivity endpoints in geographic atrophy secondary to age-related macular degeneration - exploratory analysis of two parallel randomized phase 3 trials
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019
View details for Web of Science ID 000488628105157
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The incidence of acute angle-closure attack in primary angle closure suspect after pharmacologic mydriasis: A randomized controlled trial
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2019
View details for Web of Science ID 000488628106345
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Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial.
Lancet (London, England)
2019; 393 (10181): 1609–18
Abstract
Primary angle-closure glaucoma affects 20 million people worldwide. People classified as primary angle closure suspects have a higher but poorly quantified risk of developing glaucoma. We aimed to assess efficacy and safety of laser peripheral iridotomy prophylaxis against primary angle-closure glaucoma in Chinese people classified as primary angle closure suspects.In this randomised controlled trial, bilateral primary angle closure suspects aged 50-70 years were enrolled at the Zhongshan Ophthalmic Center, a tertiary specialised hospital in Guangzhou, China. Eligible patients received laser peripheral iridotomy in one randomly selected eye, with the other remaining untreated. The primary outcome was incident primary angle closure disease as a composite endpoint of elevation of intraocular pressure, peripheral anterior synechiae, or acute angle-closure during 72 months of follow-up in an intention-to-treat analysis between treated eyes and contralateral controls. This trial is registered with the ISRCTN registry, number ISRCTN45213099.Of 11 991 screened individuals, 889 individuals were randomly assigned from June 19, 2008 (889 treated and 889 untreated eyes). Incidence of the primary outcome was 4·19 per 1000 eye-years in treated eyes compared with 7·97 per 1000 eye-years in untreated eyes (hazard ratio 0·53; 95% CI 0·30-0·92; p=0·024). A primary outcome event occurred in 19 treated eyes and 36 untreated eyes with a statistically significant difference using pair-wise analysis (p=0·0041). No serious adverse events were observed during follow-up.Incidence of angle-closure disease was very low among individuals classified as primary angle closure suspects identified through community-based screening. Laser peripheral iridotomy had a modest, albeit significant, prophylactic effect. In view of the low incidence rate of outcomes that have no immediate threat to vision, the benefit of prophylactic laser peripheral iridotomy is limited; therefore, widespread prophylactic laser peripheral iridotomy for primary angle-closure suspects is not recommended.Fight for Sight, the Sun Yat-Sen University 5010 Project Fund, Moorfields Eye Charity, and the National Natural Science Foundation of China.
View details for DOI 10.1016/S0140-6736(18)32607-2
View details for PubMedID 30878226
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Central Scotoma After Liver Transplant.
JAMA ophthalmology
2019; 137 (2): 214–15
View details for DOI 10.1001/jamaophthalmol.2018.3564
View details for PubMedID 30452508
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The Relationship Between Quantitative Pupillometry and Estimated Ganglion Cell Counts in Patients With Glaucoma.
Journal of glaucoma
2019; 28 (3): 238–42
Abstract
To assess the relationship between pupillary light reflex and estimated retinal ganglion cell (RGC) counts in patients with glaucoma.We recorded and analyzed pupil responses using an automated binocular pupillometer in 148 patients with glaucoma (mean age 67±11, 49% female) and 71 controls (age 60±9.6, 69% female) as part of a prospective clinical study. The amplitude of pupil constriction was calculated as the percentage change in pupil diameter between constriction onset and peak constriction in response to controlled stimuli. The magnitude of a relative afferent pupillary defect (RAPD) was defined as the log of the ratio of the amplitude between 2 eyes multiplied by 10. RGC counts were estimated using empirical formulas that combine estimates from both functional (eccentricity and sensitivity measured by standard automated perimetry) and structural (retinal nerve fiber layer thickness) tests. For analyses performed at the level of individual eyes, we used multilevel modeling to account for between-eye correlations within individuals.Eyes with higher estimated RGC counts had a larger pupil response amplitude (z-score=8.24, P<0.001), shorter latency (z=-3.17, P=0.002), faster constriction velocity (z=6.64, P<0.001), shorter time to maximum constriction (z=-1.96, P=0.049), and longer time to maximum dilation (z=6.66, P<0.001). For every 0.3 log unit difference in RAPD score, there was an average decrease in estimated RGC count of 37,817 (P<0.001).There is a statistically significant association between estimated RGC count and pupillary response to stimuli. Quantitative pupillography may be useful in diagnosis and monitoring of optic neuropathies.
View details for DOI 10.1097/IJG.0000000000001183
View details for PubMedID 30624390
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Darkroom prone provocative testing in primary angle closure suspects and those with open angles.
The British journal of ophthalmology
2019
Abstract
To describe the results of darkroom prone provocative testing (DRPPT) in primary angle closure suspects (PACS) and to compare the findings to controls with open angles.889 subjects with PACS in the Zhongshan Angle Closure Prevention Trial (a randomised controlled trial to compare prophylactic laser iridotomy to no treatment in PACS) and 89 with open angles in the 5-year follow-up of Liwan Eye Study were placed in a darkroom face down for 15 min. Intraocular pressure (IOP) was measured immediately before and after DRPPT.PACS participants were of similar age than controls (59.3 vs 60.5), more often female (82.9% vs 58.4%) and had lower IOP (14.3 vs 15.2 mm Hg). The average IOP increases after DRPPT was 4.3±3 mm Hg in PACS and 5.2±2.8 in controls (p<0.05). 20.5% of controls and 13.9 % of those with PACS developed an IOP spike ≥8 mm Hg after DRPPT (p<0.05). Among PACS, 15.8 % of those with all four quadrants closed had an IOP elevation of ≥ 8 mm Hg as opposed to 10.0%-12.4 % with two or three closed quadrants (p<0.05). DRPPT failed to predict who would reach a clinical trial endpoint over 6-year follow-up of those with PACS.A modified DRPPT failed to separate PACS from those with open angle. Although the test resulted in greater IOP elevation among those PACS participants with all four quadrants closed than in those with two or three closed quadrants, it did not offer any insight into the risk of developing acute or chronic angle closure disease over 6-year follow-up.
View details for DOI 10.1136/bjophthalmol-2018-313362
View details for PubMedID 30819689
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Prevalence of eye disease and reading difficulty in an inner city elementary school population - Preliminary results from the Baltimore Reading and Eye Disease Study (BREDS)
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016
View details for Web of Science ID 000394174003361
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The relationship between quantitative pupillometry and estimated ganglion cell counts in patients with glaucoma
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016
View details for Web of Science ID 000394210202182
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Results From a Modified Bleb Needling Procedure With Continuous Infusion Performed in the Operating Room.
Journal of glaucoma
2016; 25 (9): 720–26
Abstract
Needling of a scarred trabeculectomy bleb is often performed in the office using a slit-lamp microscope as an alternative to additional surgery to lower intraocular pressure (IOP). However, the success rate in an office setting is highly variable, with reported success rates as low as 13%. We report a retrospective assessment of an intraoperative needling technique for reviving failed blebs.A retrospective chart review.Patients undergoing the intraoperative modified bleb revision technique in the setting of a failed trabeculectomy due to scarring at the Wilmer Eye Institute, Johns Hopkins Hospital between August 16, 2010 and August 29, 2012.Patients with uncontrolled IOP were operated on using a modified bleb needling technique. In this technique, a 25-G infusion cannula is placed in the anterior chamber and fibrotic adhesions within the bleb are lysed with a 25-G needle. The continuous infusion of balanced salt solution from the anterior chamber causes bleb elevation, which helps to guide the endpoint of lysis for the procedure. A subconjunctival injection of 5-fluorouracil is given at the conclusion of each case.IOP reduction and number of glaucoma medications at postoperative day 1, week 1, month 1, month 3, month 6, and month 12.A total of 33 eyes of 30 patients were included. At the visit before the procedure, the mean (±SD) IOP was 22.1±9.2 (range, 11 to 58) and subjects were using an average of 2.3±1.4 (range, 0 to 4) glaucoma medications. The mean IOP reduction was 8.7 mm Hg [95% confidence interval (CI), 5.6-11.8] at postoperative day 1, 8.1 mm Hg (95% CI, 4.0-12.3) at week 1, 8.9 mm Hg (95% CI, 5.3-12.5) at month 1, 8.1 mm Hg (95% CI, 4.2-12.0) at month 3, 8.2 mm Hg (95% CI, 3.9-12.5) at month 6, and 6.2 mm Hg (95% CI, 3.6-8.7) at month 12. IOP was reduced about 30% to 40% compared with baseline at each time point (P<0.05). The average reduction in medications used was 1.7 at day 1, 1.0 at month 1, 1.2 at month 3, 1.5 at month 6, and 0.5 at month 12. Seven patients underwent repeat needling. Overall, 64% of subjects maintained IOP at or below their target after 12 months.A modified bleb needling procedure performed in the operating room can successfully lower IOP in the setting of a previous trabeculectomy in over 60% of subjects a year after the procedure.
View details for DOI 10.1097/IJG.0000000000000511
View details for PubMedID 27552502
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Parameter Estimation of Fractional-Order Chaotic Systems by Using Quantum Parallel Particle Swarm Optimization Algorithm
PLOS ONE
2015; 10 (1): e0114910
Abstract
Parameter estimation for fractional-order chaotic systems is an important issue in fractional-order chaotic control and synchronization and could be essentially formulated as a multidimensional optimization problem. A novel algorithm called quantum parallel particle swarm optimization (QPPSO) is proposed to solve the parameter estimation for fractional-order chaotic systems. The parallel characteristic of quantum computing is used in QPPSO. This characteristic increases the calculation of each generation exponentially. The behavior of particles in quantum space is restrained by the quantum evolution equation, which consists of the current rotation angle, individual optimal quantum rotation angle, and global optimal quantum rotation angle. Numerical simulation based on several typical fractional-order systems and comparisons with some typical existing algorithms show the effectiveness and efficiency of the proposed algorithm.
View details for DOI 10.1371/journal.pone.0114910
View details for Web of Science ID 000348203500006
View details for PubMedID 25603158
View details for PubMedCentralID PMC4300217
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The Association between Near Work Activities and Myopia in Children-A Systematic Review and Meta-Analysis.
PloS one
2015; 10 (10): e0140419
Abstract
Myopia has a multifactorial etiology, although environmental factors are predominant in determining its current patterns. Currently, associations between near work activities and myopia have not been consistently observed. Therefore, we performed a systematic review to quantify the effect of near work activities on myopia in children. Relevant articles published between 1989 and 2014 were identified in MEDLINE, Embase, and the Cochrane Library, and the citation lists were reviewed. Twelve cohort studies and 15 cross-sectional studies were included (25,025 children aged between 6 and 18 years). The I2 statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model or a fixed-effects model (when less than 5 studies were included). We found that more time spent on near work activities was associated with higher odds of myopia (odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.08-1.20) and that the odds of myopia increased by 2% (OR:1.02; 95% CI = 1.01-1.03) for every one diopter-hour (hr) more of near work per week. Therefore, the development of a strategy to reduce the impact of near work on myopia would be important for preventing myopia in children.
View details for DOI 10.1371/journal.pone.0140419
View details for PubMedID 26485393
View details for PubMedCentralID PMC4618477
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Longitudinal changes of angle configuration in primary angle-closure suspects: the Zhongshan Angle-Closure Prevention Trial.
Ophthalmology
2014; 121 (9): 1699–1705
Abstract
To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes.Longitudinal cohort study.Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial.Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI.Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images.No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8-1.6) in treated eyes and 1.6°/year (95% CI, 1.3-2.0) in untreated eyes (P<0.001).Angle width of treated eyes increased markedly after LPI, remained stable for 6 months, and then decreased significantly by 18 months after LPI. Untreated eyes experienced a more consistent and rapid decrease in angle width over the same time period.
View details for DOI 10.1016/j.ophtha.2014.03.039
View details for PubMedID 24835757
View details for PubMedCentralID PMC4624262
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Assessment of a rapid method to determine approximate visual acuity in large surveys and other such settings.
American journal of ophthalmology
2014; 157 (6): 1315–21.e1
Abstract
To evaluate the efficacy of an iPod application developed to rapidly measure approximate visual acuity (VA).Prospective, cross-sectional study.One hundred four subjects (104 eyes) with a wide range of VA underwent both Early Treatment Diabetic Retinopathy Study (ETDRS) VA testing and iPod application testing. The application presented 4 randomized ETDRS letters at the Snellen equivalent of 20/40 and 20/200 each. In separate analyses, sensitivity and specificity of the iPod test were determined using the ETDRS VA testing results as the gold standard and defining "failure" to see as identifying 1, 2, 3, or all 4 letters incorrectly out of 4 trials. The minimum number of iPod trials necessary to maintain high accuracy was determined by defining a "failure" as getting the first, first 2, first 3, or all trial letters incorrect. In 13 subjects, the time necessary to perform the testing was determined.Forty-six subjects had an ETDRS Snellen equivalent VA ≥20/40; 45 had a VA <20/40 and ≥20/200; and 13 had a VA <20/200. The mean ± SD testing time for the 3 groups was 43 ± 13, 60 ± 15, and 72 ± 25 seconds, respectively. The highest sensitivity and specificity combination was observed when a "failure" was defined as getting all letters incorrect for both the 20/40 (sensitivity = 98.3%/specificity = 93.5%) and 20/200 (sensitivity/specificity both 92.3%) cutoffs.An iPod application requiring about a 1-minute testing time provides an objective, portable, rapid, and low-cost method to determine approximate VA, allowing VA testing to be performed efficiently in large surveys and other settings where approximate VA should be measured.
View details for DOI 10.1016/j.ajo.2014.02.031
View details for PubMedID 24548874
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Electronic monitoring to assess adherence with once-daily glaucoma medications and risk factors for nonadherence: the automated dosing reminder study.
JAMA ophthalmology
2014; 132 (7): 838–44
Abstract
Adherence with topical glaucoma medications is low in some patients. To identify these patients, we need more information on risk factors for nonadherence.To assess adherence with once-daily glaucoma medication.Prospective cohort study involving patients who were recruited from a university-based glaucoma clinic and treated with once-daily prostaglandin eyedrops. Baseline characteristics were recorded, and each patient was provided a medication bottle to hold his or her eyedrop bottle throughout the study. An electronic cap recorded each time the larger bottle holding the eyedrops was opened. Participants were administered standardized tests of depression and mental status and answered questions about their health and their attitudes toward medication adherence. They used the electronic monitors for 3 months, during which their adherence with medications was assessed.Adherence with daily glaucoma medication and factors associated with poor adherence.Of the 491 participants enrolled, 407 (82.9%) successfully completed the 3-month adherence assessment. Of this group, 337 (82.8%) took their medication correctly on at least 75% of days and were deemed adherent. Compared with this adherent group, the 70 participants (17.2%) who were nonadherent were slightly younger, were more likely to be of African descent, took medications for a shorter time, had a lower level of educational attainment, and had worse scores on mental status and depression scales (P < .05 for all). Nonadherent participants were less likely to be able to name their glaucoma medications, reported a lower estimate of adherence, and were more likely to admit some missed doses over the past 2 weeks or in general (P < .05 for all). Those who were nonadherent were also less likely to agree that remembering their eyedrops is easy, more likely to strongly agree with the statement that eyedrops can cause problems, and less likely to agree that they followed physicians' orders.Electronic monitoring of patient adherence documented that a sizable number of patients with glaucoma do not take their medications as prescribed. Factors were identified that may prove useful in targeting those nonadherent patients for interventions.
View details for DOI 10.1001/jamaophthalmol.2014.856
View details for PubMedID 24830878
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Automated telecommunication-based reminders and adherence with once-daily glaucoma medication dosing: the automated dosing reminder study.
JAMA ophthalmology
2014; 132 (7): 845–50
Abstract
Topical glaucoma medications lower intraocular pressure and alter the course of the disease. Because adherence with glaucoma medications is a known problem, interventions are needed to help those patients who do not take their medications as prescribed.To assess the ability of an automated telecommunication-based intervention to improve adherence with glaucoma medications.We performed a prospective cohort study of medication adherence, followed by a randomized intervention for those found to be nonadherent, of individuals recruited from a university-based glaucoma subspecialty clinic. A total of 491 participants were enrolled in the initial assessment of adherence. Of those, 70 were nonadherent with their medications after 3 months of electronic monitoring and randomized to intervention and control groups.A personal health record was used to store the list of patient medications and reminder preferences. On the basis of those data, participants randomized to the intervention received daily messages, either text or voice, reminding them to take their medication. Participants randomized to the control group received usual care.Difference in adherence before and after initiation of the intervention.Using an intent-to-treat analysis, we found that the median adherence rate in the 38 participants randomized to the intervention increased from 53% to 64% (P < .05). There was no statistical change in 32 participants in the control group. To assess the real efficacy of the intervention, the same comparison was performed for the participants who successfully completed the study after randomization. Analyzed this way, the adherence rate in the 20 participants in the intervention group increased from 54% to 73% (P < .05), whereas there was again no statistical change in the 19 participants in the control group. Eighty-four percent of the participants who received reminders agreed they were helpful and would continue using them outside the study.Automated telecommunication-based reminders linked to data in a personal health record improved adherence with once-daily glaucoma medications. This is an effective method to improve adherence that could realistically be implemented in ophthalmology practices with a minimum amount of effort on the part of the practice or the patient.
View details for DOI 10.1001/jamaophthalmol.2014.857
View details for PubMedID 24831037
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Symmetry of the Pupillary Light Reflex and its Relationship to Retinal Nerve Fiber Layer Thickness and Visual Field Defect in Subjects With and Without Glaucoma
ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2013
View details for Web of Science ID 000436232705153
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Development and validation of an associative model for the detection of glaucoma using pupillography.
American journal of ophthalmology
2013; 156 (6): 1285–96.e2
Abstract
To develop and validate an associative model using pupillography that best discriminates those with and without glaucoma.A prospective case-control study.We enrolled 148 patients with glaucoma (mean age 67 ± 11) and 71 controls (mean age 60 ± 10) in a clinical setting. This prototype pupillometer is designed to record and analyze pupillary responses at multiple, controlled stimulus intensities while using varied stimulus patterns and colors. We evaluated three approaches: (1) comparing the responses between the two eyes; (2) comparing responses to stimuli between the superonasal and inferonasal fields within each eye; and (3) calculating the absolute pupil response of each individual eye. Associative models were developed using stepwise regression or forward selection with Akaike information criterion and validated by fivefold cross-validation. We assessed the associative model using sensitivity, specificity and the area-under-the-receiver operating characteristic curve.Persons with glaucoma had more asymmetric pupil responses in the two eyes (P < 0.001); between superonasal and inferonasal visual field within the same eye (P = 0.014); and smaller amplitudes, slower velocities and longer latencies of pupil responses compared to controls (all P < 0.001). A model including age and these three components resulted in an area-under-the-receiver operating characteristic curve of 0.87 (95% CI 0.83 to 0.92) with 80% sensitivity and specificity in detecting glaucoma. This result remained robust after cross-validation.Using pupillography, we were able to discriminate among persons with glaucoma and those with normal eye examinations. With refinement, pupil testing may provide a simple approach for glaucoma screening.
View details for DOI 10.1016/j.ajo.2013.07.026
View details for PubMedID 24011523
View details for PubMedCentralID PMC3880829
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Accuracy of pupil assessment for the detection of glaucoma: a systematic review and meta-analysis.
Ophthalmology
2013; 120 (11): 2217–25
Abstract
To assess the accuracy of using pupillary light reflex (PLR) in detecting glaucoma.Glaucoma is a specific disease of the optic nerve and is often more severe in 1 eye. When large enough, this asymmetry in disease severity can cause a relative afferent pupillary defect (RAPD). Better detection of RAPDs may be one way to identify persons with glaucoma.We searched Medline and Embase through June 2012 and searched bibliographies for relevant studies for additional references. Two authors independently reviewed all articles and selected studies that assessed PLRs in patients with glaucoma. We analyzed data using mixed-effect bivariate summary receiver operating characteristic meta-analysis models.A total of 30 studies were included in this review. An RAPD was observed in 9% to 82% of patients with glaucoma. Eleven studies with a total of 7271 participants were included in the analysis, and the pooled estimate corresponded to a sensitivity of 0.63 (95% confidence interval [CI], 0.43-0.80) and a specificity of 0.93 (95% CI, 0.85-0.97). After excluding 2 studies that used the swinging flashlight test, the sensitivity increased to 0.74 (95% CI, 0.59-0.85) with a specificity of 0.85 (95% CI, 0.77-0.90). Study designs and different pupil measurement techniques explained part of the heterogeneity between studies.Patients with glaucoma frequently have an abnormal PLR and comparing the responses between the 2 eyes can in part distinguish between those with glaucoma and those without the disease. Newer instruments and analytic approaches to assess pupil function may improve the performance of pupil screening.
View details for DOI 10.1016/j.ophtha.2013.04.012
View details for PubMedID 23809274
View details for PubMedCentralID PMC3818414
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Development and validation of a predictive model for nonadherence with once-daily glaucoma medications.
Ophthalmology
2013; 120 (7): 1396–1402
Abstract
To develop and validate a predictive model to estimate the probability of being nonadherent to topical glaucoma medications.Prospective cohort study.Patients being treated with once-daily prostaglandin eye drops.A predictive model for nonadherence was developed from the Travatan Dosing Aid (TDA) study (n = 196) using stepwise logistic regression. The performance of the TDA-derived model was assessed using a separate cohort of subjects from the Automated Dosing Reminder Study (ADRS; n = 407). The assessment was based on regression coefficients, discrimination, and calibration. We also developed a scoring system from the TDA-derived model to simplify the estimation of risk for clinical use.Usage of drops was monitored electronically for 3 months in both studies. Adherence was calculated as the percentage of days on which a dose was taken within 4 hours of the average dosing time for that patient. Nonadherence was defined as taking ≤ 75% prescribed doses within a window starting 2 weeks after the baseline visit until 2 weeks before the follow-up visit.Six factors, including younger age, black race, worse general health status, shorter duration of glaucoma medication therapy, lower self-reported adherence, and admitting to not following doctors' orders, were associated with being nonadherent and were included in the predictive model. The coefficients for the TDA-derived and the ADRS-derived predictive models were similar. The risk scoring system developed from the TDA study had good discrimination (area under the receiver operating characteristic curve of 0.80) and calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.102) when applied to the ADRS population.The TDA-derived predictive model for nonadherence performed well in an independent population. A risk scoring system was developed using demographic data and patient responses to 4 questions to provide an estimate of the probability of being nonadherent.
View details for DOI 10.1016/j.ophtha.2013.01.002
View details for PubMedID 23541760
View details for PubMedCentralID PMC4016983
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Development and validation of a predictive model for nonadherence with once-daily glaucoma medications.
Ophthalmology
2013; 120 (7): 1396–1402
Abstract
To develop and validate a predictive model to estimate the probability of being nonadherent to topical glaucoma medications.Prospective cohort study.Patients being treated with once-daily prostaglandin eye drops.A predictive model for nonadherence was developed from the Travatan Dosing Aid (TDA) study (n = 196) using stepwise logistic regression. The performance of the TDA-derived model was assessed using a separate cohort of subjects from the Automated Dosing Reminder Study (ADRS; n = 407). The assessment was based on regression coefficients, discrimination, and calibration. We also developed a scoring system from the TDA-derived model to simplify the estimation of risk for clinical use.Usage of drops was monitored electronically for 3 months in both studies. Adherence was calculated as the percentage of days on which a dose was taken within 4 hours of the average dosing time for that patient. Nonadherence was defined as taking ≤ 75% prescribed doses within a window starting 2 weeks after the baseline visit until 2 weeks before the follow-up visit.Six factors, including younger age, black race, worse general health status, shorter duration of glaucoma medication therapy, lower self-reported adherence, and admitting to not following doctors' orders, were associated with being nonadherent and were included in the predictive model. The coefficients for the TDA-derived and the ADRS-derived predictive models were similar. The risk scoring system developed from the TDA study had good discrimination (area under the receiver operating characteristic curve of 0.80) and calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.102) when applied to the ADRS population.The TDA-derived predictive model for nonadherence performed well in an independent population. A risk scoring system was developed using demographic data and patient responses to 4 questions to provide an estimate of the probability of being nonadherent.
View details for DOI 10.1016/j.ophtha.2013.01.002
View details for PubMedID 23541760
View details for PubMedCentralID PMC4016983
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Early lens extraction compared to standard treatment in acute primary angle closure.
The Cochrane database of systematic reviews
2012; 11
Abstract
This is the protocol for a review and there is no abstract. The objectives are as follows: To compare the efficacy as well as harms of early lens extraction versus standard treatment in patients with acute primary angle closure.
View details for DOI 10.1002/14651858.CD010220
View details for PubMedID 25152692
View details for PubMedCentralID PMC4139041
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Inequities in Cataract Surgery and Postsurgical Quality-of-Life Outcomes in Handan, China.
Asia-Pacific journal of ophthalmology (Philadelphia, Pa.)
2012; 1 (3): 147–51
Abstract
This study aimed to describe the rate of cataract surgical coverage (CSC) and the quality-of-life (QoL) outcomes after cataract surgery in rural China.Cross-sectional study.A clustered, random sampling procedure was used to select 7557 Chinese patients aged 30 years and older from Handan, China. Comprehensive eye examinations, including standardized refraction and classification of lens characteristics, were offered to all eligible subjects. Visual impairment was defined as any individual with presenting visual acuity of less than 20/60 in the better-seeing eye. The main outcome measures were CSC rate and a summary measure assessing QoL in visually impaired (VI) participants.Of 5592 participants older than 40 years, there were 41 cataract patients operated on and 54 VI cataract patients not operated on. The CSC rate among individuals with VI was 43.2%. Older age was significantly negatively associated with a history of cataract surgery (adjusted odds ratio, 0.44 per 10-year increase in age; 95% confidence interval, 0.26-0.74). Women were less likely to have had cataract surgery compared with men, although not significantly (adjusted odds ratio, 0.44; 95% confidence interval, 0.17-1.12). The QoL summary measure was significantly better in the cataract group operated on than that not operated on (P < 0.01).There is a large unmet need for cataract surgery in rural Handan, China. Those who had surgery were more likely to have better QoL outcomes than those who did not. There is a potential need to promote cataract surgery and develop age- and sex-sensitive interventions in rural China.
View details for DOI 10.1097/APO.0b013e3182531e89
View details for PubMedID 24163787
View details for PubMedCentralID PMC3806141
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Immediate changes in intraocular pressure after laser peripheral iridotomy in primary angle-closure suspects.
Ophthalmology
2012; 119 (2): 283–88
Abstract
To determine the immediate changes in intraocular pressure (IOP) after laser peripheral iridotomy in primary angle-closure suspects.Prospective, randomized controlled trial (split-body design).Seven hundred thirty-four Chinese people 50 to 70 years of age.Primary angle-closure suspects underwent iridotomy using a neodymium:yttrium-aluminum-garnet laser in 1 randomly selected eye, with the fellow eye serving as a control. Intraocular pressure was measured using Goldmann applanation tonometry before treatment and 1 hour and 2 weeks after treatment. Total energy used and complications were recorded. Risk factors for IOP rise after laser peripheral iridotomy were investigated.Intraocular pressure.The proportion of treated eyes with an IOP spike (an elevation of ≥8 mmHg more than baseline) at 1 hour and 2 weeks after treatment was 9.8% (95% confidence interval [CI], 7.7-12.0) and 0.82% (95% CI, 0.2-1.5), respectively. Only 4 (0.54%) of 734 eyes (95% CI, 0.01-1.08) had an immediate posttreatment IOP of 30 mmHg or more and needed medical intervention. The average IOP 1 hour after treatment was 17.5±4.7 mmHg in the treated eyes, as compared with 15.2±2.6 mmHg in controls. At 2 weeks after treatment, these values were 15.6±3.4 mmHg in treated eyes and 15.1±2.7 mmHg in controls (P<0.001). No significant difference was detected in the baseline IOP of the treated and untreated eyes. Logistic regression showed that the incidence of IOP spike was associated with greater laser energy used and shallower central anterior chamber.Laser peripheral iridotomy in primary angle-closure suspects resulted in significant IOP rise in 9.8% and 0.82% of cases at 1 hour and 2 weeks, respectively. Eyes in which more laser energy and a higher number of laser pulses were used and those with shallower central anterior chambers were at increased risk for IOP spikes at 1 hour after laser peripheral iridotomy.
View details for DOI 10.1016/j.ophtha.2011.08.014
View details for PubMedID 22036632
View details for PubMedCentralID PMC3570569
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Comparing approaches to screening for angle closure in older Chinese adults.
Eye (London, England)
2012; 26 (1): 96-100
Abstract
Primary angle-closure glaucoma is expected to account for nearly 50% of bilateral glaucoma blindness by 2020. This study was conducted to assess the performance of the scanning peripheral anterior chamber depth analyzer (SPAC) and limbal anterior chamber depth (LACD) as screening methods for angle closure.This study assessed two clinical populations to compare SPAC, LACD, and gonioscopy: the Zhongshan Angle-closure Prevention Trial, from which 370 patients were eligible as closed-angle participants and the Liwan Eye Study, from which 72 patients were selected as open-angle controls. Eligible participants were assessed by SPAC, LACD, and gonioscopy.Angle status was defined by gonioscopy. Area under the receiver operating characteristic curve (AUROC) for SPAC was 0.92 (0.89-0.95) whereas AUROC for LACD was 0.94 (0.92-0.97). Using conventional cutoff points, sensitivity/specificity was 93.0%/70.8% for SPAC and 94.1%/87.5% for LACD. Sequential testing using both SPAC and LACD increased the specificity to 94.4% and decreased the sensitivity to 87.0%.SPAC has significantly lower specificity than LACD measurement using conventional cutoffs but interpretation of the findings can be performed by modestly trained personnel.
View details for DOI 10.1038/eye.2011.244
View details for PubMedID 21997356
View details for PubMedCentralID PMC3259582
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Prevalence and characteristics of primary angle-closure diseases in a rural adult Chinese population: the Handan Eye Study.
Investigative ophthalmology & visual science
2011; 52 (12): 8672–79
Abstract
To investigate the prevalence and characteristics of primary angle-closure suspect (PACS), primary angle closure (PAC), and primary angle-closure glaucoma (PACG) in a rural population in China.In all, 6716 Han Chinese 30 years of age and older (5480 subjects 40 years of age and older) from 13 villages in Handan were randomly selected and completed an ophthalmologic examination, including visual acuity, intraocular pressure (IOP), slit-lamp examination, gonioscopy and stereoscopic photography, and visual field. PACS was defined as present if either eye had the posterior trabecular meshwork not visible for 180° or more on gonioscopy. PAC was present in an eye with PACS and peripheral anterior synechiae (PAS) and/or IOP ≥ 21 mm Hg, but without glaucomatous neuropathy (GON). PACG was defined as PAC with evidence of GON.The standardized prevalences of PACG, PAC, and PACS were 0.5% (95% confidence interval [CI]: 0.3-0.7%), 1.5% (95% CI: 1.2-1.8%), and 10.4% (95% CI: 9.6-11.2%) in those 40 years of age and older. The prevalence of all three conditions increased with age (P < 0.001). Females had much higher rates of PACS, PAC, and PACG (P < 0.05); 21 persons with PACG (65%) were blind in at least one eye: 13 were due to glaucoma and the other 8 likely had other causes.The prevalence of PACS, PAC, and PACG in this rural population is similar to what was previously reported in urban Chinese residents. Two thirds of those with PACG were blind in at least one eye. Strategies to detect and treat this preventable disease in rural China are needed.
View details for DOI 10.1167/iovs.11-7480
View details for PubMedID 21908580
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Prevalence of primary open angle glaucoma in a rural adult Chinese population: the Handan eye study.
Investigative ophthalmology & visual science
2011; 52 (11): 8250–57
Abstract
To estimate the prevalence and associations of primary open angle glaucoma (POAG) in a rural population of northern China.In a rural county in Handan, China, 6716 adults residing in 13 villages were randomly selected and participated in the study. All participants completed a comprehensive eye examination, including intraocular pressure (IOP), slit-lamp examination, and fundus evaluation. Visual fields were obtained with on glaucoma suspects.Sixty-five persons (1.2%) had POAG, with an adjusted prevalence of 1.0% (95% confidence interval [CI], 0.7% -1.3%) in those aged 40 years and older. Sex was not significantly associated with POAG (P > 0.05). Age (odds ratio [OR], 1.9; 95% CI, 1.4-2.5, for each 10-year increase), IOP (OR, 1.5; 95% CI 1.2-2.0 for each 5-mm Hg increase), axial length (OR, 1.3; 95% CI, 1.1-1.6), and moderate myopia (3.1-6.0 D; OR, 4.7; 95% CI, 1.6-13.5) increased the risk for POAG in multivariate analysis. The mean IOP of persons with POAG was 16.3 ± 3.5 mm Hg, and 90% of them presented with an IOP ≤ 21 mm Hg. Of those with POAG, 4.5% were blind from glaucoma in at least one eye.Approximately 1% of adults aged 40 years and older living in rural China have POAG. As seen in other populations, increasing age, higher IOP, greater axial length, and having myopia were associated with POAG. Given the rapid aging and myopic shift (acquired myopia) in China's population, POAG is likely to increase in prevalence in the coming decades.
View details for DOI 10.1167/iovs.11-7472
View details for PubMedID 21896871
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A population-based assessment of 24-hour intraocular pressure among subjects with primary open-angle glaucoma: the handan eye study.
Investigative ophthalmology & visual science
2011; 52 (11): 7817–21
Abstract
To describe the distribution of the 24-hour intraocular pressure (IOP) among subjects with primary open-angle glaucoma (POAG) in a population-based study in north China.All untreated POAG patients (n = 66) identified in the Handan Eye Study were invited to attend a follow-up study in which IOP was tested with a Goldmann applanation tonometer at 10 AM, 2 PM, 6 PM, 10 PM, 2 AM, and 6 AM.Forty-seven subjects with untreated POAG (47/66; 71.2%) attended the study. Of them, 39 (83.0%) had a peak IOP ≤ 21 mm Hg. The peak IOP (mean ± SD) was 18.4 ± 3.7 mm Hg. Peak IOP occurred in early morning in approximately 76.5% of the subjects (6 AM to 10 AM), and the trough occurred during night time in 70.2% of the subjects (10 PM to 2 AM). The 24-hour IOP (mean ± SD) was 15.4 ± 3.1 mm Hg and the mean fluctuation was 6.0 ± 2.2 mm Hg (range, 2-11 mm Hg). In the 22 persons with unilateral glaucoma, no significant differences were found in mean 24-hour IOP, peak IOP, trough IOP, or IOP fluctuation when comparing the glaucomatous eye with the nonglaucomatous eye (P > 0.05).About 80% of Chinese persons with POAG identified in a population-based study had maximum IOPs of 21 mm Hg or less over a 24-hour period. Twenty-four-hour IOP was similar between glaucomatous and contralateral nonglaucomatous eyes suggesting that factors other than IOP may play a role in the development of glaucomatous optic neuropathy in these eyes.
View details for DOI 10.1167/iovs.11-7528
View details for PubMedID 21873661
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Choroidal thickness measured by spectral domain optical coherence tomography: factors affecting thickness in glaucoma patients.
Ophthalmology
2011; 118 (8): 1571–79
Abstract
To measure choroidal thickness and to determine parameters associated with it.Cross-sectional study.Seventy-four glaucoma patients and glaucoma suspects.Spectral domain optical coherence tomography (SD-OCT) scans were obtained to estimate average choroidal thickness in a group of glaucoma suspects and glaucoma patients. The average thickness was calculated from enhanced depth SD-OCT images and manually analyzed with Image J software. Open-angle glaucoma, open-angle glaucoma suspect, primary angle-closure glaucoma, primary angle closure, and primary angle-closure suspect were defined by published criteria. Glaucoma suspects had normal visual fields bilaterally. Glaucoma was defined by specific criteria for optic disc damage and visual field loss in ≥1 eye. The most affected eye was analyzed for comparisons across individuals, and right/left and upper half/lower half comparisons were made to compare thickness against degree of visual field damage.Average macular and peripapillary choroidal thickness measured using SD-OCT.The choroidal-scleral interface was visualized in 86% and 96% of the macular and peripapillary scans, respectively. In multivariable linear regression analysis, the macular choroid was significantly thinner in association with 4 features: Longer eyes (22 μm per mm longer [95% confidence interval (CI), -33, -11]), older individuals (31 μm thinner per decade older [95% CI, -44, -17]), lower diastolic ocular perfusion pressure (26 μm thinner per 10 mmHg lower [95% CI, 8, 44]), and thicker central corneas (6 μm per 10 μm thicker cornea [95% CI, -10, 0]). The choroid was not significantly thinner in glaucoma patients than in suspects (14 μm [95% CI, -54, 26]; P = 0.5). Peripapillary choroidal thickness was not significantly different between glaucoma and suspect patients. Thickness was not associated with damage severity as estimated by visual field mean deviation or nerve fiber layer thickness, including comparisons of right with left eye or upper with lower values.Age, axial length, CCT, and diastolic ocular perfusion pressure are significantly associated with choroidal thickness in glaucoma suspects and glaucoma patients. Degree of glaucoma damage was not consistently associated with choroidal thickness.Proprietary or commercial disclosure may be found after the references.
View details for DOI 10.1016/j.ophtha.2011.01.016
View details for PubMedID 21492939
View details for PubMedCentralID PMC3139809
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Single versus sequential testing with scanning peripheral anterior chamber depth analyser, IOLMaster and anterior segment optical coherence tomography for the detection of narrow angles.
The British journal of ophthalmology
2011; 95 (10): 1410–14
Abstract
Scanning peripheral anterior chamber depth analyser (SPAC), IOLMaster and anterior segment optical coherence tomography (AS-OCT) are devices that can screen non-invasively for narrow angles (NAs) and may reduce the need for gonioscopy, especially where the availability of ophthalmologists is limited. When used individually to detect NAs, neither SPAC, AS-OCT nor IOLMaster were able to achieve both high sensitivity and specificity when using gonioscopy as a gold standard.To assess whether sequential testing improves discrimination of NAs over single testing.In a prospective community-based cross-sectional study in Singapore, 2047 phakic right eyes underwent SPAC, IOLMaster and AS-OCT. NA eyes were defined as present when Shaffer scores were 0 or 1 in ≥ 2 quadrants on gonioscopy. Sensitivities and specificities of single and sequential testing were compared.At a fixed specificity of 95%, sensitivities in detecting NA eyes were 57.8% (95% CI 52.7% to 62.7%) for SPAC, 43.3% (95% CI 38.3% to 48.3%) for IOLMaster and 52.1% (95% CI 46.4% to 57.7%) for AS-OCT. After sequential testing using SPAC followed by AS-OCT, the sensitivity rose to 70.3% (95% CI 65.5% to 74.8%) while specificity remained at 94.3% (95% CI 93.1% to 95.4%), with sensitivity significantly higher than single testing alone (p<0.001).Sequential testing significantly improves the accuracy of detecting NAs and may be useful in screening settings.
View details for DOI 10.1136/bjo.2009.175869
View details for PubMedID 21242582