Vivian Manh, OD, MS

All Publications

• Testability and test-retest reliability of SpotChecks Contrast Sensitivity Test in children with unilateral amblyopia. Optometry and vision science : official publication of the American Academy of Optometry Manh, V. M., Wu, R., Gray, M. E., Cheung, N. L., Cotter, S. A., Erickson, J. W., Fisher, J. H., Galvin, J. A., Gunton, K. B., Jastrzembski, B. G., Raghuram, A., Burgher, A. P., Whitfield, K. O., Beaulieu, W. T., Kraker, R. T., Weise, K. K., Pineles, S. L., Holmes, J. M. 2026; 103 (5): e70058

  Abstract

  To report testability and test-retest reliability of the SpotChecks contrast sensitivity (CS) test in amblyopic and nonamblyopic eyes of children with unilateral amblyopia.Children aged 3-12 years with unilateral amblyopia due to strabismus and/or anisometropia were recruited as part of a randomized trial. SpotChecks was administered twice in the left eye at 8 weeks post-randomization. This single-use paper test has a measurable CS threshold range of 0.90 to 2.09 logCS (24 lines, 1 line = 0.05 logCS). Testability was defined as the completion of a pre-test. Bland-Altman analysis was used to evaluate test-retest reliability.In children aged 3-6 years, 81% (117/145) passed the pre-test: 17 of 34 (50%) 3-year-olds, 39 of 46 (85%) 4-year-olds, 33 of 37 (89%) 5-year-olds, and 28 of 28 (100%) 6-year-olds. Fifty-four of 117 (46%) who passed the pre-test had matching test pairs for analysis. In children aged 7-12 years, all 45 passed the pre-test. Twenty-two of 45 (49%) who passed the pre-test had matching test pairs for analysis. Among 76 test-retest pairs (40 amblyopic and 36 nonamblyopic eyes), the mean difference (95% CI) was 0.01 (-0.02 to 0.03) logCS and the half-width of the 95% limits of agreement was ±0.20 (0.16-0.24) logCS. Results were similar between amblyopic and nonamblyopic eyes, as well as within age cohorts.Children aged 6-12 years were more likely to be testable. Regardless of age, half of all test-retest pairs were completed incorrectly, possibly due to examiner or participant-related factors. A greater than 4-line (0.20 logCS) change on the SpotChecks contrast sensitivity test is required to detect a change in contrast sensitivity function beyond measurement error in children 3-12 years of age with unilateral amblyopia.Clinicaltrials.Gov, registered 14 July 2022, NCT05462821.

  View details for DOI 10.1002/ovs2.70058

  View details for PubMedID 42173804

  View details for PubMedCentralID PMC13215206

• At-home visual acuity in children using a custom iPhone application compared with standardized in-office visual acuity testing. Optometry and vision science : official publication of the American Academy of Optometry Roberts, T. L., Bothun, E. D., Zhu, Y., Henderson, R. J., Boyle, N. M., Leske, D. A., Hatt, S. R., Wernimont, S. M., Marino, C. E., Raghuram, A., Manh, V. M., Youngerman, J. M., Qayum, J. N., Srinivasan, G., Titelbaum, J. R., Crouch, E. R., Colburn, J. D., Esposito, C. A., Zeto, V. L., Connolly, K. S., Bhakta, R. M., Lorenzana, I. J., McDowell, P. S., Beaulieu, W. T., Kraker, R. T., Holmes, J. M., Pineles, S. L., Weise, K. K., Cotter, S. A. 2026; 103 (4): e70040

  Abstract

  To validate a custom smartphone application for at-home visual acuity (VA) measurement in children.A total of 452 children aged 3-17.5 years participated. Certified examiners measured in-office test-retest VA (logMAR) using gold-standard Amblyopia Treatment Study HOTV (3-to-6-year-olds, younger cohort) or electronic Early Treatment of Diabetic Retinopathy Study (7-to-17.5-year-olds, older cohort) protocols at 3-4.5 m and app-based VA at 1.5 m. Caregivers measured at-home app-based VA at 1.5 m.Comparing at-home app-based with gold-standard VA, in eyes 20/40 or better, 95% (143/151) and 93% (91/98) of the younger and older cohorts were within 2 lines, respectively (mean differences: younger = -0.03, older = -0.04; 95% limits-of-agreement half-width (LOA): younger = ±0.26, older = ±0.22). In eyes 20/50 or worse, 66% (42/64) and 75% (76/101) of the younger and older cohorts were within 2 lines, respectively (mean differences: younger = 0.11, older = 0.13, LOA: younger = ±0.50, older = ±0.51). Comparing in-office app-based VA with gold-standard VA, in eyes 20/40 or better, 98% (160/164) and 94% (99/105) of the younger and older cohorts were within 2 lines, respectively (mean differences: younger = -0.03, older = -0.03; LOA: younger = ±0.22; older = ±0.24). In eyes 20/50 or worse, 85% (60/71) and 91% (101/111) of the younger and older cohorts were within 2 lines, respectively (mean differences: younger = 0.04; older = 0.04; LOA: younger = ±0.39; older = ±0.24). For gold-standard test-retest, in eyes 20/40 or better, 99% (163/164) and 99% (104/105) of the younger and older cohorts had retest within 2 lines, respectively (mean differences: younger = 0.00; older = 0.01; LOA: younger = ±0.17; older = ±0.11). For 20/50 or worse, 92% (66/72) and 100% (111/111) in the younger and older cohorts were within 2 lines, respectively (mean differences: younger = 0.01; older = 0.02; LOA: younger = ±0.35; older = ±0.15).Our app demonstrated good concordance with the gold standard at home and in the office for eyes with VA of 20/40 or better. However, concordance decreased considerably for eyes with VA 20/50 or worse, particularly at home.

  View details for DOI 10.1002/ovs2.70040

  View details for PubMedID 42062237

• Association Between Visual Acuity and Cycloplegic Refractive Error in 3- to <10-Year-Old Children. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Haensel, J. X., Chen, A. M., Raghuram, A., Manh, V. M., Cotter, S. A., Jones-Jordan, L. A., Han, S., Lorenzana, I., Huang, K., Patel, R., Lytle, A. A., Retnasothie, D., Roberts, T. L. 2026

  Abstract

  Distance visual acuity (VA) has been associated with refractive error in older children, but less is known about children <6 years of age and those without a history of refractive correction. This study examined the utility of VA testing and its relationship to refractive error in children aged 3 to <10 years without a history of refractive correction.Unaided monocular distance VA testing was performed at 3 m (age 3-6 years: ATS-HOTV chart; 7-<10 years: E-ETDRS chart) and near VA at 40 cm (ATS-4 Near VA). Cycloplegic autorefraction was used to categorise participants as myopic (sphere ≤ -0.75 dioptres (D)), hyperopic (sphere ≥2 D), astigmatic (cylinder ≥1.50 D) and emmetropic (< 0.75 D myopia and <2 D hyperopia). Receiver operating characteristic curves assessed the utility of VA testing in classifying children by refractive error type. Linear regressions examined the predictive value of refractive error magnitude in determining distance and near VA while accounting for age.Of 358 children, 84 (23.5%) had hyperopia, 30 (8.4%) myopia, 39 (10.9%) astigmatism and 229 (64.0%) emmetropia. Reduced distance VA was associated with myopia (area under the curve (AUC) = 91%, optimal cut-off = 0.15 logMAR) and astigmatism (AUC = 87%, cut-off = 0.25 logMAR), but not hyperopia (AUC = 63%, cut-off = 0.05 logMAR). Near VA showed only mildly higher performance for hyperopia (AUC = 70%, cut-off = 0.15 logMAR). For every 0.36 D increase in myopia, distance VA declined by 0.10 logMAR (p < 0.001). Distance and near VA were not predicted by the magnitude of hyperopia (distance: p = 0.30; near: p = 0.30) or astigmatism (distance: p = 0.35; near: p = 0.06).In children 3 to <10 years of age without prior refractive correction, reduced distance VA was associated with myopia and astigmatism, but not hyperopia; an incremental decline in VA with increasing refractive error magnitude was seen only in myopia.

  View details for DOI 10.1007/s44402-026-00051-1

  View details for PubMedID 41811682

  View details for PubMedCentralID 5109705

• Accommodative responses in children with high and low levels of astigmatism. Optometry and vision science : official publication of the American Academy of Optometry Haensel, J. X., Chen, A. M., Cotter, S. A., Raghuram, A., Manh, V. M., Han, S., Jones-Jordan, L. A., Lorenzana, I., Huang, K., Patel, R., Lytle, A. A., Retnasothie, D., Roberts, T. L. 2025

  Abstract

  Children with uncorrected astigmatism are often assumed to accommodate to the circle of least confusion. However, empirical evidence in children without a history of refractive correction is lacking. This study found that most children accommodate toward the anterior focal plane, with both focal planes exhibiting a lag of accommodation.To examine accommodative responses by measuring refractive states of the eye during near viewing in children with uncorrected astigmatism without a history of refractive correction.Participants aged 3 to <10 years with no history of refractive correction monocularly viewed a 20/250 letter at a 3-D demand (33 cm) while accommodative responses were measured using open-field autorefraction. Responses were classified based on the focal plane closest to the stimulus: anterior or posterior focal plane, or circle of least confusion. Cycloplegic autorefraction was used to classify participants as having low astigmatism (≤1.50 D) or high astigmatism (>1.50 D). Participants were further subdivided as having hyperopia (≥2.00 D), myopia (≥0.75 D), or emmetropia (less than 0.75 D myopia and 2.00 D hyperopia) based on their spherical cycloplegic refractive error. Chi-square analyses and Fisher exact tests were used to assess the association between accommodative response and cycloplegic refractive error classification.Of the 352 participants, 316 (89.8%) had low astigmatism and 36 (10.2%) had high astigmatism. In both groups, significantly more participants were classified as being focused at the anterior focal plane (low: 98.7%; high: 83.3%) than the posterior focal plane (low: 0.6%; high: 0.0%) or circle of least confusion (low: 0.6%; high: 16.7%; p<0.001). Almost all nonhyperopic participants in the low astigmatism group (99.2%) and hyperopic participants irrespective of astigmatism magnitude (low: 100%; high: 95.2%) accommodated closer to the anterior focal plane with accommodative lags in both meridians. Most nonhyperopic participants with high astigmatism also accommodated to the anterior focal plane (66.7%) and a third to the circle of least confusion (33.3%).In contrast to the assumption that children with astigmatism accommodate to the circle of least confusion, our findings show that most children accommodated to the anterior focal plane during near-viewing tasks, with accommodative lags in both meridians.

  View details for DOI 10.1097/OPX.0000000000002286

  View details for PubMedID 40833971

• Optical correction of hyperopia in school-aged children: a scoping review protocol. BMJ open Srinivasan, G., Kerber, K. L., Liu, S. H., Manh, V. M., Huang, K., Williamson, A., Sadhu, S., Ollinger, M. C., Tajbakhsh, Z., Fisher, J. H., Cheung, N. L., Junge, J., Chan, K. C., Hussaindeen, J. R., Simard, P., Trast, K. R., Morettin, C. E., Krueger, S., Nti, A. N., Lee Chen, D. M., Roberts, T. L. 2025; 15 (8): e103546

  Abstract

  Prescribing patterns for hyperopia in children vary widely among eye care providers worldwide. This scoping review aims to identify and map the current literature on optical correction and catalogue outcomes reported, particularly in the domains of vision, vision-related functional outcomes and quality of life (QoL) in school-aged children with hyperopia.This protocol was developed in accordance with the Joanna Briggs Institute's Manual for Evidence Synthesis. We will include studies involving school-aged children with hyperopia without restrictions on sex, gender, race, ethnicity, type of optical correction, length of intervention, publication date or country of origin. We will include studies with internal or external comparison groups. We will exclude studies associated with myopia control treatments, ocular and visual pathway pathologies affecting vision or visual function. We will search Cochrane CENTRAL, Embase.com and PubMed. Examples of data to be extracted include population demographics, visual acuity, study-specific definitions for refractive error, treatment regimens for optical correction, vision and vision-related functional outcomes and QoL (general or vision-related) as quantified by validated instruments.Informed consent and Institutional Review Board approval will not be required, as this scoping review will only use published data. The results from the scoping review will be disseminated by publication in a peer-reviewed scientific journal and at professional conferences.

  View details for DOI 10.1136/bmjopen-2025-103546

  View details for PubMedID 40819922

• Vergence and accommodation responses in the control of intermittent exotropia. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Mestre, C., Neupane, S., Manh, V., Tarczy-Hornoch, K., Candy, T. R. 2023; 43 (4): 598-614

  Abstract

  Individuals with different types of intermittent exotropia (IXT) may use neurally coupled accommodation and vergence responses differently from those without exotropia to achieve eye alignment. This study examined the relationship between simultaneously recorded accommodation and vergence responses in children and young adults with a range of types of IXT while aligned and deviated.Responses of 29 participants with IXT (4-31 years) and 24 age-matched controls were recorded using simultaneous eye-tracking and eccentric photorefraction while they watched a movie in binocular or monocular viewing at varying viewing distances. Gradient response AC/A ratios and fusional vergence ranges were also assessed. Eight participants had divergence or pseudo-divergence excess type IXT, 5 had convergence insufficiency and 16 had basic IXT.Control and IXT participants accommodated similarly both in monocular and binocular-aligned conditions to visual targets at 80 and 33 cm. When deviated in binocular viewing, most participants with IXT exhibited changes in accommodation <0.5D relative to alignment. Gradient response AC/A ratios were similar for control [0.56 MA/D (IQR: 0.51 MA/D)] and IXT participants [0.42 MA/D (0.54 MA/D); p  = 0.60]. IXT participants showed larger vergence to accommodation ratios with changes from distance to near fixation [1.19 MA/D (1.45 MA/D)] than control participants [0.78 MA/D (0.60 MA/D); p = 0.02], especially among IXT participants with divergence or pseudo-divergence excess. Participants with IXT exhibited typical fusional divergence ranges beyond their dissociated position [8.86 Δ (7.10 Δ)] and typical fusional convergence ranges from alignment [18 Δ (15.75 Δ)].This study suggests that control of IXT is typically neither driven by accommodative convergence alone nor associated with over-accommodation secondary to fusional convergence efforts. These simultaneous measurements confirmed that proximal vergence contributed significantly to IXT control, particularly for divergence or pseudo-divergence excess type IXT. For IXT participants in this study, achieving eye alignment did not conflict with having clear vision.

  View details for DOI 10.1111/opo.13093

  View details for PubMedID 36692334

  View details for PubMedCentralID PMC10973920

• Establishing Prescribing Guidelines in School-Based Eye Health Programs in Children Aged 11 to 15 Years-The Conundrum of Cost vs Benefit. JAMA ophthalmology Manh, V. 2019; 137 (4): 415-416

  View details for DOI 10.1001/jamaophthalmol.2018.6900

  View details for PubMedID 30703194

• Longitudinal Evaluation of Accommodation During Treatment for Unilateral Amblyopia. Investigative ophthalmology & visual science Chen, A. M., Manh, V., Candy, T. R. 2018; 59 (5): 2187-2196

  Abstract

  Retinal image quality is dependent on accommodative performance. This longitudinal observational study of children with unilateral amblyopia evaluated the accommodative performance of the amblyopic eye during treatment.Twenty-six participants with unilateral amblyopia and 10 participants with typical vision aged 3 to 10 years participated. Accommodative response was measured using modified Nott retinoscopy in monocular and binocular viewing conditions for target distances of 50, 33, and 25 cm, at enrollment and each follow-up visit.Participants with amblyopia accommodated less accurately when viewing with their amblyopic eye in monocular than in binocular conditions. Over the course of amblyopia treatment, accommodative performance improved with amblyopic eye visual acuity (VA) improvement, although this was not consistent across individual participants. A linear mixed model showed that accommodative error worsened with increasing depth of amblyopia for monocular viewing with the amblyopic eye (0.14 diopter [D] per line of acuity loss, P = 0.001), with an interaction between VA and stimulus demand (0.09 D of additional lag per diopter of stimulus, per line of acuity loss, P < 0.001). Participant age, patching duration, length of time in the study, history of strabismus, and stereoacuity were not significant predictors of accommodative performance.Overall, poor monocular accommodative performance of the amblyopic eye was associated with worse amblyopia and improved simultaneously with VA improvement, although there was variability across the study cohort. Further research is needed to determine the causal relationship between amblyopic eye VA and accommodation and its impact on amblyopia treatment.

  View details for DOI 10.1167/iovs.17-22990

  View details for PubMedID 29801152

  View details for PubMedCentralID PMC5916545

• A Randomized Trial of a Binocular iPad Game Versus Part-Time Patching in Children Aged 13 to 16 Years With Amblyopia. American journal of ophthalmology Manh, V. M., Holmes, J. M., Lazar, E. L., Kraker, R. T., Wallace, D. K., Kulp, M. T., Galvin, J. A., Shah, B. K., Davis, P. L. 2018; 186: 104-115

  Abstract

  To compare visual acuity (VA) improvement in teenagers with amblyopia treated with a binocular iPad game vs part-time patching.One hundred participants aged 13 to <17 years (mean 14.3 years) with amblyopia (20/40 to 20/200, mean ∼20/63) resulting from strabismus, anisometropia, or both were enrolled into a randomized clinical trial. Participants were randomly assigned to treatment for 16 weeks of either a binocular iPad game prescribed for 1 hour per day (n = 40) or patching of the fellow eye prescribed for 2 hours per day (n = 60). The main outcome measure was change in amblyopic eye VA from baseline to 16 weeks.Mean amblyopic eye VA improved from baseline by 3.5 letters (2-sided 95% confidence interval [CI]: 1.3-5.7 letters) in the binocular group and by 6.5 letters (2-sided 95% CI: 4.4-8.5 letters) in the patching group. After adjusting for baseline VA, the difference between the binocular and patching groups was -2.7 letters (95% CI: -5.7 to 0.3 letters, P = .082) or 0.5 lines, favoring patching. In the binocular group, treatment adherence data from the iPad device indicated that only 13% of participants completed >75% of prescribed treatment.In teenagers aged 13 to <17 years, improvement in amblyopic eye VA with the binocular iPad game used in this study was not found to be better than patching, and was possibly worse. Nevertheless, it remains unclear whether the minimal treatment response to binocular treatment was owing to poor treatment adherence or lack of treatment effect.

  View details for DOI 10.1016/j.ajo.2017.11.017

  View details for PubMedID 29196184

  View details for PubMedCentralID PMC6206863

• Novel findings of left ventricular non-compaction cardiomyopathy, microform cleft lip and poor vision in patient with SMC1A-associated Cornelia de Lange syndrome. American journal of medical genetics. Part A Wenger, T. L., Chow, P., Randle, S. C., Rosen, A., Birgfeld, C., Wrede, J., Javid, P., King, D., Manh, V., Hing, A. V., Albers, E. 2017; 173 (2): 414-420

  Abstract

  Relatively few patients with Cornelia de Lange syndrome (CdLS) due to SMC1A mutation have been reported, limiting understanding of the full extent of the phenotype. Compared to children with classic NIPBL-associated CdLS, patients with SMC1A-associated CdLS have a milder physical phenotype with prominent intellectual disability, high rate of cleft palate and absence of limb reductions. We present a patient with SMC1A-associated CdLS who had typical features including developmental delay, seizure disorder, feeding difficulties, hirsutism, and cleft palate. She also was found to have three novel features: (i) left ventricular non-compaction (LVNC) cardiomyopathy; (ii) microform cleft lip; and (iii) severe hyperopia and astigmatism. These features have implications regarding potential insight into the pathogenesis of the disorder, screening, and medical management. Hypertrophic cardiomyopathy has previously been reported in SMC1A-associated CdLS, but to our knowledge this is the first reported child with LVNC. Previous reports have included children with isolated clefts of the palate without involvement of the lip. When cleft palate alone is associated with a disorder, the underlying pathophysiology for clefting is sometimes secondary due to mechanical blocking of the fusion of the palatal shelves with the developing tongue. The presence of microform cleft lip in this patient suggests that the pathophysiology of clefting in SMC1A is primary rather than secondary. Few studies report ophthalmologic findings specific to SMC1A. Based on these findings, LVNC cardiomyopathy and cleft lip should be considered features of SMC1A-associated CdLS. All patients should receive echocardiogram and undergo thorough ophthalmologic evaluation as part of routine CdLS care. © 2016 Wiley Periodicals, Inc.

  View details for DOI 10.1002/ajmg.a.38030

  View details for PubMedID 28102598

• Effect of a Binocular iPad Game vs Part-time Patching in Children Aged 5 to 12 Years With Amblyopia: A Randomized Clinical Trial. JAMA ophthalmology Holmes, J. M., Manh, V. M., Lazar, E. L., Beck, R. W., Birch, E. E., Kraker, R. T., Crouch, E. R., Erzurum, S. A., Khuddus, N., Summers, A. I., Wallace, D. K. 2016; 134 (12): 1391-1400

  Abstract

  A binocular approach to treating anisometropic and strabismic amblyopia has recently been advocated. Initial studies have yielded promising results, suggesting that a larger randomized clinical trial is warranted.To compare visual acuity (VA) improvement in children with amblyopia treated with a binocular iPad game vs part-time patching.A multicenter, noninferiority randomized clinical trial was conducted in community and institutional practices from September 16, 2014, to August 28, 2015. Participants included 385 children aged 5 years to younger than 13 years with amblyopia (20/40 to 20/200, mean 20/63) resulting from strabismus, anisometropia, or both. Participants were randomly assigned to either 16 weeks of a binocular iPad game prescribed for 1 hour a day (190 participants; binocular group) or patching of the fellow eye prescribed for 2 hours a day (195 participants; patching group). Study follow-up visits were scheduled at 4, 8, 12, and 16 weeks. A modified intent-to-treat analysis was performed on participants who completed the 16-week trial.Binocular iPad game or patching of the fellow eye.Change in amblyopic-eye VA from baseline to 16 weeks.Of the 385 participants, 187 were female (48.6%); mean (SD) age was 8.5 (1.9) years. At 16 weeks, mean amblyopic-eye VA improved 1.05 lines (2-sided 95% CI, 0.85-1.24 lines) in the binocular group and 1.35 lines (2-sided 95% CI, 1.17-1.54 lines) in the patching group, with an adjusted treatment group difference of 0.31 lines favoring patching (upper limit of the 1-sided 95% CI, 0.53 lines). This upper limit exceeded the prespecified noninferiority limit of 0.5 lines. Only 39 of the 176 participants (22.2%) randomized to the binocular game and with log file data available performed more than 75% of the prescribed treatment (median, 46%; interquartile range, 20%-72%). In younger participants (aged 5 to <7 years) without prior amblyopia treatment, amblyopic-eye VA improved by a mean (SD) of 2.5 (1.5) lines in the binocular group and 2.8 (0.8) lines in the patching group. Adverse effects (including diplopia) were uncommon and of similar frequency between groups.In children aged 5 to younger than 13 years, amblyopic-eye VA improved with binocular game play and with patching, particularly in younger children (age 5 to <7 years) without prior amblyopia treatment. Although the primary noninferiority analysis was indeterminate, a post hoc analysis suggested that VA improvement with this particular binocular iPad treatment was not as good as with 2 hours of prescribed daily patching.http://www.clinicaltrials.gov Identifier: NCT02200211.

  View details for DOI 10.1001/jamaophthalmol.2016.4262

  View details for PubMedID 27812703

  View details for PubMedCentralID PMC5145771

• Accommodative performance of children with unilateral amblyopia. Investigative ophthalmology & visual science Manh, V., Chen, A. M., Tarczy-Hornoch, K., Cotter, S. A., Candy, T. R. 2015; 56 (2): 1193-207

  Abstract

  The purpose of this study was to compare the accommodative performance of the amblyopic eye of children with unilateral amblyopia to that of their nonamblyopic eye, and also to that of children without amblyopia, during both monocular and binocular viewing.Modified Nott retinoscopy was used to measure accommodative performance of 38 subjects with unilateral amblyopia and 25 subjects with typical vision from 3 to 13 years of age during monocular and binocular viewing at target distances of 50, 33, and 25 cm. The relationship between accommodative demand and interocular difference (IOD) in accommodative error was assessed in each group.The mean IOD in monocular accommodative error for amblyopic subjects across all three viewing distances was 0.49 diopters (D) (95% confidence interval [CI], ±1.12 D) in the 180° meridian and 0.54 D (95% CI, ±1.27 D) in the 90° meridian, with the amblyopic eye exhibiting greater accommodative errors on average. Interocular difference in monocular accommodative error increased significantly with increasing accommodative demand; 5%, 47%, and 58% of amblyopic subjects had monocular errors in the amblyopic eye that fell outside the upper 95% confidence limit for the better eye of control subjects at viewing distances of 50, 33, and 25 cm, respectively.When viewing monocularly, children with unilateral amblyopia had greater mean accommodative errors in their amblyopic eyes than in their nonamblyopic eyes, and when compared with control subjects. This could lead to unintended retinal image defocus during patching therapy for amblyopia.

  View details for DOI 10.1167/iovs.14-14948

  View details for PubMedID 25626970

  View details for PubMedCentralID PMC4334148

• Empirical variability in the calibration of slope-based eccentric photorefraction. Journal of the Optical Society of America. A, Optics, image science, and vision Bharadwaj, S. R., Sravani, N. G., Little, J. A., Narasaiah, A., Wong, V., Woodburn, R., Candy, T. R. 2013; 30 (5): 923-31

  Abstract

  Refraction estimates from eccentric infrared (IR) photorefraction depend critically on the calibration of luminance slopes in the pupil. While the intersubject variability of this calibration has been estimated, there is no systematic evaluation of its intrasubject variability. This study determined the within subject inter- and intra-session repeatability of this calibration factor and the optimum range of lenses needed to derive this value. Relative calibrations for the MCS PowerRefractor and a customized photorefractor were estimated twice within one session or across two sessions by placing trial lenses before one eye covered with an IR transmitting filter. The data were subsequently resampled with various lens combinations to determine the impact of lens power range on the calibration estimates. Mean (±1.96 SD) calibration slopes were 0.99±0.39 for North Americans with the MCS PowerRefractor (relative to its built-in value) and 0.65±0.25 Ls/D and 0.40±0.09 Ls/D for Indians and North Americans with the custom photorefractor, respectively. The ±95% limits of agreement of intrasubject variability ranged from ±0.39 to ±0.56 for the MCS PowerRefractor and ±0.03 Ls/D to ±0.04 Ls/D for the custom photorefractor. The mean differences within and across sessions were not significantly different from zero (p>0.38 for all). The combined intersubject and intrasubject variability of calibration is therefore about ±40% of the mean value, implying that significant errors in individual refraction/accommodation estimates may arise if a group-average calibration is used. Protocols containing both plus and minus lenses had calibration slopes closest to the gold-standard protocol, suggesting that they may provide the best estimate of the calibration factor compared to those containing either plus or minus lenses.

  View details for DOI 10.1364/JOSAA.30.000923

  View details for PubMedID 23695324

  View details for PubMedCentralID PMC3967915