Amblyopia Treatment Study Research Articles

ON-Pathway visual acuity deficits in 8-12 years old children with unilateral amblyopia.

The purpose of this article is to give an overview of amblyopia management practices to the reader so that they can incorporate the same in their clinical practice, based on evidence provided by the clinical studies and our clinical experience. A literature search was performed on the Paediatric Eye Disease Investigation Group (PEDIG) website for amblyopia treatment studies (ATS) and its related publications in PubMed. We have included the conclusions of PEDIG-ATS study and our experiences based on pediatric ophthalmology clinical practice in a tertiary eye hospital in India. PEDIG-ATS study has caused a paradigm shift in amblyopia treatment, offering an evidence-based sequential approach. Refractive correction is the first step, followed by part-time occlusion and penalization. All other modes are used as adjuvant therapy. It is important to give maintenance therapy to prevent the recurrence of successfully treated amblyopia.

National survey of amblyopia treatment in Japan: comparison with amblyopia treatment study results of the pediatric eye disease investigator group.

PurposeTo determine if visual acuity (VA) outcomes are comparable using the amblyopia treatment study HOTV protocol (ATS-HOTV) and electronic Early Treatment of Diabetic Retinopathy Study (E-ETDRS) protocol in children with optic pathway gliomas (OPGs).MethodsChildren enrolled in a prospective study of OPGs were eligible if they completed both the ATS-HOTV and E-ETDRS during the same visit. The contribution of age, testing order, having neurofibromatosis type 1, visual field loss, and circumpapillary retinal nerve fiber layer thickness to VA difference were assessed using generalized estimating equations to account for the intereye correlation.ResultsForty-eight children (median age, 10.3 years; range, 5.2–17.1 years; 49% female) met inclusion criteria and contributed 93 study eyes at their initial visit. Eleven patients (22 eyes) had more than one study visit, permitting longitudinal evaluation. ATS-HOTV measures of VA were higher than E-ETDRS at the initial (0.13 ± 0.36 vs. 0.23 ± 0.39 logarithm of the minimum angle of resolution [logMAR], P < 0.001) and all visits (0.13 ± 0.34 vs. 0.21 ± 0.36 logMAR, P < 0.001). VA remained significantly higher with ATS-HOTV regardless of test order, but the mean difference between tests was most profound when tested with ATS-HOTV first compared to E-ETDRS first (P < 0.001).ConclusionsVA results differ significantly between the ATS-HOTV and E-ETDRS testing methods in children with OPGs. Given the wide range of ages and testing ability of children, one VA testing method should be used throughout longitudinal OPG clinical trials.Translational RelevanceIt is imperative that age-appropriate VA testing methods are standardized across all pediatric OPG clinical trials.

BackgroundAmblyopia, as a neurodevelopmental preventable visual disorder, affects approximately 1.1 % in Asia. A binocular approach to treating amblyopia has been recently proposed. Whether the binocular playing game treatment is comparable to patching treatment needs further randomized clinical trials. To address this, the present research, designs, develops, and evaluates a new binocular game to treat amblyopia.MethodsThis study has been designed as a non-inferiority, randomized, two parallel-group, controlled trial. Forty-four patients between 4 and 12 years diagnosed with amblyopia will be randomly assigned to the control and intervention groups. In the intervention group, amblyopia treatment is provided with red-green anaglyphic glasses and a red filter placed in front of the amblyopic eye, along with a game to be played for 30 min twice a day. Those in the control group will receive patch therapy according to amblyopia treatment study protocol. The primary outcome is to change visual acuity in the amblyopic eye from the baseline to 3 months after randomization.Ethics and disseminationThe Ethics Committee of Mashhad University of Medical sciences’ approval date was February 28, 2018, with a reference code of IR.MUMS.fm.REC.1396.783. Thus far, the recruitment of participants has not been completed and is scheduled to end in September 2021. The results will be disseminated in a peer-reviewed journal.Trial registrationIranian Registry of Clinical Trials IRCT20180217038768N1. Registered on 22 April 2019.

Teleophthalmology: Evaluation of Phone-based Visual Acuity in a Pediatric Population

PurposeTo determine change in visual acuity (VA) in the population of a previous amblyopia treatment study (Loudon 2006) and assess risk factors for VA decrease.MethodsSubjects treated between 2001 and 2003 were contacted between December 2015 and July 2017. Orthoptic examination was conducted under controlled circumstances and included subjective refraction, best corrected VA, reading acuity, binocular vision, retinal fixation, cover‐uncover and alternating cover test. As a measure for degree of amblyopia, InterOcular VA Difference (IOD) at the end of occlusion therapy was compared with IOD at the follow‐up examination using Wilcoxon’s signed‐rank test. Regression analysis was conducted to determine the influence of clinical and socio‐economic factors on changes in IOD.ResultsOut of 303 subjects from the original study, 208 were contacted successfully, 59 refused and 15 were excluded because of non‐amblyopic cause of visual impairment. Mean IOD at end of therapy (mean age 6.4 years) was 0.11 ± 0.16 logMAR, and IOD at follow‐up examination (mean age 18.3 years) was 0.09 ± 0.21 logMAR; this difference was not significant (p = 0.054). Degree of anisometropia (p = 0.008; univariable analysis), increasing anisometropia (p = 0.009; multivariable), eccentric fixation (p < 0.001; univariable and multivariable); large IOD (p < 0.001; univariable and multivariable) and non‐compliance during therapy (p = 0.028; univariable) were associated with IOD increase.ConclusionLong‐term results of occlusion therapy were good. High or increasing anisometropia, eccentric fixation and non‐compliance during occlusion therapy were associated with long‐term VA decrease. Subjects with poor initial VA had a larger increase despite little patching, but often showed long‐term VA decrease.

Treatment outcomes for amblyopia using PEDIG amblyopia protocols: a retrospective study of 877 cases

Correlation of monocular grating acuity at age 12 months with recognition acuity at age 4.5 years: findings from the Infant Aphakia Treatment Study

Visual acuity and contrast sensitivity screening with a new iPad application

Background: Amblyopia is considered as one of the most prevalent vision problems in pediatrics age (1-5%). Recently, new methods in amblyopia treatment were reported in Amblyopia Treatment Study (ATS’).The objective of this study was to recognize amblyopia treatment knowledge of Iranian ophthalmologists and optometrists which are responsible for amblyopia treatment in our and other countries.Materials and Methods: This cross sectional study was performed during the Iranian Society of Ophthalmology annual meeting in Tehran in 2012 through questionnaire containing demographic information and 20 closed-answer questions based on ATS results. The questions were classified into seven categories and the sum of correct scores was 100. Optometrists and pediatric ophthalmologists were considered as the group 1 (153 participants), other practitioners (general ophthalmologists and other subspecialists) were regarded as the group 2 (256 participants). Criteria for inadequate, fair and good knowledge were considered by scores of 70 respectively.Results: Overall, 409 out of a total of 600 questionnaires were completed (response rate: 68.1%). Mean scores of the group 1 were significantly higher than the group 2 in all 7 categories of questions and in 5 of them the differences were statistically significant. The worst and best scores were related to prescription of atropine (12%) and visual acuity improvement with glasses alone (93%), respectively. Scores for other questions were about 50%. There was no relationship between practice status and the number of referral amblyopic cases per week with the level of knowledge. In all categories except prescription of Atropine and recurrence, mean scores of females were more than the male participants.Conclusion: knowledge about amblyopia therapy seems to be overall inadequate and should be improved by more education. We suggest paying more attention to new modified methods of amblyopia treatment and increased discussion of such method in annual and CME meetings.

To identify patient baseline characteristics that predict recognition acuity at 4.5 years of age in the Infant Aphakia Treatment Study, a study of patients with monocular infantile cataracts. We analyzed baseline characteristics of the 114 infants enrolled in the Infant Aphakia Treatment Study to determine which were most predictive of visual outcome at 4.5 years of age. All infants underwent cataract surgery between 1 and 7 months of age. Monocular acuity was assessed at 4.5 years of age by a traveling examiner using the Amblyopia Treatment Study HOTV protocol. Age at cataract surgery was weakly associated with visual acuity (Spearman rank correlation coefficient = 0.19, P = 0.041) with median visual acuity better among the younger patients (28-48 days: 0.50 logMAR, 49-210 days: 1.10 logMAR, P = 0.046). Patients from families with private insurance had significantly better median visual acuity (0.60 vs. 1.40 logMAR, P = 0.0004). No other baseline characteristic revealed a significant bivariate relationship with visual acuity. A multiple linear regression relating visual acuity to all baseline characteristics demonstrated that only the availability of private insurance was statistically significant, accounting for 12% of the variance. This analysis concurs with previous studies that early surgery is important for good visual outcomes in patients with unilateral infantile cataracts. The fact that only one baseline variable (private insurance) contributed to the multivariate analysis, accounting for 12% of the variance, suggests that predicting visual outcome for these patients is complicated at best, and cannot be estimated from baseline characteristics alone. (ClinicalTrials.gov number, NCT00212134.).

Validation of iPad-based simplified visual acuity testing in children

The Handy Eye Check: a mobile medical application to test visual acuity in children

To provide population-based normative visual acuity (VA) by age, in children participating in the Sydney Paediatric Eye Disease Study aged 6 to <72 months. Monocular VA was measured using the Amblyopia Treatment Study (ATS HOTV) protocol (24 to <72 months). Some children were also tested using linear ETDRS or HOTV logMAR VA charts (30 to <72 months). If unable to perform recognition acuity, the Teller Acuity Cards II (TAC II) was performed (6 to <42 months). Children with significant refractive error or ocular disease were excluded. Improvement in VA with age was shown on all three vision tests (all p < 0.0001). Mean VA using ATS HOTV (n = 836) was 0.13 logMAR (6/8) at <36 months, which improved to -0.01 (6/6) at 66 to <72 months. Mean ETDRS/HOTV (n = 399) VA was 0.26 logMAR (6/11) at <36 months, which improved to 0.1 (6/7.5) at 66 to <72 months. Mean monocular TAC II (n = 442) was 5.7 cycles/degree (0.72 logMAR) at 6 to <9 months and improved to 12.4 cycles/degree (0.38 logMAR) at age 30 to <33 months. Associations with ATS HOTV VA included prematurity (p = 0.027) and socio economic status (SES) factors such as home ownership (p = 0.039) and employment of one (p = 0.019) or both parents (p = 0.003). VA norms in children improved with age and were different according to the VA test used. Low SES was associated with poorer VA, supporting the need for test specific VA norms to be established for different populations. The ATS HOTV appears to be the best test to use for vision screening due to its lower false positive referral rate.

OBJECTIVES. To review the results of patching for amblyopia management in Hong Kong. DESIGN. Retrospective case series. SETTING. Regional hospital, Hong Kong. PATIENTS. Records of all patients attending Paediatric Ophthalmology Clinic at United Christian Hospital, Hong Kong from 1 January 2009 to 31 March 2009 were retrospectively reviewed. Records of all children who underwent patching for amblyopia in the study period were evaluated. RESULTS. The mean age of 50 children (50 eyes) was 4 (standard deviation, 1; range, 2-7) years and mean pretreatment visual acuity was 0.35 (0.15; 0.02-0.63) [~20/60]. The values for mean, standard deviation, and range of treatment duration were 27, 16, 4-67 months respectively, and corresponding values for prescribed patching per day were 4, 1, 2-8 hours. The mean, standard deviation, and range of visual acuity at final post-treatment assessment were 0.66, 0.16, 0.1-1.0 (~20/30), respectively. The overall success rate (ie final visual acuity >0.7 or 20/30) was 62%. Children with moderate amblyopia (20/40-20/80) and severe amblyopia (20/100-20/400) had success rates of 74% and 55%, respectively. The mean visual acuity improvements for moderate and severely amblyopic children were 2.3 lines and 5.8 lines, respectively. The mean, standard deviation, and range of patching prescriptions for moderate and severely amblyopic children were 5, 1, 2-7 hours and 5, 1, 3-6 hours, respectively. Recurrence ensued in 7% of the children with moderate amblyopia and 46% of those with severe amblyopia. Reported compliance was good (>75% of the time) in 68% of the children. CONCLUSION. Occlusion therapy is the mainstay of treatment in Hong Kong. The overall success rate was comparable to that achieved in the Amblyopia Treatment Study. Recurrence was more common in patients with severe amblyopia, for whom maintenance therapy may reduce the risk of recurrence. The duration of treatment was much longer in our locality than in western countries. Reported compliance was suspicious possibly due to traditional cultural contexts. It is important to emphasise compliance to all parents.

Lessons learned from the Amblyopia Treatment Studies

Amblyopia comes from the Greek word meaning dull sight or blunt sight. Amblyopia occurs to abnormal visual experience early in life. It can be both unilateral (U/L) and/or bilateral (B/L). Amblyopia itself produces no change in the appearance of ocular structures, but it nearly always develops in association with some other condition that is evident on physical examination, and which is responsible for abnormal visual experience. It is one of the most common causes of visual impairment in childhood. Unless it is successfully treated in early childhood, amblyopia usually persists into adulthood. In 1997, the pediatric eye disease investigator group (PEDIG) was formed to conduct clinical research in eye disorders affecting children. The studies were conducted through simple protocols with limited data collection and implemented by both university and community based pediatric eye care practitioners as part of their routine practice in USA. Hence PEDIG has laid emphasis on studies of treatment modalities of amblyopia, the Amblyopia Treatment Studies (ATS). The recent general guidelines for occlusion therapy are based on ongoing ATS. New concepts of management on amblyopia are practiced now- a-days based on ATS. This article is an update on amblyopia and its management. Nepal Journal of Medical Sciences | Volume 02 | Number 01 | Jan-Jun 2013 | Page 66-72 DOI: http://dx.doi.org/10.3126/njms.v2i1.7656

Longitudinal ophthalmologic clinical trials in young children require multiple visual acuity (VA) testing methods-especially when the subjects have cognitive and developmental delay. This study evaluated the success rate and comparability of two different VA testing methods in children with neurofibromatosis type 1 (NF1) and/or optic pathway gliomas (OPGs). Two institutions prospectively enrolled children 10 years or younger with NF1 and/or an OPG. Both Teller grating acuity (TAC) and recognition acuity using the computerized version of the Amblyopia Treatment Study VA testing protocol that limits responses to four letters (H, O, T, or V) were attempted in all subjects. The association of age and diagnosis of NF1 on success rate was analyzed. Differences in grating and recognition acuity were compared. One hundred twenty-seven children met inclusion criteria (median age = 5.58 years). Of 127 subjects, 11 (8.7%) could not complete monocular TAC testing in either eye; 39 (30.7%) could not complete HOTV testing and were younger than those able to complete HOTV testing (mean = 2.9 vs. 7.0 years, respectively; Z = -8.3, P < 0.01). Older age was associated with successful HOTV testing and remained significant in all regression analyses (P < 0.01). The within-subject logMAR values for TAC and HOTV testing results were significantly correlated (r = 0.69, P < 0.01). Young children with NF1 and/or OPGs were frequently unable to complete recognition acuity testing. These factors are important to consider when designing a clinical trial for children with NF1 and/or OPGs.

To establish standardised protocols for vision screening, testability and comparability of three different vision tests were examined in a population-based, cross-sectional sample of preschool children (Sydney Paediatric Eye Disease Study). Measurement of presenting monocular distance visual acuity (VA) using the Amblyopia Treatment Study (ATS) HOTV protocol, was attempted by all (1774) children aged≥24 months. In addition, in children aged≥60 months (576), VA was also tested using the logMAR retro-illuminated HOTV or Early Treatment Diabetic Retinopathy Study (ETDRS) linear charts (CSV 1000). Children able to have both eyes tested monocularly were considered. Testability significantly increased with age for all VA tests. The ATS HOTV with an overall testability of 80% (females: 82%, males: 78%) was the most testable of the VA tests (P<0.0001). In children aged <3 years testability was low (≤47%) rising to≥80% in children aged≥3. In children≥60 months, testability was higher for the HOTV (94%) than the ETDRS (59%) chart. In those that did two VA tests, mean difference of the ATS HOTV compared with the HOTV(CSV) was -0.1, and compared with ETDRS was -0.12 (P<0.0001). Children aged <3 years had poor VA testability, whereas those 3 years and above were highly testable using the ATS HOTV. The HOTV (CSV) retro-illuminated test was appropriate for children aged >5 years, and may be possible in younger children with early educational exposure. When comparing VA measures using these tests, the higher VA attained using the ATS HOTV, needs to be taken into account.