Risk of amblyopia recurrence after cessation of treatment

Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia.Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test.Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06-0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group.Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

Efficacy of vision therapy for unilateral refractive amblyopia in children aged 7-10 years

Background

There is a critical period for visual development, conventionally considered to be the first 6 years of life. Children aged 7 years and older are significantly less responsive to amblyopia treatment. This study investigated the efficacy of binocular vision therapy in amblyopic children aged 7–10 years.

Methods

This retrospective study enrolled 36 children with unilateral amblyopia who were divided into a case group (receiving vision therapy, optical correction, and part-time patching of the weaker eye) and a control group (receiving optical correction and part-time patching of the weaker eye). Visual acuity (VA) was measured at baseline, at the 3-month, 6-month, and 9-month visits, and 3 months after cessation of treatment.

Results

There were 19 subjects in the case group and 17 subjects in the control group. Mean VA in the case group improved from 0.39 ± 0.24 logMAR at baseline to 0.10 ± 0.23 logMAR at the endpoint of treatment (p < 0.001, paired t-test). Mean VA in the control group improved from 0.64 ± 0.30 logMAR at baseline to 0.52 ± 0.27 logMAR at the endpoint of treatment (p = 0.015, paired t-test). The improvement was significantly greater in the case group than in the control group (p = 0.006, two-samples independent t-test). All subjects underwent follow-up examinations within 6 to 12 months. There was no regression of VA in the case group 3 months after cessation of vision therapy. The patients in the case group who received visual therapy were with better VA improvement then patients with only optic correction and patching.

Conclusions

Vision therapy combined with conventional treatment (optical correction and part-time patching) is more effective than conventional treatment alone in children aged 7–10 years with unilateral refractive amblyopia. The treatment results not only in greater vision gain, but also in shorter duration of treatment.

Comparison of binocular game and patching in treating mild to moderate anisometropic amblyopia: a study protocol for a randomized controlled trial

Background

Amblyopia, 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.

Methods

This 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 dissemination

The 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 registration

Iranian Registry of Clinical Trials IRCT20180217038768N1. Registered on 22 April 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05735-2.

Correction of amblyopia in cats and mice after the critical period

Monocular deprivation early in development causes amblyopia, a severe visual impairment. Prognosis is poor if therapy is initiated after an early critical period. However, clinical observations have shown that recovery from amblyopia can occur later in life when the non-deprived (fellow) eye is removed. The traditional interpretation of this finding is that vision is improved simply by the elimination of interocular suppression in primary visual cortex, revealing responses to previously subthreshold input. However, an alternative explanation is that silencing activity in the fellow eye establishes conditions in visual cortex that enable the weak connections from the amblyopic eye to gain strength, in which case the recovery would persist even if vision is restored in the fellow eye. Consistent with this idea, we show here in cats and mice that temporary inactivation of the fellow eye is sufficient to promote a full and enduring recovery from amblyopia at ages when conventional treatments fail. Thus, connections serving the amblyopic eye are capable of substantial plasticity beyond the critical period, and this potential is unleashed by reversibly silencing the fellow eye.

Long-term follow-up of an amblyopia treatment study: change in visual acuity 15 years after occlusion therapy

Purpose

To determine change in visual acuity (VA) in the population of a previous amblyopia treatment study (Loudon 2006) and assess risk factors for VA decrease.

Methods

Subjects 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.

Results

Out 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.

Conclusion

Long‐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.

Fixational eye movements abnormalities and rate of visual acuity and stereoacuity improvement with part time patching

Residual amblyopia is seen in 40% of amblyopic patients treated with part-time patching. Amblyopic patients with infantile onset strabismus or anisometropia can develop fusion maldevelopment nystagmus syndrome (FMNS). The purpose of this study was to understand the effects of presence of FMNS and clinical subtype of amblyopia on visual acuity and stereo-acuity improvement in children treated with part-time patching. Forty amblyopic children who had fixation eye movement recordings and at least 12 months of follow-up after initiating part-time patching were included. We classified amblyopic subjects per the fixational eye movements characteristics into those without any nystagmus, those with FMNS and patients with nystagmus without any structural anomalies that do not meet the criteria of FMNS or idiopathic infantile nystagmus. We also classified the patients per the clinical type of amblyopia. Patching was continued until amblyopia was resolved or no visual acuity improvement was noted at two consecutive visits. Children with anisometropic amblyopia and without FMNS have a faster improvement and plateaued sooner. Regression was only seen in patients with strabismic/mixed amblyopia particularly those with FMNS. Patients with FMNS had improvement in visual acuity but poor stereopsis with part-time patching and required longer duration of treatment.

Long-term Effect of Intraocular Lens vs Contact Lens Correction on Visual Acuity After Cataract Surgery During Infancy: A Randomized Clinical Trial

Importance

Although intraocular lenses (IOLs) are often implanted in children, little is known whether primary IOL implantation or aphakia and contact lens correction results in better long-term visual outcomes after unilateral cataract surgery during infancy.

Objective

To compare long-term visual outcomes with contact lens vs IOL correction following unilateral cataract surgery during infancy.

Design, Setting, and Participants

This multicenter randomized clinical trial enrolled 114 infants with a unilateral congenital cataract who underwent cataract surgery with or without primary IOL implantation between 1 and 6 months of age. Data on long-term visual outcomes were collected when the children were age 10.5 years (July 14, 2015, to July 12, 2019) and analyzed from March 30 through August 6, 2019.

Interventions

Intraocular lens implantation at the time of cataract surgery.

Main Outcomes and Measures

Best-corrected visual acuity using the electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) testing protocol. Analysis was performed on an intention-to-treat basis.

Results

Best-corrected visual acuity was measured at age 10.5 years for 110 of the 114 patients (96%) enrolled as infants. The participants included 58 girls (53%) and 52 boys (47%). Overall, 27 of the children (25%) had good (logMAR 0.30 [Snellen equivalent, 20/40] or better) visual acuity in the treated eye (12 [22%] in the IOL group and 15 [27%] in the aphakia group), but 50 children (44%) had a visual acuity of logMAR 1.00 (Snellen equivalent, 20/200) or worse (25 [44%] in the IOL group and 25 [44%] in the aphakia group). The median logMAR acuity in the treated eye was similar in children randomized to receive an IOL at the time of cataract extraction (0.89; interquartile range [IQR], 0.33-1.43 [Snellen equivalent, 20/159]) and those who remained aphakic (0.86; IQR, 0.30-1.46 [Snellen equivalent, 20/145]) (IQR, 0.30-1.46; P = .82). Although the overall difference in median visual acuity between the 2 groups was small, the estimate was imprecise (99% CI for the difference in medians was -0.54 to 0.47).

Conclusions and Relevance

As in previous phases of the study, visual acuity outcomes were highly variable with only 27 children (25%) achieving excellent visual acuity in their treated eye and 50 children (44%) having poor vision in the treated eye. Implanting an IOL at the time of cataract extraction was neither beneficial nor detrimental to the visual outcome.

Trial Registration

ClinicalTrials.gov Identifier: NCT00212134.

Rethinking amblyopia 2020

Recent work has transformed our ideas about the neural mechanisms, behavioral consequences and effective therapies for amblyopia. Since the 1700's, the clinical treatment for amblyopia has consisted of patching or penalizing the strong eye, to force the "lazy" amblyopic eye, to work. This treatment has generally been limited to infants and young children during a sensitive period of development. Over the last 20 years we have learned much about the nature and neural mechanisms underlying the loss of spatial and binocular vision in amblyopia, and that a degree of neural plasticity persists well beyond the sensitive period. Importantly, the last decade has seen a resurgence of research into new approaches to the treatment of amblyopia both in children and adults, which emphasize that monocular therapies may not be the most effective for the fundamentally binocular disorder that is amblyopia. These approaches include perceptual learning, video game play and binocular methods aimed at reducing inhibition of the amblyopic eye by the strong fellow eye, and enhancing binocular fusion and stereopsis. This review focuses on the what we've learned over the past 20 years or so, and will highlight both the successes of these new treatment approaches in labs around the world, and their failures in clinical trials. Reconciling these results raises important new questions that may help to focus future directions.

Looking beyond occlusion: A novel perspective for amblyopia treatment

Purpose:

The aim of this study was to evaluate the efficacy of Orthoptek (Magnocellular Stimulator OMS; Carditek Pvt. Ltd., Bangalore) as a treatment modality for amblyopia and strabismus.

Methods:

Thirty-five patients with amblyopia of any type, reduced vision in one or both eyes with no binocular vision and or poor stereopsis were included in the study. All patients underwent a minimum of 10 sessions of therapy with each session lasting for a cumulative period of 60 min. At the end of the 10^th session, patients were evaluated for improvement in visual acuity, stereopsis, Binocular single vision and amount of strabismus, if any.

Results:

The mean logMAR corrected distance visual acuity improved from 0.31 ± 0.34 and 0.32 ± 0.44 to 0.08 ± 0.12 and 0.07 ± 0.12 posttreatment in the right eye and left eye, respectively. Following therapy, 34 (97%) patients showed improvement in stereopsis, orthophoria was noticed in 28 (80%), and binocular single vision was noted in 33 (94%). All patients were followed up for 1 year with maintenance therapy and none showed any regression.

Conclusion:

We believe that top–down impulses and the role of the attention area in the parietal cortex have not been studied well enough in the treatment of amblyopia. Our device addresses these issues and corrects the visual deficits in amblyopia. However, the study needs validation of this pilot study from independent centers. The same will be done at some stage

An update on pharmacological treatment options for amblyopia

Amblyopia is a common cause of visual impairment in children and young adults. The cornerstone in the management of this disorder is based on increasing visual stimulation of the amblyopic eye by occlusion, by administering atropine or by causing optical penalization of the dominant eye. All these treatment options have shown some limits in terms of efficacy, due to the suboptimal treatment adherence for the patients and the lack of long-term clinical outcomes. Moreover, although it is well known that clinical efficacy decreases with age, new evidence is suggesting that cortical plasticity can be induced also in older children. For these reasons, new treatment options are being studied, in order to extend the "treatment window" beyond the critical period also in older patients. In this review, we will discuss all the most promising novel pharmacological agents in the management of amblyopia.

Characterization, passive and active treatment in strabismic amblyopia: a narrative review

Strabismic amblyopia is characterized by a distorted spatial perception. In this condition, the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding, deficits in the accommodative response, contrast sensitivity, and ocular motility abilities. The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity. Passive treatments such as occlusion, optical and/or pharmacological penalization, and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia. Recent researches have proved new pharmacological options to improve and maintain visual acuity after occlusion treatment in strabismic amblyopia. Likewise, the active vision therapy, in the last years, is becoming a very relevant therapeutic option in combination with passive treatments, especially during and after monocular therapy, in the attempt of recovering the imbalanced binocular vision.

Current Management of Childhood Amblyopia

Amblyopia is defined as the reduction of best-corrected visual acuity of one or both eyes caused by conditions that affect normal visual development. The basic strategy to treat amblyopia is to obtain a clear retinal image in each eye and correct ocular dominance through forced use of the amblyopic eye. Treatment modalities include correcting any underlying organic disease, prescribing appropriate optical correction, and providing occlusion/penalization therapy for the non-amblyopic eye. Given the success of amblyopia treatment declines with increasing age, the detection and management of amblyopia should begin as early as possible during the sensitive period for visual development. Proper management of amblyopia during childhood can reduce the overall prevalence and severity of visual loss. This study aims to provide an update for the management of childhood amblyopia to provide better visual outcomes.

Patching and Suppression in Amblyopia: One Mechanism or Two?

Purpose

To determine if benefits from occlusion therapy are due to decreased suppression from the fellow eye in children with amblyopia.

Methods

Ten newly diagnosed amblyopes (7.2 ± 1.4 years old), two with strabismus and eight with anisometropia, participated. Patients were first given a 2-month period of refractive adaptation, followed by occlusion therapy (i.e., patching their fellow eye with an opaque patch for 4 h/day). Visual acuity of the amblyopic eye and interocular suppression were measured before and after 0.5, 1, 2, 4, and 6 months of occlusion therapy. We quantified interocular suppression with a binocular phase combination task.

Results

Visual acuity (in logMAR) improved from 0.50 ± 0.22 (mean ± SD) to 0.33 ± 0.20 for patients who finished a short-term (2 months) occlusion (A1–A10), from 0.53 ± 0.20 to 0.32 ± 0.22 for patients who finished a medium-term (4 months) occlusion (A1–A9), and from 0.48 ± 0.19 to 0.22 ± 0.10 for patients who finished a long-term (6 months) occlusion (A1–A8). Although their visual acuity significantly improved, their degree of suppression, which was abnormal in all cases, did not change consistently. This was true in all durations of occlusion therapy.

Conclusion

Reduced suppression from the fixing eye might not be result from occlusion therapy.

Conventional occlusion versus pharmacologic penalization for amblyopia

BACKGROUND

Amblyopia is defined as impaired visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses.

OBJECTIVES

In performing this systematic review, we aimed to synthesize the best available evidence regarding the effectiveness and safety of conventional occlusion therapy compared to atropine penalization in treating amblyopia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 8); Ovid MEDLINE; Ovid Embase; LILACS BIREME; ClinicalTrials.gov; ISRCTN; and the WHO ICTRP on 7 September 2018.

SELECTION CRITERIA

We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts and full-text articles, abstracted data, and assessed risk of bias.

MAIN RESULTS

We included seven trials (five randomized controlled trials and two quasi-randomized controlled trials) conducted in six countries (China, India, Iran, Ireland, Spain, and the United States) with a total of 1177 amblyopic eyes. Three of these seven trials were from the original 2009 version of the review. We assessed two trials as having a low risk of bias across all domains, and the remaining five trials as having unclear or high risk of bias for some domains.As different occlusion modalities, atropine penalization regimens, and populations were used across the included trials, we did not conduct any meta-analysis due to clinical and statistical heterogeneity. Evidence from six trials (two at low risk of bias) suggests that atropine penalization is as effective as conventional occlusion in improving visual acuity. Similar improvement in visual acuity was reported at all time points at which it was assessed, ranging from five weeks (improvement of 1 line) to 10 years (improvement of greater than 3 lines). At six months, although most participants (363/522) come from a trial rated as at low risk of bias with a precise estimate (mean difference (MD) 0.03, 95% confidence interval (CI) 0.00 to 0.06), two other trials rated as at high risk of bias produced inconsistent estimates and wide confidence intervals (MD -0.02, 95% CI -0.11 to 0.07 and MD -0.14, 95% CI -0.23 to -0.05; moderate-certainty evidence). At 24 months, additional improvement was found in both groups, but there continued to be no meaningful difference between those receiving occlusion and those receiving atropine therapies (moderate-certainty evidence).We did not find any difference in ocular alignment, stereo acuity, or sound eye visual acuity between occlusion and atropine penalization groups (moderate-certainty evidence). Both treatments were well tolerated. Atropine was associated with better adherence (moderate-certainty evidence) and quality of life (moderate-certainty evidence), but also a higher reported risk of adverse events in terms of mild reduction in the visual acuity of the sound eye not requiring treatment and light sensitivity (high-certainty evidence). Skin, lid, or conjunctival irritation were more common among participants receiving patching than those receiving atropine (high-certainty evidence). Atropine penalization costs less than conventional occlusion.

AUTHORS' CONCLUSIONS

Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the trials we analyzed.

[Amblyopia-Basic principles and current diagnostic and therapeutic standards]

Amblyopia is a visual deficit that occurs during childhood and results in an abnormal development of the normal cortical visual pathway. It is defined as the reduction of best corrected visual acuity of one or rarely both eyes, which is not explained by structural abnormalities of the eye alone. During the sensitive period amblyopia is completely or partially reversible. The main causes of amblyopia are strabismus and refractive errors. Congenital cataracts are less common but if present may cause pronounced amblyopia. In Germany the prevalence of Amblyopia is approximately 5%, which is relatively high in relation to other countries, even though data are not completely comparable. As amblyopia can only be successfully treated during the first years of life, early detection of amblyogenic factors is important. Screening tests help in identifying children at risk of amblyopia, while only a thorough ophthalmological examination including cycloplegic refraction reliably detects all risk factors of amblyopia. Treatment consists of removal of the amblyogenic factors and stimulation of the amblyopic eye.

Inverse Occlusion: A Binocularly Motivated Treatment for Amblyopia

Recent laboratory findings suggest that short-term patching of the amblyopic eye (i.e., inverse occlusion) results in a larger and more sustained improvement in the binocular balance compared with normal controls. In this study, we investigate the cumulative effects of the short-term inverse occlusion in adults and old children with amblyopia. This is a prospective cohort study of 18 amblyopes (10-35 years old; 2 with strabismus) who have been subjected to 2 hours/day of inverse occlusion for 2 months. Patients who required refractive correction or whose refractive correction needed updating were given a 2-month period of refractive adaptation. The primary outcome measure was the binocular balance which was measured using a phase combination task; the secondary outcome measures were the best-corrected visual acuity which was measured with a Tumbling E acuity chart and converted to logMAR units and the stereoacuity which was measured with the Random-dot preschool stereogram test. The average binocular gain was 0.11 in terms of the effective contrast ratio (z = -2.344, p = 0.019, 2-tailed related samples Wilcoxon Signed Rank Test). The average acuity gain was 0.13 logMAR equivalent (t(17) = 4.76, p < 0.001, 2-tailed paired samples t-test). The average stereoacuity gain was 339 arc seconds (z = -2.533, p = 0.011). Based on more recent research concerning adult ocular dominance plasticity, we conclude that inverse occlusion in adults and old children with amblyopia does produce long-term gains to binocular balance and that acuity and stereopsis can improve in some subjects.

Effectiveness of binocularity-stimulating treatment in children with residual amblyopia following occlusion

BACKGROUND

To evaluate the effectiveness of binocularity-stimulating treatment in children with residual amblyopia following occlusion therapy for more than 6 months.

METHODS

Of patients with amblyopia caused by anisometropia and/or strabismus, patients with residual amblyopia following more than 6 months of occlusion therapy were included. Subjects underwent one of the following types of binocularity-stimulating therapy: Bangerter foil (BF), head-mounted display (HMD) game, or BF/HMD combination (BF + HMD). Factors including age, sex, types of amblyopia, visual acuity, and duration of treatment were investigated. Baseline and final (after at least 2 months of treatment) visual acuity were also compared.

RESULTS

Twenty-two patients with a mean age of 8.7 ± 1.3 years were included. Seven patients had anisometropic amblyopia, 8 patients had strabismic amblyopia, and 7 patients had combined amblyopia. After 4.4 ± 1.8 months of treatment, logarithm of the minimum angle of resolution (logMAR) visual acuity in the amblyopic eye improved from 0.22 ± 0.20 to 0.18 ± 0.15. Five of 22 patients (22.7%) gained more than 0.2 logMAR, including 1 of 10 patients (10.0%) in the BF group, 2 of 7 patients (28.6%) in the HMD group, and 2 of 5 patients (40.0%) in the BF + HMD group. No significant differences in clinical characteristics were identified among the three groups.

CONCLUSIONS

Binocularity-stimulating therapy is somewhat beneficial in children with residual amblyopia and might be attempted when children no longer benefit from sufficient long-term period of occlusion therapy.

Improved Binocular Outcomes Following Binocular Treatment for Childhood Amblyopia

Purpose

Childhood amblyopia can be treated with binocular games or movies that rebalance contrast between the eyes, which is thought to reduce depth of interocular suppression so the child can experience binocular vision. While visual acuity gains have been reported following binocular treatment, studies rarely report gains in binocular outcomes (i.e., stereoacuity, suppression) in amblyopic children. Here, we evaluated binocular outcomes in children who had received binocular treatment for childhood amblyopia.

Methods

Data for amblyopic children enrolled in two ongoing studies were pooled. The sample included 41 amblyopic children (6 strabismic, 21 anisometropic, 14 combined; age 4–10 years; ≤4 prism diopters [PD]) who received binocular treatment (20 game, 21 movies; prescribed 9–10 hours treatment). Amblyopic eye visual acuity and binocular outcomes (Randot Preschool Stereoacuity, extent of suppression, and depth of suppression) were assessed at baseline and at 2 weeks.

Results

Mean amblyopic eye visual acuity (P < 0.001) and mean stereoacuity improved (P = 0.045), and mean extent (P = 0.005) and depth of suppression (P = 0.003) were reduced from baseline at the 2-week visit (87% game adherence, 100% movie adherence). Depth of suppression was reduced more in children aged <8 years than in those aged ≥8 years (P = 0.004). Worse baseline depth of suppression was correlated with a larger depth of suppression reduction at 2 weeks (P = 0.001).

Conclusions

After 2 weeks, binocular treatment in amblyopic children improved visual acuity and binocular outcomes, reducing the extent and depth of suppression and improving stereoacuity. Binocular treatments that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia.

Improvement of visual acuity in residual meridional amblyopia by astigmatic axis video games

Purpose:

This study was carried out to evaluate the efficacy of developed “astigmatic axis video games” in children and adolescents having meridional amblyopia, with the aim to improve the visual acuity (VA). Till date, no studies are available on the treatment of amblyopic meridian. Meridional amblyopia (MA) results when astigmatism remains untreated for a long period. The aim of the study was to assess the effectiveness of a set of novel video games, the astigmatism axis video games (AAVGs), in improving the visual acuity (VA) in MA.

Methods:

We included 50 eyes with residual myopic MA (cylinder ≥2.0 and ≤4.0 D) whose VA did not improve beyond 0.3 LogMAR equivalent, despite patching for 2 h/day for the preceding 3 months. Patients were subjected to AAVG in conjunction with best-corrected glasses and patching of the better eye for 2 h/day for 3 months.

Results:

Out of 50 eyes, 32 eyes were from children between 8 and 12 years and 18 were >12 years. Full improvement of LogMAR VA up to 0.0 was seen in 36/50 (72.0%) oblique astigmatism eyes. Partial improvement of LogMAR VA at least 0.3 LogMAR or more was observed in another 7 eyes (14%) eyes. The mean VA improved from 0.43 ± 0.1 LogMAR at baseline to 0.077 ± 0.08 at 3 months (P < 0.001). Good number of eyes (n = 16, 32%) showed speedy visual improvement between 2 and 4 weeks after initiation of AAVG. No adverse effects were observed.

Conclusion:

Satisfactory improvement in VA in eyes with residual MA provides preliminary data into the effectiveness of stimulation of the precise amblyopic axis by AAVG in conjunction with spectacles and “minimal patching” regimen of 2 h/day. Further comparative study is warranted.

An action video game for the treatment of amblyopia in children: A feasibility study

The gold-standard treatment for childhood amblyopia remains patching or penalizing the fellow eye, resulting in an average of about a one line (0.1 logMAR) improvement in visual acuity following ≈120 h of patching in children 3-8 years old. However, compliance with patching and other treatment options is often poor. In contrast, fast-paced action video games can be highly engaging, and have been shown to yield broad-based improvements in vision and attention in adult amblyopia. Here, we pilot-tested a custom-made action video game to treat children with amblyopia. Twenty-one (n = 21) children (mean age 9.95 ± 3.14 [se]) with unilateral amblyopia (n = 12 anisometropic and n = 9 strabismic) completed 20 h of game play either monocularly, with the fellow eye patched (n = 11), or dichoptically, with reduced contrast to the fellow eye (n = 10). Participants were assessed for visual acuity (VA), stereo acuity and reading speed at baseline, and following 10 and 20 h of play. Additional exploratory analyses examined improvements after 6-10 weeks of completion of training (follow-up). Following 20 h of training, VA improved, on average, by 0.14 logMAR (≈38%) for the dichoptic group and by 0.06 logMAR (≈15%) for the monocular group. Similarly, stereoacuity improved by 0.07 log arcsec (≈17%) following dichoptic training, and by 0.06 log arcsec (≈15%) following monocular training. Across both treatment groups, 7 of the 12 individuals with anisometropic amblyopia showed improvement in stereoacuity, whereas only 1 of the 9 strabismic individuals improved. Most improvements were largely retained at follow-up. Our feasibility study therefore suggests that the action video game approach may be used as an effective adjunct treatment for amblyopia in children, achieving results similar to those of the gold-standard treatment in shorter duration.

The Need for a Unified Protocol for Termination of Amblyopia Treatment

Introduction:

Many authors have investigated the methodology and outcomes of amblyopia treatment. However, the evidence on termination of treatment, specifically referring to the stability of visual outcome and timing of reviewing patients after treatment ends, has received less interest with no agreement on risk factors of visual regression.

Purpose:

To study the final part of amblyopia service with particular emphasis to stability of visual outcome; efficacy and timing of follow up after treatment ends.

Methods:

A retrospective review of patients discharged following treatment for strabismic and anisometropic amblyopia. Exclusion criteria were ocular pathology, poor attendance or poor compliance. Collected data included: age at the start of treatment, type and duration of treatment, number of visits, visual acuity (at start and end). Additionally, we analysed the duration and number of visits after stopping treatment, final visual acuity at discharge and duration of treatment with minimal change in vision.

Results:

Thirty-nine patients were identified with a mean age 4.2 ± 1.7SD years. Patients had an average of 116.6 ± 13.9SD visits over 30.5 ± 21.5SD months. Of these, 71.8% had occlusion only and 28.2% in combination with atropine. All but three patients had improved vision, with mean letters gained 13.2 ± 8.7SD LogMAR. The improvement in vision was statistically significant p < 0.005 and patients were further followed without treatment for 10 ± 13.5SD months over 5.2 ± 6.6SD visits. The mean final vision at discharge was not significantly different from vision at termination (p = 0.68) and we found no significant recurrence.

Conclusion:

Amblyopia treatment is effective; however, there is inconsistency in many aspects of ending treatment. Further improvement is needed to standardise care from termination of treatment up to discharge from service.

Binocular iPad Game vs Patching for Treatment of Amblyopia in Children: A Randomized Clinical Trial

Importance

Fellow eye patching has long been the standard treatment for amblyopia, but it does not always restore 20/20 vision or teach the eyes to work together. Amblyopia can be treated with binocular games that rebalance contrast between the eyes so that a child may overcome suppression. However, it is unclear whether binocular treatment is comparable to patching in treating amblyopia.

Objectives

To assess the effectiveness of a binocular iPad (Apple Inc) adventure game as amblyopia treatment and compare this binocular treatment with patching, the current standard of care.

Design, Setting, and Participants

This investigation was a randomized clinical trial with a crossover design at a nonprofit eye research institute. Between February 20, 2015, and January 4, 2016, a total of 28 patients were enrolled in the study, with 14 randomized to binocular game treatment and 14 to patching treatment.

Interventions

Binocular game and patching as amblyopia treatments.

Main Outcomes and Measures

The primary outcome was change in amblyopic eye best-corrected visual acuity (BCVA) at the 2-week visit. Secondary outcomes were change in stereoacuity and suppression at the 2-week visit and change in BCVA at the 4-week visit.

Results

Among 28 children, the mean (SD) age at baseline was 6.7 (1.4) years (age range, 4.6-9.5 years), and 7 (25%) were female. At baseline, the mean (SD) amblyopic eye BCVA was 0.48 (0.14) logMAR (approximately 20/63; range, 0.3-0.8 logMAR [20/40 to 20/125]), with 14 children randomized to the binocular game and 14 to patching for 2 weeks. At the 2-week visit, improvement in amblyopic eye BCVA was greater with the binocular game compared with patching, with a mean (SD) improvement of 0.15 (0.08) logMAR (mean [SD], 1.5 [0.8] lines) vs 0.07 (0.08) logMAR (mean [SD], 0.7 [0.8] line; P = .02) after 2 weeks of treatment. These improvements from baseline were significant for the binocular game (mean [SD] improvement, 1.5 [0.8] lines; P < .001) and for patching (mean [SD] improvement, 0.7 [0.8] line; P = .006). Depth of suppression improved from baseline at the 2-week visit for the binocular game (mean [SD], 4.82 [2.82] vs 3.24 [2.87]; P = .03) and for patching (mean [SD], 4.77 [3.10] vs 2.57 [1.67]; P = .004). Patching children crossed over to binocular game treatment, and all 28 children played the game for another 2 weeks. At the 4-week visit, no group difference was found in BCVA change, with children who crossed over to the binocular games catching up with children treated with binocular games, for a mean (SD) improvement of 0.17 (0.10) logMAR (mean [SD], 1.7 [1.0] lines) for the binocular game vs a mean (SD) improvement of 0.16 (0.12) logMAR (mean [SD], 1.6 [1.2] lines) for the patching crossover (P = .73).

Conclusions and Relevance

A binocular iPad game was effective in treating childhood amblyopia and was more efficacious than patching at the 2-week visit. Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia.

Trial Registration

clinicaltrials.gov Identifier: NCT02365090.

Binocular treatment of amblyopia using videogames (BRAVO): study protocol for a randomised controlled trial

Background

Amblyopia is a common neurodevelopmental disorder of vision that is characterised by visual impairment in one eye and compromised binocular visual function. Existing evidence-based treatments for children include patching the nonamblyopic eye to encourage use of the amblyopic eye. Currently there are no widely accepted treatments available for adults with amblyopia. The aim of this trial is to assess the efficacy of a new binocular, videogame-based treatment for amblyopia in older children and adults. We hypothesise that binocular treatment will significantly improve amblyopic eye visual acuity relative to placebo treatment.

Methods/design

The BRAVO study is a double-blind, randomised, placebo-controlled multicentre trial to assess the effectiveness of a novel videogame-based binocular treatment for amblyopia. One hundred and eight participants aged 7 years or older with anisometropic and/or strabismic amblyopia (defined as ≥0.2 LogMAR interocular visual acuity difference, ≥0.3 LogMAR amblyopic eye visual acuity and no ocular disease) will be recruited via ophthalmologists, optometrists, clinical record searches and public advertisements at five sites in New Zealand, Canada, Hong Kong and Australia. Eligible participants will be randomised by computer in a 1:1 ratio, with stratification by age group: 7–12, 13–17 and 18 years and older. Participants will be randomised to receive 6 weeks of active or placebo home-based binocular treatment. Treatment will be in the form of a modified interactive falling-blocks game, implemented on a 5th generation iPod touch device viewed through red/green anaglyphic glasses. Participants and those assessing outcomes will be blinded to group assignment. The primary outcome is the change in best-corrected distance visual acuity in the amblyopic eye from baseline to 6 weeks post randomisation. Secondary outcomes include distance and near visual acuity, stereopsis, interocular suppression, angle of strabismus (where applicable) measured at baseline, 3, 6, 12 and 24 weeks post randomisation. Treatment compliance and acceptability will also be assessed along with quality of life for adult participants.

Discussion

The BRAVO study is the first randomised controlled trial of a home-based videogame treatment for older children and adults with amblyopia. The results will indicate whether a binocular approach to amblyopia treatment conducted at home is effective for patients aged 7 years or older.

Trial registration

This trial was registered in Australia and New Zealand Clinical Trials Registry (ACTRN12613001004752) on 10 September 2013.

Risk factors for treatment failure and recurrence of anisometropic amblyopia

PURPOSE

The aim of this study was to identify factors associated with failed vision improvement and recurrence following occlusion therapy for anisometropic amblyopia in children aged 7-9 years.

METHODS

We retrospectively reviewed the medical records of 64 children aged 7-9 years who had been diagnosed as having anisometropic amblyopia and were treated with patching. Functional treatment failure was defined as final visual acuity in the amblyopic eye of worse than 20/32. Improvement of fewer than two logMAR lines was considered relative treatment failure. Recurrence was defined as the reduction of at least two logMAR levels of visual acuity after decreased or discontinued patching.

RESULTS

Functional and relative success rates were 51.6 and 62.5 %, respectively. The most important factor for functional treatment failure [adjusted odds ratio (OR) (95 % confidence interval, CI) 11.57 (1.4-95.74)] and the only risk factor for recurrence [adjusted OR (95 % CI) 3.04 (1.13-8.12)] were the same: high spherical equivalent (SE) of the amblyopic eye. A large interocular difference in the best-corrected visual acuity was found to be a risk factor for both functional and relative failure.

CONCLUSION

High SE of the amblyopic eye was the most influential risk factor for treatment failure and recurrence in compliant children aged 7-9 years.

The challenges of amblyopia treatment

The treatment of amblyopia, particularly anisometropic (difference in refractive correction) and/or strabismic (turn of one eye) amblyopia has long been a challenge for many clinicians. Achieving optimum outcomes, where the amblyopic eye reaches a visual acuity similar to the fellow eye, is often impossible in many patients. Part of this challenge has resulted from a previous lack of scientific evidence for amblyopia treatment that was highlight by a systematic review by Snowdon et al. in 1998. Since this review, a number of publications have revealed new findings in the treatment of amblyopia. This includes the finding that less intensive occlusion treatments can be successful in treating amblyopia. A relationship between adherence to treatment and visual acuity has also been established and has been shown to be influenced by the use of intervention material. In addition, there is growing evidence of that a period of glasses wearing only can significantly improve visual acuity alone without any other modes of treatment. This review article reports findings since the Snowdon's report.

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years

BACKGROUND

Current treatments for amblyopia in children, occlusion and pharmacological blurring, have had limited success, with less than two-thirds of children achieving good visual acuity of at least 0.20 logMAR in the amblyopic eye, limited improvement of stereopsis, and poor compliance. A new treatment approach, based on the dichoptic presentation of movies or computer games (images presented separately to each eye), may yield better results, as it aims to balance the input of visual information from each eye to the brain. Compliance may also improve with these more child-friendly treatment procedures.

OBJECTIVES

To determine whether binocular treatments in children aged three to eight years with unilateral amblyopia result in better visual outcomes than conventional occlusion or pharmacological blurring treatment.

SEARCH METHODS

We searched the Cochrane Eyes and Vision Group Trials Register (last date of searches: 14 April 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2015), EMBASE (January 1980 to April 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA

Two review authors independently screened the results of the search in order to identify studies that met the inclusion criteria of the review: randomised controlled trials (RCTs) that enrolled participants between the ages of three and eight years old with unilateral amblyopia, defined as best-corrected visual acuity (BCVA) worse than 0.200 logMAR in the amblyopic eye, and BCVA 0.200 logMAR or better in the fellow eye, in the presence of an amblyogenic risk factor such as anisometropia, strabismus, or both. Prior to enrolment, participants were to have undergone a cycloplegic refraction and comprehensive ophthalmic examination including fundal examination. In addition, participants had to have completed a period of optical treatment, if indicated, and BCVA in the amblyopic eye had to remain unchanged on two consecutive assessments despite reportedly good compliance with glasses wearing. Participants were not to have received any treatment other than optical treatment prior to enrolment. We planned to include any type of binocular viewing intervention; these could be delivered on different devices including computer monitors viewed with LCD shutter glasses or hand-held screens including mobile phone screens with lenticular prism overlay. Control groups were to have received standard amblyopia treatment; this could include occlusion or pharmacological blurring of the better-seeing eye. We planned to include full-time (all waking hours) and part-time (between 1 and 12 hours a day) occlusion regimens.

DATA COLLECTION AND ANALYSIS

We planned to use standard methodological procedures expected by The Cochrane Collaboration. We had planned to meta-analyse the primary outcome, that is mean distance BCVA in the amblyopic eye at 12 months after the cessation of treatment.

MAIN RESULTS

We could identify no RCTs in this subject area.

AUTHORS' CONCLUSIONS

Further research is required to allow decisions about implementation of binocular treatments for amblyopia in clinical practice. Currently there are no clinical trials offering standardised evidence of the safety and effectiveness of binocular treatments, but results from non-controlled cohort studies are encouraging. Future research should be conducted in the form of RCTs, using acknowledged methods of visual acuity and stereoacuity assessment with known reproducibility. Other important outcome measures include outcomes reported by users, compliance with treatment, and recurrence of amblyopia after cessation of treatment.

Designing clinical trials for amblyopia

Randomized clinical trial (RCT) study design leads to one of the highest levels of evidence, and is a preferred study design over cohort studies, because randomization reduces bias and maximizes the chance that even unknown confounding factors will be balanced between treatment groups. Recent randomized clinical trials and observational studies in amblyopia can be taken together to formulate an evidence-based approach to amblyopia treatment, which is presented in this review. When designing future clinical studies of amblyopia treatment, issues such as regression to the mean, sample size and trial duration must be considered, since each may impact study results and conclusions.

Atropine vs patching for treatment of moderate amblyopia: follow-up at 15 years of age of a randomized clinical trial

IMPORTANCE

Initial treatment for amblyopia of the fellow eye with patching and atropine sulfate eyedrops improves visual acuity. Long-term data on the durability of treatment benefit are needed.

OBJECTIVE

To report visual acuity at 15 years of age among patients who were younger than 7 years when enrolled in a treatment trial for moderate amblyopia.

DESIGN, SETTING, AND PARTICIPANTS

In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40 to 20/100) were randomly assigned to patching (minimum of 6 h/d) or atropine sulfate eyedrops, 1% (1 drop daily), for 6 months. Treatment after 6 months was at the discretion of the investigator. Two years after enrollment, an unselected subgroup of 188 children were enrolled into long-term follow-up.

INTERVENTION

Initial treatment with patching or atropine with subsequent treatment at investigator discretion.

MAIN OUTCOMES AND MEASURES

Visual acuity at 15 years of age with the electronic Early Treatment Diabetic Retinopathy Study test in amblyopic and fellow eyes.

RESULTS

Mean visual acuity in the amblyopic eye measured in 147 participants at 15 years of age was 0.14 logMAR (approximately 20/25); 59.9% of amblyopic eyes had visual acuity of 20/25 or better and 33.3%, 20/20 or better. Mean interocular acuity difference (IOD) at 15 years of age was 0.21 logMAR (2.1 lines); 48.3% had an IOD of 2 or more lines and 71.4%, 1 or more lines. Treatment (other than spectacles) was prescribed for 9 participants (6.1%) aged 10 to 15 years. Mean IOD was similar at examinations at 10 and 15 years of age (2.0 and 2.1 logMAR lines, respectively; P = .39). Better visual acuity at the 15-year examination was achieved in those who were younger than 5 years at the time of entry into the randomized clinical trial (mean logMAR, 0.09) compared with those aged 5 to 6 years (mean logMAR, 0.18; P < .001). When we compared subgroups based on original treatment with atropine or patching, no significant differences were observed in visual acuity of amblyopic and fellow eyes at 15 years of age (P = .44 and P = .43, respectively).

CONCLUSIONS AND RELEVANCE

At 15 years of age, most children treated for moderate amblyopia when younger than 7 years have good visual acuity, although mild residual amblyopia is common. The outcome is similar regardless of initial treatment with atropine or patching. The results indicate that improvement occurring with amblyopia treatment is maintained until at least 15 years of age.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000170.

Factors predicting recurrence in successfully treated cases of anisometropic amblyopia

Context:

Recurrence after successful treatment of amblyopia is known and understanding the risk factors could help effective management.

Aim:

To measure incidence of recurrence in successfully treated cases of anisometropic amblyopia and evaluate factors predicting it.

Settings and Design:

Cohort Study at a tertiary level institution.

Materials and Methods:

Successfully treated anisometropic amblyopes aged 4−12 years were followed up for 1 year after stopping therapy. Best corrected visual acuity (BCVA), refractive error, stereoacuity and contrast sensitivity were evaluated at baseline and follow-up.

Statistical Analysis:

Intergroup analysis with appropriate tests: Chi-square test, Fisher's exact test, Wilcoxon rank sum test and paired t-test.

Results:

One hundred and two patients with mean age at diagnosis 7.06 ± 1.81 years were followed-up for a mean duration of 1.0 ± 0.2 years. The mean pre-treatment BCVA (LogMAR score) at diagnosis was 0.73 ± 0.36 units which improved to 0.20 ± 0.00 with treatment and after 1 year of stopping treatment was 0.22 ± 0.07. Thirteen (12.74%) patients showed amblyopia recurrence during follow-up. Risk of recurrence was higher with older age of onset of treatment (6.64 ± 1.77 years without recurrence v/s 8.53 ± 1.39 years with recurrence, P = 0.0014). Greater extent of improvement of VA (P = 0.048) and final VA at stopping occlusion (P = 0.03) were associated with higher recurrence. Binocularity status or stereoacuity changes were not associated with risk of recurrence.

Conclusions:

Significant numbers of children suffer recurrence of amblyopia after stopping therapy. Older age, better BCVA after stopping therapy and greater magnitude of improvement in BCVA are important risk factors for recurrence. Careful follow-up is essential for early detection and management of recurrence.

A randomized trial of increasing patching for amblyopia

OBJECTIVE

After treatment with refractive correction and patching, some patients have residual amblyopia resulting from strabismus or anisometropia. We conducted a clinical trial to evaluate the effectiveness of increasing prescribed daily patching from 2 to 6 hours in children with stable residual amblyopia.

DESIGN

Prospective, randomized, multicenter clinical trial.

PARTICIPANTS

A total of 169 children aged 3 to <8 years (mean, 5.9 years) with stable residual amblyopia (20/32-20/160) after 2 hours of daily patching for at least 12 weeks.

INTERVENTION

Random assignment to continue 2 hours of daily patching or increase patching time to an average of 6 hours/day.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (VA) in the amblyopic eye after 10 weeks.

RESULTS

Baseline VA was 0.44 logarithm of the minimum angle of resolution (logMAR) (20/50(-2)). Ten weeks after randomization, amblyopic eye VA had improved an average of 1.2 lines in the 6-hour group and 0.5 line in the 2-hour group (difference in mean VA adjusted for acuity at randomization = 0.6 line; 95% confidence interval, 0.3-1.0; P = 0.002). Improvement of 2 or more lines occurred in 40% of participants patched for 6 hours versus 18% of those who continued to patch for 2 hours (P = 0.003).

CONCLUSIONS

When amblyopic eye VA stops improving with 2 hours of daily patching, increasing the daily patching dosage to 6 hours results in more improvement in VA after 10 weeks compared with continuing 2 hours daily.

Amblyopia and binocular vision

Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia.

Conventional occlusion versus pharmacologic penalization for amblyopia

BACKGROUND

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses.

OBJECTIVES

To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009.

SELECTION CRITERIA

We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias.

MAIN RESULTS

Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and atropine penalization was found. Although both treatments were well tolerated, compliance was better in atropine. Atropine penalization costs less than conventional occlusion. The results indicate that atropine penalization is as effective as conventional occlusion.

AUTHORS' CONCLUSIONS

Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the three trials. Atropine penalization can be used as first line treatment for amblyopia.

Visual outcome following the reduction or cessation of patching therapy after early unilateral cataract surgery

OBJECTIVE

To evaluate the impact on visual acuity of reducing or abandoning patching therapy during the first 6 years of life following early unilateral cataract surgery.

METHODS

We reviewed the medical records of 9 children with unilateral congenital cataracts who underwent cataract surgery when 6 weeks or younger. All had good compliance with optical correction until 6 years of age and with patching therapy until at least 12 months of age.

RESULTS

The children underwent cataract surgery at a mean (SD) age of 21.7 (9.5) days. At 12 months of age, the children were patched a mean (SD) of 6.7 (2.4) hours/d. Patching compliance declined steadily thereafter. By 6 years of age, they were only being patched a mean (SD) of 1.7 (2.0) hours/d. Four of the 9 children abandoned patching prior to the 6-year examination. Acuities improved or remained the same for 3 of these children but worsened for 1 child by 2 lines.

CONCLUSION

Our study suggests that some children who undergo early unilateral cataract surgery and are compliant with their optical correction and patching during early childhood can maintain a good visual outcome even if patching therapy is reduced or discontinued prior to their sixth birthday.

A randomized trial of atropine vs patching for treatment of moderate amblyopia: follow-up at age 10 years

OBJECTIVE

To determine the visual acuity outcome at age 10 years for children younger than 7 years when enrolled in a treatment trial for moderate amblyopia.

METHODS

In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40-20/100) were randomized to patching or atropine eyedrops for 6 months. Two years after enrollment, a subgroup of 188 children entered long-term follow-up. Treatment after 6 months was at the discretion of the investigator; 89% of children were treated.

MAIN OUTCOME MEASURE

Visual acuity at age 10 years with the electronic Early Treatment Diabetic Retinopathy Study test.

APPLICATION TO CLINICAL PRACTICE

Patching and atropine eyedrops produce comparable improvement in visual acuity that is maintained through age 10 years.

RESULTS

The mean amblyopic eye acuity, measured in 169 patients, at age 10 years was 0.17 logMAR (logarithm of the minimum angle of resolution) (approximately 20/32), and 46% of amblyopic eyes had an acuity of 20/25 or better. Age younger than 5 years at entry into the randomized trial was associated with a better visual acuity outcome (P < .001). Mean amblyopic and sound eye visual acuities at age 10 years were similar in the original treatment groups (P = .56 and P = .80, respectively).

CONCLUSIONS

At age 10 years, the improvement of the amblyopic eye is maintained, although residual amblyopia is common after treatment initiated at age 3 years to younger than 7 years. The outcome is similar regardless of initial treatment with atropine or patching.

Stability of visual acuity improvement following discontinuation of amblyopia treatment in children aged 7 to 12 years

OBJECTIVE

To assess the stability of visual acuity improvement during the first year after cessation of amblyopia treatment other than spectacle wear in children aged 7 to 12 years.

METHODS

At the completion of a multicenter randomized trial during which amblyopia treated with patching and atropine improved by at least 2 lines on the electronic Early Treatment of Diabetic Retinopathy Study testing protocol, 80 patients aged 7 to 12 years were followed up while not receiving treatment (other than spectacle wear) for 1 year.

MAIN OUTCOME MEASURE

Ten letters or more (> or =2 lines) worsening of visual acuity (measured using the electronic Early Treatment of Diabetic Retinopathy Study testing protocol) during the year following treatment discontinuation.

RESULTS

During the year following cessation of treatment, the cumulative probability of worsening visual acuity (> or =2 lines) was 7% (95% confidence interval, 3%-17%); 82% of patients maintained an increase in visual acuity of 10 letters or more compared with their visual acuity before starting treatment.

CONCLUSION

Visual acuity improvement occurring during amblyopia treatment is sustained in most children aged 7 to 12 years for at least 1 year after discontinuing treatment other than spectacle wear.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00094692.

Factors associated with recurrence of amblyopia on cessation of patching

PURPOSE

In a prospective observational study, we previously reported that weaning (tapering or gradually reducing) treatment in children treated with 6 to 8 hours of daily patching for amblyopia resulted in a 4-fold reduction in odds of recurrence. We now report the association of additional factors with recurrence or regression of amblyopia in this same cohort.

DESIGN

Prospective, nonrandomized, observational study.

PARTICIPANTS

Sixty-nine children aged <8 years with successfully treated anisometropic or strabismic amblyopia (improved > or =3 logarithm of the minimum angle of resolution [logMAR] lines).

METHODS

Patients were enrolled at the time they stopped patching for amblyopia. Patients were classified according to whether patching was stopped abruptly or weaned before cessation. They were followed off treatment for 52 weeks to assess recurrence of amblyopia.

MAIN OUTCOME MEASURE

Recurrence of amblyopia defined as a > or =2-logMAR level reduction of visual acuity from enrollment (cessation of patching) confirmed by a second examination. Recurrence was also considered to have occurred if treatment was restarted with a > or =2-logMAR level reduction of visual acuity, even if it was not confirmed by a second examination.

RESULTS

The risk of recurrence was higher with better visual acuity at the time of cessation of treatment (adjusted risk ratio [RR], 0.68 per line of worse visual acuity; 95% confidence interval [CI], 0.51-0.90), a greater number of lines improved during the previous treatment (adjusted RR, 1.5 per line increase; 95% CI, 1.1-2.0), and a history of recurrence (adjusted RR, 2.7; 95% CI, 1.5-4.9). Orthotropia or excellent stereoacuity at the time of patching cessation did not appear to have a protective effect on the risk of recurrence.

CONCLUSIONS

The higher risk of recurrence in the most successfully treated children with amblyopia and absence of protection from orthotropia and excellent random dot stereoacuity suggests that careful and prolonged follow-up is needed for all children who have been previously treated for amblyopia.

Factors affecting the stability of visual function following cessation of occlusion therapy for amblyopia

AIM

To identify factors that predict which children with amblyopia are at greatest risk of regression of visual acuity (VA) following the cessation of occlusion therapy.

METHOD

A retrospective analysis was performed of 182 children (mean age at cessation of treatment; 5.9+/-1.6 years) who had undergone occlusion therapy for unilateral amblyopia, and had been followed up at least once within 15 months of cessation. Statistical analysis was used to identify whether change in VA following treatment cessation had any association with various factors, including the child's age, type of amblyopia, degree of anisometropia, initial severity of amblyopia, binocular vision status, length and dose of occlusion therapy, and VA response to treatment.

RESULTS

At 1 year, follow-up from treatment cessation, children with "mixed" amblyopia (both anisometropia and strabismus) demonstrated significantly (p=0.03) greater deterioration in VA (0.11+/-0.11 log units) than children with only anisometropia (0.02+/-0.08 log units) or only strabismus (0.05+/-0.10 log units). However, none of the other factors investigated were found to be significant predictors.

CONCLUSION

This study supports previous research that it is possible to identify those children most at risk of deterioration in VA following cessation of occlusion therapy. The presence of mixed amblyopia was the only risk factor identified in this study. Management of amblyopia should take this into account, with a more intensive follow-up recommended for those with both anisometropia and strabismus (mixed) amblyopia.

Part-time occlusion therapy for anisometropic amblyopia detected in children eight years of age and older

Purpose

To determine the outcome of part-time occlusion therapy in children with anisometropic amblyopia detected after they were 8 years of age.

Methods

We analyzed 29 eyes with anisometropic amblyopia in children 8 years of age and older. The mean age was 8.79±0.98 (range 8~12) years old. The subjects whose best-corrected visual acuity (BCVA) did not improve by two lines or better within 2 weeks of wearing glasses full-time were prescribed occlusion therapy for 6 hours a day outside of school hours, along with the instruction to wear glasses full-time. Subjects who complied with occlusion for more than 3 hours a day were considered to comply well.

Results

The major component of the anisometropia was hyperopia in 51.7% of the subjects, and hyperopia plus astigmatism was found in 24.1%. The mean pretreatment BCVA score was 0.51±0.23 (LogMAR). Compliance was 89.66%. The mean posttreatment BCVA was 0.03±0.01 (LogMAR), and the success rate, based on a posttreatment BCVA of 0.1 (LogMAR) and better, was 96.43%. It took an average of 4.79±3.35 months to reach the desired posttreatment BCVA. The mean posttreatment stereopsis was 79.78±37.61 seconds of arc. The recurrence rate was 8%. The visual improvement was related to the degree of compliance (p=0.000). The time taken to reach the posttreatment BCVA was shorter in subjects with a better pretreatment BCVA (p=0.019), but it did not relate to the compliance (p=0.366).

Conclusions

The most common component of anisometropia detected after 8 years of age was hyperopia. The part-time occlusion therapy, which had been carried out after school hours, was successful in most cases.

Does amblyopia affect educational, health, and social outcomes? Findings from 1958 British birth cohort

OBJECTIVE

To determine any association of amblyopia with diverse educational, health, and social outcomes in order to inform current debate about population screening for this condition.

DESIGN, SETTING, AND PARTICIPANTS

Comparison of 8432 people with normal vision in each eye with 429 (4.8%) people with amblyopia (childhood unilateral reduced acuity when tested with correction and unaccounted for by eye disease) from the 1958 British birth cohort, with respect to subsequent health and social functioning.

RESULTS

No functionally or clinically significant differences existed between people with and without amblyopia in educational outcomes, behavioural difficulties or social maladjustment, participation in social activities, unintended injuries (school, workplace, or road traffic accidents as driver), general or mental health and mortality, paid employment, or occupation based social class trajectories.

CONCLUSIONS

It may be difficult to distinguish, at population level, between the lives of people with amblyopia and those without, in terms of several important outcomes. A pressing need exists for further concerted research on what it means to have amblyopia and, specifically, how this varies with severity and how it changes with treatment, so that screening programmes can best serve those who have the most to gain from early identification.