A randomized trial of atropine regimens for treatment of moderate amblyopia in children

Dose Dependent Effects of Atropine on Static and Dynamic Pupil and Accommodation Metrics in Young Adults

Purpose

The purpose of this study was to investigate short-term effects of a range of low-dose atropine concentrations on static and dynamic pupil and accommodation metrics in young adults.

Methods

This double blinded study tested pupil and accommodation metrics at baseline and 1 hour and 24 hours after topical instillation of a single drop of placebo, 0.01%, 0.025%, 0.05%, and 0.1% atropine in the right eyes of 20 healthy adults (18-35 years). Static pupil diameter was measured under photopic, mesopic, and scotopic illumination, and dynamic responses were recorded as illumination changed from 0.3 to 140 lux using a pupillometer (MYAH). Peak constriction and dilation velocities were extracted. Accommodative lag and maximum accommodation were determined (WAM-5500) and dynamic responses were recorded for targets at 33 cm and 6 m (PowerRef). Dynamic responses were fitted with exponential functions to calculate amplitude, time constant, and peak velocities.

Results

Static pupil diameters under all lighting conditions and dynamic metrics, including constriction amplitude and peak constriction and dilation velocities, showed significant dose-response effects at 1 hour and 24 hours (P < 0.05 for all). Maximum accommodation significantly decreased at 1 hour and 24 hours after atropine administration compared to placebo for all concentrations (P < 0.05 for all). Accommodative time constant increased and peak velocity decreased over 24 hours after atropine administration (P < 0.05). On the other hand, accommodative and disaccommodative amplitudes, disaccommodative time constant, and peak velocity did not significantly change after atropine administration (P > 0.05).

Conclusions

A single drop of 0.01%, 0.025%, 0.05%, and 0.1% atropine induced significant changes in static and dynamic pupil and accommodation metrics in a dose-dependent manner in young adults.

Functional consequences of amblyopia and its impact on health-related quality of life

Amblyopia (lazy eye) is the most common cause of monocular vision loss, affecting up to 4% of children and often persisting into adulthood. While treating the visual acuity deficit is often the focus of treatment, there is a pressing need for researchers, educators, and clinicians to understand the effects of amblyopia that extend beyond visual acuity. This review article highlights recent advances in understanding the impact of amblyopia on everyday life functioning. Amblyopia can significantly interfere with contrast sensitivity, attention, reading, eye-hand coordination, body composition, physical activity, and health-related quality of life. A deeper understanding of the functional consequences of amblyopia can be applied to patient management and inform amblyopia treatment, as well as support research into more effective interventions to prevent or rehabilitate deficits that can hinder children's physical, social, and academic success.

Assessing Previous Strategies and Presenting a Novel Smart Glasses to Enhance Adherence to Amblyopia Therapy in Children

Amblyopia treatment in children, often involving patching or atropine, faces significant challenges with adherence. Adherence to patching is often poor due to discomfort and psychosocial factors such as social stigma, while adherence data for atropine treatment remains scarce, hindering a clear understanding of patients' adherence in real-world settings. This review assesses both traditional methods and alternative strategies aimed at improving adherence, including Bangerter filters, binocular therapies, intermittent occlusion, and perceptual learning. While these alternatives help reduce the treatment burden, they do not consistently outperform conventional methods in improving visual outcomes and still face notable adherence challenges, especially in older children. Educational interventions, such as cartoons and motivational tools, show promise in improving adherence, especially in low-adherence populations, but their long-term effectiveness has yet to be established. Digital therapies such as Luminopia and CureSight represent promising alternatives to traditional amblyopia treatments, with preliminary evidence indicating improvements in visual outcomes and adherence. Nevertheless, further research is necessary to determine their efficacy and how they compare to established methods. Building on this, we hypothesize that the AmblySmart glasses, a novel technology that integrates with smart devices, could further improve adherence by linking treatment to children's screen time. However, further studies are needed to investigate this technology's effectiveness and practicality compared to traditional methods. Overall, this review highlights the importance of developing innovative approaches to optimize adherence and improve treatment outcomes in amblyopic children.

Comparative Outcomes of Amblyopia Treatment in High Astigmatism: Stability and Sustained Improvements

Background/Objectives: Astigmatism is a major risk factor for amblyopia. While optical correction improves visual acuity (VA), the long-term treatment outcomes, particularly in children with high astigmatism, remain understudied. This study aimed to determine the treatment effects, time course, and visual outcomes in children aged 3-7 years with high astigmatism and compared their VA improvement with those with low astigmatism. Methods: This retrospective cohort study included 63 children with untreated high with-the-rule astigmatism (≥+2.50 diopters [D]) and 46 with low astigmatism (≤1.50 D). The children with high astigmatism were classified based on their baseline best-corrected VA (BCVA) into good-VA (20/25 or better, n = 24), mild-VA-impairment (20/25-20/40, n = 19), and amblyopia (20/40 or worse, n = 20) groups. The primary outcomes include maximal improvement in mean BCVA post treatment, the cumulative probability of achieving a VA of 20/25 or better, and being within one line of the fellow eye. Results: The amblyopia, mild-VA-impairment, good-VA, and low astigmatism control groups showed mean improvements of logarithm of the minimum angle of resolution of 0.36 ± 0.08, 0.15 ± 0.05, 0.03 ± 0.04, and 0.01 ± 0.04, respectively. Post treatment with optical correction and/or patching over a mean duration of 46.61 ± 35.22 weeks, amblyopia resolved in all affected children. In the mild-VA-impairment group, only one child did not respond successfully to the treatment. The mean final VA showed no significant intergroup differences (p = 0.115). No amblyopia recurrence was observed at a mean follow-up of 118.33 weeks post resolution. Conclusions: Timely optical correction and patching effectively improve VA in children with high astigmatism, achieving outcomes comparable to those with low astigmatism.

The impact of eye movements on amblyopic vision: A mini-review

Our eyes move constantly to search for and inspect objects of interest, to track moving objects, to read along a line of text and to prevent image fading. However, persons with amblyopia (PWA), in addition to a broad array of visual deficits, have abnormal eye movements. This review briefly describes the types of eye movements deficits in persons with amblyopia and how they are measured. We then go on to discuss what is known about how abnormal eye movements in persons with amblyopia affect their vision. Finally, we ask whether the abnormal eye movements are amenable to amblyopia treatment and whether they can be used to diagnose/classify amblyopia.

Comparative analysis of optic disc and macular microvasculature in children with anisometropic amblyopia before and after treatment

PURPOSE

To evaluate optic disc and macular microvasculature changes in children with anisometropic amblyopia before and after treatment.

METHODS

In all, 60 children with unilateral anisometropic amblyopia between the ages of 6 and 12 were randomly selected from the ophthalmology clinic of Fuyang People's Hospital, while 60 children with non-amblyopia in the same age range were randomly selected as a normal control group. The right eye was uniformly taken in the control group with at least 6 months of follow-up. Optical coherence tomography angiography (OCTA) was used to evaluate the macular vessel density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), optic disc vascular density (VD), foveal avascular zone (FAZ) area, macular thickness, and retinal nerve fiber layer thickness (RNFLT).

RESULTS

Before treatment, the vessel density of the optic disc, macular SCP and DCP in the amblyopic group was significantly lower than those in the fellow eyes and the control group (P < 0.05), while there were no statistically significant differences in the vessel densities of the optic disc, macular SCP and DCP between the amblyopic eyes, the fellow eyes, and the control group after treatment (P > 0.05). Statistically significant negative correlations were found between the alterations of BCVA in amblyopic eyes and the alterations of the vessel densities of the optic disc, macular SCP and DCP in amblyopia eyes (P < 0.05) except for superior nasal (SN) and inferior nasal (IN) regions of the optic disc radial peripapillary capillary, temporal and nasal regions of macular parafoveal SCP, nasal regions of macular parafoveal DCP and inferior regions of macular perifoveal DCP (P > 0.05).

CONCLUSION

Macular and optic disc vessel density in OCTA are lower in children with anisometropic amblyopia and tend to return to normal levels to a certain extent following treatment for amblyopia.

Comparison of Virtual Reality-Assisted Visual Training with Conventional Strategies in the Treatment of Bilateral Refractive Amblyopia

BACKGROUND

Visual training based on perceptual learning and dichoptic stimulation has been developed for amblyopic treatment. However, reports on virtual reality-assisted (VR) training for amblyopia are limited. The aim of this study was to evaluate the effects of VR training and compare the visual outcomes of different treatments in children with bilateral refractive amblyopia.

METHODS

Children aged 4-8 years with a best-corrected visual acuity (BCVA) less than 20/25 were included. All of the patients had worn glasses for at least 2 months before enrollment. At enrollment, age, gender, refractive status, baseline BCVA, and amblyopia severity were recorded. The treatment outcomes were evaluated in terms of BCVA at 24 weeks, the change in BCVA from baseline to 24 weeks, and the time taken to achieve treatment success (BCVA ≥ 20/25).

RESULTS

The longitudinal study included 30 patients in the Cambridge Visual Stimulator (CAM) training group, 14 in the VR training group, and 26 in the control group (glasses only). Among patients with an initial BCVA between 20/100 and 20/40, a significantly higher proportion of those in the VR training group achieved treatment success compared to the control group (p = 0.022). Among those who achieved treatment success, the time taken to achieve success was significantly shorter in the CAM and VR training groups compared to the control group (p < 0.001).

CONCLUSIONS

Visual training can shorten the time taken to achieve treatment success compared to glasses alone. While VR training seems more effective than CAM training, both are valuable strategies for amblyopic children who respond poorly to glasses alone.

Transformative Gamified Binocular Therapy for Unilateral Amblyopia in Young Children: Pilot Prospective Efficacy and Safety Study

Background

Amblyopia is a common cause of visual impairment in children. Compliance with traditional treatments for amblyopia is challenging due to negative psychosocial impacts. Recent shifts in amblyopia treatment have moved from suppressing the dominant eye to enhancing binocular visual function. Binocular digital therapy has become a promising approach.

Objective

The aim of this study was to evaluate the effects of binocular gamified digital therapy on visual acuity and stereoacuity (SA) in children with unilateral amblyopia.

Methods

This pilot prospective study enrolled 11 children aged 4-6 years with unilateral amblyopia. Following at least 8 weeks of refractive correction, participants underwent binocular gamified digital therapy for 60 minutes per day, 5 days a week. The therapy used a roguelike shooting game delivered under binocular conditions through two independent channels with a real-time artificial intelligence visual engine. Assessments of distance visual acuity (DVA), near visual acuity (NVA), and SA were conducted at baseline and again at 4, 8, and 12 weeks.

Results

At 12 weeks, the following significant improvements were noted: amblyopic eye DVA improved by 1.0 line (P=.01; d=0.77), binocular DVA improved by 0.7 lines (P=.006; d=1.00), and SA improved by 0.3 logarithm (log) arcseconds (P=.01; d=0.97). At 8 weeks, improvements included amblyopic eye DVA by 0.9 lines (P=.046; d=1.00) and SA by 0.28 log arcseconds (P=.02; d=0.90). No significant adverse events were observed, although one participant developed progressive esotropia.

Conclusions

Binocular gamified digital therapy is effective and safe for improving visual outcomes in children aged 4-6 years with unilateral amblyopia.

Leveraging neural plasticity for the treatment of amblyopia

Amblyopia is a form of visual cortical impairment that arises from abnormal visual experience early in life. Most often, amblyopia is a unilateral visual impairment that can develop as a result of strabismus, anisometropia, or a combination of these conditions that result in discordant binocular experience. Characterized by reduced visual acuity and impaired binocular function, amblyopia places a substantial burden on the developing child. Although frontline treatment with glasses and patching can improve visual acuity, residual amblyopia remains for most children. Newer binocular-based therapies can elicit rapid recovery of visual acuity and may also improve stereoacuity in some children. Nevertheless, for both treatment modalities full recovery is elusive, recurrence of amblyopia is common, and improvements are negligible when treatment is administered at older ages. Insights derived from animal models about the factors that govern neural plasticity have been leveraged to develop innovative treatments for amblyopia. These novel therapies exhibit efficacy to promote recovery, and some are effective even at ages when conventional treatments fail to yield benefit. Approaches for enhancing visual system plasticity and promoting recovery from amblyopia include altering the balance between excitatory and inhibitory mechanisms, reversing the accumulation of proteins that inhibit plasticity, and harnessing the principles of metaplasticity. Although these therapies have exhibited promising results in animal models, their safety and ability to remediate amblyopia need to be evaluated in humans.

Frequency-dependent effects of 0.05% atropine eyedrops on myopia progression and peripheral defocus: a prospective study

BACKGROUND

Atropine, specifically 0.05% eyedrops, has proven effective in slowing myopia progression. This study aims to investigate peripheral refraction (PR) characteristics in myopic children treated with 0.05% atropine eyedrops at different frequencies.

METHODS

One hundred thirty-eight myopic children completed this one-year prospective study, randomly assigned to once daily (7/7), twice per week (2/7), or once per week (1/7) groups. Spherical equivalent (SE) and axial length (AL) were measured. PR was assessed using a custom-made Hartmann-Shack wavefront peripheral sensor, covering a visual field of horizontal 60° and vertical 36°. Relative peripheral refraction (RPR) was calculated by subtracting central from peripheral measurements.

RESULTS

After one year, SE increased more significantly in the 1/7 group compared to the 7/7 group (P < 0.001) and 2/7 group (P = 0.004); AL elongation was also greater in the 1/7 group compared to the 7/7 group (P < 0.001). In comparison with higher frequency groups, 1/7 group exhibited more myopic PR in the fovea and its vertical superior, inferior, and nasal retina; and less myopic RPR in the periphery retina after one-year (P < 0.05). Additionally, RPR in the 7/7 group demonstrated myopic shift across the entire retina, the 2/7 group in temporal and inferior retina, while the 1/7 group showed a hyperopic shift in the superior retina (P < 0.05). Moreover, myopic shift of RPR in the temporal retina is related to less myopia progression, notably in the 7/7 group (P < 0.05).

CONCLUSIONS

Atropine inhibits myopia progression in a frequency-dependent manner. The once-daily group showed the slowest myopia progression but exhibited more myopic shifts in RPR. Additionally, RPR in the temporal retina was related to myopia progression in all groups.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100043506. Registered 21 February 2021, https://www.chictr.org.cn/showproj.html?proj=122214.

Feasibility of a new 'balanced binocular viewing' treatment for unilateral amblyopia in children aged 3-8 years (BALANCE): results of a phase 2a randomised controlled feasibility trial

OBJECTIVES

This study aimed to evaluate the safety of dichoptic balanced binocular viewing (BBV) for amblyopia in children, plus feasibility, adherence, acceptability, trial methodology and clinical measures of visual function.

DESIGN

We carried out an observer-masked parallel-group phase 2a feasibility randomised controlled trial.

SETTING

Two study sites, a secondary/tertiary and a community site.

PARTICIPANTS

We enrolled 32 children aged 3-8 years with unilateral amblyopia who had completed optical adaptation where indicated. 20 children attended the 16-week exit visit (retention 63%).

INTERVENTIONS

Children were randomised to BBV (movies customised to interocular acuity difference at baseline) for 1 hour a day (active intervention) or standard management as per parental choice (part-time occlusion or atropine blurring, control). All interventions were used at home, daily for 16 weeks.

PRIMARY OUTCOME MEASURE

'VacMan suppression test' of interocular balance at 16 weeks from randomisation.

SECONDARY OUTCOME MEASURES

feasibility outcomes (recruitment and retention ratios, adherence with the allocated intervention); safety outcomes at other time points (changes in prevalence of diplopia, manifest strabismus, suppression/interocular balance on a range of tests); efficacy outcomes (clinical measures of visual function, such as best-corrected visual acuity, BCVA). Outcome measures were identical to those planned in the protocol.

RESULTS

Primary outcome: At baseline, values for the interocular balance point were higher (indicating greater suppression of the amblyopic eye) in the occlusion group than in the BBV group. These values shifted downwards on average for the occlusion group, significantly decreasing from baseline to week 16 (t8=4.49, p=0.002). Balance values did not change between baseline and week 16 for the BBV group (t9=-0.82, p=0.435). At 16 weeks, there was no statistical difference in interocular balance/suppression change over time between the two arms. The difference at follow-up between the arms, adjusted for baseline, was -0.02 (95% CI -0.28 to 0.23, p=0.87).

FEASIBILITY

We prescreened 144 records of potentially eligible children. Between 28 October 2019 and 31 July 2021, including an interruption due to the COVID-19 pandemic, 32 children were screened and randomised (recruitment rate 22%), 16 to BBV and 16 to standard treatment. 20 children attended the 16-week exit visit (retention 63%). Mean adherence with BBV as proportion of viewing time prescribed was 56.1% (SD36) at 8 and 57.9% (SD 30.2) at 16 weeks. Mean adherence with prescribed occlusion time was 90.1% (SD 19.7) at 8 and 59.2% (SD 24.8) at 16 weeks.

SECONDARY SAFETY/EFFICACY OUTCOMES

One child in the BBV arm reported transient double vision, which resolved; two reported headaches, which led to withdrawal. BCVA improved from mean 0.47 (SD0.18) logMAR at randomisation to 0.26 (0.14) with standard treatment, and from 0.55 (0.28) to 0.32 (0.26) with BBV. Outcomes at 16 weeks did not differ between treatments.

PARTICIPANT EXPERIENCE

Families were generally positive about BBV, but families found both patching and BBV difficult to integrate into family routines.

CONCLUSIONS

Recruitment rates indicate that a future phase 3 trial will require multiple sites or a longer enrolment period. Retention and adherence rates were lower than anticipated, which will influence future study designs. Dichoptic treatment may be equal to occlusion treatment in safety and efficacy; headaches may lead to discontinuation. Integration into family routines may constitute a barrier to implementation.

TRIAL REGISTRATION NUMBER

NCT03754153.

Childhood amblyopia: A systematic review of recent management options

This study reviews the current information on treatment of childhood amblyopia, with the goal of improving visual functions. The authors searched various online databases including PubMed, Web of Science, ProQuest, Scopus, Google Scholar, Ebsco, and Medline. The articles, published between 2002 and 2023, included in this study were used to assess the different modalities for the management of different types of childhood amblyopia. The final systematic review included 41 studies from different countries, covering 4060 children with a mean age 6.8 ± 124 years. The findings showed that childhood amblyopia commonly treated through a systemic approach, i.e., starting with treatment of refractive errors with given optical adaptation time, followed by visually stimulating amblyopic eye by covering the dominant eye with patching, Atropine or Bangerter filters. Refractive adaptation period of 18-22 weeks has proven to show a significant improvement in visual acuity. It has been confirmed that 2 h patching is effective for the first time treated amblyopes, and if there is no improvement, increase the period to 6 h daily. Novel methods that improve binocular function such as dichoptic, perceptual training, video gaming, and drugs that facilitate visual neuroplasticity, are useful in the treatment of amblyopia that is not responsive to conventional therapy. The study concludes that significant evidence show that childhood amblyopia is treated through a systemic approach. Starting from correcting refractive errors with a period of optical adaptation, followed by patching therapy and atropine penalization. New methods that improve the binocular functions and medications that facilitate visual neuroplasticity have found to be useful in the treatment of amblyopia that is not responsive to conventional treatment.

Harnessing brain plasticity to improve binocular vision in amblyopia: An evidence-based update

Amblyopia is a developmental visual disorder resulting from atypical binocular experience in early childhood that leads to abnormal visual cortex development and vision impairment. Recovery from amblyopia requires significant visual cortex neuroplasticity, i.e. the ability of the central nervous system and its synaptic connections to adapt their structure and function. There is a high level of neuroplasticity in early development and, historically, neuroplastic responses to changes in visual experience were thought to be restricted to a "critical period" in early life. However, as our review now shows, the evidence is growing that plasticity of the adult visual system can also be harnessed to improve vision in amblyopia. Amblyopia treatment involves correcting refractive error to ensure clear and equal retinal image formation in both eyes, then, if necessary, promoting the use of the amblyopic eye by hindering or reducing visual input from the better eye through patching or pharmacologic therapy. Early treatment in children can lead to visual acuity gains and the development of binocular vision in some cases; however, many children do not respond to treatment, and many adults with amblyopia have historically been untreated or undertreated. Here we review the current evidence on how dichoptic training can be used as a novel binocular therapeutic approach to facilitate visual processing of input from the amblyopic eye and can simultaneously engage both eyes in a training task that requires binocular integration. It is a novel and promising treatment for amblyopia in both children and adults.

Can viewing a 3D movie improve visual function in children with a history of amblyopia and neurotypical children?: A pilot study

PURPOSE

The aim of this pilot study was to determine whether viewing an immersive 3D movie with large disparities in a cinema resulted in improved visual acuity (VA), stereoscopic depth perception (ST), and improved eye alignment in residual amblyopic children and children without amblyopia.

METHODS

A total of 24 children aged between 5 and 12 years with a history of anisometropic and/or strabismic amblyopia, that had been previously treated and who currently have residual amblyopia (N = 14), and in children with typical development without amblyopia (N = 10) viewed the movie in 3D Sing 2 in a cinema for 110 minutes. Visual acuity, stereoacuity and ocular deviation were assessed before viewing the movie, and three months later. Stereoacuity and ocular deviation were also measured immediately after viewing the movie.

RESULTS

We observed an improvement in visual acuity in the non-dominant (amblyopic) eye 3 months after viewing the movie in the amblyopic group (P<0.001). Stereopsis improved immediately after viewing the movie (P = 0.02), and after 3 months by ≈ 40% (P = 0.01). Moreover, improvements in stereopsis were also observed in children without amblyopia (P = 0.04). No significant changes in ocular deviation were observed in either group.

CONCLUSIONS

These pilot results suggest that brief exposure to large disparities by viewing a 3D movie in a cinema can help to improve stereopsis and visual acuity in children aged 5‒12 years with previously treated amblyopia, and provide a rationale for a randomized clinical trial.

Myopia control: Seeing beyond efficacy

SIGNIFICANCE

The availability of a range of effective myopia control modalities enables the clinician to exercise judgment when discussing the treatment plan with the patient and their parents. This article outlines important considerations beyond efficacy.Clinically meaningful myopia control may be attained with some spectacle lenses, select soft contact lenses, some concentrations of atropine, and overnight orthokeratology. Given that satisfactory efficacy can be achieved with a range of modalities, other factors should be considered when deciding upon the best intervention for a given child. Four key factors-compliance, quality of vision, quality of life, and safety-are discussed in this review. Compliance directly impacts efficacy regardless of the modality and is the most important consideration, as it is influenced by quality of vision and comfort. Daily disposal myopia control contact lenses and overnight orthokeratology are generally associated with high compliance, provide better vision-related quality of life than spectacles, and carry a very low risk when used appropriately. A further benefit of overnight orthokeratology is the elimination of a need for optical correction during the day.

Amblyopia Treatment Outcomes Re-Audit, Comparing Current Outcomes to Those from the 2011-12 Audit

Aim

An audit of the effectiveness of amblyopia treatment in the Newcastle Eye Centre (NEC) to determine how current visual acuity (VA) outcomes compare to those found in the 2011-12 audit.

Methods

A retrospective database review. VA outcomes of patients who had undergone treatment for anisometropic, strabismic and mixed amblyopia; discharged between 31.08.2016 - 01.09.19, were compared with VA outcomes found in the previous audit. The previous audit reviewed patients commencing amblyopia treatment during 1.1.11-31.12.12.An unpaired T-test was used to assess if results were statistically significantly different to those found previously. Proportion of visual change from commencement to completion of treatment was calculated. The duration of episode from first visit to discharge, adverse events and percentage of patients who achieved acceptable visual outcomes following only six to eight weeks of occlusion, were also analysed.

Results

Between 31.8.16 and 01.09.19, 1,100 patients were discharged, of which 174 had completed amblyopia treatment and fit the inclusion criteria for the audit. Results show no statistically significant difference between current and previous VA outcomes for each type of amblyopia. The majority of patients (60%) achieve a VA outcome of ≤0.250 (logMAR) in the amblyopic eye. This is comparable to the previous audit where 59% of patients achieved a VA outcome of ≤0.250. Most patients still achieve a level of VA which is equal or almost equal to the fellow eye following amblyopia treatment. Treatment is still completed within a two-year period for the majority of patients (62%). There was only one adverse event and this related to atropine occlusion. Only 18 out of the 174 (10%) patients showed that occlusion could be discontinued following just six to eight weeks of treatment.

Conclusions

The treatment of amblyopia in the NEC is as successful as found in the previous audit and the current amblyopia treatment protocol remains effective. Only 10% of patients achieved the appropriate VA for amblyopia treatment to be ceased on their first return visit. This indicates that the follow-up length for patients undergoing amblyopia treatment could be extended beyond six to eight weeks without causing a detriment to VA outcome.

A Prospective Trial to Assess the Efficacy of Eye-Tracking-Based Binocular Treatment versus Patching for Children's Amblyopia: A Pilot Study

PURPOSE

To assess visual acuity (VA) and stereoacuity (SA) improvements in children with amblyopia treated with either binocular dichoptic treatment or patching treatment.

METHODS

In this pilot prospective coherent study, 34 participants between 4 and 9 years of age with unilateral anisometropic amblyopia and without history of prior amblyopia treatment were enrolled into three groups. Full treatment group (FTG; n = 12): participants were prescribed the binocular dichoptic treatment to watch for 90 minutes per day, 5 days a week. Part-time treatment group (PTTG; n = 8): participants were prescribed the same binocular treatment as FTG, 90 minutes per day, 3 days per week. Patching treatment group (PTG; n = 14): participants wore an adhesive patch over the dominant eye for 2 hours per day, 7 days per week. Amblyopic-eye distance visual acuity (DVA), near visual acuity (NVA) and SA were evaluated at baseline, 4, 8, and 12 weeks.

RESULTS

At 12 weeks, mean amblyopic-eye DVA improved 1.8 lines (95% CI, 1.1-2.5) in FTG, 1.5 lines (95% CI, 0.4-2.7) in PTTG and 3.0 lines (95% CI, 2.0-4.0) in PTG. The amblyopic-eye NVA improved 2.9 lines (95% CI, 2.4-3.5) in FTG, 1.7 lines (95% CI, 0.5-3.0) in PTTG and 2.8 lines (95% CI, 1.8-3.9) in PTG. The SA improved 0.38 log-arcseconds (95% CI, 0.24-0.53) in FTG, 0.59 log-arcseconds (95% CI, 0.36-0.82) in PTTG and 0.40 log-arcseconds (95% CI, 0.13-0.67) in PTG. No significant differences were found in DVA, NVA or SA improvement between FTG and PTG at 12 weeks.

CONCLUSIONS

VA and SA after binocular dichoptic treatment produced a similar therapeutic outcome to patching, suggesting a potential value for binocular therapy when treating anisometropic moderate degree of Children's amblyopia.

Comprehensive review of amblyopia: Types and management

The optimal method of treatment for a child depends on the patient's age at the time of diagnosis, the onset and type of amblyopia, and the degree of compliance attainable. In deprivation amblyopia, the cause of visual impairment (e.g., cataract, ptosis) needs to be treated first, and then the disorder can be treated such as other types of amblyopia. Anisometropic amblyopia needs glasses first. In strabismic amblyopia, conventionally amblyopia should be treated first, and then strabismus corrected. Correction of strabismus will have little if any effect on the amblyopia, although the timing of surgery is controversial. Best outcomes are achieved if amblyopia is treated before the age of 7 years. The earlier the treatment, the more efficacious it is. In selected cases of bilateral amblyopia, the more defective eye must be given a competitive advantage over the comparatively good eye. Glasses alone can work when a refractive component is present, but occlusion might make the glasses work faster. The gold standard therapy for amblyopia remains occlusion of the better eye although penalization is also evidenced to achieve equal results. Pharmacotherapy has been shown to achieve suboptimal outcomes. Newer monocular and binocular therapies based on neural tasks and games are adjuncts to patching and can also be used in adults.

Characteristics and predictive factors of visual function improvements after monocular perceptual learning in amblyopia

Monocular perceptual learning has shown promising performance in restoring visual function in amblyopes beyond the critical period in the laboratory. However, the treatment outcome is variable and indeterminate in actual clinical and neuroscientific practice. We aimed to explore the efficacy of monocular perceptual learning in the clinical setting. By combining continuous monitoring of perceptual learning and clinical measurements, we evaluated the efficacy and characteristics of visual acuity and contrast sensitivity function improvement and further explored the individualized effect after perceptual learning. Amblyopes (average age:17 ± 7 years old) were trained in a monocular two-alternative forced choice identification task at the 50% contrast threshold of the amblyopic eye for 10-15 days. We found that monocular perceptual learning improves both visual acuity and contrast sensitivity function in amblyopia. The broader activation of spatial contrast sensitivity, with a significant improvement in lower spatial frequencies, contributed to improving visual acuity. Visual acuity changes in the early stage can predict the endpoint treatment outcomes. Our results confirm the efficacy of monocular perceptual learning and suggest potential predictors of training outcomes to assist in the future management of clinical intervention and vision neuroscience research in amblyopia beyond the critical period of visual plasticity.

Amblyopia and the whole child

Amblyopia is a disorder of neurodevelopment that occurs when there is discordant binocular visual experience during the first years of life. While treatments are effective in improving visual acuity, there are significant individual differences in response to treatment that cannot be attributed solely to difference in adherence. In this considerable variability in response to treatment, we argue that treatment outcomes might be optimized by utilizing deep phenotyping of amblyopic deficits to guide alternative treatment choices. In addition, an understanding of the broader knock-on effects of amblyopia on developing visually-guided skills, self-perception, and quality of life will facilitate a whole person healthcare approach to amblyopia.

Gamification to Support Adherence to a Therapeutic Ambylopia Treatment for Children: Retrospective Study Using a Focal Ambient Visual Acuity Stimulation Game

BACKGROUND

The gold standard treatment for amblyopia is patching the better eye. Improvement of visual acuity in the amblyopic eye is significantly impacted by the adherence to the patching therapy. It is known that the overall adherence is rather low.

OBJECTIVE

This retrospective study evaluated whether an updated version of attention-binding digital therapeutic games based on the principle of focal ambient visual acuity stimulation (FAVAS) would result in improved patient adherence in 4- to 16-year-old patients with amblyopia associated with anisometropia or strabismus.

METHODS

We analyzed electronically pseudonymized recorded data from patients treated with occlusion therapy and FAVAS therapeutic games. One group used an older version (2015) and the other group used a newer version (2020) that provided more attractive therapeutic games with tablet computer functionality. Objective adherence was calculated by comparing the number of minutes using the therapeutic games as monitored in the automatized logbook versus the prescribed number of minutes for using the games.

RESULTS

Children in group 2015 (n=138) spent on average 2009.3 (SD 1372.1; range 36-5556) minutes using FAVAS; children in group 2020 (n=129) spent on average 2651.2 (SD 1557.1; range 38-5672) minutes using the newer version. Group 2020 spent on average 641.9 more minutes on FAVAS than group 2015 (t_255.49=3.56, P<.001, d=0.45; 95% CI 0.69-0.20). Although patient adherence was very variable, compared to the 55.0% (SD 29.4%) in group 2015, it significantly improved up to 68.5% (SD 33.7%) in group 2020 (t_254.38=3.48, P=.001, d=0.44; 95% CI 0.68-0.19).

CONCLUSIONS

FAVAS 2020, with improved gamification aspect as well as tablet computer functionality, increased adherence significantly compared to the earlier version of FAVAS 2015, indicating that FAVAS 2020 could be an effective approach to support adherence to amblyopia treatment.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS) DRKS00017633; https://drks.de/search/de/trial/DRKS00017633.

Amblyopia: A review of unmet needs, current treatment options, and emerging therapies

Amblyopia is a global public health issue with extensive, multifaceted impacts on vision and quality of life (QoL) for both patients and families. Geographical variation exists in the management of amblyopia, with traditional mainstay treatments, optical correction, and fellow eye occlusion most successful when implemented at an early age. In recent years, however, studies demonstrating meaningful improvements in older children and adults have challenged the concept of a complete loss of visual processing plasticity beyond the critical period of visual development, with growing evidence supporting the potential efficacy of emerging, more engaging, binocular therapies in both adults and children. Binocular approaches aim to restore deficits in amblyopia that extend beyond monocular visual acuity impairment, including binocular fusion and visuomotor skills. In view of this, incorporating outcome measures that evaluate the visual performance and functional ability of individuals with amblyopia will provide a clearer understanding of the effect of amblyopia on QoL and a more comprehensive evaluation of amblyopia therapies.

Ocular and visual perceptive factors associated with treatment outcomes in patients with anisometropic amblyopia

BACKGROUND

The aim of this observational study was to identify ocular and visual perceptive risk factors related to treatment results following refractive correction and patching in children with anisometropic amblyopia, who were between the ages of 4 to 14 years old.

METHODS

One-hundred and two children with newly diagnosed anisometropic amblyopia were recruited. Successful treatment of amblyopia was defined as the final best corrected visual acuity (BCVA) better than or equal to 0.1 logMAR and amblyopic eye BCVA within 1 line of the sound eye BCVA by the end of the treatment period. BCVA, cycloplegic refraction, stereoacuity, perceptual eye position (PEP) and interocular suppression were measured.

RESULTS

Of these patients, 45.10% achieved successful treatment of amblyopia after refractive correction and patching for 10.5 months. The mean age was not significantly different between patients who were successfully and unsuccessfully treated (5.50 ± 1.59 years vs 6.14 ± 2.19 years, respectively). Patients who failed treatment had significantly larger interocular difference of BCVA at the time of initial treatment (successful group: 0.33 ± 0.29 logMAR, unsuccessful group: 0.65 ± 0.35 logMAR) and after refractive adaptation (successful group: 0.15 ± 0.13 logMAR, unsuccessful group: 0.42 ± 0.35 logMAR). They also had higher spherical equivalent (SE) of amblyopic eyes (successful group: 3.08 ± 3.61 D, unsuccessful group: 5.27 ± 3.38 D), bigger interocular difference of SE (successful group: 0.94 ± 2.71 D, unsuccessful group: 3.09 ± 3.05 D), worse stereoacuity (successful group: 2.32 ± 0.37 log seconds of arc, unsuccessful group: 2.75 ± 0.32 log seconds of arc), larger vertical PEP deviation (successful group: 6.41 ± 6.08 pixel, unsuccessful group: 19.07 ± 24.96 pixel) and deeper interocular suppression (successful group: 21.7 ± 19.7%, unsuccessful group: 37.8 ± 27.1%) than those of successfully treated patients. The most influential treatment failure risk factors were larger vertical PEP deviation [adjusted odds ratio (OR) (95% confidence interval) 1.12 (1.02-1.22)] and worse stereoacuity [adjusted odds ratio (OR) (95% confidence interval) 7.72 (1.50-39.85)] in multiple logistic regression analysis.

CONCLUSIONS

Larger vertical PEP deviation and worse stereoacuity were the most influential treatment failure risk factors in children with anisometropic amblyopia. The vertical PEP deviation and stereoacuity, which can reflect interocular interaction, may be useful in predicting the response to therapy.

Cost-effectiveness of Universal School- and Community-Based Vision Testing Strategies to Detect Amblyopia in Children in Ontario, Canada

IMPORTANCE

Screening for amblyopia in primary care visits is recommended for young children, yet screening rates are poor. Although the prevalence of amblyopia is low (3%-5%) among young children, universal screening in schools and mandatory optometric examinations may improve vision care, but the cost-effectiveness of these vision testing strategies compared with the standard in primary care is unknown.

OBJECTIVE

To evaluate the relative cost-effectiveness of universal school screening and mandated optometric examinations compared with standard care vision screening in primary care visits in Toronto, Canada, with the aim of detecting and facilitating treatment of amblyopia and amblyopia risk factors from the Ontario government's perspective.

DESIGN, SETTING, AND PARTICIPANTS

An economic evaluation was conducted from July 2019 to May 2021 using a Markov model to compare 15-year costs and quality-adjusted life-years (QALYs) between school screening and optometric examination compared with primary care screening in Toronto, Canada. Parameters were derived from published literature, the Ontario Schedule of Benefits and Fees, and the Kindergarten Vision Testing Program. A hypothetical cohort of 25 000 children aged 3 to 5 years was simulated. It was assumed that children in the cohort had irreversible vision impairment if not diagnosed by an optometrist. In addition, incremental costs and outcomes of 0 were adjusted to favor the reference strategy. Vision testing programs were designed to detect amblyopia and amblyopia risk factors.

MAIN OUTCOMES AND MEASURES

For each strategy, the mean costs per child included the costs of screening, optometric examinations, and treatment. The mean health benefits (QALYs) gained were informed by the presence of vision impairment and the benefits of treatment. Incremental cost-effectiveness ratios were calculated for each alternative strategy relative to the standard primary care screening strategy as the additional cost required to achieve an additional QALY at a willingness-to-pay threshold of $50 000 Canadian dollars (CAD) ($37 690) per QALY gained.

RESULTS

School screening relative to primary care screening yielded cost savings of CAD $84.09 (95% CI, CAD $82.22-$85.95) (US $63.38 [95% CI, US $61.97-$64.78]) per child and an incremental gain of 0.0004 (95% CI, -0.0047 to 0.0055) QALYs per child. Optometric examinations relative to primary care screening yielded cost savings of CAD $74.47 (95% CI, CAD $72.90-$76.03) (US $56.13 [95% CI, $54.95-$57.30]) per child and an incremental gain of 0.0508 (95% CI, 0.0455-0.0561) QALYs per child. At a willingness-to-pay threshold of CAD $50 000 (US $37 690) per QALY gained, school screening and optometric examinations were cost-effective relative to primary care screening in only 20% and 29% of iterations, respectively.

CONCLUSIONS AND RELEVANCE

In this study, because amblyopia prevalence is low among young children and most children in the hypothetical cohort had healthy vision, universal school screening and optometric examinations were not cost-effective relative to primary care screening for detecting amblyopia in young children in Toronto, Canada. The mean added health benefits of school screening and optometric examinations compared with primary care screening did not warrant the resources used.

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

PURPOSE

To investigate the treatment policy for amblyopia in Japan as of 2017 through a survey of multiple facilities and to compare the findings with those obtained by the Amblyopia Treatment Study (ATS) of the Pediatric Eye Disease Investigator Group.

STUDY DESIGN

Questionnaire survey study.

SUBJECTS AND METHODS

A questionnaire was sent to 181 facilities where patients with amblyopia are being treated. The outcomes of the present survey were compared with the results of the ATS study, and the coincidence rates were evaluated.

RESULTS

The questionnaire response rate was 68.0%. The treatment plan that showed the highest agreement between the outcomes of the ATS study and the present study was whether or not treatment was to be given to patients aged 10-15 years who had received no previous treatment; 90% of the facilities answered that they would provide treatment to such patients as well. The next highest agreement was the future treatment of amblyopia with stable visual acuity in the affected eye; 82.6% of the facilities responded that they would reduce the occlusion time. On the other hand, the lowest agreement rate was the follow-up period of the refractive correction for moderate anisometropic amblyopia. The ATS showed "4 months," whereas most of the facilities in the present survey replied "3 months." The agreement rate was 10.8%.

CONCLUSION

The amblyopia treatment in Japan survey did not always agree with the research results of the ATS. Japanese ophthalmologists tend to make treatment plans for amblyopia according to their clinical experience.

Evaluation of the SpotChecks contrast sensitivity test in children

PURPOSE

The purpose of this study was to determine intrasession repeatability of a worksheet style contrast sensitivity test (SpotChecks) in children and agreement with an established contrast sensitivity test (Pelli-Robson).

METHODS

Forty-three children aged 4 to 12 years participated in this single visit study that included two administrations of the SpotChecks binocularly, a single administration of the Pelli-Robson test and other measures of visual performance such as high-contrast visual acuity. Test order was randomised, and participants wore their habitual correction (39 unaided, 4 wearing glasses) for testing. Bland-Altman plots were used to assess the test-retest repeatability of SpotChecks and its agreement with the Pelli-Robson test. Multiple linear regressions were performed to evaluate whether contrast sensitivity was related to participant characteristics such as age, sex and near binocular visual acuity.

RESULTS

The mean difference in log contrast sensitivity (logCS) between two administrations of the SpotChecks was 0.01, with a coefficient of repeatability (1.96*SD of differences) of 0.14 logCS. The mean difference between SpotChecks and Pelli-Robson was 0.00 logCS with 95% limits of agreement of -0.19 to +0.20. For both tests, a statistically significant increase in logCS was associated with age (slopes were 0.02 logCS/year, p < 0.001 and 0.01 logCS/year, p = 0.02 for the SpotChecks and Pelli-Robson tests, respectively).

CONCLUSIONS

The SpotChecks test shows good intrasession repeatability and excellent agreement with the Pelli-Robson test in children. Contrast sensitivity showed an increase in logCS with age in children for both tests.

Validation of the PowerRef 3 for Measuring Accommodation: Comparison With the Grand Seiko WAM-5500A Autorefractor

Purpose

This validation study examines the PowerRef 3 as a method for measuring accommodation objectively. We assess agreement with refractive measurements obtained simultaneously by the Grand Seiko WAM-5500A autorefractor.

Methods

Refractive measurements were recorded simultaneously using the PowerRef 3 and WAM-5500A in 32 noncyclopleged participants aged 15 to 46 years. Accommodative states were recorded for 10 seconds at six accommodative demands (5 diopters [D], 4 D, 3 D, 2.5 D, 2 D, and 0 D) while participants fixated a high-contrast Maltese cross. WAM-5500A measurements were converted to power in the vertical meridian for comparison with PowerRef 3 data. Dioptric difference values were computed, and agreement was assessed using Bland-Altman plots with 95% limits of agreement (LOA) and intraclass correlation coefficient analyses.

Results

The mean absolute dioptric differences measured 0.14 D or less across accommodative demands. Analyses showed an excellent intraclass correlation coefficient across the tested demands (0.93). Bland-Altman plots indicated a bias of -0.02 D with 95% LOA of -1.03 D to 0.99 D. The 95% LOA was smallest for the 3 D demand (-0.71 D to 0.64 D), and largest at 5 D demand (-1.51 D to 1.30 D).

Conclusions

The mean dioptric differences between the PowerRef 3 and WAM-5500A autorefractor were small and not clinically significant. While some variability in agreement was observed depending on the tested demand, the PowerRef 3 demonstrated good agreement with the WAM-5500A.

Translational Relevance

The PowerRef 3 may be used to obtain objective measures of accommodation both monocularly and binocularly and provides a more flexible method, especially in pediatric populations.

Treatment compliance in amblyopia: A mini-review and description of a novel online platform for compliance tracking

Patient compliance with amblyopia therapies, including eye patching and atropine drops, is crucial for optimal visual acuity outcomes. Studies utilizing objective measures of compliance measurement have consistently shown that a majority of patients receive significantly less treatment than prescribed. We review the subjective and objective compliance rates reported in the literature, assess possible explanations for poor compliance and describe studies of interventions to improve compliance. Additionally, we report our experience implementing Inside Out Care, a novel online platform designed to improve monitoring of amblyopia patient compliance, in our clinics. We have found that this platform, which is accessible via both computer and smartphone, has improved monitoring of amblyopia patient patching compliance, as well as allowed for enhanced doctor-patient communication.

Recent Treatment Advances in Amblyopia

Occlusion therapy has a long history as the gold standard treatment for amblyopia. Over the past two decades, large multicenter randomized controlled trials and objective dose-monitoring studies have characterized the effects of refractive correction, patching, and atropine penalization, providing insights into the impact of factors such as age and treatment dose. More recent approaches, whose development has been accelerated by advances in technology, are designed to provide different stimulation to the amblyopic eye and the fellow eye. This review explores a variety of such dichoptic approaches, categorized according to whether they primarily feature requisite use of the amblyopic eye in the face of fellow-eye masking, integration of visual information from both eyes, or reduction of stimulus salience in the fellow eye. It is still unclear whether dichoptic treatments are superior to traditional, low-cost treatment methods or whether their therapeutic mechanisms are fundamentally different from those of established treatments. Expected final online publication date for the Annual Review of Vision Science, Volume 8 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Randomized clinical trial of streaming dichoptic movies versus patching for treatment of amblyopia in children aged 3 to 7 years

Contrast-rebalanced dichoptic movies have been shown to be an effective binocular treatment for amblyopia in the laboratory. Yet, at-home therapy is a more practical approach. In a randomized clinical trial, we compared dichoptic movies, streamed at-home on a handheld 3D-enabled game console, versus patching as amblyopia treatment. Sixty-five amblyopic children (3–7 years; 20/32–125) were randomly assigned to one of two parallel arms, binocular treatment (3 movies/week) or patching (14 h/week). The primary outcome, change in best corrected visual acuity (BCVA) at the 2-week visit was completed by 28 and 30, respectively. After the primary outcome, both groups of children had the option to complete up to 6 weeks of binocular treatment. At the 2-week primary outcome visit, BCVA had improved in the movie (0.07 ± 0.02 logMAR; p < .001) and patching (0.06 ± 0.01 logMAR; p < 0.001) groups. There was no significant difference between groups (CI₉₅%: − 0.02 to 0.04; p = .48). Visual acuity improved in both groups with binocular treatment up to 6 weeks (0.15 and 0.18 logMAR improvement, respectively). This novel, at-home, binocular movie treatment improved amblyopic eye BCVA after 2 weeks (similar to patching), with additional improvement up to 6 weeks. Repeated binocular visual experience with contrast-rebalanced binocular movies provides an additional treatment option for amblyopia.

Clincaltrials.gov identifier: NCT03825107 (31/01/2019).

Visual Acuity Outcomes and Loss to Follow-up in the Treatment of Amblyopia in Children From Lower Socioeconomic Backgrounds

PURPOSE

To compare visual acuity outcomes and loss to follow-up after initiation of treatment for unilateral amblyopia in children from different socioeconomic backgrounds.

METHODS

Medical records of children diagnosed as having unilateral amblyopia at an initial encounter between 2015 and 2018 were reviewed. Medicaid and private insurance were used as proxies for socioeconomic status (SES). Data points were collected at the patients' initial, follow-up, and final visits. Visual acuity improvement was the primary outcome variable in patients with at least one follow-up appointment. In a separate analysis, failure to attend a single follow-up appointment was examined for associations with SES, race, sex, and distance traveled to appointments.

RESULTS

Seventy-three patients met the inclusion criteria; of these, 28 had Medicaid and 45 had private insurance. Visual acuity improved by 2.86 lines in the Medicaid group and 2.98 lines in the private insurance group (P = .84). Number of missed appointments and distance traveled did not correlate with visual acuity improvement. In the loss to follow-up subanalysis, 40 of 141 (28.4%) patients with Medicaid and 11 of 107 (10.3%) patients with private insurance failed to attend a single follow-up visit (P = .001). No association was found between loss to follow-up and race, sex, or distance traveled.

CONCLUSIONS

Visual acuity outcomes of treatment for amblyopia did not differ between patients with Medicaid and patients with private insurance who followed up. However, patients with Medicaid were much more likely to be immediately lost to follow-up. Measures should be taken by eye care providers and pediatricians to increase follow-up in patients from low SES populations. [J Pediatr Ophthalmol Strabismus. 2022;59(2):110-117.].

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.

Management of amblyopia in pediatric patients: Current insights

Amblyopia is a cause of significant ocular morbidity in pediatric population and may lead to visual impairment in future life. It is caused due to formed visual deprivation or abnormal binocular interactions. Several risk factors in pediatric age group may lead to this disease. Author groups have tried managing different types of amblyopia, like anisometropic amblyopia, strabismic amblyopia and combined mechanism amblyopia, with optical correction, occlusion therapy, penalization, binocular therapy and surgery. We review historical and current management strategies of different types of amblyopia affecting children and outcomes in terms of visual acuity, binocularity and ocular deviation, highlighting evidence from recent studies. Literature searches were performed through Pubmed. Risk factors for amblyopia need to be identified in pediatric population as early in life as possible and managed accordingly, as visual outcomes in amblyopia are best if treated at the earliest. Although, monocular therapies like occlusion or penalization have been shown to be quite beneficial over the years, newer concepts related to binocular vision therapy are still evolving.

Current Management of Amblyopia with New Technologies for Binocular Treatment

Amblyopia is the most common cause of monocular poor vision affecting up to 3.7% of the global population. Classically, the first step in treatment has been optical correction, followed by patching and/or pharmacological treatment. However, this is an evolving scenario, since researchers and clinicians are interested in new binocular treatments due to the increasing development of new technologies. In this article main, current binocular treatments as Dig Rush, falling blocks, I-BiT, Occlu-tab, Vivid Vision, and movies are reviewed for binocular amblyopia management.

Effects of Atropine Treatment on Choroidal Thickness in Myopic Children

Purpose

To examine the changes in choroidal thickness (ChT) after 6 months of 1% or 0.01% atropine treatment and the independent factors associated with eye elongation.

Methods

A total of 207 myopic children aged 6 to 12 years were recruited and randomly assigned to groups A and B in a ratio of 1:1. Participants in group A received 1% atropine once a day for 1 week, and then once a week for 23 weeks. Participants in group B received 0.01% atropine once a day for 6 months. ChT and internal axial length (IAL) were measured at baseline, 1 week, 3 months, and 6 months.

Results

In group A, the ChT significantly increased after a 1-week loading dose of 1% atropine (26 ± 14 µm; P < 0.001) and the magnitude of increase stabilized throughout the following weekly treatment. The internal axial length did not significantly change at the 6-month visit (−0.01 ± 0.11 mm; P = 0.74). In contrast, a decreased ChT (−5 ± 17 µm; P < 0.001) and pronounced eye elongation (0.19 ± 0.12 mm; P < 0.001) were observed in group B after 6 months. Multivariable regression analysis showed that less increase in ChT at the 1-week visit (P = 0.03), younger age (P < 0.001), and presence of peripapillary atrophy (P = 0.001) were significantly associated with greater internal axial length increase over 6 months in group A.

Conclusions

One percent atropine could increase the ChT, whereas 0.01% atropine caused a decrease in ChT after 6 months of treatment. For participants receiving 1% atropine, the short-term increase in ChT was negatively associated with long-term eye elongation. Younger age and the presence of peripapillary atrophy were found to be risk factors for greater eye elongation.

The Risks and Benefits of Myopia Control

PURPOSE

The prevalence of myopia is increasing around the world, stimulating interest in methods to slow its progression. The primary justification for slowing myopia progression is to reduce the risk of vision loss through sight-threatening ocular pathologic features in later life. The article analyzes whether the potential benefits of slowing myopia progression by 1 diopter (D) justify the potential risks associated with treatments.

METHODS

First, the known risks associated with various methods of myopia control are summarized, with emphasis on contact lens wear. Based on available data, the risk of visual impairment and predicted years of visual impairment are estimated for a range of incidence levels. Next, the increased risk of potentially sight-threatening conditions associated with different levels of myopia are reviewed. Finally, a model of the risk of visual impairment as a function of myopia level is developed, and the years of visual impairment associated with various levels of myopia and the years of visual impairment that could be prevented with achievable levels of myopia control are estimated.

RESULTS

Assuming an incidence of microbial keratitis between 1 and 25 per 10 000 patient-years and that 15% of cases result in vision loss leads to the conclusion that between 38 and 945 patients need to be exposed to 5 years of wear to produce 5 years of vision loss. Each additional 1 D of myopia is associated with a 58%, 20%, 21%, and 30% increase in the risk of myopic maculopathy, open-angle glaucoma, posterior subcapsular cataract, and retinal detachment, respectively. The predicted mean years of visual impairment ranges from 4.42 in a person with myopia of -3 D to 9.56 in a person with myopia of -8 D, and a 1-D reduction would lower these by 0.74 and 1.21 years, respectively.

CONCLUSIONS

The potential benefits of myopia control outweigh the risks: the number needed to treat to prevent 5 years of visual impairment is between 4.1 and 6.8, whereas fewer than 1 in 38 will experience a loss of vision as a result of myopia control.

Amblyopia treatment: an evidence‐based approach to maximising treatment outcome

The basis of treatment for amblyopia (poor vision due to abnormal visual experience early in life) for 250 years has been patching of the unaffected eye for extended times to ensure a period of use of the affected eye. Over the last decade randomised controlled treatment trials have provided some evidence on how to tailor amblyopia therapy more precisely to achieve the best visual outcome with the least negative impact on the patient and the family. This review highlights the expansion of knowledge regarding treatment for amblyopia and aims to provide optometrists with a summary of research evidence to enable them to better treat amblyopia. Treatment for amblyopia is effective, as it reduces overall prevalence and severity of visual loss in this population. Correction of refractive error alone significantly improves visual acuity, sometimes to the point where further amblyopia treatment is not required. Atropine penalisation and patch occlusion are effective in treating amblyopia. Lesser amounts of occlusion or penalisation have been found to be just as effective as greater amounts. Recent evidence has highlighted that occlusion or penalisation in amblyopia treatment can create negative changes in behaviour in children and impact on family life. These complications should be considered when prescribing treatment because they can negatively affect compliance. Studies investigating the maximum age at which treatment of amblyopia can still be effective and the importance of near activities during occlusion are ongoing.

Amblyopia: prevalence, natural history, functional effects and treatment

Amblyopia, defined as poor vision due to abnormal visual experience early in life, affects approximately three per cent of the population and carries a projected lifetime risk of visual loss of at least 1.2 per cent. The presence of amblyopia or its risk factors, mainly strabismus or refractive error, have been primary conditions targeted in childhood vision screenings. Continued support for such screenings requires evidence-based understanding of the prevalence and natural history of amblyopia and its predisposing conditions, and proof that treatment is effective in the long term with minimal negative impact on the patient and family. This review summarises recent research relevant to the clinical understanding of amblyopia, including prevalence data, risk factors, the functional impact of amblyopia and optimum treatment regimes and their justification from a vision and life skills perspective. Collectively, these studies indicate that treatment for amblyopia is effective in reducing the overall prevalence and severity of visual loss from amblyopia. Correction of refractive error alone has been shown to significantly reduce amblyopia and less frequent occlusion can be just as effective as more extensive occlusion. Occlusion or penalisation in amblyopia treatment can create negative changes in behaviour in children and impact on family life, and these factors should be considered in prescribing treatment, particularly because of their influence on compliance. Ongoing treatment trials are being undertaken to determine both the maximum age at which treatment of amblyopia can still be effective and the importance of near activities during occlusion. This review highlights the expansion of current knowledge regarding amblyopia and its treatment to help clinicians provide the best level of care for their amblyopic patients that current knowledge allows.

Efficacy of vision-based treatments for children and teens with amblyopia: a systematic review and meta-analysis of randomised controlled trials

Objective

To identify differences in efficacy between vision-based treatments for improving visual acuity (VA) of the amblyopic eye in persons aged 4-17 years old.

Data sources

Ovid Embase, PubMed (Medline), the Cochrane Library, Vision Cite and Scopus were systematically searched from 1975 to 17 June 2020.

Methods

Two independent reviewers screened search results for randomised controlled trials of vision-based amblyopia treatments that specified change in amblyopic eye VA (logMAR) as the primary outcome measure. Quality was assessed via risk of bias and GRADE (Grading of Recommendations, Assessment, Development, and Evaluations).

Results

Of the 3346 studies identified, 36 were included in a narrative synthesis. A random effects meta-analysis (five studies) compared the efficacy of binocular treatments versus patching: mean difference -0.03 logMAR; 95% CI 0.01 to 0.04 (p<0.001), favouring patching. An exploratory study-level regression (18 studies) showed no statistically significant differences between vision-based treatments and a reference group of 2-5 hours of patching. Age, sample size and pre-randomisation optical treatment were not statistically significantly associated with changes in amblyopic eye acuity. A network meta-analysis (26 studies) comparing vision-based treatments to patching 2-5 hours found one statistically significant comparison, namely, the favouring of a combination of two treatment arms comparing combination and binocular treatments, against patching 2-5 hours: standard mean difference: 2.63; 95% CI 1.18 to 4.09. However, this result was an indirect comparison calculated from a single study. A linear regression analysis (17 studies) found a significant relationship between adherence and effect size, but the model did not completely fit the data: regression coefficient 0.022; 95% CI 0.004 to 0.040 (p=0.02).

Conclusion

We found no clinically relevant differences in treatment efficacy between the treatments included in this review. Adherence to the prescribed hours of treatment varied considerably and may have had an effect on treatment success.

The use of atropine for treatment of amblyopia using the OptumLabs Data Warehouse

Atropine and patching are standard treatments for amblyopia, but the prevalence of atropine therapy in the United States is unknown. This study used the OptumLabs Data Warehouse to evaluate pharmacy claims for topical atropine to evaluate the frequency of its treatment for amblyopia and to compare demographic factors in cohorts of amblyopic children who were and were not prescribed atropine. Overall, 55.2% of amblyopic children were prescribed atropine more than once. The children who were prescribed atropine had a higher likelihood of living in geographic regions in the South or Midwest.

Amblyopia

Amblyopia is a neurodevelopmental abnormality that results in physiological alterations in the visual pathways and impaired vision in one eye, less commonly in both. It reflects a broad range of neural, perceptual, oculomotor, and clinical abnormalities that can occur when normal visual development is disrupted early in life. Aside from refractive error, amblyopia is the most common cause of vision loss in infants and young children. It causes a constellation of perceptual deficits in the vision of the amblyopic eye, including a loss of visual acuity, position acuity, and contrast sensitivity, particularly at high spatial frequencies, as well as increased internal noise and prolonged manual and saccadic reaction times. There are also perceptual deficits in the strong eye, such as certain types of motion perception, reflecting altered neural responses and functional connectivity in visual cortex (Ho et al., 2005). Treatment in young children consists of correction of any refractive error and patching of the strong eye. Compliance with patching is challenging and a substantial proportion of amblyopic children fail to achieve normal acuity or stereopsis even after extended periods of treatment. There are a number of promising experimental treatments that may improve compliance and outcomes, such as the playing of action video games with the strong eye patched. Although there may be a sensitive period for optimal effects of treatment, there is evidence that amblyopic adults may still show some benefit of treatment. However, there is as yet no consensus on the treatment of adults with amblyopia.

High Rates of Uncorrected Vision Conditions among Schoolchildren in Rural Queensland, Australia

SIGNIFICANCE

This study is the first to report high rates of uncorrected vision conditions among Australian secondary schoolchildren living in a rural area and to comment on the rate of eye examinations undertaken on Australian Indigenous children. Uncorrected vision problems that continue throughout the school years have significant implications for children's quality of life and education.

PURPOSE

This study aimed to investigate the prevalence of uncorrected vision conditions among Australian schoolchildren.

METHODS

Participants included 280 students from rural primary and secondary schools (aged 4 to 18 years), of whom 40% identified as being of Aboriginal and/or Torres Strait Islander descent (Indigenous). All participants underwent an eye examination including measurements of monocular distance and near visual acuity, assessment of accommodative and vergence function, stereoacuity, color vision, and cycloplegic autorefraction. A parental questionnaire was used to determine whether the child had previously had his/her eyes examined.

RESULTS

The overall prevalence of uncorrected vision conditions in this population was 35%. The odds of previously having had an eye examination were 2.3× higher for non-Indigenous compared with Indigenous children despite both groups exhibiting high rates of uncorrected vision conditions (Indigenous, 31 [29%]; non-Indigenous, 66 [40%]; χ21 = 3.24, P = .07). Of the children who had significant refractive error (Indigenous, 23 [21%]; non-Indigenous, 49 [30%]; χ21 = 2.70, P = .10), 82% were uncorrected, and only 39% of Indigenous children and 54% of non-Indigenous children had previously had an eye examination.

CONCLUSIONS

These findings suggest that high rates of uncorrected vision conditions are present among Australian primary and secondary schoolchildren from a rural area and highlight that Indigenous children are much less likely to have had an eye examination. Understanding factors that affect the rate of eye examinations and compliance with spectacle correction must be addressed given the potential impact of these vision conditions.

A Randomized Trial of Objective Spectacle Prescriptions for Adults with Down Syndrome: Baseline Data and Methods

SIGNIFICANCE

It is difficult to determine the most efficacious refractive correction for individuals with Down syndrome using routine clinical techniques. New objective methods that optimize spectacle corrections for this population may reduce limitations on daily living by improving visual quality.

PURPOSE

This article describes the methods and baseline characteristics of study participants in a National Eye Institute-sponsored clinical trial to evaluate objectively derived spectacle corrections in adults with Down syndrome. Intersession repeatability of the primary outcome measure (distance visual acuity) is also reported.

METHODS

Adults with Down syndrome were enrolled into a nine-visit study to compare clinically derived spectacle corrections and two different objective spectacle corrections derived from wavefront aberration data. Spectacle corrections were randomized and dispensed for 2 months each. Distance visual acuity was measured with a Bailey-Lovie-style chart. Intersession repeatability of acuity was established by performing difference versus mean analysis from binocular acuity measures obtained through habitual corrections at visits 1 and 2.

RESULTS

Thirty adults (mean ± standard deviation age, 29 ± 10 years) with a large range of refractive errors were enrolled. Presenting visual acuity at visit 1 was reduced (right eye, 0.47 ± 0.20 logMAR; left eye, 0.42 ± 0.17 logMAR). The mean difference between visits 1 and 2 was 0.02 ± 0.06 logMAR, with a coefficient of repeatability (1.96 × within-subject standard deviation) of 0.12 logMAR.

CONCLUSIONS

This study seeks to investigate new strategies to determine optical corrections that may reduce commonly observed visual deficits in individuals with Down syndrome. The good intersession repeatability of acuity found in this study (six letters) indicates that, despite the presence of reduced acuity, adults with Down syndrome performed the outcome measure for this clinical trial reliably.

Using OCT Fixation Shift to Assess Eccentric Fixation in Children With Residual Amblyopia

Purpose

Eccentric fixation in amblyopia is often estimated grossly without precision. Although the usefulness of optical coherence tomography (OCT) fixation shift in the quantification of eccentric fixation in a small cohort of amblyopic children was recently reported, there is a lack of understanding of characteristics of OCT fixation shift. In a retrospective cohort study, we evaluated eccentric fixation with OCT in a large cohort of children with residual amblyopia.

Methods

Children, age 4 to 17 years, with residual amblyopia (amblyopic, n = 56) and without amblyopia (control, n = 75) were enrolled. Amblyopia was associated with anisometropia alone (anisometropia subtype, n = 28) and strabismus without or with anisometropia (strabismic subtype, n = 28). Spectral domain OCT was used to estimate fixation. The OCT fixation shift, defined as the distance between the fovea and the fixation point, was measured and adjusted with calculated axial length and converted into visual degrees. Fixation shift in amblyopic eyes, fellow nonamblyopic eyes, and right eyes of the control group were compared. Fixation shift between the anisometropic and strabismic amblyopia subtypes was also compared. Its correlation with visual acuity was estimated.

Results

The mean fixation shift was significantly different: 0.17° ± 0.29° for control right eyes, 0.94° ± 1.24° for amblyopic eyes, and 0.34° ± 0.57° for fellow eyes (χ² = 23.3; P < 0.001). There was no significant difference between fellow eyes and control eyes (P = 0.11). Fixation shift in amblyopic eyes was significantly correlated with visual acuity (R = 0.44; P < 0.001), and it was significantly smaller in the anisometropic subtype than in the strabismic subtypes (0.34° ± 0.46° vs. 1.54° ± 1.48°, W = 338, P < 0.001).

Conclusions

OCT fixation shift can be used both in detection and quantification of eccentric fixation in children with residual amblyopia, especially in those with strabismus.

Translational Relevance

OCT fixation shift offers a convenient clinical approach in quantitative evaluation of eccentric fixation in children with strabismic amblyopia.

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.