Effect of a Binocular iPad Game vs Part-time Patching in Children Aged 5 to 12 Years With Amblyopia

Abstract

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

Amblyopia: New molecular/pharmacological and environmental approaches

“…Since the lack of binocular function is a key risk factor for persistent amblyopia, the development of new binocular training strategies may have a substantial impact on improving acuity and recovering stereopsis (reviewed in Levi et al, 2015). Unfortunately, recent randomized clinical trials have failed to provide evidence that video games are any better than patching in older children or that they improve binocular function (Holmes et al, 2016; Kelly et al, 2016). Future work will be required to elucidate how monocular and dichoptic experience contribute to amblyopia recovery across distinct patient populations.…”

From suppression to stereoacuity: a composite binocular function score for clinical research

“…In addition to reporting visual acuity change, recent amblyopia treatment studies, including randomised clinical trials, have sought to quantify changes in the level of suppression or stereoacuity . This requires recording binocular function in individuals with a broad range of measureable stereoacuity through to those with complete suppression and no measurable stereopsis.…”

Optical treatment of amblyopia in older children and adults is essential prior to enrolment in a clinical trial

“…However, the drug and dosage varied depending on local clinical standards and participant characteristics such as age and iris pigment. Study prescribing criteria were based on established amblyopia clinical trial protocols published by PEDIG . Myopia and astigmatism were fully corrected for each eye, hyperopia could be under‐corrected by up to 1.50 DS from the cycloplegic refraction but the reduction in plus sphere was symmetrical so that anisometropia was fully corrected, and presbyopia (if present) was corrected with near addition lenses (see Appendix ).…”

“…Study prescribing criteria were based on established amblyopia clinical trial protocols published by PEDIG. 13,[38][39][40] Myopia and astigmatism were fully corrected for each eye, hyperopia could be under-corrected by up to 1.50 DS from the cycloplegic refraction but the reduction in plus sphere was symmetrical so that anisometropia was fully corrected, and presbyopia (if present) was corrected with near addition lenses (see Appendix S1). Clinicians could prescribe standard spectacle lenses, lenses designed to reduce aniseikonia, and/or soft contact lenses at their discretion.…”

“…Additional improvements in DVA and stereoacuity outside the main analyses were found for some ineligible participants when follow-up was extended, indicating that our 0.30 logMAR eligibility cut-off prevented measurement of maximum possible improvements. In addition, our stability criterion of ≤0.10 logMAR change per four weeks, which was based on known test-retest variability of the e-ETDRS test 35,36 and clinical trial protocols for children, 22,38,39 may miss improvements slower than one logMAR line per four weeks. The criterion also did not account for other visual outcomes that potentially may follow a different time-course, such as stereoacuity.…”