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

Abstract

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.

Conflict of interest statement

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported.

Figures

Figure 1.. Consolidated Standards of Reporting Trials (CONSORT) Diagram

Shown are the numbers of completed and missed visits during the 4-week study. One child randomized to the binocular game missed the 2-week visit because of a scheduling conflict but attended the 4-week visit. There were no dropouts between baseline and the 4-week visit.

Figure 2.. Screen Shot of Dig Rush

High-contrast red elements (miners and fireball) are seen by the amblyopic eye. Low-contrast blue elements (gold and cart) are seen by the fellow eye. Gray elements (rocks and ground) are seen by both eyes. Both eyes must see the game for successful play. Dig Rush was developed in collaboration with Robert Hess, PhD, DSc, at McGill University (Montréal, Québec, Canada), and Amblyotech (Atlanta, Georgia) and UbiSoft (Montréal).

Figure 3.. Best-Corrected Visual Acuity (BCVA) at Baseline, the 2-Week Visit, and the 4-Week Visit

Shown is amblyopic eye BCVA for the binocular game and patching at each visit. The patching group crossed over to the binocular game at the 2-week visit. Error bars represent SEs.

Figure 4.. Best-Corrected Visual Acuity (BCVA) Improvement From Baseline at 4 Weeks

Shown is amblyopic eye BCVA for the binocular game first children (circles) and patching crossover children (squares) at the 4-week visit. Data points above the line indicate improvement. Overlapping symbols are slightly shifted for clarity.

Figure 5.. Improvement in Depth of Suppression

Depth of suppression improved from the baseline visit to the 2-week visit for the binocular game and patching. Error bars represent SEs.