Clinic Trial: Binocular iPad Game vs Patching for Treatment of Amblyopia in Children

Key Points

Questions  Will a binocular iPad (Apple Inc) game be effective in treating childhood amblyopia, and how does the visual acuity improvement compare with that obtained with 2 hours of daily patching?

Findings  In this randomized clinical trial with a crossover design at the 2-week visit, binocular treatment with an iPad game improved amblyopic eye visual acuity by 1.5 lines compared with 0.7 line with patching.

Meaning  Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia; however, whether long-term binocular treatment is as effective in remediating amblyopia as patching remains to be investigated.


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 Identifier: NCT02365090.

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Lab Study: A binocular iPad treatment for amblyopic children



Monocular amblyopia treatment (patching or penalization) does not always result in 6/6 vision and amblyopia often recurs. As amblyopia arises from abnormal binocular visual experience, we evaluated the effectiveness of a novel home-based binocular amblyopia treatment.


Children (4–12 y) wore anaglyphic glasses to play binocular games on an iPad platform for 4h/w for 4 weeks. The first 25 children were assigned to sham games and then 50 children to binocular games. Children in the binocular group had the option of participating for an additional 4 weeks. Compliance was monitored with calendars and tracking fellow eye contrast settings. About half of the children in each group were also treated with patching at a different time of day. Best-corrected visual acuity, suppression, and stereoacuity were measured at baseline, at the 4- and 8-week outcome visits, and 3 months after cessation of treatment.


Mean (±SE) visual acuity improved in the binocular group from 0.47±0.03 logMAR at baseline to 0.39±0.03 logMAR at 4 weeks (P<0.001); there was no significant change for the sham group. The effect of binocular games on visual acuity did not differ for children who were patched vs those who were not. The median stereoacuity remained unchanged in both groups. An additional 4 weeks of treatment did not yield additional visual acuity improvement. Visual acuity improvements were maintained for 3 months after the cessation of treatment.


Binocular iPad treatment rapidly improved visual acuity, and visual acuity was stable for at least 3 months following the cessation of treatment.

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S L Li1, R M Jost1, S E Morale1, D R Stager2, L Dao3, D Stager3 and E E Birch1,4

  1. 1Crystal Charity Ball Pediatric Vision Evaluation Center, Retina Foundation of the Southwest, Dallas, TX, USA
  2. 2Pediatric Ophthalmology and Center for Adult Strabismus, Dallas, TX, USA
  3. 3Pediatric Ophthalmology and Adult Strabismus, Plano, TX, USA
  4. 4Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA

Correspondence: EE Birch, Crystal Charity Ball Pediatric Vision Evaluation Center, Retina Foundation of the Southwest, 9600 North Central Expressway, Suite 200, Dallas, 75231, TX, USA Tel: +1 214 363 3911; Fax: +1 214 363 4538. E-mail:

Received: 20 December 2013; Accepted in Revised form: 13 June 2014
Advance online publication 25 July 2014

The data presented in this manuscript were presented, in part, at the 2013 Annual Meeting of the Association for Research in Vision and Ophthalmology in Seattle, WA, USA.