Binocular Video Game for Unilateral Amblyopia
JAMA Ophthalmology, February 2018
Binocular treatment of amblyopia by contrast-rebalanced stimuli has shown promise in laboratory studies and is being investigated in real-world settings. Gao et al. compared a binocular video game with a placebo version. They found that the binocular game was not superior for improving visual function.
The multicenter, double-masked, randomized clinical trial included 115 participants aged 7 to 55 years (mean, 21.5 years). All had unilateral amblyopia caused by anisometropia, strabismus, or both; the visual acuity of the amblyopic eye was 0.30 to 1.00 logMAR (Snellen equivalent, 20/40 to 20/200). Eighty-nine participants (77.4%) had previously undergone occlusion or penalization therapy. Patients were classified by age group and were assigned randomly to play the active-treatment (binocular) video game or the placebo game.
The Falling Blocks game was used in both study arms and was played at home on an iPod Touch. The active-treatment game split visual elements between the eyes, with a dichoptic contrast offset, whereas the placebo game presented identical images to both eyes. Patients were instructed to play the game for 1 hour a day for 6 weeks. The main outcome measure was change in visual acuity of the amblyopic eye from baseline through week 6. Secondary outcomes included compliance, stereoacuity, and interocular suppression.
The mean (SD) visual acuity of the amblyopic eye improved 0.06 (0.12) logMAR (3 letters) from baseline in the active-treatment group and 0.07 (0.10) logMAR (3.5 letters) in the placebo group. Compliance with at least 25% of prescribed play was achieved by 64% of the active-treatment group and by 83% of the placebo group. By 6 weeks, fellow-eye contrast > 0.9 was attained in 36 active-arm participants (64%). There were 3 reports of asthenopia (2 in the active-treatment group), which was transient, and no reports of diplopia. There were no significant differences between groups for any primary or secondary outcomes.
Various requisites presumably should be satisfied before binocular video games are ready for clinical use. These include robust effectiveness data from randomized trials; sophisticated methods to monitor compliance; and development of more engaging games, aimed at improving compliance and effectiveness. (Also see related commentary by Jonathan M. Holmes, BM, BCh, in the same issue.)
The original article can be found here.