Abstract
Purpose:
We developed a custom action video game that offers targeted training of the amblyopic eye under dichoptic viewing conditions (Vedamurthy et al., 2012). The game renders perceptually-matched input to both eyes and a Gabor orientation discrimination task targeting only the amblyopic eye. The main goals of the present study are a) to assess the game’s efficacy in amblyopic adult subjects and b) to compare the game with conventional patching treatment.
Methods:
Seventeen amblyopic adults with anisometropia (AA, n=9), strabismus (SA, n=4), or both etiologies (MA, n=4) were trained binocularly with a stereoscope for 40 hours, 1-2 hours/day, on a custom Unreal Tournament game (UT) over 8-16 weeks. In the monocular patching group, ten adults (n = 3AA, 3 SA, 4 MA) were trained for 40 hours with the good eye patched over a similar time course. To keep the patching intervention as engaging as the action games, subjects watched thrilling action series while patched. A range of visual functions was measured pre and post training.
Results:
Visual acuity (VA) improved significantly (mean VA gain of 0.14 ± 0.02 logMAR) in the amblyopic eye post UT training (p <0.05), with no difference in magnitude of VA gain between AA (n=9) and SA+MA (n=8) subjects. Sub-typing strabismic subjects into those with and without vertical deviation (n=4 each) did not reveal any difference. Randot stereopsis improved post-training in 6 AA subjects and 2 strabismic subjects that had no vertical component. There was no significant correlation between magnitudes of VA and stereo gains. Benefits were retained in all but one subject who was followed up after a two-month non-intervention period (n=8). In the patching group, no significant post-training gains in VA or stereo were noted for the group (mean VA change: 0.03 ± 0.02 logMAR), although 3 of the 10 subjects did show stereo improvements and ~0.1 VA logMAR enhancement post-patching.
Conclusions:
Our study confirms the therapeutic benefits of binocular action video game training in amblyopic adults. VA recovered irrespective of the presence or absence of strabismus; however, clinical stereo gain was found in only anisometropic and nonvertical strabismus subjects. A systematic patching approach combined with an engaging task such as watching action series may have limited benefit for some amblyopic adults.
Keywords: 417 amblyopia •
434 binocular vision/stereopsis •
753 vision and action