Abstract
Playing action videogames with the amblyopic eye results in improved visual acuity, Vernier acuity, visual counting and in some anisometropic amblyopes, stereo acuity in adults with amblyopia (Li et al., 2011). To promote binocular fusion and stereopsis we developed a customized dichoptic action videogame game in which: i) the input to the two eyes is balanced by reducing the luminance of the non-amblyopic eye's image, and ii) the images to the two eyes are viewed in a mirror stereoscope, enabling fusion. To assess performance during game play we embedded a Gabor orientation discrimination task into the game. Importantly, the Gabor patch is only presented to the amblyopic eye, and its spatial frequency adapts to the resolution level of the player (the highest spatial frequency that the observer is able to discriminate), enabling us to monitor the amblyopic eye's resolution during binocular game play. Twenty-three adults with amblyopia played the game for 40 hours. All but one improved in visual acuity (by, on average, a factor of 1.4) and nine improved in stereopsis. The Interocular Luminance Ratio (ILR – the ratio of non-amblyopic eye to amblyopic eye luminance), a measure of suppression, showed a decrease in suppression by about a factor of 1.6, with a different time course in anisometropic and strabismic amblyopes. Importantly, the resolution of the amblyopic eye during binocular game play increased by a factor of 2.2, suggesting a reduction in suppression. Interestingly, the improved visual acuity and stereopsis were not significantly correlated with either the increased resolution, or decreased suppression in a binocular setting during game play. These results indicate that while reduced suppression or increased resolution may be necessary for improvements in stereopsis, they are not sufficient, calling for a more direct training of stereopsis in the next generation of video games for amblyopic patients.
Meeting abstract presented at VSS 2014