Rehabilitation of visual functions in adult amblyopic patients with a virtual reality videogame: a case series

Amblyopia or lazy eye is a dysfunction of the visual system that appears during childhood and traditionally has been considered untreatable in adults. Its main consequences are the loss of visual acuity and contrast sensitivity of the amblyopic eye and binocular vision impairments. During the last years videogames have been used as a therapeutic tool for amblyopia with the inconclusive results. The present work has assessed the effectiveness of a virtual reality videogame (AmbliOK (R)) in the neurorehabilitation of four adult clinical cases with anisometropic amblyopia. Visual acuity, contrast sensitivity, stereopsis and interocular suppression were assessed before, during, immediately after, one month and one year (in one patient) after the training. The intervention was conducted along four weeks (10 h) and yielded the variable results. In general, all patients showed an improvement in visual functions although not all ameliorated in the same way. Visual acuity measures improved in all patients, falling outside the amblyopia criterion at the end of the treatment. However, the improvement was not maintained one month later in two patients. Contrast sensitivity progressively improved for the amblyopic and the fellow eyes with all patients showing better results one month after the treatment. The patient assessed one year after still showed better results than in the baseline. Patients showing bad stereopsis in the baseline reached a performance considered normal one month and even one year after the treatment. The effectiveness of the treatment seems to be related to the characteristics of patients.