Virtual reality-based vision therapy versus OBVAT in the treatment of convergence insufficiency, accommodative dysfunction: a pilot randomized controlled trial

Abstract Background Virtual reality is being increasingly applied in vision therapy. However, the differences in effectiveness, optimal treatment cycle, and prognosis between virtual reality-based vision therapy and traditional therapies remain unknown. The purpose of this study was to compare the effectiveness of virtual reality-based vision therapy and office-based vergence/accommodative therapy in young adults with convergence insufficiency or accommodative dysfunction. Methods The patients were randomly assigned to either the virtual reality-based vision therapy group or the office-based vergence/accommodative therapy group. The vision therapy lasted 12 weeks (1 h/week) in both groups. Binocular visual functions (vergence and accommodation) were measured and a subjective questionnaire-based assessment was performed at baseline and after 6 and 12 weeks of therapy. Results In total, 33 patients with convergence insufficiency and 30 with accommodative dysfunction completed the study. After 12 weeks of treatment for convergence insufficiency, the Convergence Insufficiency Symptom Survey score (F 2,31 = 13.704, P < 0.001), near point of convergence (F 2,31 = 21.774, P < 0.001), positive fusional vergence (F 2,31 = 71.766, P < 0.001), and near horizontal phoria (F 2,31 = 16.482, P < 0.001) improved significantly in both groups. Moreover, the monocular accommodative amplitude (F 2,25 = 22.154, P < 0.001) and monocular accommodative facility (F 2,25 = 86.164, P < 0.001) improved significantly in both groups after 12 weeks of treatment. A statistically significant difference was observed in monocular accommodative facility (F 1,25 = 8.140, P = 0.009) between the two groups, but not in other vergence and accommodative functions (0.098 < P < 0.687). Conclusion Virtual reality-based vision therapy significantly improved binocular vision functions and symptoms in patients with convergence insufficiency and accommodative dysfunction, thereby suggesting its effectiveness as a new optional or additional treatment for young adults with these conditions. Trial registration This study was registered at the Chinese Clinical Trials Registry on 16/04/2019 (identifier: ChiCTR1900022556 ).