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

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). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12886-022-02393-z.