Comparison of Three Vision Therapy Approaches for Convergence Insufficiency

Purpose: We compared the effectiveness of three active vision therapy approaches for convergence insufficiency (CI). Methods: This randomized clinical trial included patients meeting the eligibility criteria and with symptomatic CI, who were allocated into three groups. In the home‑based vision orthoptic therapy (HBVOT) group, patients performed the pencil push‑up procedure 15 min/day for 5 days/week. In the office‑based vision orthoptic therapy (OBVOT) group, patients underwent 60‑min orthoptic therapy using a major amblyoscope twice weekly with additional home orthoptic therapy. In the augmented office‑based vision orthoptic therapy (AOBVOT) group, patients performed orthoptic exercises using 3‑diopter over‑minus lenses and a base‑out prism in addition to major amblyoscope therapy, and additional home reinforcement was prescribed during the same time period. Results: All 84 subjects (mean age, 26.8 ± 8.3 years) showed a statistically significant improvement in near exophoria, positive fusional vergence (PFV) at near, near point of convergence (NPC), stereoacuity, and Convergence Insufficiency Symptom Survey (CISS) scores at follow‑up. Exophoria decreased by 64%, 68%, and 85% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.2). PFV increased by 68%, 100%, and 100% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P < 0.001). NPC decreased (improved) by 86%, 89%, and 96% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.4). The CISS scores decreased by 75%, 96%, and 100% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.003). Conclusion: Our results showed that in adults with CI, the augmented office‑based orthoptic treatment was relatively more effective than the other treatments.