Comparison of Three Vision Therapy Approaches for Convergence Insufficiency

Comparison of Three Vision Therapy Approaches for Convergence Insufficiency

We compared the effectiveness of three active vision therapy approaches for convergence insufficiency (CI). Patients with eligible criteria and symptomatic CI were included in a prospective study and randomly allocated into three groups. In the home-based vision orthoptic therapy (HBVOT) group, patients were trained to do the pencil push-ups procedure 15 minutes per day, five days a week. In the office-based vision orthoptic therapy (OBVOT) group, 60 minutes of orthoptic therapy using a major amblyoscope twice weekly with additional home orthoptic therapy was prescribed. For the augmented office-based vision orthoptic therapy (AOBVOT) group, orthoptic exercises using three diopter over-minus lenses and a base out prism, in addition to major amblyoscope and additional home reinforcement was prescribed in the same period of time.

Inclusion Criteria:

• patients between 15 and 35 years of age who have symptomatic CI using the Convergence Insufficiency Symptom Survey (CISS) scoring system.
• best-corrected visual acuity ≥ 20/25
• exophoria at near at least 4 prism diopters (△) greater than at distance
• near point of convergence more than 6.0 cm break
• insufficient positive fusional vergence (PFV) (failing Sheard's criterion or PFV ≤ 15 △ base-out) at near distance.

Exclusion Criteria:

• amblyopia (VA worse than 20/30 in each eye), presence of manifest strabismus, history of ocular surgery, any systemic disorder, anisometropia of more than 1.5 diopter of myopia or hyperopia or significant refractive error, and nystagmus and usage of medications that may impair accommodation or convergence. ,ocular surface abnormalities or history of ocular allergy or those who had previously been treated for CI