PURPOSE: To identify factors that influence binocular function in anisometropic, nonstrabismic children before and after optical correction and amblyopia therapy. METHODS: This was a prospective observational study of consecutive patients with nonstrabismic anisometropia. Visual acuity and responses to the 4(Δ) base-out prism test, the Worth 4-dot test, and the TNO test were recorded after spectacle correction and every 3 months for 1 year. Factors affecting visual acuity and binocular function were analyzed using univariate and multiple stepwise regression analysis. RESULTS: A total of 118 subjects were enrolled. At the end of the first year, the mean improvement in visual acuity was 2.6 ± 2.3 lines. The percentage of patients showing a positive response to the 4(Δ) base-out prism test increased from 47% to 79%; fusion in the Worth 4-dot test, from 37% to 66%; and measurable stereopsis on TNO testing, from 59% to 80%. Better initial visual acuity and better final visual acuity were associated with better binocular function. Interocular refractive error difference was a predictor of poor binocular function in multiple regression analysis if the difference in spherical error exceeded 4 D. Patients with amblyopia showed significantly worse binocular function compared to those with no amblyopia. CONCLUSIONS: Binocular function of anisometropic children can be improved with refractive correction and amblyopia therapy.
PURPOSE: To identify factors that influence binocular function in anisometropic, nonstrabismic children before and after optical correction and amblyopia therapy. METHODS: This was a prospective observational study of consecutive patients with nonstrabismic anisometropia. Visual acuity and responses to the 4(Δ) base-out prism test, the Worth 4-dot test, and the TNO test were recorded after spectacle correction and every 3 months for 1 year. Factors affecting visual acuity and binocular function were analyzed using univariate and multiple stepwise regression analysis. RESULTS: A total of 118 subjects were enrolled. At the end of the first year, the mean improvement in visual acuity was 2.6 ± 2.3 lines. The percentage of patients showing a positive response to the 4(Δ) base-out prism test increased from 47% to 79%; fusion in the Worth 4-dot test, from 37% to 66%; and measurable stereopsis on TNO testing, from 59% to 80%. Better initial visual acuity and better final visual acuity were associated with better binocular function. Interocular refractive error difference was a predictor of poor binocular function in multiple regression analysis if the difference in spherical error exceeded 4 D. Patients with amblyopia showed significantly worse binocular function compared to those with no amblyopia. CONCLUSIONS: Binocular function of anisometropic children can be improved with refractive correction and amblyopia therapy.