Effect of Ocular Alignment on Emmetropization in Children <10 Years With Amblyopia

PURPOSE: To determine whether change in refractive error is associated with ocular alignment in 105 children 3 to <7 years of age who previously participated in a randomized trial comparing atropine and patching for moderate amblyopia. DESIGN: Prospective cohort study. METHODS: One hundred five children 3 to <7 years of age previously participated in a randomized trial comparing atropine with patching for moderate amblyopia. Cycloplegic refraction was measured at baseline and 10 years of age. Ocular alignment at baseline was categorized as orthotropic, microtropic (1-8 Delta horizontal tropia), or heterotropic ( >8 Delta horizontal tropia). Multivariate regression models evaluated whether change in spherical equivalent refractive error was associated with alignment category, after adjusting for age, baseline spherical equivalent refractive error, and type of amblyopia treatment. RESULTS: Between enrollment and the age 10-year examination, there was a decrease in spherical equivalent refractive error from hyperopia to less hyperopia (amblyopic eye: -0.65 diopter, 95% CI -0.85, -0.46; fellow eye: -0.39 diopter, 95% CI -0.58, -0.20). A greater decrease in amblyopic eye refractive error was associated with better ocular alignment category (P = .004), with the greatest decrease occurring in orthotropic patients. There was no relationship between ocular alignment category and change in fellow-eye refractive error. CONCLUSIONS: Among children treated for anisometropic, strabismic, or combined mechanism amblyopia, there is a decrease in amblyopic eye spherical equivalent refractive error to less hyperopia after controlling for baseline refractive error. This negative shift toward emmetropia is associated with ocular alignment, which supports the suggestion that better motor and sensory fusion promote emmetropization. (Am J Ophthalmol 2012;154:297-302. (c) 2012 by Elsevier Inc. All rights reserved.)