The role of anisometropia in the development of accommodative esotropia

Purpose: To determine whether anisometropia increases the risk for the deve lopment of accommodative esotropia with hypermetropia. Methods: Records of all new patients with a refractive error of +2.00 D or more (mean spherical equivalent of both eyes) over a 42-month period were reviewed. Three hundr ed forty-five patients were thus analyzed to determine the effect of anisom etropia (greater than or equal to1 D) on the relative risk of developing ac commodative esotropia and of developing unsatisfactory control with spectac les once esotropia was present. Results: Anisometropia (greater than or equ al to1 D) increased the relative risk of developing accommodative esotropia to 1.68 (P <.05), Anisometropia (<greater than or equal to>1 D) increased the relative risk for esotropia to 7.8 (P<.05) in patients with a mean sphe rical equivalent less than +3.00 D and increased it to 1.49 (P<.05) in pati ents with a mean spherical equivalent of +3.00 D or more (P =.016). In pati ents with esotropia and anisometropia (greater than or equal to1 D), the re lative risk for a deviation that was unsatisfactorily controlled with spect acles was 1.72 (P <.05) compared with patients with esotropia but without a nisometropia. Unsatisfactorily controlled esotropia was present in 33% of p atients with anisometropia versus 0% of patients without anisometropia, wit h a mean hypermetropic spherical equivalent of less than +3.00 D (P=.003); however, anisometropia did not significantly increase the relative risk of unsatisfactory control of esotropia with spectacles in patients with a hype rmetropic spherical equivalent of +3.00 D or more. Although amblyopia and a nisometropia were closely associated, anisometropia increased the relative risk for esotropia to 2.14 (P<.05), even in the absence of amblyopia. Concl usions: Anisometropia (greater than or equal to1 D) is a significant risk f actor for the development of accommodative esotropia, especially in patient s with lower overall hypermetropia (>+3.00 D). Anisometropia also increases the risk that an accommodative esotropia will not be satisfactorily aligne d with spectacles.