Unilateral refractive keratotomy for anisometropia.

Abstract

In anisometropia, the asymmetry of refractive error produces disparity of image magnification (aniseikonia) that can create visual discomfort, especially when asymmetry is 3.00 diopters or more. A prospective study of 20 eyes of 20 patients between 18 and 61 years of age who underwent unilateral radial and/or transverse keratotomy was conducted; results of at least 12 months follow-up are presented. The efficacy of keratotomy was evaluated by the following criteria: 1) change in spherical and cylindrical refraction, 2) decrease in refraction difference between two eyes of each patient, 3) change in spectacle-corrected visual acuity, and 4) change in binocular vision functions and asthenopic complaints. Mean decrease in spherical refractive error was 3.66 +/- 1.58 D (range, 1.25 to 7.50 D) and 2.08 +/- 0.81 D (range, 1.00 to 3.50 D) in astigmatic refraction. The mean refraction difference between two eyes was 4.90 +/- 2.20 D preoperatively, and this difference regressed to 1.79 +/- 1.42 D postoperatively. Spectacle-corrected visual acuity increased in seven eyes (35%), remained the same in 12 eyes (60%) and decreased in one eye (5%). All patients reported relief of asthenopic complaints. Fusion amplitudes increased in 12 (60%) patients. Stereoscopic vision improved in five (25%) patients. Monocular refractive keratotomy can significantly decrease anisometropia.