UNILATERAL REFRACTIVE KERATOTOMY FOR ANISOMETROPIA

BACKGROUND: In anisometropia, the asymmetry of refractive error produc es disparity of image magnification (aniseikonia) that can create visu al discomfort, especially when asymmetry is 3.00 diopters or more. MET HODS: A prospective study of 20 eyes of 20 patients between 18 and 61 years of age who underwent unilateral radial and/or transverse keratot omy was conducted; results of at least 12 months follow-up are present ed. The efficacy of keratotomy was evaluated by the following criteria : 1) change in spherical and cylindrical refraction, 2) decrease in re fraction difference between two eyes of each patient, 3) change in spe ctacle-corrected visual acuity, and 4) change in binocular vision func tions and asthenopic complaints. RESULTS: Mean decrease in spherical r efractive 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 r efraction difference between two eyes was 4.90 +/- 2.20 D preoperative ly, and this difference regressed to 1.79 +/- 1.42 D postoperatively. Spectacle-corrected visual acuity increased in seven eyes (35%), remai ned the same in 12 eyes (60%) and decreased in one eye (5%). All patie nts reported relief of asthenopic complaints. Fusion amplitudes increa sed in 12 (60%) patients. Stereoscopic vision improved in five (25%) p atients. CONCLUSION: Monocular refractive keratotomy can significantly decrease anisometropia.