Unilateral Photorefractive Keratectomy for Myopic Anisometropia Improves Contrast Sensitivity

Abstract

Abstract: : Purpose: To evaluate visual performance after unilateral photorefractive keratectomy (PRK) performed for >2.50 D myopic anisometropia. Methods: PRK was performed on 11 eyes of 11 patients for myopic anisometropia ranging from -2.75 to -9.00 D. Best spectacle corrected visual acuity (BSCVA), contrast sensitivity (CS), and pattern visual evoked potentials (pVEPs) were measured preoperatively and at 3 and 6 months. Results: BSCVA increased non-significantly six months after PRK. A tendency towards decreased latency time of pVEPs for both eyes were observed after PRK. A significant increase in contrast sensitivity was observed after PRK in the operated eye at 6 months. On the other hand, a tendency for decreased contrast sensitivity appeared in the unoperated eye at 3 months. However, preoperative CS was reached at 6 months. Conclusions: The adult central visual system is sensitive to visual deprivation caused by anisometropia. The imbalance between eyes may increase visual performance in the more emmetropic eye. Anisometropia appears to decrease the visual performance in the more myopic eye and this can probably be reversed by refractive correction.

Keywords: contrast sensitivity • image processing • refractive surgery