Photorefractive keratectomy to correct hyperopic shift after radial keratotomy

Abstract

Purpose To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) to correct post-radial-keratotomy (RK) hyperopic shift. Setting University of Sherbrooke, Sherbrooke, Québec, Canada. Methods This retrospective nonconsecutive case series comprised 53 eyes of 53 patients who had PRK to correct hyperopic shift after RK. Both RK and PRK were performed by the same surgeon at the same clinic from 1993 to 2001. Results The mean time after RK was 57 months (range 24 to 84 months). The mean follow-up after hyperopic PRK (HPRK) was 10 months (range 3 to 33 months). The mean hyperopic shift 1 month post-RK to HPRK was +1.6 diopters (D) ± 1.0 (SD) (range +0.25 to +4.125 D). The mean pre-HPRK spherical equivalent (SE) was +2.15 ± 0.80 D (range +1.00 to +4.125 D) and the mean post-HPRK SE, –0.10 ± 0.80 D (range –2.00 to +2.125 D). At the last examination, 47 eyes (88.7%) had a refractive error within ±1.0 D of emmetropia and 38 eyes (71.7%) had an uncorrected visual acuity of 20/25 or better. Two eyes lost 1 Snellen line of best corrected visual acuity. No significant haze or complications developed in any eye. Conclusions Hyperopic PRK with a conservative technique (large optical zone and small ablation thickness) can be used successfully to correct RK-induced hyperopia in patients with small to moderate refractive errors. It appeared to be effective, predictable, and safe.