Photorefractive keratectomy for post-penetrating keratoplasty myopia and astigmatism

Abstract

Purpose To determine the safety, effectiveness, and predictability of photorefractive keratectomy (PRK) for the correction of myopia and astigmatism after penetrating keratoplasty. Setting Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Methods Photorefractive keratectomy was performed in 16 eyes of 16 patients with postkeratoplasty myopia and astigmatism who were unable to wear glasses due to anisometropia and were contact lens intolerant. They were examined for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and corneal transplant integrity before and after surgery. Results The mean follow-up after PRK was 26.0 months ± 15.7 (SD) (range 12 to 63 months). The mean preoperative spherical equivalent refraction of −4.47 ± 1.39 diopters (D) was −3.39 ± 1.84 D ( P > .05) at the last postoperative visit and the mean preoperative cylinder of −5.62 ± 2.88 D was −3.23 ± 1.70 D ( P < .05); refractive regression correlated with the amount of ablation performed. The BSCVA decreased in 3 eyes (18.8%), and the UCVA decreased in 2 (12.5%). Six eyes (37.5%) had grade 2 to 3 haze, which resolved spontaneously in 4 eyes within a relatively long time but caused a decrease in BSCVA in 2 (12.5%). Two of the eyes (12.5%) had a rejection episode after PRK and were successfully treated with topical steroids. Conclusions Photorefractive keratectomy to correct postkeratoplasty myopia and astigmatism appears to be less effective and less predictable than PRK for naturally occurring myopia and astigmatism. Corneal haze and refractive regression are more prevalent, and patient satisfaction is not good.