Comparison of photorefractive keratectomy and laser in situ keratomileusis for the treatment of compound hyperopic astigmatism

Abstract

Purpose To compare photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for compound hyperopic astigmatism. Setting University laser center. Methods This prospective nonrandomized study evaluated 41 consecutive eyes (27 patients) that had PRK and 24 consecutive eyes (15 patients) that had LASIK to correct compound hyperopic astigmatism. Results The mean preoperative error was +3.06 diopters of sphere (DS) ±1.73 (SD)/+1.31 ± 0.60 diopters of cylinder (DC) in the PRK eyes and +2.86 ±1.28 DS/+1.55 ± 0.96 DC in the LASIK eyes. The mean maximal pain score in PRK eyes was 1.95 ± 1.19 (range 0.0 to 3.0) in PRK eyes and 0.84 ±1.12 in LASIK eyes ( P=.0014). The uncorrected visual acuity was 20/20 or better in 7.7% of the PRK eyes and 58.3% of the LASIK eyes at 1 month ( P<.001) and 57.9% and 66.7%, respectively, at 9 months ( P=.586). The mean postoperative spherical error was −0.95 ± 0.92 D in PRK eyes and +0.33 ± 0.56 D in LASIK eyes at 1 month ( P<.001) and +0.64 ± 1.01 D and +0.44 ± 0.57 D, respectively, at 9 months ( P=.375). There was no statistically significant between-group difference in the mean residual astigmatic error. Mild peripheral haze (grade 0.5 to 1.0) occurred in 19.5% of PRK eyes and no LASIK eye. No eye in either group lost more than 2 lines of best spectacle-corrected visual acuity. Conclusions Photorefractive keratectomy was more painful than LASIK and led to a slower visual recovery, a higher incidence of peripheral haze, and an initial myopic overcorrection, which self-corrected by 3 to 6 months. Efficacy and stability of the astigmatic correction were similar in both groups. Long-term stability of both procedures requires further study.