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

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.