The Effect of PRK and LASIK for the Correction of Postkeratoplasty Astigmatism

ABSTRACT

PURPOSE: To evaluate the effect of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) procedure on eyes with high astigmatism after penetrating keratoplasty. METHODS: Thirteen eyes of 12 patients who had PRK (6 eyes) or LASIK (7 eyes) after penetrating keratoplasty were retrospectively reviewed. All patients had a stable postkeratoplasty astigmatism over 4.0D for a minimum of 6 months after all sutures were removed. We followed up patients in early phase (1~3 months) and late phase (6~12 months). RESULTS: Mean preoperative astigmatism in PRK patients was 7.96 +/- 2.63D and in LASIK patients 8.27 +/- 2.96D. Astigmatic magnitude decreased 54% in early phase, and 34% in late phase in PRK group. It decreased 58% in early phase, and 55% in late phase in LASIK group. The reduction of astigmatism and postoperative regression were not stastically significant between two groups. Postoperative uncorrected visual acuity improved 67% in PRK group and 86% in LASIK group above 2 Snellen chart lines. Postoperative corneal haze developed in 3 eyes of PRK group. CONCLUSIONS: PRK and LASIK resulted in improved uncorrected visual acuity and refraction in postkeratoplsty eyes with high astigmatism. But both procedures showed cylinderical undercorrection and postoperative regression in refraction. Mild corneal haze was common after PRK procedure.