Comparison of Clinical Results of PRK with LASIK for Myopia between 3.00 & 7.75 Diopters

Kim, H B; Kim, Y S; Tchah, H W

Abstract

We evaluated the results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for the correction of myopia patients between-3.00 and -7.75 diopters(D)who were followed up for at least 6 months. PRK was performed on 35 eyes of 32 patients and LASIK on 32 eyes of 24 patients. At last follow-up period 94.3% of PRK group and 100% of LASIK group had an uncorrected visual acuity of 0.5 or better,74.3%of PRK group and 90.6% of LASIK group had an uncorrected visual acuity of 0.8 or better.Best corrected visual acuity was within 1 line of preoperative in all LASIK eyes, 1 eye (2.9%) of PRK eyes lost 2 line or more of preoperative at last follow-up. Mean spherical equivalent preoperatively was -5.56 +/- 1.06D, -5.62 +/-1.20D in PRK group and LASIK group respectively. Myopic regression had occured to -0.38 +/-0.67D, -0.35 +/-0.48D at 12 months postoper-atively. 82.9% of PRK group and 93.8%of LASIK group had refraction within +/-1.0D of emmetropia at last follow-up.There was no difference between uncorrected visual acuity and glare visual acuity at 1, 3 months postoperatively in both group. There was no significant contrast sensitivity change in both group.Corneal opacity increased progressively upto 3 months postoperatively in PRK group,but no eye had postoperative corneal opacity in LASIK group. Postoperative complication included 1 eye (2.9%) of irregular astigmatism in PRK group, 2 eyes (6.3%) of cap microwrinkle and 2 eyes (6.3%) of interface foreign bodies in LASIK group. Mean duration of postoperative pain was 2.61 +/-0.91 days, 0.59 +/-1.06 days in PRK group and LASIK group, respectively. We concluded that PRK and LASIK are both effective for correction between -3.00 and -7.75 diopters and need long term follow up about corneal opacity, myopic regression & complications.