Correction of myopia using laser in situ keratomileusis (LASIK)

In contrast to photorefractive keratectomy (PRK), the corneal epithelium and Bowman's layer are preserved in LASIK. Thus, there should be less scarring and regression after LASIK than after PRK. Between December 1993 and October 1995, we treated 113 eyes (66 patients). The Automated Corneal Shaper and the Keracor 116 excimer laser were used. We evaluated refraction, visual acuity and corneal topography. To date, 61 eyes reached six months follow up. Mean preoperative refraction was -14.3 D (-3.3 to -29 D; SD = 7). Mean deviation from target refraction was -1.4 D (-9.5 to +2.5 D; SD = 2.7) at six months. 34% were within +/-0.5 D of target refraction, 46% within +/-1 D, 67% within +/-2 D, and 82% within +/-3 D. Mean change of refraction ("regression") from one to six months postoperatively was +0.13 D (-7.5 to +8 D; SD = 2.1). Refractive change was < 0.5 D in 51%, < 1 D in 66%, < 2 D in 84%, and < 3 D in 89%. In 88% of eyes, the corneal interface was not or just barely visible, while it was clearly visible in 12%. No scars were observed. Our results indicate that LASIK is an effective procedure in the correction of high myopia. The incidence of scar formation and regression is considerably lower than after PRK.