CORRECTION OF MYOPIA BY LASER IN-SITU KER ATOMILEUSIS (LASIK)

Background In contrast to photorefractive keratectomy (PRK), the corne al epithelium and Bowman's layer are preserved in LASIK. Thus, there s hould be less scarring and regression after LASIK than after PRK. Pati ents Between December 1993 and October 1995, we treated 113 eyes (66 p atients). The Automated Corneal Shaper and the Keracor 116 excimer las er were used. We evaluated refraction, visual acuity and corneal topog raphy. Results To date, 61 eyes reached six months follow up. Mean pre operative refraction was -14.3 D (-3.3 to -29 D: SD = 7). Mean deviati on from target fraction was -1.4 D (-9.5 to +2.5 D; SD = 2,7) at six m onths, 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 interfa ce was not or just barely visible, while it was clearly visible in 12% . No scars were observed. Conclusions Our results indicate that LASIK is an effective procedure in the correction of high myopia. The incide nce of scar formation and regression is considerably lower than after PRK.