Abstract
Abstract: :
Purpose: To assess the predictability, the safety and the stability of photorefractive keratectomy for the correction of high myopia. Methods:124 eyes of 71 patients were included. Mean preoperative spherical equivalent refraction of – 8,35 +/– 1,63 D (range, –6 D to –14,125 D) These eyes were treated by photorefractive keratectomy using the laser Excimer Keracor 217. Eyes were divided into three groups : spherical equivalents ranging betwenn –6 and –8 D, –8 and –10 D an more than –10 D. The visual acuity, the subjective refraction, the evaluation of the central corneal haze and corneal topography were carried out in preoperative, in one month and more than six months after surgery. Results: After six months, the mean spherical equivalent was – 0,31 +/– 0,76 D (range – 3,75 D to + 2,375 D) ; 88 % of eyes were within +/– 1,00 D of attempted correctoin ; the uncorrected visual acuity was 20/40 or better in 92 % of eyes. One eye lost two Snellen lines, no eye lost more than two Snellen lines. These results were analyzed according to various parameters (ablation depth, size of the optical zone, pupil size in photopic environment). Corneal haze was correlated with ablation depth and with size of optical zone. Conclusions: Photorefractive keratectomy for high myopia appears to be safety and efficient. The optical zone diameter of treatment seems to be the most important factor for predicatbility and wound healing.
Keywords: refractive surgery • myopia • refractive surgery: PRK