Photorefractive keratectomy for 1.5 to 18 diopters of myopia.

The purpose of this study was to evaluate the refractive outcome and the stability of refraction after excimer laser photorefractive keratectomy (PRK). Forty-five eyes were treated in three different refractive groups: low myopes, 23 eyes, -1.50 diopters (D) to -6.00 D; intermediate myopes, 14 eyes, -6.10 D to -10.00 D; and high myopes, 8 eyes, -10.10 D to -18.00 D. At 9 months after surgery the low myopes had a mean refraction of -0.14 D (range -1.00 D to + 1.50 D) and were easy to refract. Intermediate myopes mean refraction was +0.14 D (range -1.50 D to +2.50 D). In the high myope group the mean refraction was -0.47 D (range -10.00 D to +2.50 D) and four eyes (50%) lost more than two lines of spectacle corrected visual acuity. Refraction the high myopes was more difficult compared to the lower myopes. PRK produced good results for myopes from -1.50 D to -10.00 D. Myopes greater than -10.00D are not stable at 9 months after PRK and are difficult to refract.