Photorefractive keratectomy for myopia: one-year follow-up in 97 eyes

We made a comprehensive study of 97 eyes that received photorefractive keratectomy (PRK) for myopia and followed them for one year. In 95 eyes, uncorrected visual acuity improved and best-corrected acuity remained unchanged. In eyes with myopia of more than -3.0 diopters (D), the postoperative refraction was within -1.0 D of attempted correction. Predictability decreased with higher myopia. We also examined the changes of both epithelium and endothelium with the specular microscope and found no significant changes after photorefractive keratectomy. Videokeratography showed an average of inferior decentration in most eyes by 0.51 mm +/- 0.31 (n = 60); only one clinical problem was noted--one eye experienced monocular diplopia for seven months. Pachometry showed a small percentage had corneal thinning--the amount depended on the degree of myopia. A rise in intraocular pressure over 21 mm Hg was observed in 8.9% of eyes but it was controlled without surgery. Haze was observed in most eyes, but faded gradually without significant problems. Reduced contrast sensitivity in night vision was noted and some patients experienced glare. Day vision contrast sensitivity was related to corneal haze.