Three-Year Results of Photorefractive Keratectomy for Myopia

Abstract

We evaluated the results of single-step photorefractive keratectomy (PRK) on 35 consecutive myopic eyes (19 patients) with follow up of 3 years or more. The range of preoperative myopia was from -2.00 diopters (D) to -6.00 D with astigmatism of less than 1.50 D. The excimer laser used in this study was the ExciMed UV 200LA, (Summit Technology), which was set to a maximum correction of -6.00 D at a 5.0-mm diameter ablation zone. Uncorrected visual acuity better than 20/25 was achieved in 82.9% of eyes. Spectacle corrected visual acuity was equal to or better than that of preoperative levels in 94.3%. The difference between attempted and achieved correction was within 1.00 D in 60.0% of eyes. The myopic regression curve was Y = 3.679-0.6876 log (X). If the regression remains constant, we expect that refraction at 5 years after PRK would be -1.48 D. Trace corneal haze was present in 12 eyes (34.3%). At three years the most common subjective complaint was mild decreased night vision with asthenopia. The findings suggest that myopic regression can occur as long as 3 years after PRK.