Ten-year follow-up of photorefractive keratectomy for myopia

Background The aim of this study is to evaluate the long-term (10-year) outcome of excimer laser photorefractive keratectomy (PRK) on myopic eyes. Methods This retrospective study included 42 eyes of 29 patients (13 male, 16 female; mean age 33.4 years, range 21 to 60) who were treated with myopic PRK at St. Luke's International Hospital, Tokyo, Japan, from May 1 1995 to December 311998, and followed up for more than 10 years. The main outcome measures were efficacy, predictability, stability, safety, and complications. We also evaluated the progress of intraocular pressure, corneal thickness, and endothelial cell density after the surgery. The cases of retreatments were excluded from this study. Results Ten years after the surgery, 17 eyes (40%) had 20/20 vision or better, and 35 eyes (81%) had 20/40 or better. With regard to the refractive predictability, 55 percent of the eyes were within +/- 1.0D and 76% were within +/- 2.0D, 10 years after the surgery. There was myopic regression with a mean change in refraction of-0.51 +/- 1.78D. Best spectacle-corrected visual acuity (BCVA) was unchanged or improved in 95%, and only two eyes lost 1 line of BCVA. The mean corneal haze score was 0.19 +/- 0.40, and the decreasing rate of endothelial cell was 8.30 +/- 9.94% at 10 years, which was slightly higher than the spontaneous decreasing rate with age. Conclusions PRK is safe and effective in refraction even 10 years after surgery; however, further long-term follow-up is needed to evaluate the decreasing of endothelial cells.