Photorefractive keratectomy for hyperopia and aphakia with a scanning spot excimer laser.

Abstract

To study the safety, efficacy, predictability, and stability of photorefractive keratectomy (PRK) for hyperopia and aphakia. Fifteen eyes of 15 patients (mean age, 33 +/- 5.95 yrs) were enrolled in the study and divided into three groups. The first group was comprised of six eyes that had hyperopia ranging from +1.75 to +4.75 D; the second group had seven hyperopic eyes ranging from +5.00 to +9.75 D; the third group included two eyes of two aphakic patients. All eyes had PRK with a 193 nm argon fluoride excimer laser (Chiron-Technolas, Keracor 116) with a 10 Hz repetition rate and a fluence of 120 mJ/cm2. The total follow-up time in all eyes was 12 months. In the lower hyperopia group, 0% eyes were within +/- 0.50 D and 66% (N = 4) of eyes were within +/- 1.00 D of emmetropia with the other two eyes between +1.00 and +2.00 D at 1 year after PRK. In the higher hyperopia group, all eyes had at least +3.00 D of hyperopia at 1 year. In the aphakic group, both eyes achieved less than 50% of the target correction of +10.00 D at 1 year. Final uncorrected visual acuity ranged from 20/20 to 20/30 in the lower hyperopia group, 20/30 to 20/50 in the higher hyperopia group, and count fingers in the aphakic group. PRK is a relatively safe, stable, and effective procedure with reasonably good predictability for eyes with less than +5.00 D of baseline hyperopia, and poor predictability for eyes with more than +5.00 D of baseline hyperopia. PRK is ineffective in the correction of aphakia.