A Comparison of Photorefractive Keratectomy and Radial Keratotomy in Low Myopia : One-year Results

The aim of this study is to compare the efficacy and predictability of photorefractive keratectomy (PRK) and radial keratotomy (RK) in low myopia. This study consisted of 40 eyes of 24 patients that were divided into two groups. In group I, comprising 20 eyes, was performed excimer laser photorefractive keratectomy using the Summit excimer laser with a 6.0-mm diameter ablation zone. In group II, comprising 20 eyes, was performed 4 or 6 incisions of radial keratotomy. The range of preoperative myopia was from -1.75 diopters (D) to -3.75 D with astigmatism less than -1.0 D in both groups. At 1 year, the mean refraction was -1.02 ± 0.99 D (range, -0.12 to -3.25 D) in group I, and -1.25±0.68 (range, -0.37 to -1.87) in group II. One year postoperatively, in the PRK group, uncorrected visual acuity was 20/40 or better in 95%, 20/25 or better in 65% of eyes, and in 30% of eyes were within ± 0.50 D of emmetropia, 70% of eyes were within ± 1.0 D of emmetropia. In the RK group, 75% of the eyes achieved uncorrected visual acuity of 20/40 or better, 45% achieved uncorrected visual acuity of 20/25 or better, and 20% of eyes were within ± 0.50 D of emmetropia, 55% of eyes were within ± 1.0 D of emmetropia. No statistically significant differences were detected between two groups in achieved refractive results and visual acuity (p>0.05). One eye in RK group lost two or more lines of spectacle-corrected visual acuity. It was detected that PRK and RK are both effective refractive procedures and give almost similar results in low myopia up to -3.75 D. [Journal of Turgut Özal Medical Center 1997;4(1):63-66]