To evaluate prospectively the efficacy and safety of excimer laser photorefractive keratectomy in the treatment of myopia and myopic astigmatism.
Up to 15 diopters (D) of myopia with or without astigmatism of less than 6 D was treated with an excimer laser (VISX Twenty/Twenty). One hundred fifty procedures have been followed up for more than 12 months.
Postoperative refractions were generally stable after 3 months without significant early overcorrection. Of those eyes treated with spherical equivalents of 5 D or less, 96% were within 1 D of the targeted refraction after photorefractive keratectomy and 88% had uncorrected visual acuities of 20/40 or better. At 12 months, 77% of all 150 eyes treated achieved an uncorrected visual acuity of 20/40 or better and 81% were within 1 D of the intended correction. Nine eyes (6%) lost 2 or more lines of best corrected visual acuity and 14 (9%) gained 2 or more lines. Adverse reactions were reported in 12 patients (8%) during the postoperative period.
Photorefractive keratectomy is capable of correcting low and moderate myopic errors with a relatively high degree of accuracy and safety. The predictability and stability of the postoperative refraction during the first 12 months seem to be good.
Snibson GR, Carson CA, Aldred GF, Taylor HR. One-Year Evaluation of Excimer Laser Photorefractive Keratectomy for Myopia and Myopic Astigmatism. Arch Ophthalmol. 1995;113(8):994-1000. doi:10.1001/archopht.1995.01100080044028