One-year evaluation of excimer laser photorefractive keratectomy for myopia and myopic astigmatism. Melbourne Excimer Laser Group
G. R. Snibson, C. A. Carson, G. F. Aldred and H. R. Taylor
Department of Ophthalmology, University of Melbourne, Australia.
OBJECTIVE: To evaluate prospectively the efficacy and safety of excimer
laser photorefractive keratectomy in the treatment of myopia and myopic
astigmatism. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
