Purpose: To study the results of the two-zone photorefractive keratectomy (PRK) in 35 eyes of 27 patients with moderate myopia of 6 to 8 diopters (D) over 6 to 18 months.
Methods: An excimer laser was used with a fluence of 160 mJ/cm2 at a frequency of 5 Hz. The ablation was performed with two zones (6 and 5 mm). All patients received topical steroid (0.1 fluorometholone) tapered over 4 months.
Results: There were no significant untoward effects in any patient. There were minimal changes in contrast sensitivity, brightness acuity, and astigmatism. Uncorrected visual acuity of 20/40 or better was obtained in 77% of patients at 6 months, in 73% at 12 months, and in 71% at 18 months. A refraction of +/-1.0 diopter was obtained in 69% at 6 months, in 65% at 12 months, and in 71% at 18 months. There is no statistically significant difference at 6, 12, and 18 months in both visual acuity and refraction.
Conclusions: Two-zone PRK in moderate myopia is safe and reasonably effective. The results are stable from 6 to 18 months.