Results of a prospective evaluation of photorefractive keratectomy at 1 year after surgery.

The 1-year results obtained in 193 eyes of 146 patients who were enrolled in a prospective study investigating photorefractive keratectomy for myopia correction with the excimer laser are reported. Because of lost follow-up (17 eyes) and reoperations (15 eyes), a complete 1-year follow-up was available in 161 eyes of 115 patients that were included in the analysis. At 12 months after surgery, the percentage of eyes showing refractions within +/- 1.0 D of the attempted refraction was 97.6% in the lower group (up to -3.0 D), 91.8% in the middle group (-3.1 to -6.0 D), 44.4% in the higher group (-6.1 to -9.0 D), and 25% in the high-myopia group (more than -9.0 D). Best spectacle-corrected visual acuity was unchanged in 95% of the eyes, two eyes (1.2%) lost two lines, and six eyes (3.7%) gained two lines. Visual acuity under glare conditions was reduced from 0.71 at baseline to 0.625 at 1 year after surgery (P < 0.001). The incidence of manifest corneal scars was significantly related to the attempted refractive change (P < 0.0001). Complications were rare and not severe. These data suggest that photorefractive keratectomy is an effective and relatively safe procedure for the correction of myopia of up to -6.0 D, once long-term stability is proven. However, in eyes involving an attempted correction of more than 6.0 D (52 eyes), we found high rates of scarring in 8 eyes (15.4%) and undercorrection in 27 eyes (52%), and reoperations were needed because of scarring or undercorrection in 14 eyes (25%).