One-year results of excimer laser photorefractive keratectomy for low to moderate myopia

Abstract

Objective: Excimer photorefractive keratectomy is a promising method to reduce myopia. We evaluated the effectiveness, predictability, stability, and safety of photorefractive keratectomy performed by two surgeons at a single site with a 1-year follow-up.

Methods: An excimer laser (Summit Excimed UV200, Summit Technology, Waltham, Mass) was used to treat 47 eyes. Preoperative uncorrected visual acuity averaged 20/277 and ranged from 20/60 to 20/500. Spherical equivalent averaged -3.9 diopters and ranged from -1.5 to -6.1 D.

Results: One year postoperatively, best corrected visual acuity averaged 20/13 and ranged from 20/10 to 20/20. No patients lost any of best corrected visual acuity. The uncorrected visual acuity at 1 year averaged 20/20 and ranged from 20/10 to 20/200. Ninety-four percent of eyes had an uncorrected visual acuity of 20/40 or better; 83%, 20/25 or better; and 74%, 20/20 or better. An initial hyperopic overcorrection is followed by gradual regression to emmetropia during a 12-month period. Refractive spherical equivalent averaged 0.44 D and ranged from -3 to +2.6 D at 1 year. The proportion of eyes within 1 D of emmetropia was 80% at 1 year. The most significant shifts in refraction occurred between the first and second months, but small shifts occurred up to 12 months. Subgrouping the results according to age revealed a significantly greater effect with larger residual hyperopia in those older than 40 years. Patient satisfaction with the procedure was high.

Conclusion: During a 1-year period, excimer photorefractive keratectomy appears to be an effective, predictable, stable, and safe method to reduce myopia. Age may play a role in the effectiveness of the procedure, with greater hyperopia resulting in those older than 40 years.