Visual and symptomatic outcome of excimer phototherapeutic keratectomy (PTK) for corneal dystrophies

Abstract

Purpose: To determine the visual results and outcome of excimer laser phototherapeutic keratectomy (PTK) for corneal dystrophies.

Methods: Twenty-nine eyes of 19 patients who underwent excimer PTK for recurrent erosions and reduced vision due to corneal dystrophies, between February 1996 and July 1999, were reviewed. Data regarding the preoperative and postoperative best-corrected visual acuity (BCVA), change in spherical equivalent (SE), depth of excimer laser ablation, symptomatic relief, and incidence of recurrence were analysed by a retrospective chart review. RESULSTS: The range of follow-up was 12-48 months. Twenty-seven out of 29 eyes (93%) maintained or improved BCVA. All patients (17/17) were free of symptoms of recurrent erosions although two eyes needed repeat treatment to achieve this. In those eyes undergoing PTK for reduced vision, there was a trend towards a hyperopic shift postoperatively but this was not statistically significant. Five eyes showed recurrence of the dystrophy (Reis-Bücklers (one eye), Lattice (two eyes), and Granular (two eyes)) that required repeat treatment. Two of these eyes required a single repeat PTK procedure, and three eyes underwent three repeat treatments. There were no major complications during the follow-up period.

Conclusions: Excimer PTK is a safe and effective procedure for relieving symptoms of recurrent erosions and improving visual acuity in patients with corneal dystrophies. Optimal visual results are achieved when treating more anterior disease. Multiple treatments are possible without significant detrimental effects for those patients with recurrence of their dystrophy.