Treatment of Corneal Dystrophies with Phototherapeutic Keratectomy

PURPOSE: To evaluate the excimer laser as a surgical instrument for treatment of corneal dystrophies. METHODS: Excimer laser photoablation was performed with the Summit UV 200 and VISX 20/20 excimer lasers on 30 eyes of 21 patients with different types of corneal dystrophies; phototherapeutic keratectomy (PTK) on 28 eyes (20 patients) and photorefractive keratectomy (PRK) on two eyes (one patient). The treatment goals were to improve visual acuity (26 eyes of 18 patients), heal recurrent corneal erosions (eight eyes of five patients), and treat fluctuating refraction and visual acuity (three eyes of two patients). Mean follow-up was 37 months (range 24 to 54 mo). The dystrophy groups included: map-dot-fingerprint (nine eyes of seven patients), lattice type I (five eyes of four patients), lattice type II (two eyes of one patient), granular (five eyes of three patients), central crystalline (four eyes of three patients), Reis-Bücklers' (two eyes of one patient), Meesmann's (two eyes of one patient), and Fuchs' endothelial (one eye). RESULTS: In 22 of 26 eyes (84.6%) there was an improvement in spectacle-corrected visual acuity after 6 to 12 months. This improvement remained stable in 18 eyes (69.2%). Pronounced recurrences of dystrophic changes with reduction in visual acuity were seen in three eyes of two patients: lattice type II (two eyes) and granular (one eye). In one eye with Fuchs' endothelial dystrophy, there was a recurrence of subepithelial fibrosis which had been previously removed. In eight of eight eyes (100%) treated for recurrent corneal erosions (map-dot-fingerprint, Meesmann's, and lattice type I), the erosions healed shortly after treatment and did not recur. Preoperative fluctuating refraction stabilized in three of three eyes (100%) with mapdot-fingerprint after treatment. The mean hyperopic refractive shift was +2.55 +/- 2.16 D. In none of the patients did the treatment per se lead to a decrease in spectacle-corrected visual acuity or any corneal surface problems. CONCLUSION: In corneal dystrophies with epithelial and anterior stromal opacities, excimer laser PTK may be successful in improving vision and healing recurrent corneal erosions over the long term.