Recurrence of corneal dystrophy after excimer laser phototherapeutic keratectomy

Abstract

Background: Excimer laser phototherapeutic keratectomy (PTK) can be useful to treat anterior corneal dystrophies both before and after penetrating keratoplasty.

Objective: To evaluate the recurrence of corneal dystrophies after excimer laser PTK.

Design: Retrospective case series.

Participants: Fifty excimer laser PTK procedures were performed in 43 eyes of 33 patients with corneal dystrophies. Preoperative diagnoses included Reis-Bücklers dystrophy (13 eyes), granular dystrophy (11 eyes), anterior basement membrane (ABM) dystrophy (11 eyes), lattice dystrophy (7 eyes), and Schnyder crystalline dystrophy (1 eye).

Intervention: Two excimer lasers (VISX 20/20 model B and VISX Star) were used to perform all PTKs.

Main outcome measures: After PTK, patients were followed on a regular basis with measurement of best-corrected visual acuity and biomicroscopic examination. Evidence of recurrent dystrophy was noted according to specific criteria.

Results: Follow-up range was from 1.1 to 71.2 months (mean, 19.5 months). Clinically significant recurrent dystrophy occurred in 17 eyes. The ABM dystrophy recurred in the form of recurrent corneal erosions in 5 (42%) of the 12 eyes within 6 to 9 months of PTK. Four of these five eyes had mild erosions, which were treated successfully with topical medications while one eye required an additional PTK for an erosion outside the initial treatment area. Eight (47%) of 17 eyes with Reis-Bücklers dystrophy developed clinically significant recurrence an average of 21.6 months after PTK. Three (23%) of 13 eyes with granular dystrophy were found to have a significant recurrence a mean of 40.3 months after PTK. Only one (14%) of seven eyes with lattice dystrophy developed a significant recurrence at 6 months after PTK. Six eyes with significant recurrence after PTK were retreated successfully with additional PTK. Three eyes later developed recurrence of granular and Reis-Bücklers dystrophy after the second PTK. The probability of recurrence of these dystrophies after PTK was calculated using the Kaplan-Meier survival analysis.

Conclusion: Phototherapeutic keratectomy can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies. Even though corneal dystrophies are likely to recur eventually after PTK, successful retreatment with PTK is possible.