PURPOSE: To assess the long-range outcomes of photorefractive keratectomy (PRK) using functional and topographic criteria in myopic eyes with suspected keratoconus.
SETTING: Rothschild Foundation, Paris, France.
DESIGN: Retrospective interventional case series.
METHODS: Eyes of patients classified as keratoconus suspects or keratoconus by the Corneal Navigator software of the OPD-Scan II device were included. They were treated with myopic PRK using an EC-5000 excimer laser between 2004 and 2007. The main outcome measures were refractive stability, mean corneal keratometry, mean central pachymetry, mean thinnest point value, and the occurrence of postoperative complications such as corneal ectasia.
RESULTS: The study evaluated 62 eyes of 42 patients. The mean patient age was 34.6 years ± 15.1 (SD) and the mean spherical equivalent (SE), -3.96 ± 3.05 diopters (D). The mean central pachymetry was 529.4 ± 32.8 μm and the mean simulated keratometry, 45.75 ± 1.75 D. The percentage of similarity to keratoconus suspects or keratoconus was positive in all 62 eyes and exceeded a 50% similarity score in 30 eyes (48.4%). The mean follow-up was 4.8 ± 1.4 years. The mean magnitude of the SE was -0.53 ± 1.35 D over the follow-up. Two patients required glasses postoperatively because of significant myopic regression. No case of corneal ectasia was reported.
CONCLUSION: Photorefractive keratectomy in eyes with suspected keratoconus based on a Placido neural network may be safe and effective for myopia and astigmatism in carefully selected patients.