Keratectasia induced by laser in situ keratomileusis in keratoconus.

PURPOSE Corneal thinning disorders weaken the mechanical strength of affected corneas, suggesting that photorefractive procedures may be contraindicated in keratoconus. Few cases have been reported to confirm this hypothesis. METHODS A 45-year-old man had two laser in situ keratomileusis (LASIK) procedures and one photorefractive keratectomy (PRK) performed on his left eye, and three LASIK procedures on his right eye. After these surgeries, a dramatic corneal ectasia and grade III haze occurred in both eyes, with a clinical diagnosis of keratoconus. The changes in his corneas were followed with videokeratography and slit-lamp microscopy. RESULTS Preoperative videokeratograph of both eyes suggested keratoconus. After multiple refractive procedures, the best spectacle-corrected visual acuity was as low as 20/1200 bilaterally. Both eyes displayed dramatic corneal protrusion with corneal scarring. CONCLUSIONS This case emphasizes the need for preoperative corneal thickness measurement and detailed analysis of videokeratographs. Thinning corneal disorders such as keratoconus, keratoconus suspects, or pellucid marginal degeneration are a contraindication for excimer laser ablative refractive procedures.