Iatrogenic Keratectasia after Laser in situ Keratomileusis

Abstract

Lamellar refractive surgery reduces the biomechanical strength of the cornea which may lead to mechanical instability and keratectasia. Three eyes had laser in situ keratomileusis (LASIK) for myopia from -10.00 to -13.50 D. The procedures were performed with two different wide-field excimer lasers and two different microkeratomes. The patients were followed up to 1 year after surgery. Central steep areas developed between 1 and 8 months after surgery. In contrast to conventional central steep islands, these showed rapid progression and were interpreted as keratectasia. Iatrogenic keratectasia represents a complication after LASIK that may limit the range of myopia correction. Based on biomechanical considerations we recommend a residual corneal thickness of the stromal bed of at least 250 microm.