Corneal aberrations after astigmatic keratotomy combined with laser in situ keratomileusis☆

Abstract 

Purpose: To evaluate the optical aberrations in the cornea before and after astigmatic keratotomy (AK) combined with laser in situ keratomileusis (LASIK) in a group of patients with high myopic astigmatism.

Setting: Refractive Surgery Unit, NISA Hospital Virgen del Consuelo, Valencia, Spain.

Methods: Twelve patients (24 eyes) with high myopic astigmatism (from 3.50 to 6.00 diopters) participated in the study. Astigmatic keratotomy was performed as the first step to reduce astigmatism; after 2 months, the residual refractive error was corrected with LASIK. Videokeratography measurements were conducted before and after each procedure. Topography maps were used to calculate the wavefront corneal aberrations for a 6.0 mm pupil diameter.

Results: Total, coma-like, and spherical-like aberrations increased significantly from preoperatively to post LASIK (×6.34, ×2.52, and ×10.50, respectively; P<.01). Astigmatic keratotomy significantly increased coma-like (×4.04; P<.01) and spherical-like (×5.66; P<.01) aberrations. After LASIK, the coma-like aberration was significantly reduced (×0.62; P = .008) and the spherical-like aberration was significantly increased (×1.86; P<.01).

Conclusion: Astigmatic keratotomy increased higher-order corneal aberrations, both coma-like and spherical-like, whereas LASIK performed after AK increased the spherical-like aberration and reduced the coma-like aberration.