Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism

Abstract

Purpose: To evaluate and characterize the clinical features of corneal ectasia after myopic laser in situ keratomileusis (LASIK) considering internal astigmatism and corneal aberrations and their correlation with other clinical data.

Setting: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain.

Design: Retrospective comparative case series.

Methods: In this multicenter study, eyes were divided into 2 groups. The study group comprised eyes that had corneal ectasia after myopic LASIK. The control group comprised eyes that had successful LASIK to correct high myopia. The clinical outcomes were analyzed and compared. Internal astigmatism was calculated using vectorial analysis.

Results: The study enrolled 91 eyes (48 study group; 40 control group) of 81 patients (age 18 to 67 years). Uncorrected and corrected (CDVA) distance visual acuities and the refractive status were significantly worse in the study group (P ≤ .01). Corneas in the study group had a significantly higher steepest keratometry (K) reading and a more negative central asphericity (P < .01). Internal astigmatism and corneal aberrations were also significantly higher in the study group (P < .01). The CDVA was significantly correlated with primary spherical aberration (r = -0.561, P =.01) and primary coma root mean square (r = 0.451, P =.04). Age was significantly correlated with mean K (r = -0.44, P =.01) and internal astigmatism (r = -0.34, P =.04).

Conclusion: Larger levels of internal astigmatism and anterior corneal aberrations leading to a visual deterioration were present in eyes with corneal ectasia after myopic LASIK.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.