Effect of Corneal and Lens Eccentricity Difference on Rigid Corneal Lens Treatment in Patients With Keratoconus.

Abstract

OBJECTIVE To evaluate the effects of rigid corneal lenses (RCL) in patients with keratoconus, based on eccentricity. METHODS Eighty-four eyes from 84 patients were included in this retrospective comparative study. Based on the median value of eccentricity difference between the cornea and back surface of the RCL, the patients were divided into groups 1 (<0.08) and 2 (≥0.08). Visual acuity, refractive index, and corneal topography indices were compared before and three months after lens use. RESULTS Visual acuity, astigmatism, refractive error, corneal curvature, and corneal thickness improved significantly in both groups. Apical power and anterior elevation improved significantly in group 1, with small differences in eccentricity, but not in group 2. Changes in apical power before and after lens use were significantly different between the two groups. CONCLUSION The RCL was effective for the cornea of keratoconus, especially when the prescription was made with a small difference in eccentricity.