Predictive Value of Corneal Topography for ClearKone Hybrid Contact Lenses

Purpose. The purpose of this study was to evaluate the predictive value of corneal topography data for fitting ClearKone hybrid contact lenses on eyes with corneal ectasia. Methods. Ophthalmic records from eyes with established corneal ectasia that had been successfully fitted with SynergEyes ClearKone lenses (n = 73) were retrospectively reviewed. Correlations between corneal parameters (simulated steep and flat keratometry values, average corneal sagittal height, inferior-superior index for keratoconus, corneal eccentricity, cone displacement, and cone diameter) and ClearKone lens parameters (vault and skirt curvature) were analyzed. Results. Two topographical correlates to ClearKone lens parameters were identified. Mean weighted corneal sagittal height at a 7.4-mm chord was strongly predictive of the optimal ClearKone lens vault; a linear relationship was observed between these parameters (R-2 = 0.96). More significant vertical decentration of the corneal apex was found to be associated with the need for a steeper lens skirt curvature (p < 0.05). Conclusions. This study demonstrates that baseline corneal topography-derived data are valuable for predicting lens parameters for an optimally fit SynergEyes ClearKone hybrid contact lens.