Laura E Downie1. 1. Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia.
Abstract
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 = 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.
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 = 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.