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Predictive Value of Corneal Topography for ClearKone Hybrid Contact Lenses

Downie, Laura E.

doi: 10.1097/OPX.0b013e318297da25

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.

PhD, BOptom, PGCertOcTher

Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia.

Laura Downie Department of Optometry and Vision Sciences University of Melbourne Parkville Victoria Australia 3010 e-mail:

© 2013 American Academy of Optometry