Computer assistance in keratoconus lens design.

In the past, keratoconus patients have been custom fit with multi-curve spherical contact lenses. Recently it has become possible to commercially manufacture aspherical contact lenses of high-Dk material. A computer assisted fitting technique may be used with these new lenses. We report 90 consecutive keratoconus eyes that were fit with aspherical high-Dk contact lenses using a computer-aided fitting system. Mild and severe grades of keratoconus cases were included, with a 6 to 12 month follow-up time. The combination of new lens geometry and lens material produced a reduction in corneal complications. The asphericity of the lens geometry had a slight negative influence on the visual acuity in mild keratoconus cases, but the visual acuity in the severe keratoconus cases was good. The contact lens material proved acceptably durable, despite the high oxygen transmissibility. We found the computer assisted fitting technique very accurate in determining the initial fitting lens and much faster than the former trial-and-error procedure.