Corneal topography for rigid gas permeable lens fitting after penetrating keratoplasty

Computerized videokeratography may facilitate rigid gas permeable (RGP) contact lens fitting in post-penetrating keratoplasty (post-PK) eyes. We used the EyeSys Corneal Analysis System to create topographic maps of 19 post-PK eyes from October 1990 to April 1991. An initial trial lens was selected based on the average keratometric value from two separate topographic color maps. A standard protocol was used to select the initial trial lens on the basis of computer generated topographic keratometry readings. Final lens selection was based on clinical performance. A comparison of the base curve of the initial contact lens selected using computerized videokeratography and the base curve that would have been selected by standard keratometry showed a statistically significant difference (P = 0.02). Three month follow-up data were also evaluated. There was no statistically significant difference between the base curve of the initially dispensed contact lens and the base curve of the lens worn after 3 months. However, modifications in the fit were made in 9 of 19 patients. Two patients were RGP contact lens failures and were refit with SoftPerm lenses.