[Astigmatism after penetrating keratoplasty. Videokeratoscopic analysis on a series of 60 grafts].

PURPOSE: To study the factors which induce post keratoplasty astigmatism. To assess the reliability of different methods in the astigmatism measurement and to study the visual acuity predicting factors.

METHODS

We retrospectively studied the corneal topography in 60 eyes with penetrating keratoplasty after suture removal, using the CAS* (Eye Sys). The diagnosis was keratoconus in 65% of the cases and bullous keratopathy in 15% of the cases. The graft was secured with a single running suture in 38.3% of the cases, interrupted sutures in 23.3% of the cases, or a combination of both running and interrupted sutures in remaining 28.3%.

RESULTS

The suture method, diagnosis and surgeon did not influence subjective refraction nor visual acuity. The topographic pattern correlated with subjective cylinder (rs = 0.52 p = 0.02). The refractive power cylinder ("Holladay diagnostic summary") correlated well with subjective cylinder (rs = 0.81 p < 0.001) and visual acuity (rs = -0.63; p < 0.001). The Javal keratometry remains the best method to measure astigmatism axis (rs = 0.58; p < 0.001).

CONCLUSIONS

The Holladay diagnostic summary (refractive power) is a useful tool for evaluating qualitative outcome of corneal transplantation.