An experimental comparison of three methods for trephination of the cornea and the consequent variations in the configurations of the trephine openings.

We used the pig eye as an experimental model. The corneas of 51 whole eyes were trephined in a laboratory setting, using three different techniques to compare the variations in the trephine openings. Since it is difficult to assess the diameter of the hole created by trephination, we measured both the epithelial and endothelial diameters, as well as the angle between the epithelial surface and the cut of the excised corneal button, since these dimensions reflect the true shape of the hole. Trephination with either a free-standing trephine blade without a handle or with a motor-driven instrument gave the same results. However, our findings showed that the results obtained using a trephine in a holder--as is commonly used in clinical practice--were statistically significantly inferior.