Background: Tissue damage in corneal transplantation procedures was previously assessed in comparative pilot studies using vacuum-assisted metal blade trephines and a noncontact hydrogen fluoride laser trephine system. With the laser, endothelial damage was less than 20 x 30 microns at the edge of the posterior corneal perforation.
Methods: In this study, a second generation vacuum-assisted Hessburg-Barron trephine was evaluated in full-thickness penetrating trephination performed in 16 rabbit eyes and eight fresh human donor eyes.
Results: We found a relatively large, 150-micrometer wide, annular zone of endothelial damage on the recipient cornea located 1.25 mm away from the trephined opening. Our study demonstrates that endothelial damage is linked to the instrument's vacuum fixation ring.
Conclusion: With this trephine, endothelial damage may be avoided by using partial-depth trephination, filling the anterior chamber with viscoelastic and completing the procedure using a metal blade or diamond knife.