[Trephination using an Excimer laser]

We compared histologically and ultrastructurally donor buttons and recipient beds trephined mechanically with those trephined by the Excimer laser at 193 nm. The laser allowed for superior cutting precision and perfect centering. This non-contact method obviated the need for any pressure or suction during trephination, thereby eliminating problems associated with distortion of corneal topography. We studied wound healing after penetrating keratoplasty with mechanical and laser trephination in an animal model. The laser did not adversely affect wound healing processes.