Effects of epikeratoplasty on the host cornea. An experimental study.

The effects of epikeratoplasty on the host cornea was studied using albino rabbits. Eyes underwent midperipheral partial trephination alone (group I), midperipheral partial trephination and peripheral undermining (group II), midperipheral partial trephination and circular keratectomy (group III), and trephination, peripheral undermining, and circular keratectomy (group IV). Corneal topography was assessed weekly using keratometry and photokeratoscopy. All eyes showed central corneal steepening with enhancing effects of increased surgical manipulation. Results were stable by 4 weeks in all eyes. Histopathologic evaluation revealed a constant wound depth of approximately 0.1 mm, with an increased accumulation of glycosaminoglycan material at the base of the wound. This was stained with PAS and alcian blue. Steepening of the host cornea may be another reason for lack of predictability and refractive regression following epikeratoplasty.