Expression and Distribution of Extracellular Matrices during Corneal Wound Healing after Keratomileusis in Rabbits

Abstract

We compared the corneal wound healing responses of keratomileusis and keratectomy in rabbits. A single pass of thin lamellar keratectomy was performed with a microkeratome in rabbits. The lenticule was repositioned with a hinge in one group and discarded in the other. With immunofluorescence techniques, we studied the appearance and distribution of fibronectin, fibrinogen and type III collagen at follow-up intervals from 1 h to 3 months. Fibronectin and fibrinogen began to deposit on the periphery of the denuded stroma 3 h after induced injury and diminished once reepithelialization had completed in both groups. In the corneas with attached lenticules, type III collagen was detected 7 days after surgery and lasted for at least 3 months. Type III collagen was detected only in the periphery of the interface and not in its center. These findings suggest that fibronectin and fibrinogen may play roles in epithelial healing after in situ keratomileusis in rabbits. Stromal healing of colla- gen seems to take place 7 days after keratomileusis and to last for several months. No deposits of new collagens in the center of the interface between lenticule and stromal bed may explain the optical clarity in the keratomileusis.