In vitro studies of corneal wound healing: epithelial endothelial interactions

Full thickness explants of rabbit cornea were grown in organ culture and the migratory behavior of both epithelium and endothelium was observed under different experimental conditions. Following explantation, epithelial migration along the cut surface of the stroma began within 6 hr. By 24 hr, the epithelium reached the cut edge of Descemet's membrane and made contact with the endothelium at this point. Further epithelial advancement was then completely inhibited for up to 30 days following contact with the endothelium. Likewise, there was no migratory endothelial movement. If the endothelium was mechanically removed from the posterior corneal surface just prior to culture, the epithelium subsequently moved onto Descemet's membrane and completely encircled the explant after only 48 hr in vitro. Prior removal of epithelium permitted the endothelium to behave in a similar manner. However, endothelial migration was not completed until 96 hr in vitro because of a 48 hr delay before movement began. The results show that epithelium and endothelium mutually inhibit each other's forward movement and suggest an important role for this inhibitory interaction during corneal wound healing.