SLIDING OF EPITHELIUM IN EXPERIMENTAL CORNEAL WOUNDS

Publisher Website
Google Scholar
Abstract
The morphological changes in the rabbit cornea due to a linear wound and a central keratectomy and its reepithelization were examined under the scanning electron microscope. After the rounding off and retraction of the wound edges during the 1st 6 h, the stroma was infiltrated by leukocytes. In the 1st process of healing, superficial epithelial cells migrated over the edges of the wound to protect the exposed cleft in the tissue. After 15 h the basal epithelial cells sent pseudopodia-like processes of varying lengths into the wound area. The migrating cells were mainly flat. During this phase the primary migration of the basal epithelial cells was followed by subsequent cell layers. In the migration 3 types of cells were distinguished: very flat cells with smooth edges without microprojections, which adapt their shape to the clefts in the damaged stroma; flat cells with considerably folded plasma membrane on the cell surface giving a coral-like appearance; and cells with voluminous cytoplasmic processes. The rapidly sliding epithelium covered the defect with star-shaped growths; after only 48 h the wound was almost completely closed. After 96 h the deep wound was completely covered by epithelium. The epithelial cells did not yet possess their original surface structure, i.e., they had fewer microvilli and microplicae than normal. The earliest normal surface relief appeared after 5 days. The surface cells were predominant in the 1st stage of the healing process and the basal cells only in the 2nd stage.