Assessment of corneal wound repair in vitro

The time course for the closure of linear wounds produced in cultured cell monolayers following either mechanical debridement or excimer laser photoablation were compared. Wounds were produced in the central zone of a confluent layer of bovine corneal epithelial cells, keratocytes, or endothelial cells, and the residual area of the wound measured at regular intervals. Differences in the rate of wound closure between cell types were demonstrated. For epithelial cells the rate of resurfacing after mechanical or excimer laser damage was similar; for keratocytes there was a lag period before cell slide began after laser injury, but the subsequent rate of resurfacing was then similar to mechanical wounds; only for endothelial layers was a significantly reduced rate of closure observed after photoablation as compared to mechanical wounding. In this model of wound healing it appears that it is the mechanism of removal of the extracellular matrix formed by endothelial cells that produces the major difference in the rate of wound closure between mechanical injury or photoablation.