The role of fibronectin in corneal wound healing was studied both in man and in experimental animals. Studies were carried out in order to characterize the possible effect of fibronectin on facilitating wound healing of the epithelium. a. Alkali burn model in rabbits. During the healing of an alkali burn, the surface epthelium does not heal normally, and it was found that there was less fibronectin and other basement membrane components, such as laminin, on the wounded surface. Topical fibronectin was found to allow the epithelial layer to remain intact longer during the healing of this wound, suggesting that exogenous fibronectin added in the form of an eyedrop may facilitate corneal wound healing. Experiments with other components, such as laminin, have also been done and are being analyzed. b. Because of the positive effect of fibronectin in experimental systems involving corneal epithelial wound healing, a clinical protocol was initiated in collaboration with the Massachusetts Eye & Ear Infirmary. This study is a randomized clinical trial comparing fibronectin eyedrops prepared from the patient's own plasma to placebo (serum albumin). c. Biopsy specimens from patients have been studied for the presence of fibronectin in healing wounds Fibronectin is present in retrocorneal fibrous membrane, as well as in certain conjunctival and corneal inflammatory conditions. Type III collagen appears to be associated with fibronectin in wounds involving healing fibroblasts or endothelium. d. Additional current laboratory studies are directed at mechanisms of corneal cell attachment mediated by fibronectin.
