Vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 in the regulation of corneal neovascularization and wound healing

Purpose: To study the change in expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 in the rabbit cornea and limbus following a penetrating, central corneal alkali burn. The influence of different cells on VEGF and VEGFR-2 expression was studied by excluding granulocytes from the wound area. Methods: Fourteen New Zealand white rabbits were subjected to a penetrating, 5-mm diameter, central corneal alkali burn in one eye under general anaesthesia. Seven of the rabbits were given injections of fucoidin for 36 hours. The rabbits were killed after 36 hours and the corneas were excised with a sclera rim and prepared for immunohistochemistry. Results: Both VEGF and VEGFR-2 are strongly expressed in the frontline of repopulating epithelial, stromal and endothelial cells during wound healing, irrespective of granulocyte presence. Vascular endothelial cells express VEGF strongly after injury, but only in the presence of granulocytes. Conclusion: Corneal neovascularization requires the presence of granulocytes to stimulate vascular endothelial cells. During wound healing in this area, VEGF is a factor that stimulates proliferation and migration and that is not influenced by granulocytes.