Purpose: To examine whether the topical application of keratinocyte growth factor (KGF) can enhance corneal epithelial healing in vivo. In addition, the distribution of S-phase cells in KGF-treated and control corneas was investigated during regeneration and under normal conditions.
Methods: A 10-mm diameter epithelial defect was made in the center of rabbit corneas. A 50-microliters aliquot of 10 micrograms/ml human keratinocyte growth factor (hKGF) was then applied topically five times a day. The same volume of phosphate-buffered saline (PBS) vehicle was applied to the contralateral eye as a control. Each corneal epithelial defect was subsequently photographed every 12 hours and was measured by a computer-assisted digitizer. For the S-phase cell analysis, entire corneas were labeled with 3H-thymidine and were subjected to autoradiography at 24 hours after wounding or in the normal cornea at 24 hours after the application of KGF or PBS.
Results: Topical application of 10 micrograms/ml hKGF significantly accelerated corneal epithelial wound healing when compared with controls. In the S-phase cell analysis, KGF did not have any effect on normal corneal epithelial cells. However, in the regenerating cornea, the number of S-phase cells in the KGF-treated limbal epithelium was twofold higher than in the controls.
Conclusions: Topical application of KGF accelerated corneal epithelial wound healing in vivo and increased cell proliferation in the limbal epithelium of the regenerating cornea.