Toxicology study of long-term administration of rhKGF-2 eye drops on rabbit corneas.

Keratinocyte growth factor -2 promotes corneal repair. Its mechanism of action involves regulating regeneration and migration of corneal cells, as well as activating corneal limbal stem cells. However, KGF-2 being a carcinogenic growth factor and its potential adverse effect in over dosage long-term treatment had not yet been reported. In this study, we used New Zealand white rabbits to study possible toxic effects of ocular administration of recombinant human keratinocyte growth factor-2 eye drops. Animals in the medium- and high-dose groups had some ocular irritant reactions during the course of drug administration; however this reaction was harmless to the cornea and it ended up when administration was stopped. Serum biochemistries were largely unaffected by treatment. Pathological examinations were unremarkable. We found that over-dosed administration of these eye drops caused some ocular irritation, but this irritant reaction was harmless to the eye, and it reversed after the drug was stopped. There were no apparent systemic effects of the drug.