Inhibition Of Corneal Angiogenesis By RPEDF In The Rat Model

Objective To evaluate the effect of topically administered rPEDF on experimentally induced corneal neovascularization in the rat model. Method Corneal chemical cauterization of 160 eyes (left eye) in Sprague-Dawley male rats was induced by silver nitrate sticks. All 160 rat models were randomly assigned to 4 groups: 40, 40, 40, 40 rats for rPEDF, Chloramphenicol, Chondroitin Sulfate and saline solution groups, respectively. Rats in the four groups were anesthetized and their corneas were removed for immunohischemistry and western blot analysis in different time periods (3^rd, 10^th, 15^th, 30^th day) after treatment. VEGF and CD34 expression levels of the four groups were evaluated. The right eyes were served as normal controls.Results There was a high level of PEDF expression and very low level of VEGF and CD34 expression in the normal corneas. VEGF and CD34expression level increased with time in the three groups (Chloramphenicol, Chondroitin Sulfate and saline solution), which peaked at 10^th day after treatment and maintained at a high level afterwards. In contrast, the rPEDF group did not show such a high increase and maintained at a low level 15 days after treatment.Conclusions VEGF expression was down-regulated and the endothelial cell proliferation was reduced by rPEDF in the corneal chemical cauterization rat models, which lead to inhibition of corneal neovascularization. The results suggested that rPEDF was a potent drug for the treatment of corneal angiogenesis.