Effect Of COX-2 And Its Inhibitor Celcoxib On Corneal Neovascularization

Objective To investigate the relationship between corneal neovascularization and cyclooxygenase-2 (COX-2) and to study the effects of Celecoxib on corneal neovascularization.Methods The corneal neovascularization was induced by corneal cautery with filtering paper soaked 1 mol/L NaOH in 80 eyes of 40 Sprayue-Dawley(SD) rats. The rats were randomly divided into group I, II, III and control group. 1 mol/L, 2μmol/L and 3μmol/L of Celecoxib and saline were separately injected subconjunctivally in group I, II, III and control group after induction of neovascularization.The expression of COX-2 and VEGF was examined by immunohistochemistry and RT-PCR. Integration optic density (IOD) of COX-2 and vascular endothelial growth factor(VEGF) on cornea of rat were measured with computerized image analysis.Results The corneal neovascularization grew rapidly in 2-4 days after corneal cautery. The edema and inflammation of cornea were slighter in group II in comparison with control group. The expressions of activated COX-2 and VEGF were significantly increased in 2-4 days after corneal cautery, showing a heavy brown staining mainly in epithelium, basement layer and neovascular endothelium of cornea, and a gradually weaken tendency was seen after 7 days later. There were weaker expression of COX-2 and VEGF in group II, III compared with control group (P=0.008, P = 0.007), but no significant difference was found between group I and control group(P=0.998). There were positive correlations between COX-2 and VEGF in experimental and control group.Conclusion The activity of COX-2 is increased in the early stage of corneal neovascularization of SD rat. COX-2 plays an important role in the pathogenesis of corneal neovascularization by regulating VEGF. Topical application of Celecoxib has significant effects on the inhibition of activity of COX-2 and corneal angiogenesis.