The Research Of Treatment Of Doxycycline On Corneal Neovascularization

Objective To investigate the effects and mechanisms of doxycycline , an inhibitor of matrix metal-loproteinase,on rabbit corneal neovascularization(CNV).Methods Corneal neovascularization was induced by implantation of LPS pellet on 28 rabbits.The experimental rabbits then were randomly divided into CNV control group and doxycycline groups[received daily intraperitoneal injections of 20 mg/(kg·d)or subconjunctival injection every other day],and 7 rabbits worked as normal control group. Digital slitlamp image system was used to observe new vessels at the 3rd,7th,14th and 21th day. The CNV area was calculated in different groups. Immunohistochemistry were used to determine VEGF protein level,respectively.Results Doxycycline by intraperitoneal injection and subconjunctival injection inhibited corneal neovascularization significantly,and the later was more effective(P<0.01).The expression of VEGF in the basis epithelium was markedly increased in CNV control group in comparison with normal control group and suppressed significantly in doxycycline—injected group.The expressions of protein followed a similar pattern.Conclusion Subconjunctival injection of doxycycline is a more effective angiostatic approach.Inhibition of doxycycline on matrix metal1oproteinase activities is probably a proportional contributor to the overall suppression of angiogenesis.