Inhibitory effect of doxycycline on neovascularization in a rat model of corneal alkali burn

Objective To investigate the inhibited effect of doxycycline on neovascularization( NV) in a rat model of corneal alkali burn and its mechanism. Methods Thirty-two healthy SD rats were randomly divided into control group and doxycycline-treated group,with16 rats in each group. After the corneal alkali burn model was established,the doxycycline-treated group was given 0. 5% doxycycline eye drop,while the control group was given the solution of eye drop without doxycycline. The inflammatory index was observed 3,7,14 and 21 days after injury,respectively,and the area of corneal NV was calculated. The cornea was detected for the expression of vascular endothelial growth factor( VEGF) by enzyme-linked immunosorbent assay( ELISA). Results The doxycycline-treated group showed slighter conjunctival congestion and corneal edema at all time points compared with the control group. The inflammatory indexes 3,7,14 days after injury in the doxycycline-treated group were significantly lower than those in the control group( P 0. 05). The areas of corneal NV 3,7,14,21 days after injury in the doxycycline-reated group were smaller than those in the control group( P 0. 05). There was no significant difference in the expression of corneal VEGF between two groups( P 0. 05). Conclusion Doxycycline can relieve the corneal inflammatory reaction and corneal neovascularization in rats with corneal alkali burn,which might be associated with the inhibition of inflammatory reaction,but might not be associated with the expression of VEGF.