AIM:To investigate the expression levels and correlation of VEGF and MMP-9 in the retinal ischemia/reperfusion injury(RIRI).

METHODS: Eighty-four Wistar rats were divided into normal control group and at 6h, 12h, 24h, 48h, 3d and 7d group after retinal ischemia/reperfusion. The model of RIRI was constructed by elevating the intraocular pressure. The expression levels of VEGF and MMP-9 was measured using immunohistochemical staining.

RESULTS: No VEGF positive cells were found in normal group and it began to express at 12h, increased gradually and reached maximal levels at 48h after RIRI. MMP-9 positive expression was rarely detected in the normal control group and began to increase at 6h, reached the peak at 24h. There was statistical difference between normal control group and ischemia/reperfusion group(P<0.01)with regard to the expression of VEGF and MMP-9.The expression of VEGF was positively correlated to MMP-9(P<0.05).

CONCLUSION: The high expression of VEGF and MMP-9 is significantly correlated with RIRI and may play an important role in the occurrence and development of retinal ischemic injury.