Expression Of Vascular Endothelial Growth Factor In Experimental Anterior Segment Ischemia In Rabbits

Objective: To investigate the expression of vascular endothelial growth factor (VEGF) in experimental anterior segment ischemia (ASI) in rabbits, in which tenotomy of various recti was performed.Method: 26 adult New Zealand white rabbits were divided into 4 groups: Group N, A, B and C. Group A was subdivided into 4 groups: Group A1, A 3 ,A 7 and A14. There were 2 rabbits in Group N, 4 in the other groups each. Group N was subjectded to no operation. In the right eyes of Group A, B and C, various recti were isolated and sectioned, while in the left ones , only conjunctival limbal peritomy was performed. The eyes were enucleated 1,3,7 or 14 days after surgery, then fixed with 4% formaldehyde. Morphological change were studied by light and electron microscopy. Specimens of Group A and N were examined immunohistochemically for VEGF.Results: Mild to severe histological changes of ASI occurred in the the right eyes in Group A, B, while no evident change in the Group C compared with Group N. Immunohistochemically, VEGF protein was detected in the epithelial cells of the ciliary and iris, anterior capsule of lens and several lays of retina in Group A.Conclusion: Simultaneous tenotomy of 3 or 4 recti causes anterior segment ischemia in rabbits. VEGF may play an important role in mechanism of ASI.