Expression of inflammatory markers in the monkey iris after intravitreal application of vascular endothelial growth factor (VEGF)

Purpose Aqueous VEGF concentration is increased in eyes with neovascular glaucoma (NVG). To examine the possible role of VEGF in the pathogenesis of NVG, we carried out a pilot study of ocular cytokine release and inflammatory marker expression following intravitreal application of VEGF in a monkey model. Methods Monkeys received intravitreal injection of 1.25 ug / 50ul VEGF and were enucleated at Day 3 and Day 7 after VEGF injection. 1 monkey served as the naïve control. Monkeys. Pro‐inflammatory consequences of intravitreal VEGF were assessed by two methods: immunohistochemical analysis and Luminex panel. Results Intravitreal VEGF resulted in profound histological alterations at the limbus, ciliary body and iris characterized by widespread stromal edema, vascular dilatation and infiltrating polymorphonuclear neutrophils that were myeloperoxidase (MPO) reactive. Increased expression of MPO reactive neutrophils were scattered around the draining angle at day 3, with reduced incidence by day 7. Luminex panel showed increased levels of myeloperoxidase, MCP‐1 Interleukin 6, MIP‐1beta, Interleukin 1ra and MMP‐2 at Day 3 and significant decreases by day 7. . Conclusion Intravitreal VEGF caused significant inflammation and the expression of proinflammatory cytokines at the limbus, ciliary body and iris. Thus, inhibition of VEGF or related cytokines may constitute a useful adjunct in the therapeutic management of NVG.