The study of pathological iris and retinal neovasculization has been hindered by the scarcity of good animal models. We will attempt to produce iris and/or retinal neovascularization by implanting ethylene-vinyl acetate (ELVAX) sustained-release polymers containing a purified retina-derived growth factor (RDGF) into the anterior chamber of rabbit and vitreous cavity of vitrectomized monkey eyes. These polymers will provide a long term, sustained delivery of RDGF to the intraocular tissues, and any resultant changes in the vasculature of the iris or retina will be documented by photography and fluorescein angiography. We will attempt to show that iris and retinal neovascularization can be produced by the presence of a diffusible angiogenic agent alone. This model will give insight into the mechanism of production of pathological ocular neovascularization as well as serve as an experimental tool for the study of various other aspects of ocular neovascularization. The feasibility of using sustained-release polymers as a long-term intraocular drug delivery system will also be assessed.
