We have been investigating experimentally the factors which initiate and perpetuate ocular neovascularization (NV). Our studies can be divided into four categories: production of a primate experimental model of ocular NV, morphological studies, tissue culture studies, and biochemical studies. We have been successful in producing a reliable primate model of ocular NV following retinal vein occlusion (RVO). The morphological and fluorescein angiographic studies have established that the new vessels seen in the animal model represent true NV and not simple dilatation of the pre-existing vessels. The tissue culture studies have shown the presence of vasoproliferative activity in the intraocular fluids in eyes with ocular NV in our animal model. The various biochemical studies conducted so far have provided preliminary results on various aspects, including the protein electrophoretic pattern and lysosomal enzymes in the intraocular fluids from eyes with and without ocular NV and effects of anoxia and of corticosteroids. The results of our various studies are very briefly reviewed and the importance of angiogenesis is discussed.