[Recent findings on the etiopathogenesis of subretinal neovascularization]

The proliferation of new vessels originating from the choriocapillaris, constitute the turning point in Age Related Macular Degeneration. Vaso-proliferative, or better vaso-modulator, factors have an effect upon the subsequent steps of angiogenesis. Receptors especially for the fibroblast growth factor have been identified on ocular vascular endothelial cells. Basement membranes are the storage site of the factor. In vitro, vaso-proliferative factors, as Fibroblast growth factors, and vaso-inhibitor factors, as Transforming Growth Factor B, were identified in cell cultures of pigment epithelium. On the other hand, proliferations of pigment epithelium cells surround the neovascular sprouts and induce involution of experimental subretinal new vessels. Experimentally and clinically, inflammatory cells are found in the vicinity of the new vessels. Their effect could add or initiate new vessel proliferation. Angiogenesis is an extremely complex phenomenon but results of research on the role of pigment epithelium and vaso-modulators factors help to clarify it partially.