Impact of Non-Exudative Type 1 MNV on AMD Progression

The overall goal of the proposed research project is to provide evidence that a specific subtype of neovascularization that may develop in eyes with age-related macular degeneration (AMD) prevents vision loss. This concept challenges the current view that the development of neovascularizations in AMD represents a harmful event in general. Notably, before the era of anti-vascular endothelial growths factor (VEGF) therapy, destruction and surgical removal of neovascular membranes have been tested as treatment options for neovascular AMD. This research project aims to substantiate the hypothesis that type 1 macular neovascularization (MNV) is intrinsically protective, in sense of a positive response to the degenerative processes in AMD. This concept has actually been proposed by pathologists decades ago but has not been systematically investigated in vivo. With the immense advances in retinal imaging, 'sub-clinical', non-exudative type 1 MNVs that are located beneath the retinal pigment epithelium (RPE) can now be detected non-invasively and characterized in vivo. There is currently a growing body of evidence that photoreceptor and RPE degeneration is indeed slowed down in eyes exhibiting type 1 MNV. However, the proof of a direct protective effect of non-exudative type 1 MNV on visual function in AMD is lacking. Here, the aim is to demonstrate relative preservation of function along with preserved structure in the immediate vicinity of type 1 MNV, while there is progressive loss of sensitivity and degeneration in the surrounding tissue.