Age-related macular degeneration

Age-related macular degeneration

Age-related macular degeneration (AMD) is a degenerative disease of the macula resulting in loss of central vision. Clinically, it is classified as dry (atrophic) or wet (neovascular or exudative).

The pathogenesis of dry type AMD is unclear; abnormalities in Bruch's membrane, inflammation, and chronic infection may all play a role.

The wet form of AMD is characterized by vascular growth in the subretinal space. The newly formed blood vessels are abnormal and leak, causing fluid collection under the retina. Research suggests that vascular endothelial growth factor (VEGF), a signal protein that is released in response to hypoxia, is responsible for this neovascularization. This process intially causes damage to the retinal pigment epithelium and later affects the rods and cones in the retina.