Treatment of macular degeneration by interfering RNA. Representation of the treatment for macular degeneration (red spot on the retina) thanks to the injection of interfering RNA (on the left) that enables to stop the growth of the blood vessels at the level of the macula lutea. The age-related macular degeneration (AMD, also named senile macular degeneration) is a degenerative disease of the macula lutea, central area of the retina, point where visual acuity is maximal and point on which acute vision of the details is made. This degenerescence mainly affects persons over 65 years old and lead to an important loss of the visual field. Juvenile forms of degeneration also exist (genetic diseases). AMD can take a dry form or, as here, a humid form (also named exsudative or neovascular). In this case, new choroidial blood vessels form (neovascularization) and invade the region located under the macula lutea ; retinal hemorrhages can occur as these new vessels are very fragile, leading to a destruction of the macula lutea and to cecity (on the bottom left). Humid AMD is the first pathology for which the treatment is tryied by RNA interference (RNAi). An injection of interfering RNA directed against the mRNA of the vEGF (vascular endothelial growth factor) is done in the vitreous humor (on the top left). The clinical study has revealed a decrease of the neovascularization (on the bottom right) accompanied by an improvement of the sight (Bevasiranib, Acuity Pharmaceuticals, June 2006).
