Macular degeneration. Computer artwork of an eye affected by wet age-related macular degeneration. Details of the back of the retina are shown at upper right. At left are the photoreceptors (red and brown) with the blood vessels that supply the eye behind them in the choroid layer. In wet, or neovascular, macular degeneration new blood vessels grow in the back of the eye. The blood vessels are weak and bleed. The vessels and the bleeding can prevent light reaching the back of the eye. This causes a central spot in the vision as well as distortion, and often leads to blindness. Treatment is either with laser therapy to destroy the new blood vessels or with injection of anti-angiogenesis drugs (drugs that prevent new blood vessels forming).