Angiography of retinal vessels (FA) is a diagnostic method for evaluating the retina and optic nerve head. In principle, retinal vessels are imaged using a dye. This imaging method is used for identifying disease patterns in i.e. diabetic retinopathy, vascular occlusions, tumours, or age-related macular degeneration. In FA imaging retinal photographs are acquired using red-free light, applying a green filter glass. This causes contrast between ocular vessels and proximity. Retinal vessels are imaged using fluorescein, choroidal vessels using indocyanine green.
Basically, the time-interval between dye injection and the visualization of the dye within the retinal region of interest is evaluated. This allows drawing conclusions about perfusion and related disturbances.