How is fluorescein angiography performed?
In fluorescein angiography, a small amount of vegetable-based dye (sodium fluorescein which is either orange or yellow in color) is injected into an arm vein. The dye travels through the circulatory system and, in about 15 seconds, reaches the blood vessels in the retina and the choroid, the major blood vessel of the eye lying between the retina and the sclera. During a period of 2 to 5 seconds, the dye travels through the capillaries and fills the veins. Rapid, sequential black and white photographs, taken as the dye circulates, document how the dye enters the different blood vessels. Diseases of the retina, choroid, and retinal blood vessels will interrupt the progression of dye. Depending on the specific problem, another set of photographs may be taken about 15 minutes later in order to show staining that can possibly indicate leakage or swelling on the retina. These photographs will detect any abnormalities in the retina that are not visible by other procedures. Fluorescein angiogr
