Fluorescein angiography, a clinical test to look at blood
circulation inside the back of the eye, aids in the diagnosis of
retinal conditions associated with diabetes, age-related macular
degeneration, and other eye abnormalities. The test can also help
follow the course of a disease and monitor its treatment. It may be
repeated on multiple occasions with no harm to the eye or body.
Fluorescein is an orange-red dye that is injected into a vein in the
arm. The dye travels through the body to the blood vessels in the
retina, the light-sensitive nerve layer at the back of the eye. A
special camera with a green filter flashes a blue light into the eye
and takes multiple photographs of the retina. The technique uses
regular photographic film, or, more commonly, is performed with digital
equipment. No X-rays are involved.
If there are abnormal blood vessels, the dye leaks into the retina
or stains the blood vessels. Damage to the lining of the retina or
atypical new blood vessels may be revealed as well. These abnormalities
are determined by a careful interpretation of the photographs by an
ophthalmologist (Eye M.D.).
The dye can discolor skin and urine until it is removed from the
body by the kidneys. There is little risk in having fluorescein
angiography, though some people may have mild allergic reactions to the
dye. Severe allergic reactions have been reported but only very rarely.
Being allergic to X-ray dyes with iodine does not mean you will be
allergic to fluorescein. Occasionally, some of the dye leaks out of the
vein at the injection site, causing a slight burning sensation that
usually goes away quickly.
(c) 2007 The American Academy of Ophthalmology