Fluorescein angiography is a time-stamped test for evaluating the health of the macula in any suspected disease state. It is particularly useful for patients with macular degeneration (ARMD). It can detect vascular problems, swelling, neovascularization, macular degeneration and inherited/congenital retinal disorders. It is a very helpful test.
When do we use fluorescein angiography? We use this test anytime we suspect a vascular problem, can not explain a decrease in vision, but most often to study the macula. Most commonly, we are looking for macular swelling in diabetes or changes associated with macular degeneration.
The macula is the functional center of the retina. It is the only area sensitive enough to give us 20/20 vision, color perception and central vision. When patients complain of decreased vision, including distortion, a fluorescein angiogram may be an appropriate test to obtain.
Fluorescein angiography is an important diagnostic test to manage macular degeneration (ARMD). Macular degeneration can destroy the pigment layer of the retina causing decreased vision, distortion, etc. This is common in non-exudative macular degeneration. There is loss of the retinal pigment layer (RPE) underneath the superificial layer of the retina. In “wet” macular degeneration, abnormal blood vessels can form within the layers of the retina. This, too, destroys the retinal pigment layer (RPE). Vision loss is much more rapid and can be more severe than the non-exudative form.
This test can quickly determine any damage to the underlying pigment layer (RPE) and the presence, or absence, of abnormal retinal neovascularization (aka choroidal neovascularization).
What does a fluorescein angiogram do? A fluorescent dye is injected into a vein. The dye takes about 12-15 seconds to reach the retina. Photographs are taken with a filter to highlight the dye as it perfuses the retina. Characteristic flow patterns can determine if there is vascular problem, abnormal dye patterns can detect swelling, neovascularization or damage to the retinal pigment.
In the end, fluorescein angiography is the most important diagnostic test for patients with macular degeneration. It can explain changes in vision, yet also determine if your disease is stable or requires additional treatment.
Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist