What Is It?
Flourescein angiography is a diagnostic procedure which uses a special camera to take a series of photographs of the retina, the light sensitive tissue in the back of the eye. A special water-soluble dye (flourescein) is injected into a vein in the arm. The dye travels through the veins and into the arteries which circulate throughout the body. This procedure is often confused with an X-ray angiogram where an iodine dye is injected into a vessel.
As the dye passes through the blood vessels of the retina, a special camera flashes a blue light into the eye and takes multiple photographs of the retina.
If the blood vessels are abnormal, the dye may leak into the retina or stain the blood vessels. Damage to the lining underneath the retina or the appearance of abnormal new blood vessels growing beneath the retina may also be revealed. The precise location of theses abnormalities can be determined by a careful interpretation of the fluorescein angiogram by your ophthalmologist.
Why is fluorescein angiography done?
If after examining your eyes, your ophthalmologist suspects abnormalities in the back of the eye, he or she may recommend fluorescein angiography. It is often done to follow the course of disease and monitor treatment results.
Diabetes, the leading cause of blindness in patients under the age of 55, can cause the blood vessels of the retina to leak fluid or blood. In some cases, these abnormalities can be treated with a laser in an attempt to prevent severe visual loss.
Without the help of fluorescein angiography, your ophthalmologist would not be able to thoroughly diagnose these and other abnormalities. Knowing exactly where a leak is, for example, can guide laser treatment with pinpoint accuracy.
What are the risks of fluorescein angiography?
After the flourescein dye is injected, your skin may turn yellowish for several hours. This color disappears as the dye is filtered out of the body by the kidneys. Because the dye is removed by the kidneys, your urine will turn dark orange for up to 24 hours following the test.
Some individuals may experience slight nausea during the procedure, but this usually passes within a few seconds. If the dye leaks out of a fragile vein during the injection, some localized burning may occur. This burning usually lasts only a few minutes and the staining will go away in a few days.
Allergic reactions to fluorescein dye are rare. If they occur, they may cause a skin rash and itching. This is usually treated with oral or injectable antihistamines, depending on the severity of the symptoms. Even more rarely, severe allergic reactions (anaphylaxis) can occur and be life threatening.
Why are regular medical eye examinations important for everyone?
Eye disease can occur at any age. Many eye diseases do not cause symptoms until the disease has done damage. Since most blindness is preventable if diagnosed and treated early, regular medical examinations by an ophthalmologist are very important. Why an ophthalmologist? Because an ophthalmologist (MD or osteopath) provides total eye care: medical, surgical and optical.