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Fluorescein angiography
Definition
Fluorescein angiography is an eye test that uses a special dye and camera to look at blood flow in the retina and choroid, the two layers in the back of the eye.
Alternative Names
Retinal photography; Eye angiography
How the Test is Performed
Eye drops that make the pupil dilate will be given. You will be asked to place your chin on the camera's chin rest and your forehead against a support bar to keep your head still during the test.
The health care provider will take pictures of the inside of your eye. After the first group of pictures are taken, a dye called fluorescein is injected into a vein, usually at the bend of your elbow. Then, a special camera takes pictures as the dye moves through the blood vessels in the back of your eye.
How to Prepare for the Test
You will need someone to drive you home, because your vision may be blurred up to 12 hours after the test.
You may be told to discontinue drugs that could affect the test results. Tell your health care provide about any allergies, particularly reactions to iodine.
You must sign an informed consent form. You must remove contact lenses before the test.
Tell the health care provider if you may be pregnant.
How the Test Will Feel
When the needle is inserted, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
When the dye is injected, you may have mild nausea and a warm sensation. These symptoms are usually very brief.
The dye will cause your urine to be darker, and possibly orange in color, for a day or two after the test.
Why the Test is Performed
This test is done to see if there is proper blood flow in the blood vessels in the two layers in the back of your eye (the retina and choroid).
It can also be used to diagnose problems in the eye or to determine how well certain eye treatments are working.
Normal Results
A normal result means the vessels appear a normal size, there are no new abnormal vessels, and there are no blockages or leakages.
What Abnormal Results Mean
If blockage or leakage is present, the pictures will map the location for possible treatment.
An abnormal value on a fluorescein angiography may be due to:
- Blood flow (circulatory) problems, such as blockage of the arteries
- Cancer
- Diabetic or other retinopathy
- High blood pressure
- Inflammation or edema
- Macular degeneration
- Microaneurysms -- enlargement of capillaries in the retina
- Tumors
- Swelling of the optic disc
Additional conditions under which the test may be performed:
Risks
There is a slight chance of infection any time the skin is broken. Rarely, a person is hypersensitive to the dye and may experience:
- Dizziness or faintness
- Dry mouth or increased salivation
- Hives
- Increased heart rate
- Metallic taste in mouth
- Nausea and vomiting
- Sneezing
Serious allergic reactions are rare.
Your urine will be darker, and possibly orange in color, for a day or two after the test.
Considerations
The test results are harder to interpret in people with cataracts.
References
Maguire JI, Federman JL. Intravenous fluorescein angiography. In: Tasman W, Jaeger EA, eds. Duane’s Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 44.
Ciardella AP, Kaufman SR, Yannuzzi LA. The use of fluorescein angiography in acquired macular diseases. In: Tasman W, Jaeger EA, eds. Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 113F.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
