Fluorescein dye is injected into a vein in the arm. As it circulates through blood vessels in the eye, a rapid series of photographs is taken with a special camera. The camera uses a cobalt blue light to intensify the yellow-green color produced by the dye in the blood vessels of the retina (the light-sensitive layer of tissues that lines the back of the eye) and choroid (the layer of tissue behind the retina).
Purpose of the Fluorescein Angiography
- To reveal fine details of retinal circulation that is not visible with a routine eye exam
- To diagnose and evaluate a variety of eye diseases, including age-related macular degeneration, or AMD (a degenerative condition of the most sensitive area of the retina, or macula); diabetic retinopathy (deterioration of the retina resulting from diabetes); circulatory or inflammatory disorders; and tumors
- To assist in the planning of laser treatments for neovascular AMD, diabetic retinopathy, and other disorders
- As part of permanent medical record of the vessels at the back of the eye
- To identify and locate subretinal neovascularization (new blood vessels growing under the retina, which will leak and bleed)
Who Performs Fluorescein Angiography
- An ophthalmological photographer
Special Concerns about Fluorescein Angiography
- The presence of cataracts or blood in the vitreous (the jelly-like mass that fills the cavity of the eyeball) may limit or preclude use of fluorescein angiography because clear pictures cannot be obtained. The procedure may be performed after cataracts are removed.
- This test should not be done in people with a known allergy or sensitivity to fluorescein dye or dilating eye drops.
Before the Fluorescein Angiography
- Inform your doctor if you have any allergies, use any medications, or have another eye disorder such as glaucoma.
- If you have glaucoma, do not use any eye drop medication on the day of the test.
- The examiner will administer eye drops to dilate your pupils. It may take 15 to 40 minutes to achieve maximum dilation.
What You Experience during Fluorescein Angiography
- You are asked to place your head in a brace with a padded chin rest and forehead bar. Keep your teeth together, focus your eyes straight ahead, and breathe and blink normally.
- Several preliminary photographs may be taken.
- Fluorescein dye is injected into a vein in your arm. You may feel mild discomfort and a feeling of warmth or nausea soon after the dye is injected.
- As the dye passes through the blood vessels in the back of your eye over the next 30 to 60 seconds, a series of photographs is taken using a special camera.
- In some cases, additional photographs may be taken as much as 30 minutes later.
- The test usually takes about 30 minutes.
Risks and Complications of Fluorescein Angiography
- Transient nausea or vomiting occurs in 2 to 4 percent of patients.
- Minor allergic reactions to the fluorescein dye may produce hives or asthmatic symptoms.
- In rare cases, a severe, potentially fatal allergic reaction may occur. Emergency medications and equipment and trained personnel are present in most facilities performing this test.
After the Fluorescein Angiography
- Since your pupils will remain dilated for 3 to 4 hours, arrange for someone to drive you home. Your vision may remain blurred for up to 12 hours.
- The fluorescein dye may result in a harmless yellow discoloration of the skin and urine for 24 to 48 hours.
- Blood (hematoma) or fluorescein may collect under the skin at the injection site; this is harmless and resolves on its own. For a large hematoma that causes swelling and discomfort, apply ice initially; after 24 hours, use warm, moist compresses to help dissolve the clotted blood.
Results of Fluorescein Angiography
- An ophthalmologist will examine the photographs for abnormalities, such as blood vessel leakage or blockage, bleeding (hemorrhage), or new vessel growth.
- Depending on the results, the doctor will recommend appropriate course of treatment, if possible. You may be referred to a low vision center for advice on measures to help you manage daily activities with vision loss.
- If fluorescein angiography cannot produce an adequate image of any abnormal blood vessels, a similar procedure that uses a different dye, called indocyanine green angiography, is sometimes performed.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media