Fluorescein and indocyanine green angiography are tests that use special cameras to photograph the structures in the back of the eye. These tests are very useful for locating the damage to the blood vessels that nourish the retina (light sensitive tissue) and in turn, checking on the health of the retina itself. In both tests, a colored dye is injected into a vein in the arm of the patient. The dye travels through the circulatory system and reaches the vessels in the retina and those of a deeper tissue layer called the choroids. Neither of the tests uses any harmful forms of radiation.
Fluorescein is a yellow dye, which glows in visible light.
How is fundus angiography done?
Before the procedure, you will be asked questions about your general health and the medications that you are using. A self-explanatory consent form, which explains the side effects in detail, will be provided to you. You will have to give your consent before the procedure.
You should have a light meal before undergoing the procedure and must be accompanied by a family member or friend.
Eye drops will be administered to enlarge the pupils — this takes approximately 30 minutes. You will then be asked to sit still in front of the camera while a series of color photographs of your eyes are taken. You will be given an injection in your arm, and more photographs will be taken.
The test takes approximately 15-30 minutes.
What are the side effects?
Fluorescein angiography is considered very safe and serious side effects from these tests are uncommon. However, there is the possibility that a patient may have a reaction to the dyes. While fluorescein contains no iodine and is safe in patients known to be allergic.
Some people may experience slight nausea after the dye injection, but the feeling usually passes quickly.
Patients who are allergic to the dye can develop itching and a skin rash. These symptoms generally respond quickly to oral medications such as antihistamines or steroids. Very rarely, a sudden life-threatening allergic reaction called anaphylaxis can occur. This condition requires medical treatment.
There is also the possibility of an infiltrate of the dye into the skin at the injection site; this may cause some discomfort or discoloring of the skin for several days.
The fluorescein dye will turn the patient’s urine orange and may slightly discolor the skin as well for a brief period. Your physician can explain the individual risks of these procedures for certain patients, including pregnant women.
