What is Fluorescein Angiography?
Fluorescein angiography is a photographic test of the retina, the ‘film’ in the back of the eye. A water-soluble dye called fluorescein is injected into a vein in your arm, where it travels through the body reaching the eye. A special camera uses bright flashes of light to take multiple photographs of the back of your eyes as the dye passes through the blood vessels, providing information about the retina and nearby tissues.
Why is Fluorescein Angiography performed?
Fluorescein angiography is used to diagnose certain eye conditions, determine if treatment is possible, and plan or guide treatment. Common conditions requiring fluorescein angiography include diabetic retinopathy, macular degeneration, and retinal vascular diseases. In some cases, the angiogram may need to be repeated to monitor your response to treatment or changes in your eye condition.
What are the side effects of Fluorescein Angiography?
After fluorescein angiography, your skin will turn yellow for several hours. This will fade as the dye is filtered out by the kidneys – this leads to the urine turning a dark yellow-orange colour for up to 24 hours. Your vision will be blurred and you should not drive for at least four hours after the angiogram, but there is no permanent effect on the vision from having the test done.
Are there any risks?
Fluorescein angiography is a safe and very helpful test. Tens of thousands of fluorescein angiograms are performed every year. The chance of adverse effects is low, but as with any medical procedure, there are some risks involved. Some patients may vomit. Occasionally, some fluorescein will leak from a fragile vein, which may cause a localized burning feeling and yellow staining of the skin. The burning usually lasts a few minutes and the staining takes a few days to disappear.
Some patients may experience allergic reactions to the fluorescein dye. The most frequent allergic reaction is a skin rash, which is often itchy and may appear within minutes after the fluorescein injection. More severe allergic reactions are fortunately rare.
The most severe allergic reaction is called anaphylaxis (1/10 000), which is rare but may be life-threatening. Very rarely patients may experience breathing difficulty or heart rhythm disturbances, which can be severe and even cause death. If you feel any itching, tingling in the lips or tongue, difficulty breathing or pain during or after the angiogram, let us know immediately. You may require medication to control the reaction and your condition will be monitored until it has resolved. Delayed reactions are very uncommon, but it is important that you tell us if you experience any delayed effects that you feel may be related to your fluorescein angiogram.
It is very important for you to tell us about any health conditions that you may have, all the medications that you are taking, and especially any allergies to medications that you have had in the past. It is preferred you bring this information as a letter from your doctor. If you have had a previous fluorescein angiogram, please let us know. You do not need to fast for this test.
Fluorescein is reported to be safe in pregnancy, but we prefer to avoid this test in pregnant patients if possible. Please advise if you are pregnant, or suspect you could be pregnant.
Fluorescein can cause renal impairment in 1% of cases, therefor please inform us if you have pre-existing kidney disease.
If you have any further questions or concerns, please ask us before you have your angiogram.