By Moorfields Eye Hospital
What is fluorescein (FFA) and indocyanine green (ICG)
These are simple diagnostic tests, which involve the injection of fluorescein (yellow) dye and/or indocyanine green into your bloodstream via a vein in your hand or arm, followed by a series of photographs taken over several minutes. The FFA test gives your doctor more information about the condition of your retina in the back of your eye and the ICG test provides information about the choroid which lies underneath the retina. The tests help the doctor to consider the best treatment options for you.
Please take your medication as normal on the day of your procedure. You may eat and drink as normal.
What does the test involve?
• On arrival at the outpatient department, your vision will be tested.
• You will be asked about your general health. Please tell us if you have any chest or breathing problems. It is also very important to inform us of any allergies particularly to shellfish, medications, fluorescein, sulpha drugs or latex.
• Your blood sugars and blood pressure will be checked.
• Your pupils will then be dilated with eye drops; these drops might blur your vision. It is therefore advisable not to drive home after your appointment.
• You will have the procedure explained to you and you will be asked to sign a consent form to agree to the procedure. Please feel free to ask any questions.
• Once your pupils are dilated, you will be taken into the fluorescein photography room.
• You will be seated at a camera with your arm supported, and some photos will be taken.
• A cannula (small plastic tube) will be inserted into a vein in the back of your hand.
• The fluorescein dye and/or indocyanine green will be injected into your arm while a series of photos is taken as the dye enters the vessels at the back of your eye.
• The whole test only takes about 10 - 30 minutes, but please expect to be in the department for one to two hours so that we can do the necessary pre and post test checks.
• It is very important to keep your eye in the position requested by the photographer.
Are there any side effects?
• The fluorescein dye will give your skin a yellow tinge and your urine will be bright yellow for one or two days. The ICG procedure does not affect the colour of your skin or urine.
• You might experience a hot flush sensation as the dye is injected,
• One in 10 patients might feel nauseous or short of breath, or develop a transient rash, but this rarely lasts for more than a few seconds.
• There is a very remote risk of a severe allergic reaction to these intravenous drugs. For this reason, an emergency
resuscitation team is always available. After the fluorescein angiogram
• The cannula will be left in your hand for half an hour. Once we are certain that you have not suffered any adverse
reactions, the cannula will be removed.
• The doctor will discuss the results with you and make recommendations for any treatment you might need.