What is Fundus Fluorescein Angiography and Indocyanine Green Angiography?

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Introduction

Fundus Fluorescein Angiography (FFA) is a routine retinal examination of the tiny blood vessels of the retina at the back of your eye. Indocyanine Green Angiography (ICGA) is used to examine the layer beneath the retina, called the choroid.

This information is essential to help your eye consultant diagnose any possible problem and plan your treatment.

Tests are carried out by a specialist eye nurse and a ophthalmic photographer.

Before the procedure

On arrival for your appointment you will have your vision tested and have dilating eye drops put into your eyes to enlarge the pupils. This makes sure we get the best photographs possible.

It is important to take photographs of both eyes even if you only have a problem with one.

These drops may cause your vision to be blurred for 4 – 6 hours. You are advised NOT to drive after you have had this procedure, as your driving ability will be affected until the effects of the drops have worn off.#

You will be asked about any allergies, medications and medical conditions you may have. If you have inhalers for asthma or spray / tablets for angina, please bring these with you. If you had any problems with a previous fluorescein angiography test, please tell us.

You may eat and drink normally before coming to the hospital. If you have diabetes please bring a snack with you.

To do either of the two examinations we need to inject some dye into your vein. This is done through a small plastic tube (called a cannula) inserted into your hand or arm. This will be left in place until 30 minutes after the test has finished.

What the procedure will involve

In the photography room you will sit in front of the camera with your chin and forehead resting firmly on the frame.

It is important that you follow the instructions given to you by the ophthalmic photographer to make sure that we get good quality images.

Once you are correctly positioned on the scanning machine, the pre-prepared dye will be injected through the cannula in your vein. Once the dye reaches the back of your eye (this only takes a few seconds) the photographer will begin to take images. The photographer will then take some more images at various intervals.

Are there any side effects?

Both dyes may cause side-effects, but have been proven to be safe for use in both young and older patients. The most common side-effects are blurred vision from the eye drop and some dazzle from the scanner light. Other side-effects usually occur within a few minutes of the dye being injected and last for just for a short time. The most common of these are:

Nausea (feeling sick) and vomiting.
Skin rashes and itching.
A very small number of people may experience an allergic reaction to the dye. These range from shortness of breath.
(1 in 9000 people) to severe anaphylactic reactions (occurring in around 1 in 220,000 people)*. In such cases emergency care may be needed. Please remember these side-effects are rare.

The fluorescein dye will turn your skin yellow for up to 24 hours and your urine will be yellow as the body flushes the dye out of your system. Drinking plenty of fluids afterwards will help.

The fluorescein dye is a deep orange / yellow colour and the indocyanine green dye is a green colour. If the dye leaks outside the vein it may cause temporary pain. This can be relieved by cold compression – either a towel soaked in cold water or an ice pack held firmly on the injection site. If the injection site remains painful or causes you concern, please seek medical advice from your GP or hospital emergency department.

Patients with diabetes

The fluorescein dye gives a false high reading in the urine so it is recommended that you test your blood sugar rather than your urine during this period. If you are concerned, please seek medical advice.

Will I get the results on the same day?

The results will either be discussed with you by the doctor after the test, or you may receive a follow up appointment to discuss the results.

When you go home

Most patients do not have any problems after they leave clinic. If you begin to feel unwell, please contact your own GP. If you have any questions about your ophthalmic photography, please feel free to discuss this with one of our ophthalmic photographers, or contact us on: