Overview

A fundus fluorescein angiography is a common procedure that is done to give us more information about the condition of the back of your eye.

A small amount of yellow fluorescein dye will be injected into a vein in your arm. The dye travels to your eye where it highlights the blood vessels. It's particularly useful in showing leaking blood vessels, and highlighting where the blood supply at the back of the eye is poor. We then take photographs of your eye.

The test takes place in the eye (ophthalmology) department at St Thomas’ Hospital and takes 10 to 15 minutes. The results will help your ophthalmologist to decide the best way to treat your eye condition.

Taking an unlicensed medicine

The use of fluorescein in this test is unlicensed, which means that the manufacturer of the medicine has not specified it can be used in this way. However, there is evidence that it works for this particular procedure.

Read our information about unlicensed medicines. 

Side effects

After the injection of fluorescein dye, your skin and your pee (urine) will turn yellow for about 24 to 48 hours. This is normal and not harmful, so please do not be worried by this.

Drinking plenty of water afterwards can help flush the dye through your system.

Some of the other more common side effects (affecting about 5 in 100 people) include:

• feeling sick (nausea) or being sick (vomiting). This usually happens in the first few minutes after you're given the injection, and normally passes within seconds. Taking deep breaths often helps.

• A rash, itching or tingling sensation to your skin. Your doctor might prescribe you an antihistamine to help reduce the itching.

Very rare side effects

The dye leaking

Very rarely, if the tube becomes displaced and dye leaks into the skin surrounding the tube, you might get a burning sensation. If this happens, the injection will be stopped, and the burning should resolve by itself within a few days.

Serious allergic reaction (anaphylaxis) 

People can have a serious allergic reaction (anaphylaxis) to the fluorescein dye. This can cause breathing or circulatory difficulties. We're equipped to deal with this emergency and if it happens the emergency medical team will be contacted. 

You must tell us before your procedure, if you have had a reaction to fluorescein in the past.  

Deciding not to have the test

Your doctor thinks that a fundus fluorescein angiography is the best way to get a detailed picture of the condition of your eyes. If you do not want to have the test, we might not be able to monitor the condition of your eyes as accurately. If you do not have the test, you will not be treated any differently by your doctor.

Asking for your permission (consent)

We want to involve you in decisions about your care and treatment. If you decide to go ahead, you will be asked to sign a consent form. This states that you understand what the procedure involves and you agree to have it. 

Read about our consent process. 

Preparing for the procedure

Your appointment will be in the eye department at St Thomas’ Hospital.

You'll have eye drops put in to dilate your pupils (make them bigger). You'll need to remove your contact lenses before the drops are put in, so please bring your glasses with you.

The drops will give us a clearer view of the retina at the back of your eye (also called the fundus).

You will be asked a few questions about your general health.

It's important to let us know if you have any allergies, or if you have had an unexpected reaction to fluorescein dye before.

During the procedure

A small tube (cannula) will be placed into a vein in your arm. The fluorescein dye will be injected through this into your blood stream. Within seconds, the dye travels through the blood vessels to reach your eye.

A series of rapid photographs will be taken. It's important that you keep as still as possible for this. The nurse can help you to keep your eyes open by gently holding your eye lids. You will then be asked to sit back for a few minutes to rest before another series of photos are taken. The test should take no longer than 15 minutes.

Please tell the nurse if you feel unwell at any point. It's common to feel slightly sick (nauseous) as the dye goes in, but this passes quickly. Taking deep breaths often helps.

After the procedure

You'll be asked to stay in the department for about 30 minutes after the test, so that we can observe you for any late side effects. The cannula will be removed before you go home.

As your pupils will still be dilated, your eyes will be very sensitive to sunlight for at least 2 hours. You should wear sunglasses or a hat to reduce the discomfort.

You are advised to bring someone with you to help you get home.

Driving 

You must not drive for at least 2 hours after the procedure or until your pupils return to their normal size.

Getting your results

Your doctor might be able to give you the results of the test on the same day. Sometimes, they might want to make another appointment for you to come and discuss them at a later date.