Fluorescein and indocyanine green angiography
This page gives you information about tests used to help identify problems at the back of the eye.
What is angiography?
Angiography is a test which can give further information about problems you might have at the back of your eye. The test does this by photographing the flow of blood through the eye. To do this, an injection of a dye of either fluorescein and in some cases indocyanine green (ICG) is needed. The dye is given into a vein in your arm before we take photographs of your eye. Not everyone will need both types of dye. No X-rays or radioactive materials are used.
This test will help the doctor decide on the best treatment for you.
The test is carried out in the Ophthalmology Out-patients Department. You should allow 1½ hours for the whole test.
What does the test involve?
Eye drops are used to enlarge your pupils. The drops will cause some temporary blurring of your vision so you are advised not to drive to or from your appointment.
You will have a cannula (thin tube) put into a vein in your arm by a trained nurse practitioner. If your eye specialist has requested the use of ICG, a small quantity of the dye is injected.
The dye travels through your blood circulation and reaches your eye very quickly. This dye is useful for examining the deeper blood vessels at the back of the eye, called the choroidal circulation.
Photographs, video and scans are taken using a special digital camera, with the aid of infrared light, over a period of about 30 minutes.
A further injection of fluorescein dye will be given 2 to 3 minutes after the ICG. Fluorescein is used to examine the retinal circulation. You will then have further pictures taken for 5 to 8 minutes.
What do I need to bring with me?
Please bring with you your glasses and a list of any medication that you are currently taking. If you use inhalers or a GTN spray you should bring these with you. You may also want to bring a snack or some refreshments.
When will I know the results?
You may be given some provisional test results straight away, otherwise you will be told the results at your next out-patient appointment. If you do not already have a date and time for your next appointment then details will you be sent to you within 2 weeks. If you have not received an appointment within this time please call the Triage Line. The number is at the end of this page.
If the angiography reveals that urgent treatment is needed you will be contacted by telephone. Please make sure that we have your up to date contact details.
Are there any side effects?
Before having the test you should let the doctor know if you have had any recent serious problems with your general health and any allergy history.
Please let the nurse know when you attend for your test if you:
- suffer from asthma
- have any allergies, especially to shellfish or iodine
- think you may be pregnant
- are breastfeeding
Fluorescein dye gives the skin a slight yellow tinge and your urine will be a bright yellow colour. This fades after 1 or 2 days.
If you have diabetes, the fluorescein dye may temporarily cause your blood sugar readings to be higher than normal.
Most people feel no ill effects from having either or both dyes injected, apart from the blurring of vision caused by the drops and some dazzle from the camera flash. A small number of people feel slightly sick during the test, but the feeling rarely lasts for more than a few seconds. Serious side effects are rare.
After the test
You will be asked to wait in the Eye Department for 15 minutes, before leaving the hospital.
If you develop skin blotches, irritation or breathing problems after the test you should immediately return to the hospital and go to the Accident and Emergency Department.
On rare occasions you may have some discomfort in your eyes caused by the drops.
If you have any questions about the test not covered on this page please ask any member of the medical or nursing staff.
Contact information
If you are unable to keep your appointment, please let the Booking Office know as soon as possible. This will allow us to give the appointment to someone else. You will find the contact number for the Booking Office on your appointment letter. The Booking Office is open:
Monday to Thursday, 8:30am to 4:30pm
Friday, 8:00pm to 4:00pm
Please contact the Eye Triage if you have an urgent eye/vision problem:
Eye Triage
Tel: 0300 422 3578
Monday to Friday, 9:00am to 5:30pm
This number can also be used out of hours for an emergency eye problem.