- Reference Number: HEY-917/2024
- Departments: Ophthalmology Department
- Last Updated: 1 January 2024
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This leaflet has been produced to give you general information about having a Fluorescein and/or Indocyanine green angiogram. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and the healthcare team but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.
What is a Fluorescein angiogram?
A fluorescein angiogram is a test that provides information about problems at the back of the eye. It involves the injection of a special yellow dye called fluorescein into a vein in your hand or arm which then travels round your body and takes only a few seconds to reach the blood vessels at the back of your eye. An ophthalmic medical photographer takes a series of photographs as the dye passes through the blood vessels in your retina (light sensitive lining at the back of your eye) at timed intervals up to a 15 minute period. The fluorescein dye highlights these blood vessels and this helps with their assessment. It may show abnormalities such as blood leaking from the vessels or swelling at the back of the eye.
What is an Indocyanine Green Angiogram?
Indocyanine green (ICG) angiogram is a test which can provide further information about problems at the back of the eye by photographing the flow of blood through it. ICG dye shows up under infrared light after injection into a vein and the photographer will take a series of photographs. These photographs are taken at timed intervals up to a 30 minute period and provide information about the choroid (blood vessel layer) which lies underneath the retina. No X-rays or radioactive materials are used.
Why do I need an angiogram?
These tests are used to help the doctor determine the condition of the blood circulation in the retina at the back of your eye. You may need one or both tests. If the doctor requests both tests, this can be done at the same time.
There are many eye conditions where these tests may be performed to aid a diagnosis but the most common indications are in eye conditions such as:
- Diabetes to look at the health of the circulation in the retina before laser treatment is planned.
- Assist in the diagnosis of and extent of macular degeneration.
- Determine the extent of damage due to retinal vein blockages.
- Assessment of macular diseases such as central serous chorioretinopathy.
- Assessment of inflammatory conditions of the retina and choroid such as posterior uveitis.
Can there be any complications or risks?
Everyone having a Fluorescein angiogram will have some mild side effects which do not require treatment. They will resolve and leave no lasting complications.
The Fluorescein dye will give your skin a slight yellow tinge and your urine will be bright yellow for 1 or 2 days. ICG dye does not have this effect.
Nausea and vomiting
Some people experience this when the dye is injected. If this happens, try and take some deep breaths as it only lasts for a few seconds and will wear off quickly.
Reaction to dye
Sometimes as the dye is being injected it can leak into the surrounding tissue and this can be very painful. This can take a few days to resolve and you will be advised to put cold compresses onto the area.
An itching sensation, may occur, usually within 30 minutes of the injection.
Patients with diabetes are advised that the dye may interfere with blood and urine glucose monitoring, you may have false higher than normal glucose readings for a few days.
MILD REACTIONS ARE ESTIMATED TO OCCUR IN 1 TO 10 CASES IN EVERY 100 CASES
Moderate reactions: are also not permanent, but some form of medical treatment is required to resolve them.
- Urticaria: itching wheals or hives, usually on the face, head and trunk. If this happens an antihistamine can be given. If you develop this at home you can contact your doctor or nearest Emergency Department or contact the Eye Hospital.
- Vaso-vagal reaction: Fainting can occur immediately after the dye has been injected.
- Thrombophlebitis: is a chemical irritation of the wall of the vein. This causes a local inflammatory reaction resulting in a swollen, sore, red arm. The treatment is elevation of the affected limb and sometimes an anti-coagulant may be required to treat an underlying blood clot.
IT IS IMPORTANT TO STRESS THE ABOVE ARE RARE
Severe reactions have been reported on rare occasions, including strokes, heart attacks, severe allergic reactions and even fatalities. The reported incidence of death is 1 in 200,000 cases following a fluorescein angiogram and 1 in every 300,000 cases following an ICG test.
Can I take my normal tablets prior to the procedure?
Yes, you must take all prescribed medication as normal before coming to the department and please remember to bring a list of your prescribed medications.
Can I eat and drink normally?
Yes, you do not have to fast prior to the procedure and you can eat and drink as normal. If you are a diabetic, clinic visits can be lengthy and it is advisable that if you need to eat whilst at the outpatients then bring a snack with you. Food and drinks are not provided in the outpatients department.
How do I prepare for this test?
A specially trained nurse performs the test, along with an Ophthalmic Medical Photographer who will take the photographs.
It is important to tell the nurse if you: know of any allergies to medicines, food or animals.
Please bring with you a list of any tablets or medicines you are currently taking.
If you use asthma inhalers or GTN (Glyceryl trinitrate) spray, please bring these with you.
There are several stages to the test.
- You will have your vision checked by a nurse. The nurse will then instill drops to dilate the pupils of one or both of your eyes depending upon your doctor’s request. After approximately 10 minutes a second set of drops are instilled. This is done, as we need a well-dilated pupil to enable a good view of the retina and to provide good quality photographs. Your vision will remain blurred for the rest of the day and sensitive to bright light; it is advisable you do not drive to the appointment.
- When the drops have had sufficient time to work you will be shown into a room where a cannula is inserted into a vein on the back of your hand or the front of your elbow. Other than the prick of the needle the injection is not painful.
- You will then be shown into the room where the angiogram is to be carried out and seated at a special machine called a fundus camera; this is used to take the photographs of your eye.
- Once you have been positioned as comfortably as possible at the camera with your chin on a rest, some preliminary photographs are taken.
- As the Fluorescein and/or ICG dyes are injected, a series of photographs are taken using different coloured lights to show up the dye as it passes through the circulation in the eye. There are some bright flashes of light and a whistling sound as the camera scans the blood vessels.
- After the initial photographs are taken, you sit back in the seat for a period of time to allow any pooling of the dye to take place in the eye and a further series of photographs are taken. There will not be a further injection of dye. The whole procedure may take up to 30 minutes.
- After the test, the cannula is removed. After a short rest you will be able to go home.
- In the majority of patients, the doctor will be able to discuss the results with you on the same day.
What happens afterwards?
The drops will cause some blurring of vision and may last up to 12 hours. For this reason, you are advised not to drive on this day. The flash from the camera dazzles you for about 10 minutes.
Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Ophthalmology Department on 01482816658.
General Advice and Consent
Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.
Consent to treatment
Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.
The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:
- you must be able to give your consent
- you must be given enough information to enable you to make a decision
- you must be acting under your own free will and not under the strong influence of another person
Information about you
We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.
We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.
Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.
If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.