Fluorescein retinal angiography: what it is and how it works
Fluorescein retinal angiography (often shortened to FFA or FA) is an eye test that photographs the blood flow in the retina, the light-sensitive layer at the back of the eye. A yellow-orange dye called sodium fluorescein is injected into a vein, usually in the arm. Within seconds it reaches the vessels of the eye. A special camera uses blue light to make the dye glow, and takes a rapid series of images that show where blood vessels are blocked, leaking, abnormally new or damaged. It is a diagnostic test, not a treatment, and it is used to decide whether and how a retinal disease should be treated.
This guide explains what the test shows, who needs it, how it compares with scans such as OCT, what it feels like, which side effects to expect, approximate costs in Turkey compared with the UK, US and Germany, and how to choose a hospital. It sits within our section on eye treatments in Turkey.
What can fluorescein angiography show that a normal eye exam cannot?
An ordinary examination, even with the pupil dilated, shows the surface of the retina. The dye test shows how blood moves through it over time, so it can reveal leakage and blocked vessels that are not visible by looking in. Ophthalmologists use it mainly for conditions that damage the retinal circulation or grow abnormal vessels:
- diabetic retinopathy, including macular oedema and areas of poor blood supply;
- wet age-related macular degeneration and other causes of new vessel growth under the macula;
- retinal vein or artery occlusion;
- inflammation of the retina or the vessels (vasculitis), and central serous retinopathy;
- tumours and unexplained swelling of the optic disc.
The pictures help the doctor mark exactly which areas need laser treatment or an injection, and they can be repeated later to check whether treatment has worked.
Who should have the test, and who should not?
You may be advised to have it if you have unexplained loss of vision, a swollen macula, diabetes with changes at the back of the eye, or signs on a scan that suggest abnormal vessels. It is not a routine screening test and is not needed for most cataract, glasses or squint problems; if you are being assessed for strabismus surgery, for example, you will normally have eye movement and vision tests instead.
It is usually avoided or delayed in people who have had a serious allergic reaction to fluorescein, and doctors take extra care in people with significant kidney problems, severe asthma or a history of allergy. It is generally avoided in early pregnancy unless the benefit is clear; tell the clinic if you are pregnant or breastfeeding. Bring a list of your medicines and any previous reactions to injected dyes.
Fluorescein angiography, OCT or OCT angiography: which test answers which question?
Newer scans have reduced how often the dye test is needed, but they do not replace it in every case. OCT (optical coherence tomography) gives a cross-section of retinal layers and thickness, without any injection; see our page on the OCT eye scan. OCT angiography shows blood vessels without dye but cannot show leakage. Indocyanine green angiography uses a different dye to look at the deeper choroid layer.
| Test | Best suited to | Typical limits |
|---|---|---|
| Fluorescein angiography | Leakage, blocked vessels, abnormal new vessels, planning laser | Needs injection; small risk of nausea or allergy; two-dimensional image |
| OCT scan | Retinal thickness, fluid, macular holes and membranes | Does not show blood flow or leakage over time |
| OCT angiography | Mapping vessels without dye, repeat monitoring | Does not show leakage; image can be affected by movement |
| Indocyanine green angiography | Deeper choroid vessels, some macular conditions | Different dye; used in selected cases |
The right test is the one that answers your doctor's question, and many patients have more than one. The retina is also described in our overview of the retina and its conditions.
Fluorescein retinal angiography cost in Turkey compared with the UK, US and Germany
The figures below are approximate ranges for one test on both eyes, not hospital quotes. Each hospital confirms its own price in writing.
| Country | Approximate cost range |
|---|---|
| Turkey | €60 – €250 |
| United Kingdom | €150 – €500 |
| United States | €250 – €900 |
| Germany | €120 – €450 |
The price depends on whether one or both eyes are photographed, whether the test is bundled with a consultation, OCT or wide-field imaging, and whether the images and a written report are provided. Because the test is short, it is normally one line in a larger diagnostic package. Ask whether the doctor's reading of the images, a copy on disc or by secure link, and a letter for your own doctor are included.
What happens during the test, step by step?
You will have your eyes checked and the pupils widened with drops, which takes about 20 to 30 minutes to work. A nurse or technician may take baseline photographs. A small needle is placed in a vein in your arm or hand and the dye is injected over a few seconds, while you rest your chin on a support and look at the camera. Pictures are taken at once and then repeatedly for the next several minutes, with further images a little later to see leakage. The whole appointment usually takes 30 to 60 minutes. You are not put to sleep, and you remain in the clinic for a short time afterwards so staff can watch for a reaction.
What does it feel like, and what are the side effects?
Most people feel only the needle prick and the flash of the camera, which can be bright and leave spots in the vision for a short time. The dye often causes a brief feeling of warmth or mild nausea, and about a few in every hundred people feel sick or vomit. The skin turns a pale yellow and the urine becomes bright yellow-orange for up to a day or two. Because the pupils are dilated, vision is blurry and sensitive to light for several hours, so do not drive and bring sunglasses.
Serious reactions are uncommon. Allergic reactions such as itching or hives can occur, and rarely a severe reaction (anaphylaxis); that is why the test is done where staff can treat it and why you should report previous reactions. The injection can leak into the skin around the vein, which is sore for a day or two. The NHS and the Royal College of Ophthalmologists describe the test as safe for most people when done by trained staff.
How long is recovery, and can I fly or drive afterwards?
There is no surgery and no wound, so recovery is only the settling of the dilating drops and dye. Blurred vision usually clears within four to six hours; avoid driving until it has gone. Skin colour returns to normal in a day or so and urine within 24 to 48 hours. You can usually travel the same or the next day, and the test fits easily into a short visit. If the test leads to laser treatment or an injection, your ophthalmologist will advise a separate plan and timing, which is why many people combine it with a full retinal assessment. Treatments such as photocoagulation are sometimes planned directly from these images.
How do I read the results, and what happens next?
The doctor looks for areas where dye leaks out of vessels (bright haze), pools in spaces, fails to fill (dark patches from blocked vessels) or shows abnormal new vessels. The report should say which eye, which area and how severe, and relate the findings to your symptoms. It is the start of the decision, not the end: you may be advised to keep monitoring, to have an injection, laser treatment or surgery, or to see a retinal specialist. Ask for copies of the images so that your own ophthalmologist can compare them, and ask how long the results will take to arrive.
How to choose an eye hospital for retinal tests, and red flags
Look for a hospital with an ophthalmologist who reads the images and explains them in a consultation, not a test sold alone with no report. The unit should have resuscitation equipment and staff trained to treat an allergic reaction, and a clear policy on pre-test checks. Red flags include no medical history taken before the injection, no written report, a price with no breakdown, and promises of a cure or of treatments before the images are reviewed. Read how our process works and use our free quote page to send your records so that the hospital can plan the visit.
Questions to ask the clinic:
- Will the ophthalmologist read the images, and will I get a written report?
- Is the test priced for one eye or both, and does it include OCT or a consultation?
- What checks are done for allergy, kidney disease and pregnancy beforehand?
- Can I have the images on disc or online for my own doctor?
- If treatment is needed, who will plan it and what will it cost?
Hospitals with Eye Surgery in Turkey
Frequently asked questions
It is an eye test in which a yellow dye is injected into a vein and a special camera photographs the dye as it passes through the retinal blood vessels. It shows leakage, blockages and abnormal vessels that a normal examination cannot show.
Approximate prices are about €60 to €250 in Turkey, against roughly €150 to €500 in the UK. The price depends on one or both eyes, the report and any OCT or consultation included, and the hospital confirms it in writing.
For most people it is safe when done by trained staff. Common effects are nausea and yellow skin; serious allergic reactions are rare. Tell the clinic about allergies, kidney disease, asthma and pregnancy before the test.
You feel a needle prick and the dye may cause warmth or mild nausea. The camera flashes are bright but not harmful. The test is not usually described as painful by patients, and no anaesthetic is needed.
The whole visit is usually 30 to 60 minutes, including pupil drops. The dye photographs themselves take about 10 minutes, with a few later images to show leakage.
Fluorescein is a yellow dye that passes through the body. Skin can look pale yellow for a day or so and urine can turn bright orange-yellow for 24 to 48 hours. This is expected and not harmful.
Not straight away. The drops that widen the pupils blur vision and increase light sensitivity for about four to six hours. Arrange a lift and bring sunglasses.
OCT scans take a cross-section of the retina without injection and show thickness and fluid. The dye test shows blood flow and leakage over time. Doctors often use both, depending on the condition.
The ophthalmologist may suggest monitoring, laser treatment, an eye injection, or referral to a retinal specialist. The test itself does not treat the eye; it guides the decision.
Yes, it is a short outpatient test and fits into a one- or two-day visit. If treatment follows, the ophthalmologist will explain how long you need to stay or whether to continue with your own doctor.