Fluorescein Angiography | Procedure and Risks | Ophthalmology

Fluorescein Angiography

What is a Fluorescein Angiography?

A fluorescein angiogram or fluorescein angiography is a medical procedure in which a fluorescent dye is injected into the bloodstream. The dye highlights the blood vessels at the back of the eye so they can be photographed.

This fluorescein angiography test is often used to monitor eye disorders. Your doctor may order it to confirm a diagnosis, determine an appropriate treatment, or monitor the condition of the vessels in the back of your eye.

How is fluorescein angiography performed?

FA is usually done in your ophthalmologist’s office. It often takes less than 30 minutes. This is what will happen:

  • Your ophthalmologist or an associate will put drops in your eyes to open (widen) your pupil.
  • A yellowish dye (fluorescein) is injected into a vein, usually in the arm. It takes 10-15 seconds for the dye to travel throughout your body. Over time, the dye reaches the blood vessels in the eye, causing them to “fluoresce” or glow.
  • As the dye clearances through your retina, a particular camera takes pictures. These imageries help your ophthalmologist see any difficulties or where to focus on treatment.

Fluorescein angiography used to

AF is often recommended to find and diagnose eye diseases that include:

  • Macular edema (swelling in the retina that distorts vision)
  • Diabetic retinopathy (damaged or abnormal blood vessels in the eye caused by diabetes)
  • Macular degeneration
  • blockage of the veins within the eye, called BRVO or CRVO
  • Macular fold (a wrinkle on the retina caused by a buildup of fluid behind it)
  • Ocular melanoma (a type of cancer that affects the eye)

FA is also used to:

  • Track changes in eye disease over time
  • Target treatment areas

Test administered in fluorescein angiography

Your doctor will perform the test by inserting standard dilating eye drops into your eyes. These make your pupils dilate. Then, you will be asked to rest your chin and forehead against the camera supports so that your head remains still throughout the test.

Then your doctor will use the camera to take many pictures of your inner eye. After your doctor has completed the first batch of images, they will give you a small injection into a vein in your arm. This injection contains a dye called fluorescein. Then your doctor will continue to take pictures as the fluorescein moves through your blood vessels to your retina.

Side effects and risks of fluorescein angiography

You may have about side effects from fluorescein angiography. This is what you may notice:

  • When you look at objects, they may appear dark or tinted. This side effect disappears in a few minutes.
  • Your skin may look a little yellow. This happens because the dye travels to all the veins in your body. Your skin will arrive at its normal colour in a few hours.
  • Your urine may aspect orange or dark yellow for up to 24 hours. This is because your kidneys will filter the dye from your blood.
  • You may feel a skin burn if the dye leaks out during the injection. This side effect disappears in a few minutes.

Although rare, there is a risk that you may have an allergic reaction to the fluorescein dye. People allergic to the dye may have hives or itchy skin. Very rarely, a person may have breathing problems or other serious problems. Your doctor can treat an allergic reaction with pills or injections.

Although rare, there is a risk that you may have an allergic reaction to the fluorescein dye. People allergic to the dye may have hives or itchy skin. Very rarely, a person may have breathing problems or other serious problems. Your doctor can treat an allergic reaction with pills or injections.

Understanding the results

Normal results

If your eye is healthy, the blood vessels will be normal in shape and size. There will be no blockages or leaks in the vessels.

Abnormal results

Abnormal results will reveal a leak or blockage in the blood vessels. This may be due to:

  • A circulatory problem
  • Cancer
  • Diabetic retinopathy
  • Macular degeneration
  • Hypertension
  • A tumor
  • Enlarged capillaries in the retina
  • Swelling of the optic disc

Expectation after the fluorescein angiogram test

Your pupils may remain dilated for up to 12 hours after the test is done. Fluorescein dye can also make your urine darker and orange for a few days.

Test addresses

Your doctor may recommend a fluorescein angiogram to determine if the blood vessels in the back of your eye are receiving adequate blood flow. It can also be used to help your doctor diagnose eye disorders, such as macular degeneration or diabetic retinopathy.

Macular degeneration

Macular degeneration occurs in the macula, which is the part of the eye that allows you to focus on fine details. Sometimes the disorder worsens so slowly that you may not notice any changes at all. In some people, it causes vision to deteriorate rapidly and blindness can occur in both eyes.

Because the disease destroys your focused central vision, it prevents you from:

  • See objects clearly
  • Drive
  • Reading
  • Watching television

Diabetic retinopathy

Diabetic retinopathy is caused by long-term diabetes and results in permanent damage to the blood vessels in the back of the eye or the retina. The retina converts the images and light that enter the eye into signals, which are then transmitted to the brain through the optic nerve.

There are two types of this disorder:

  • Non-proliferative diabetic retinopathy, which occurs in the early stages of the disease
  • Proliferative diabetic retinopathy, which develops later and is more severe

Your doctor may also order a fluorescein angiogram to see if treatments for these eye disorders are working.

Preparation for the fluorescein angiogram test

  • You will need to arrange for someone to pick you up and drive you home, as your pupils will be dilated for up to 12 hours after the test.
  • Be sure to inform your doctor before the test of any prescriptions, over-the-counter medications, and herbal supplements you are taking. You should also inform your doctor if you are allergic to iodine.
  • If you wear contact lenses, you will need to remove them before the test.

The risks in the tests

The most common reaction is nausea and vomiting. You may also experience dry mouth or increased salivation, increased heart rate, and sneezing. In rare cases, you may have a severe allergic reaction, which may include the following:

  • Swelling of the larynx
  • Hives
  • Laboured breathing
  • Fainting
  • Heart attack

If you are pregnant or think you may be, you should avoid having a fluorescein angiogram. The risks to the unborn fetus are unknown.

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