FLUORESCEIN ANGIOGRAPHY (FFA)

Fluorescein angiography (FFA) has been the gold standard to understand, diagnose and treat retinal disorders.

Fluorescein angiography (FA) allows study of the circulation of the retina and choroid in normal and diseased states. Photographs of the retina are taken after intravenous injection of sodium fluorescein dye. Fluorescein can leak out of retinal capillaries into the retina only when the capillary endothelium is damaged, as in diabetic retinopathy. Similarly, fluorescein can leak from the choriocapillaris through pigment epithelial cells into the subretinal space and the retinal interstitium only when the latter are abnormal, as in central serous chorioretinopathy. Thus, patterns of hyperfluorescence and stereoscopic images yield valuable information about leakage from retinal vessels or through abnormal pigment epithelium.

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

Preparation for the Test

You’ll need to arrange for someone to pick you up and drive you home since your pupils will be dilated for up to 12 hours after the test.

Be sure to tell your doctor before the test about any prescriptions, over-the-counter drugs, and herbal supplements you’re taking. You should also tell your doctor if you’re allergic to iodine.

If you wear contact lenses, you’ll need to take them out before the test.

How Is the Test Administered?

Your doctor will perform the test by inserting standard dilation eye drops into your eyes. These make your pupils dilate. They’ll then ask you to rest your chin and forehead against the camera’s supports so that your head remains still throughout the test.

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

What Are the Risks of the Test?

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

• swelling of the larynx
• hives
• difficulty breathing
• fainting
• cardiac arrest

If you’re pregnant or think you may be, you should avoid having a fluorescein angiography. The risks to an unborn foetus are not known.

Understanding the Results

Normal Results

If your eye is healthy, the blood vessels will have normal 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
• high blood pressure
• a tumour
• enlarged capillaries in the retina
• swelling of the optic disc