By looking into the back of your eye (the retina), eye doctors can see changes in the blood vessels there that show whether you are at risk for losing vision from diabetes or other causes. The earliest changes can be seen only with a special test called fluorescein angiography. For this test, a chemical that temporarily makes the blood vessels fluorescent and shows very tiny leaks in them is injected into one of your arm or hand veins while you are having your eyes examined.
This test is used to determine if there is proper circulation in the blood vessels of the retina. It can also be used to diagnose problems in the eye or to determine how well treatment is working.
Preparation for the test:
You should arrange to have someone else drive you home from the eye doctor, because your eyes will be dilated; this can make your eyes sensitive to the sun and your vision blurry for a while.
You may be told to discontinue drugs that could affect the test. results. Tell your health care provide about any allergies, particularly reactions to iodine.
You must sign an informed consent form. You must remove contact lenses before the test.
Tell the health care provider if you may be pregnant.
How the Test Is Performed
Eye drops that make the pupil dilate will be given. You will be asked to place your chin on a chin rest, and your forehead against a support bar to keep your head still during the test.
Fluorescein angiography->…..CLICK & SEE
The health care provider will take pictures of the inside of your eye. After the first group of pictures are taken, a special dye called fluorescein is injected into your vein, usually at the bend of the elbow. A special camera takes pictures of the dye as it moves through the blood vessels in the back of the eye.
More photographs are taken up to 20 minutes after the injection.
What happens when the test is performed?
You have drops put into your eye to make the pupil dilate (open), and you have to wait for about half an hour while the drops take effect. Before giving you any other medicine, your doctor might first examine your eyes for signs of bleeding or debris outside of your retina arteries; these are signs of more advanced eye disease from diabetes. Then a nurse inserts a small needle into one of the veins in your arm or hand so that you can have a dose of medicine injected. Your doctor uses a special eye camera to take pictures of your retina. You look into one side of the camera while your doctor looks through the other side. The camera shines a dim blue light into your eye, which causes the dye flowing through the retina arteries to show up as fluorescent green. The doctor takes a collection of pictures of your eyes to review more closely later.
This color retinal photograph demonstrates nonproliferative diabetic retinopathy. The image is centered on the macula (the part of the retina responsible for central fine vision) with part of the optic nerve seen on the left of the photo (left eye). There are hemorrhages within the retinal tissue on the right side of the photograph.
How the Test Will Feel
When the needle is inserted , some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
When the dye is injected, you may have mild nausea and a warm sensation. These symptoms are usually very brief.
A normal result means the vessels appear a normal size and there are no blockages or leakages.
Back to TopWhat Abnormal Results Mean
If blockage or leakage is present, the pictures will map the location for possible treatment.
An abnormal value on a fluorescein angiography may be due to:
*Blood flow (circulatory) problems
*Diabetic or other retinopathy
*Inflammation or edema
*Microaneurysms — enlargement of capillaries in the retina
*Swelling of the optic disc
Additional conditions under which the test may be performed:
There are no special risks from this test, although your vision may be blurry for an hour or more after the test because your pupils are dilated. The dye fluorescein is excreted from your body in your urine, which might give your urine a bright or discolored appearance for a day.
There is a slight chance of infection any time the skin is broken. Rarely, a person is hypersensitive to the dye and may experience:
Your urine will be darker, and possibly orange in color, for a day or two after the test.
Must you do after the test is over?
You will need to wear sunglasses for a few hours until your pupils are no longer dilated.
People with cataracts will have less accurate test results.
How long is it before the result of the test is known?
Your doctor can often discuss the results of the test with you at the end of your visit. He or she might recommend treatment (such as eye laser treatments) if your test reveals retina disease.
Click to see:->How does diabetes affect the retina?