Fluorescein angiography. Eye exam using a special dye and camera to examine blood flow to the retina and choroid , the two layers at the back of the eye.
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- 1 How the test is performed
- 2 Preparation for the exam
- 3 How the test will feel
- 4 Reasons why the exam is performed
- 5 Normal Values
- 6 Meaning of abnormal results
- 7 What are the risks
- 8 Special considerations
- 9 Alternative names
- 10 Source
How the test is performed
Eye drops will be administered to dilate the pupil . You are asked to place your chin on a camera chin rest and forehead against a support bar to keep your head still during the exam.
The doctor takes pictures of the inside of the eye. After the first set of pictures is taken, a special dye, called fluorescein, is injected into the vein , usually on the inside of the elbow. Then a special camera takes pictures as the dye passes through the blood vessels at the back of the eye.
Preparation for the exam
The patient will need someone to drive him home, as his vision may be blurred for up to 12 hours after the exam. The doctor may recommend stopping drugs that could affect the test. The doctor should be told about any allergies, particularly reactions to iodine.
The patient has to sign an authorization. Also, you should remove your contact lenses before the exam. You should tell the doctor if you can be pregnant.
How the test will feel
When the needle is inserted, some people feel moderate pain, while others feel only a prick or stinging sensation. Subsequently, there may be some throbbing sensation. When the contrast medium is injected, you may experience mild nausea and a warm sensation. These symptoms are generally very brief.
The contrast medium will make the urine darker and possibly orange in color for a day or two after the test.
Reasons why the exam is performed
This test is done to see if there is adequate circulation in the blood vessels in the two layers at the back of the eye (the retina and the choroid ). It can also be used to diagnose eye problems or to determine how well certain eye treatments are working.
A normal result means that the vessels appear normal in size, that there are no new blood vessels, and no obstruction or leakage.
Meaning of abnormal results
If an obstruction or leak occurs, the images will plot the location for possible treatment. An abnormal value from a fluorescein angiography may be due to:
- Blood flow (circulatory) problems, such as blockage of the arteries
- Diabeticor other retinopathy
- Arterial hypertension
- Inflammation or edema
- Macular degeneration
- Microaneurysms (enlarged capillaries in the retina)
- Inflammation of the optic disc
Additional conditions under which the examination can be carried out:
- Retinal detachment
- Retinal vessel occlusion
- Retinitis pigmentosa
What are the risks
There is a slight chance of infection whenever there is a break in the skin. In very few cases, a person is hypersensitive to the contrast medium and may experience:
- Dizziness or fainting
- Dry mouth or increased salivation
- Increased heart rate
- Metallic flavor in the mouth
- Nausea and vomiting
Serious allergic reactions are rare. The urine will look darker and possibly orange in color for a day or two after the test.
The test results are more difficult to interpret in people with cataracts .
Retina photography; Angiography of the eye