Retinal photography; Fluorescein angiography
Fluorescein angiography is an eye test that uses fluorescein dye and a special camera to take pictures and analyze the blood circulation of the retina and choroid.
How the test is performed
Mydriatic eye drops (drops that make the pupil dilate) are administered. The chin is placed on a chin rest, and the forehead against a support bar to keep the head still during the test.
Photographs of the inside of the eye are taken. Then, dye is injected into a vein, usually at the bend of the elbow (the antecubital vein).
As the dye is injected, a series of photographs are taken. Afterwards, the needle is removed and pressure is applied to the injection site for several minutes.
More photographs are taken up to 20 minutes after the injection.
Allergy to the dye is rare, but may occur. A history of allergies will be taken before the test.
How to prepare for the test
Arrange for transportation because your vision may be blurred up to 12 hours after the test. The health care provider may instruct you to discontinue drugs that could affect the test. (See “Special considerations”.) You must sign an informed consent form. You must remove contact lenses before the test. Tell the health care provider if you have a hypersensitive reaction to iodine. Tell the health care provider if you may be pregnant.
Infants and children:
The test is more commonly performed on adults, but may be performed on children. The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- Schoolage test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
When the needle is inserted, a small amount of pain or stinging may be felt. When the dye is injected, mild nausea and a warm sensation may be experienced. These symptoms are usually very brief.
Why the test is performed
This test is useful in determining if there is proper circulation in the retinal vessels. It can also be performed to diagnose or follow treatment of problems in the eye.
Normal values will show the vessels appearing of a normal size and without blockages or leakage. If blockage or leakage is present, the pictures will map the location for possible treatment.
What abnormal results mean
An abnormal value on a fluorescein angiography can detect:
- Diabetic or other retinopathy
- Macular degeneration
- Circulatory problems
- Inflammation or edema
- Papilledema (swelling of the optic disc)
Additional conditions under which the test may be performed:
- Diabetic retinopathy
- Hypertensive retinopathy
- Macular degeneration
- Retinal detachment
- Retinal vessel occlusion
- Retinitis pigmentosa
What the risks are
There is a slight chance of infection any time the skin is broken. Rarely, a person is hypersensitive to the dye and may experience:
- Nausea and vomiting
- Dry mouth or increased salivation
- A “metallic” taste
- Feeling dizziness or faint
- Increased heart rate
- Rarely, serious allergic reactions may occur
Miotic eye drops (drops which cause contraction of the pupil) can prevent a clear view of the fundus by preventing wide dilation of the pupils.
People with cataracts will have less accurate test results because of the difficulty seeing the fundus.
by Harutyun Medina, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.