What Is a Fluorescein Angiogram?

A fluorescein angiogram is a medical imaging study of the eye performed with the assistance of a fluorescent dye that will highlight blood vessels. This test does not involve radiological materials and has very low risks for the patient. An ophthalmologist may request it in a patient complaining of low vision or a person with a history of macular degeneration and other eye issues. The length of time required for the procedure can vary, but is usually around 30 minutes to an hour with all of the patient preparation.

In the fluorescein angiogram, the doctor administers a medication to dilate the patient's pupil. This will make it easier to visualize structures in the back of the eye. Then, the doctor injects the fluorescein dye and allows it to travel to the eye, which usually takes just a few minutes. A technician will take a series of images of the eye to track the dye as it moves through the vessels. These involve a light that may feel very bright because the pupil cannot contract, but it is not dangerous.

This test will not only highlight the blood vessels, it may also show fluid leaks. Large blotches of dye can indicate that the patient's blood vessels are leaking into the back of the eye and could pose a health risk. The doctor can usually analyze the images very quickly to generate meaningful information about the patient's condition. The test may create a useful reference to look at in the future and compare with other tests, and it can also be used to gauge response to treatment.

Some medications can cause problems with a fluorescein angiogram. Patients should make sure their doctors are familiar with all their prescriptions before this test occurs in case they need to stop taking a medication temporarily. Pregnant and breastfeeding patients should also discuss the risks with their doctors, as they may not be good candidates for the test. Likewise, anyone with a history of allergies should discuss them. Allergic reactions to fluorescein are rare, but they can occur and may be very serious.

After the fluorescein angiogram, the patient will need a ride home because the eyes do not dilate and contract normally for several hours. Eye protection such as sunglasses can be advisable while outdoors. Patients may also notice their urine and skin turn yellow for several days after the fluorescein angiogram, until the body is able to fully eliminate the dye. Issues like rashes, fatigue, difficulty breathing, and extreme pain should be reported, as these may be signs of an allergic reaction.