Fluorescein angiography is an eye exam in which the blood vessels of the retina are photographed after the patient is injected with a fluorescent dye. The dye is introduced into the patient’s bloodstream through their arm or hand. It is a fluorescent chemical material which absorbs blue light with visible radiation. Once in the patient’s bloodstream, it highlights the retinal blood vessels making it possible to photograph them.
Therefore, the eye angiogram is a picture of the patient’s retina showing the state of the blood vessel, including abnormal growth and other disorders. It helps the doctor to verify a diagnosis, establish guidelines for treatment and to maintain a permanent record of the condition of the patient’s retinal blood vessels. It is particularly helpful in the management of retinal disorders, such as macular degeneration and diabetic retinopathy.
Also Known As
- Fluorescein angiography
- Eye angiogram
- Eye angiography
The test can be conducted at the eye clinic or the doctor’s office by:
- A technician
- An optometrist
- An ophthalmologist
The doctor can order an eye angiogram to assess the blood flow in the vessels at the back of the patient’s eyes. He/she can also use the test in the diagnosis of eye disorders, including:
The disease is caused by diabetes and leads to permanent retinal blood vessels damage. The retina is the light-sensitive spot on the back wall lining of the eye. It converts light and images entering the eye into pulses, which flow through the optic nerve to the brain. The initial stage of the disease is known as non-proliferative diabetic retinopathy, while proliferative diabetic retinopathy is the advanced and more severe stage.
The disorder occurs in the macula. It is the area of the eye that enables a person to focus on fine detail. The disease impacts the patient’s focused and central vision. It can prevent them from seeing, driving, reading, and watching television. The disorder may progress slowly, such that the patient might not notice any change at all. However, in some patients, it advances quickly, causing their vision to deteriorate fast and can lead to blindness. The test is useful in detecting the new blood vessels that grow beneath the retina that leak and bleed.
The test can also help the doctor to detect:
- Blockage of retinal veins (BRVO or CRVO)
- A form of cancer affecting the eye (ocular melanoma)
- Swelling in the retina that distorts vision (macular edema)
- A wrinkle in the retina caused by a buildup of fluid behind it (macular pucker)
The doctor may also order the FA to track changes in the eye conditions over time and determine whether treatments are working.
Preparation & Expectation
Patients who wear contact lenses will have to remove them before the test. The exam requires the patient’s pupils to be wide open. So before the test, the doctor will dilate the patient’s pupils by inserting the standard dilation eye drops into their eyes. The patient’s pupils may remain dilated many hours after the test. The fluorescein dye might cause the patient’s urine to be dark orange for several days.
The patient should alert the doctor before the exam about any prescriptions, herbal supplements and over-the-counter drugs they are taking. They should also inform the doctor if they are allergic to iodine.
The patient will sit while resting their chin and forehead on the support of a camera. It keeps the patient’s head steady during the procedure. The doctor will take many photographs of the interior of the patient’s eye. After completing the first batch of photos, he/she administers a small injection with fluorescein dye into a vein in the patient’s arm.
The patient may experience a hot flush or a warm feeling during the injection of the dye. It only lasts a few seconds and disappears. The doctor will again take photos as the dye runs through the patient’s blood vessels and into the retina. It takes between 10 and 15 seconds for the fluorescein to travel throughout the patient’s body. The doctor’s camera flashlights may appear bright, but they can’t damage the patient’s eyes. These pictures help the doctor to have a better view of the retinal structures and blood vessels.
Often, the test takes less than 30 minutes to complete.
The doctor might have to order additional physical exams and laboratory tests before he/she is able to give the patient a proper diagnosis.
Where the patient’s eyes are healthy, the retinal blood vessels will have the average size and shape. The results will not show any leakages or blockages in the blood vessels.
If the FA results show that there is a leakage or blockage in the retinal blood vessels, it may indicate:
- A tumor
- High blood pressure
- Diabetic retinopathy
- A circulatory problem
- Macular degeneration
- Swelling of the optic disc
- Enlarged capillaries in the retina
Treatment of the diseases will depend on the type of disorder and the patient.
Risks & Complications
The most common side effect of the dilation eye drops is nausea and vomiting. The patient may also experience increased salivation, dry mouth, sneezing, increased heart rate, and sneezing. The doctor can treat an allergic reaction with shots or pills. In rare cases, the patient can have a severe allergic reaction such as:
- Cardiac arrest
- Difficulty breathing
- Swelling of the larynx
- Narrow-angle glaucoma
Expectant women and those who suspect they are pregnant should avoid having the test because its risks to an unborn child are not known. The patient should discuss the potential risks of the procedure with the doctor before undergoing the exam.