Fluorescein angiography (FA) is a diagnostic imaging technique. To perform it, eye doctors use a special dye and camera to view the back of the eye. This enables them to detect and monitor various eye conditions.

Ophthalmology is the study of conditions that affect the eye, and ophthalmologists are eye doctors that can diagnose and treat ocular conditions.

To help diagnose and monitor these conditions, they may use tools such as FA. Using a special camera and dye, an ophthalmologist can view the back of the eye and detect problems with the retina.

Read on to learn more about the technique and how it can diagnose eye disease and track changes in the eye.

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FA, also known as a fundoscopic exam or fundus fluorescein angiography, is a diagnostic test that examines the retina.

During the procedure, a fluorescent dye enables an ophthalmologist to visualize the blood vessels and other structures at the back of the eye.

The exam utilizes the fluorescent properties of a yellow dye known as fluorescein. This property means the dye glows brightly after exposure to specific wavelengths of light. The term angiography describes the examination of blood vessels after the dye has entered circulation.

Using a special camera emitting light, a clinician can capture real-time images of the blood vessels in the back of the eye. This allows the ophthalmologist to monitor eye health and detect various eye diseases.

FA serves several purposes in diagnosing and monitoring eye conditions.

By observing the structures at the back of the eye, an ophthalmologist can make accurate diagnoses and determine appropriate treatment plans.

Ophthalmologists can use FA to:

  • diagnose eye conditions
  • monitor changes in eye conditions over time
  • target specific areas of the eye for treatment

They may use it to help diagnose and track changes in the following conditions:

The procedure typically takes less than 30 minutes. An ophthalmologist can perform it in their office.

Prior to the exam, the doctor will advise whether a person needs to do anything beforehand. This may include taking medications as usual, drinking water, and avoiding caffeinated beverages. These beverages may interfere with the results.

They will also generally review a person’s medical history. It is advisable to inform the ophthalmologist of any medications a person takes and if they have any allergies. If someone is allergic to fluorescein dye, the doctor may prescribe an antihistamine or corticosteroid medication.

A person will need to remove contact lenses before the procedure if they wear them. They will also need to arrange to have someone bring them home after the appointment, as it may not be safe to drive.


The exam generally involves the following steps:

  1. Eye drops dilate, or widen, the pupils.
  2. A nurse or technician inserts a small needle into a vein, usually in the arm, and slowly injects the fluorescein dye. It takes roughly 10–15 seconds for the dye to travel through the bloodstream and reach the blood vessels in the eye.
  3. Alternatively, a person can swallow the fluorescein dye. However, using this approach means it can take up to 30 minutes for the dye to travel to the blood vessels supplying the retina.
  4. The person sits in front of a special camera and rests their head on chin and forehead supports. This will help them remain comfortable and still during the FA procedure.
  5. A technician uses a special camera to take photographs of the eye. The images will be in black and white. The camera records the dye in the blood vessels as light gray or white.

An ophthalmologist will then view these images, interpret the results, and see any problems or where to focus treatment.

Health experts generally consider FA to be safe.

However, there are a few potential side effects a person may experience following the procedure. These will typically subside within a day or two.

Side effects may include:

In rare cases, a person may experience an allergic reaction to the fluorescein dye. This may result in symptoms such as:

After capturing the images, the ophthalmologist will analyze them to evaluate the health of the blood vessels. In combination with the person’s medical history, they will look for signs that may indicate the presence of an eye condition.

If the eye is healthy, the blood vessels and other structures in the back of the eye should have a typical shape and size. The blood vessels should also not leak, and no blockages will be present.

However, if an ophthalmologist notices any problems, such as blood leaking from vessels or swelling at the back of the eye, this will indicate eye disease. Through FA, the doctor will also be able to see which area of the eye requires treatment and can record details of the eye condition.

Fluorescein angiography (FA) is a valuable imaging tool that enables ophthalmologists to monitor eye health and diagnose eye conditions. It involves using a special dye and camera to view blood vessels and other structures at the back of the eye.

This enables them to see problems with the blood vessels, such as swelling or leaking, and can help in diagnosing conditions such as diabetic retinopathy and macular degeneration. A doctor can also use FA to help them monitor eye diseases and select appropriate treatments.