What is Fluorescein Angiography?

Fluorescein angiography is a photographic means of imaging the retina. Prior to the introduction of the OCT (ocular coherence tomography), it was the primary method of imaging the eye for the diagnosis and documentation of its condition, evaluating response to therapy, and to discovering any changes in the eye which could not be perceived clinically. It continues to be an important means of studying the blood circulation within the eye.  It is still a valuable diagnostic tool for a retinal specialist.

How is a Fluorescein Angiography Performed?

Fluorescein angiography is an office procedure which takes approximately 15 to 30 minutes. A fluorescein dye is injected into a vein in the arm, and as the dye circulates throughout the body, multiple photographs are taken of the back of the eye as the dye passes through both the arteries and veins within the retina. The camera used to take the photos is equipped with special filters which allow it to project a certain wavelength of light into the eye which activates the fluorescein dye, which is then photographed as it passes through the eye. As the photographs are taken, the camera also records the time taken for the dye to first enter the artery in the eye and the time to completely fill the vein.

What is Actually Recorded on the Photographs?

Documented on the photographs is the circulation of the dye as it passes first through the arteries, then the capillaries, and finally the veins. Delays in the normal circulation time indicate either arterial or venous occlusion. Fluorescein staining of the blood vessels occurs with inflammation and/or damage to the vessel wall, and if the damage is severe or the vessels are abnormal, dye will stain and/or leak out of the blood vessels and accumulate in the retina.

Also documented by these photos is the circulation of the vascular layer under the retina, any defects in the pigmented layer of the retina, and any abnormality which disturbs the normal fluorescein pattern of the retina.

Indications for Fluorescein Angiography

As discussed above, fluorescein angiography is used to document and diagnose eye disease, as well as monitor response to therapy. Ocular coherent tomography (OCT) is currently, being used more often to perform these functions; however, there are still a number of conditions and circumstances which still require the use of fluorescein angiography. These conditions include:

  • Retinal arterial occlusive disease
  • Retinal venous occlusive disease
  • Vascular anomalies and other diseases
  • Vasculitis and autoimmune conditions of the eye
  • Diabetes
  • Macular degeneration
  • Temporal Arteritis
  • Hereditary conditions involving the retina
  • Intraocular tumors

Are There Complications to Fluorescein Angiography?

The procedure is generally uncomplicated; however, on occasion there may be side effects. When starting the injection of the fluorescein dye, there may be difficulty entering a vein to inject the dye, in which case, multiple attempts will be made before a successful and clean entry is accomplished. If a good entry is not made, there may be bleeding around the injection site, or the dye may be injected outside the vein, which can cause significant discomfort depending upon the amount of dye that is misdirected.

As the dye circulates throughout the body, the most common side effect is a mild sensation of nausea, which quickly passes after a few deep breaths. Some people may develop hives and/or some tightness in breathing which are treated with Benadryl. If these side effects are known to occur, the Benadryl is given in advance.

On very rare occasions, there may be a much more severe reaction to the dye, an anaphylactic reaction, which can be life threatening.  All practices should have an emergency tray to handle this situation as well as immediate access to a 911 facility.

There are two additional, but benign, side effects of which the patient should be aware. First, there is a discoloration of the skin as the dye passes through the body. It will take on a yellow/orange appearance which lasts a few hours. Secondly, as the dye is eliminated from the body through the kidneys, the urine will appear orange.

Comments

  1. I had an awful experience with my Fluorescein Angiography. The dye got under the skin and the pain was unbearable. I threw up and felt so sick. It’s been 6 days and I still feel sick and have a headache. Got diagnosed with MS early July. Anything I should do?

    • JAbramsMD says:

      Leslie,
      I am sorry to hear that. I would make sure that the doctor who did the test knows about your symptoms. The MS is unlikely to be unrelated to the reaction to the dye but once again would talk to that doctor. The dye can get under the skin if the vein can not handle the injection, this is called extravasation. Usually best to place cold packs for the first few days followed by hot packs.

  2. Christine Collum says:

    I was diagnosed as having open angle glaucoma 2 years ago. I have had decreased vision fields R>L for many years. My eye pressures are normal now without drops? I saw another specialist and he thinks I may actually have Drusens. I have always been told that I have a tilted disc in my right eye. The specialist stated that my optic nerve is “tiny’ and my eye vessels are tortuous. I have decreased vision in my right eye and it is blurry even with correction. My left eye sees 20/25 with correction. He also stated that my astigmatism is so bad that there isn’t a place for it in there new computer program. Any Ideas???
    Chris

  3. JAbramsMD says:

    Christine there are many factors that could be at work here. Even though your pressures are normal on the readings, they should of checked your cornea to make sure they are not to thin. Thin corneas can give a false low reading when the pressure inside your eye is actually high. Also while the pressure reading can be normal at one time of the day it can go up or down throughout the day, so it is important to check it at different times of the day.

    If you have optic nerve head drusen these are deposits in the optic nerve that calcify. The are often present at a young age but often not seen on normal exam since they are buried in the nerve tissue. As the patient ages the drusen move towards the top and get more calcium (think bone like) material in it so they become more evident. The grow can cause some visual field changes that could mimic glaucoma changes (remember both are optic nerve disease so have a lot of similarity). Optic nerve head drusen rarely cause central visual loss. They can sometimes be very obvious to detect on examination but sometimes can also be sneaky. Tools such as fluorescein angiography, ocular B scan/ultrasound, optical coherence tomography (OCT), and even a CT scan of the head can help make the diagnosis. It is important to try and get a firm diagnosis on this over disease such as low tension glaucoma because the treatments and prognosis is different.

    As for the computer I assume you mean an OCT machine. While this machine is possible the biggest thing to come out in ophthalmology in the last few decades we are still learning a lot about the information they give us. People who are near sighted, far sighted, have astigmatism and or just variations in their optic nerve can give false readings as to the possibility of true disease. I find it always important to not only see where the patient is upon initial evaluation but also if there is change in the nerve over time.

    I hope this helps answer some of your questions and gives you some insight into what is going on. Without preforming an exam on you I am not able to make a diagnosis or recommend treatment, but hope that by giving you insight help you understand what you are being told.

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