What is the Retina?

Your retina is the light sensitive lining in the back of your eye. It contains millions of special nerve cells that react to light. These photoreceptors send electrical impulses to your optic nerve, which your brain converts into the images you see.

Most people never give their eyes – let alone their retinas – a second thought until something goes wrong. Yet, retinal diseases are the leading causes of blindness in adults in the United States.

Downloads and Guides

  • Download our free Retinal Diseases Guide for a complete listing of our retinal disease treatments and services.
What We Treat Diagnostic Testing

Diagnostic Testing

Fluorescein and Indocyanine Angiograms

If your ophthalmologist suspects an abnormality with your retina or choroid (the inside of the back of your eye), he or she may recommend special tests called fluorescein and/or indocyanine green (ICG) angiograms. What are fluorescein/ICG angiograms?

What are Fluorescein/ICG angiograms?

Fluorescein/ICG angiograms are diagnostic procedures that involve taking a rapid series of photographs (not X-rays) of your eye while a small amount of dye (fluorescein or indocyanine green) is injected into a vein in your arm. The dye is carried by your blood stream throughout the whole body, reaching your eye in about 10 seconds. Photographs are taken at different intervals up to 30 minutes after the injection.

The photographs show what changes have taken place in the retina and choroid and where the changes are located. The two dyes allow visualization of structures within the eye and may or may not be used together, depending on what abnormality your ophthalmologist suspects.

A fluorescein and/or ICG angiogram may be necessary to establish a diagnosis or if your doctor feels that you may benefit from treatment. If you are going to be treated with a laser, the photographs provide a kind of “map” for the doctor to use during the treatment.

Note: Fluorescein and/or ICG angiography is often performed several times after treatment to evaluate the effectiveness of your therapy.

The fluorescein dye may make your skin yellowish for several hours after the procedures. The dye also discolors your urine bright yellow for a day or so.

Unlike fluorescein dye, indocyanine green contains 5% iodine; therefore, patients with iodine allergies may have reactions to ICG dye.

Fortunately, allergic reactions to either dye are rare and are usually treated with antihistamine medications. Although severe allergic reactions (anaphylaxis) can occur, these are considered extremely rare.

Note: Fluorescein/ICG angiography is generally not performed on patients who are pregnant or who have liver disease.

Other Diagnostic Tests

  • Spectral Domain Optical Coherence Tomography (OCT)
  • Intraoperative Optical Coherence Tomography (iOCT)
  • Ultra Wide field Fundus Photography and Angiography