Indocyanine Green Angiography

Similar to Fluorescein Angiography, Indocyanine Green Angiography is a diagnostic test that uses an intravenously injected dye to help the ophthalmologist visualize specific anatomic areas of the retina and choroid.  Indocyanine, a green dye that becomes visible when excited by infrared light, is injected into vein, usually in the arm. The dye disperses throughout all vessels in the body, include those in the retina. Serial photographs are then taken of the eye to capture the flow of the indocyanine through the retina and choroid (the tissue just behind the retina). While fluorescein is used to evaluate blood flow through the retina, Indocyanine is used to study flow through get choroid, the tissue just deep to the retina.

Indocyanine is iodine-based. People who have an allergy to iodine or shellfish should let their ophthalmologist know prior to the procedure. Unlike fluorescein, indocyanine is processed by the liver, no the kidneys, before it is excreted.