Indocyanine Green (ICG) is a medical dye. ICG injections are used in tests to determine liver function, cardiac output, and blood flow in the liver. These injections help diagnose or identify problems in blood flow, blood vessels and tissue perfusion, prior to, during, and after a surgery or transplant.

Indocyanine green injections are also used for ophthalmic angiography. During medical procedures such as angiography, an ICG injection helps to increase visibility of certain parts of the eye. Recently, (ICG)-enhanced fluorescence has been used in laparoscopic surgery to get an enhanced view and detailed anatomical information during the surgical procedure.