Indocyanine Green (ICG) Angiography
Indocyanine green angiography is a diagnostic test that involves taking photographs of the blood vessels in the eye with the help of a contrast dye. Indocyanine is a green dye that works with infrared light and is visualized with a special camera. The images produced by this test help doctors evaluate the retina and diagnose or monitor problems, such as macular degeneration, abnormal vessel growth, macular edema, certain types of retinal detachment, and tumors.
During these exams, the patient’s pupils are dilated with eye drops. A few photographs are then taken with a special ophthalmic camera. Next, the contrast dye is injected, usually into a vein in the arm. The dye travels up to the eye within a few seconds and “lights up” the blood vessels for the camera. Once the dye is injected, multiple photographs are taken.
These tests are considered safe for most patients, although it is possible to have a reaction to the dye and develop itching, nausea and a rash. These symptoms can usually be managed through oral medication if severe. Patients with an iodine or shellfish allergy should inform the doctor since indocyanine green is contraindicated in these cases.