Angiography is an important diagnostic test in which detailed photographs of the retina and choroid are taken after injecting a dye into an arm vein. The test is performed in the office and involves sitting in front of a special camera while flash photographs are taken. Initially, the dye is painlessly injected into an arm vein and then travels up into the eyes. When the dye arrives in the eye circulation, the photographs begin. The test usually lasts from 10 to 30 minutes. No X-rays are taken. Patients who are allergic to x-ray dye are not necessarily allergic to sodium fluorescein.
Two different dyes are available for injection into the vein: fluorescein or indocyanine green. Fluorescein dye is removed from the body by the kidneys and ICG dye by the liver. After fluorescein angiography, the urine and skin turn orange for up to 24 hours, after ICG angiography, no color changes in the urine or skin are noticed. Fluorescein angiography is the best test to view the retinal circulation while ICG angiography is better to view the choroidal (layer under the retina) circulation.