Specialist Care Complemented by Technology

Investigations

Indocyanine Green Angiography (ICG)

Indocyanine green angiography (ICG) is used to gain information about the circulation in the retina, the light-sensitive tissue at the back of the eye and in the choroid, which is the vascular tissue just under the retina. It is useful in the investigation of several conditions in the eye, in particular inflammatory diseases and a variant of wet age-related macular degeneration known as polypoidal vasculopathy.

Structures of the eye

The Procedure

Prior to the test your vision will be measured and then drops will be put in your eyes to dilate your pupils.

A small needle will be placed into a vein in your arm or hand. You will then sit at a special retinal camera, and have several photographs taken of your eyes before, during and after injection of the indocyanine green dye into your vein. Because they give complimentary information, ICG angiography is often combined with fluorescein angiography, so you may also have an injection of fluorescein dye at the same time.

Are there any side effects?

Some people feel brief nausea during or just after injection of the dye.

Occasionally some patients have an allergic reaction to the indocyanine green dye, and in extremely rare cases this can be a serious allergic reaction known as anaphylaxis. If you have any known allergies, particularly shellfish allergy, it is important to let your doctor know, as this may make it unsafe for you to have the procedure.

Early phase ICG angiography showing
idiopathic polypoidal vasculopathy.
Late phase ICG angiography showing
idiopathic polypoidal vasculopathy.