By
Jonathan Yoken, MD
FLUORESCEIN
AND INDOCYANINE GREEN (ICG) ANGIOGRAPHY
In order to
examine the retina and choroid (a layer of blood vessels under
the retina), your doctor has recommended one or both of these
diagnostic techniques.
What is
fluorescein and ICG?
Fluorescein
and ICG are both non-radioactive dyes that are injected into a
vein in your arm. The dye then travels through the blood stream
and enters the blood vessels in your eye. As the dye passes through
these vessels in your eye, a special camera takes photographs
(not x-rays) of the retinal and choroidal blood vessels. Fluorescein
angiography is the best way to examine the retinal blood vessels,
but often times, the choroidal blood vessels are difficult to
visualize with fluorescein alone. Therefore, ICG is occasionally
used in conjunction with or instead of fluorescein because it
demonstrates choroidal vessels much more clearly.
Why do
I need angiography?
Angiography
helps your doctor see what is happening in your retina or choroid.
The dye highlights abnormalities that may not be detectable by
examining your eye alone. It is most often used to help diagnose
and monitor eye diseases such as macular degeneration, diabetic
retinopathy, retinal vein occlusions and cystoid macular edema.
It is also used to determine the need for and guide laser surgery
as well as monitor the effects of laser surgery.
How is
angiography performed?
After your
pupils are dilated with drops, an experienced technician will
insert a small needle into a vein in your arm and inject one or
both dyes. As the dye enters your bloodstream and then passes
through the vessels in your retina and choroid, a special camera
will be used to take a series of photographs. Your doctor will
then review the photographs with you. The entire procedure takes
less than 30 minutes.
Are there
any side effects?
Side effects
are rare and minimal. The most common side effects include:
