Fluorescein Angiography is a procedure used mostly to discover if blood vessels are leaking blood serum in the retina, choroid, and optic nerve. It is also used to measure the success of laser treatment on leaking blood vessels.

HOW THE DYE WORKS:

If the leaking holes in the blood vessels are large enough, what leaks out will be red, since it will contain red blood cells. Fluorescein Angiography is not needed to observe leakage when the holes are large enough for red blood cells to escape. However, if the holes in the vessels are smaller than the diameter of a red blood cell, then only the blood serum will leak out, leaving the red blood cells behind. Blood serum is clear, and therefore it can not be seen when looking at the back of the eye (fundus), considering how the back of the eye is covered with "wet, clear vitreous" already. With Fluorescein dye mixed with the blood serum, the blood serum can now be seen. The fluorescein dye will remain in the entire individual's blood for about 2 hours. Fluorescein is an inert vegetable dye, so the kidneys will easily remove the dye from the blood, at which time the individual will notice that their urine is discolored.

PROCEDURE:

Fluorescein dye can be administered in two ways. It can be injected intraveniously or ingested by drinking a glass of juice containing fluorescein. After waiting only a brief period, the camera containing a blue filter, is used. As the dye begins to illuminate to its peak point, the camera is used to take pictures of the areas in question. Black and white film is used in the traditional cameras, while newer electronic digital cameras are becoming more common place. With digital cameras, the images are available immediately, while with film type cameras, there is usually a period of time needed to wait for the development of the film.

RESULTS:

The lighter areas, on the developed film, indicate areas of leakage. The real value of Fluorescein Angiography is that with this procedure you can see where the leaking spots are even though the fluid leaking is actually clear (free of red blood cells).

Add'l keywords/misspellings:

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