OK, it's not an angiogram like the kind that checks circulation in your whole body.
It's a fluorescein angiogram, in which the dye is injected into your arm (rather than your leg) and goes directly up to the blood vessels in your eyes. Then they use a digital camera to take photos of the eye.
I recall now that the doc mentioned that there seemed to be an abnormality in the vessels in my right eye (not the one with the spot on the retina), which is why she ordered the exam.
Retinal photograph of a patient complaining of decreased vision.
Fluorescein angiogram indicating fluid leakage within the retina