You may have had fundus fluorescein angiography:-
"Fundus fluorescein angiography is a common procedure that is performed to give your doctor more information about the condition of the back of your eye. A small amount of yellow fluorescein dye will be injected into a vein in your arm. The dye travels to your eye where it highlights the blood vessels." - quote from Guys and St Thomas's patient information leaflet.
The test gives the ophthalmologist useful information about the blood vessels in the eye. For example, in diabetics it may be used to show up new vessels (which may need laser) or to show up an occlusion (a blockage in one of the blood vessels due to a tiny clot) which may need further tests.