Fluorescein angiography is a test used to assess blood flow in the retina and choroid. Blood flow is assessed using a camera that is able to visualize a special dye as it passes though blood vessels. Before the test, your pupils will be dilated using drops. Then, just before the test, the fluorescein dye will be injected in your arm. It takes around ten seconds for the dye to reach the eye. The angiography system will then record the flow of the dye as it enters and leaves the blood vessels in the retina. Fluorescein angiography is used to help in the diagnosis of various conditions affecting the retina. For example, in Wet AMD, abnormal blood vessels can be detected leaking the dye below the macula. Fluorescein angiography also helps detect areas in the retina where blood flow has been blocked due a variety of vascular conditions. Angiography also confirms the presence of conditions such as central serous retinopathy, which result in a pooling of the dye within the retina.