Fluorescein Angiography: What to Expect

Conditions like diabetic retinopathy, retinal vein occlusion, and retinal artery occlusion affect blood circulation in the retina. Fluorescein angiography maps the flow of blood through these vessels and identifies areas where circulation is compromised. This is particularly important for patients with diabetes, who benefit from regular diabetic eye screening and may need angiography to assess the extent of vascular damage.

When blood vessel walls become damaged, fluid or blood can leak into surrounding retinal tissue. Fluorescein angiography highlights these leaks with exceptional clarity. The test also reveals neovascularization, which is the growth of fragile new blood vessels that can form in response to conditions like proliferative diabetic retinopathy or wet age-related macular degeneration.

The detailed vascular map provided by fluorescein angiography helps our retina specialists determine whether treatment such as anti-VEGF injections, laser photocoagulation, or photodynamic therapy is appropriate. It also serves as a baseline for comparing future tests so we can track how well a condition is responding to treatment over time.

Fluorescein dye is generally very safe. The most common side effects are temporary nausea and a yellowish discoloration of the skin and urine that typically resolves within 24 to 48 hours. Mild itching or warmth at the injection site can also occur. Severe allergic reactions are very rare, occurring in fewer than 1 in 200,000 cases, and our team is fully prepared to manage any reaction immediately.

The actual imaging portion of the test takes about 10 minutes. However, when you account for pupil dilation and preparation, you should plan to be in the office for approximately 45 minutes to one hour. Your vision may remain blurry from the dilation drops for a few hours afterward, so plan your schedule accordingly.

This test is used to evaluate a broad range of retinal and choroidal conditions, including diabetic retinopathy, macular degeneration, retinal vein occlusion, retinal artery occlusion, macular edema, central serous retinopathy, and ocular tumors. It is also helpful for assessing inflammatory conditions that affect the blood vessels of the eye. Patients whose fundus photography findings suggest vascular abnormalities are often referred for fluorescein angiography to obtain a more detailed assessment.

Optical coherence tomography (OCT) creates cross-sectional images of the retinal layers and measures their thickness, while fluorescein angiography captures the dynamic flow of blood through retinal vessels. OCT is excellent for detecting structural changes like fluid accumulation or thinning of the retina, but it does not show blood vessel activity in real time the way angiography does. The two tests complement each other, and our retina specialists often use both to build a complete picture of your eye health.

After the test, your skin may appear slightly yellow for several hours, and your urine will likely be a bright yellow-orange color for up to two days as your body clears the dye. These changes are completely normal and harmless. Your vision will remain blurry from the dilation drops for a few hours, so wearing sunglasses and avoiding bright light is recommended until your pupils return to their normal size. You can resume eating, drinking, and most normal activities right away.

The frequency of repeat testing depends on the condition being monitored and how it responds to treatment. Some patients need follow-up angiography every few months during active treatment, while others may not need it again for a year or longer. In many cases, our retina specialists use other imaging tools such as B-scan ultrasound and OCT for interim monitoring, reserving fluorescein angiography for situations that require a detailed view of blood vessel activity.