Fluorescein Angiography – A Complete Guide
Fluorescein Angiography is a critical procedure in diagnosing serious eye diseases. A retinal specialist uses one of their most powerful diagnostic tools, the so-called angiography known more commonly as FA. A retinal specialist uses this quick, but intensive imaging test to detect and monitor diseases affecting the retina’s delicate blood vessels. In this guide, we will cover everything one should know about online consulting with fluorescein angiography; from the science behind it to the before-after precautions. We hope you will get to read this information if your Fluorescein Angiography test was referred to you or if you were just in search of what procedures your retina needs.
What is Fluorescein Angiography?
Ophthalmologists use fluorescein angiography to evaluate blood flow in the retina that lines the back of your eyes. The procedure involves the injection of fluorescein or fluorescent dye colour into a vein, usually in the arm or hand. The dye goes with the blood movement and ultimately reaches the retinal vessels, where a special camera captures real-time high-contrast photos of the blood vessels filling the retina. FA is useful in diagnosing and managing diabetic retinopathy, age-related macular degeneration, and retinal vein and artery occlusion.
Why is Fluorescein Angiography Performed?
It is used to:
- Identify diabetic retinopathy due to the long-term adverse effects of high blood sugar on retinal vessels.
- Assess macular degeneration and macular oedema for white spot deterioration documenting central vision.
- Determine retinal vein or artery occlusions before poor visual acuity develops.
- Monitor the progression of retinopathy after diagnosis.
- Assist in determining the cause of unexplained severe vision loss.
Uveitis: Inflammatory eye conditions, such as uveitis, may also have an impact on the blood flow seen in the retina. But that’s where the similarities end. In addition to diagnosis, FA helps track developments in your eyes and the rate at which your condition responds to therapy, so it is also critical for follow-up care in this setting.
Fluorescein Angiography Stages: Step-by-Step Process
In the following stages, learn what to anticipate during the FA process:
- Preparation: Before beginning the test, the clinician may dilate your pupils with eye drops to provide a better look at your retina. They may inquire about your previous medical history, including allergies or whether you are pregnant.
- Dye Injection: The technician injects fluorescein dye with a tiny needle into a vein, which is frequently placed in the arm or hand. The dye reaches the eye within seconds through the bloodstream.
- Image Capture: As the dye circulates, a retinal camera designed specifically for the procedure captures a series of timed images. These images provide detailed representations of the blood flow and highlight any potential irregularities in the retina.
- Post-Procedure Monitoring: You will be monitored for a few minutes for any harmful effects, and then you are free to leave.
Is Fluorescein Angiography Painful?
The standard test of sensitivity is our practice. At the very least, you will feel a bit of stinging during the dye’s injection, similar to the sensation of a blood test. The flashes of light may be shiny and dazzling, but the procedure is not painful and does not entail contact with the eye.
Patients may also encounter a short-lived metallic taste in the mouth or slight nausea after dye injection. This is a common response; the sensation passes quickly.
Risks and Side Effects of Fluorescein Angiography
Considering safety, Fluorescein Angiography is a safe procedure, but there may be some side effects. Significant adverse effects from the examination are uncommon, and they frequently resolve within 1 or 2 days.
Normal side effects include:
- Mild allergic reactions (e.g., rash or itching).
- Temporary yellow discolouration of the skin and urine (due to dye excretion).
However, severe reactions are extremely rare but possible and include anaphylaxis. There is no need to panic, as the risks are minimal due to the presence of qualified healthcare professionals, and the entire process is conducted in a controlled environment.
Interpreting Fluorescein Angiography Results
Finally, the images created are assessed by your ophthalmologist, who looks for leakage indicators, which imply oedema or damaged vessel condition, blocks that might indicate retinal ischaemia, or abnormal new blood vessels that are often the result of diseases like diabetic retinopathy. A common case of the last scenario is hyperfluorescence, a bright spot that indicates fluid leakage, a typical phenomenon in diabetic eye disease.
Preparing for Your Fluorescein Angiography
The baseline tips are the following:
- Avoid caffeine before the test.
- Arrange for someone to drive you home, as dilation may blur vision temporarily.
These basic recommendations will help you avoid additional stress from the procedure or complications.
Post-Procedure Care and Recovery
Be prepared for possible side effects:
- In rare cases, patients might experience nausea or dizziness.
- Drink sufficient amounts of water to help your body eliminate the dye as soon as possible.
- If you feel faint or nauseous, contact a doctor.
Alternative Options to Fluorescein Angiography
There are several alternatives for retinal evaluation:
- OCT (Optical Coherence Tomography): Provides cross-sectional imaging of the retina without dye, optimal for structural assessment but less effective at blood flow observation.
- ICG Angiography: Uses indocyanine green dye, allowing visualisation of deeper layers (e.g., choroid), beneficial for central retinal disease.
Conclusions
Fluorescein angiography is a safe and necessary technology for the diagnosis and treatment of retinal vascular diseases. Timely use of this method can prevent partial or total vision loss caused by retinal pathologies. If your ophthalmologist recommends FA, take advantage of this procedure to protect your eyesight.
Still worried about your retinal health? Make an appointment with our experts!
Additional Reading:
- GOSH guide to FA
- Chase Lodge Hospital
