There are several diagnostic tests used by a retina specialist which provide us with unique information about the health of the retina. A fluorescein angiogram has long been the gold standard of the retina specialist to study;
- Patients with diabetic retinopathy
- Macular degeneration
- Abnormal swelling of the retina
- Retinal Vascular Occlusions
The study principally allows the retina specialist to study abnormalities in blood supply and blood flow of the retina.
The Fluorescein Angiogram
To perform the test, a small amount of fluorescein dye is usually injected into an arm vein. The same vein used when drawing blood, located in the antecubital fossa of your forearm, is usually sufficient.
The dye then travels to the retina in 12-20 seconds. A series of photographs are now taken as the dye circulates through the retina.
Thanks to digital photography, the results are reviewed instantaneously by your retina specialist. Before digital photography, camera film needed to be processed before the results could be reviewed adding hours or days to the process.
Reactions to Fluorescein
As with any compound, certain patients can have a reaction to fluorescein. Symptoms can range to itching, hives, nausea/vomiting or worse, severe anaphylaxis.
Death from anaphylaxis due to fluorescein is very unlikely and estimated to be about 1 chance in 220,000.
Fluorescein angiography is performed in the presence of a medical doctor.
Because fluorescein is unique to ophthalmology and is a plant based vegetable dye, there is no chemical similarity to the contrast dyes used in radiologic xrays and MRIs.
Results of the Fluorescein Angiogram
This test is very helpful in confirming the diagnosis of many disease or elucidating the cause of subtle changes in vision.
In cases of macular degeneration, an “FA” can:
- Confirm the diagnosis of ARMD
- Determine any evidence of the wet form of macular degeneration
- Provide evidence of progressive changes (when compared to previous studies)
In cases of diabetic retinopathy, a fluorescein angiography can be useful for:
- Demonstrating otherwise undetectable evidence of early disease
- Provide proof of macular edema, a common complication of diabetic retinopathy
- Demonstrate evidence of neovascularization of the retina, a potentially blinding complication
Overall, the fluorescein angiogram is regarded as a very safe and effective diagnostic tool for the retina specialist. Other diagnostic testing for retinal diseases includes the OCT, or optical coherence tomography.