INTRAVENOUS FLUORESCEIN ANGIOGRAPHY (IVFA)
Intravenous fluorescein angiography or IVFA is an imaging technique used to document the circulation of the arteries and veins in the retina. The retina is the neurosensory tissue of the eye that transmits the optical images we see into the electrical images our brain understands. Your physician may order this test in order to better evaluate any abnormal blood vessels in your eyes. The IVFA test is beneficial when evaluating pathology such as macular degeneration, diabetic retinopathy, macular edema, macular telangiectasia, central serous retinopathy, branch retinal vein occlusion, and central retinal vein occlusion.
What can I expect during an IVFA test?
After your eyes are dilated, the physician or nurse will use a butterfly needle to inject a small amount (2-5 ml) of a sodium mineral dye called fluorescein into the vein of your arm or hand. The butterfly needle is then removed. The dye only takes moments to reach the eye so you will be positioned in the camera at the time of injection when a live high-resolution video will be obtained. Special filters are used in the camera that allow the dye to fluoresce and even subtle changes can be noted in retinal circulation. The actual test itself only takes about 5-10 minutes once the injection is complete and a specific series of timed videos and photographs are taken. This test is usually ordered in combination with other imaging techniques as well in order to best evaluate your retina.
Are there side effects to an IVFA test?
A small percentage, between 1 and 10% of patients may experience nausea that quickly passes at the start of the test.
Allergic reactions to sodium fluorescein are rare, effecting less than 2% of patients in which itching with rash and/or hives may be experienced. If you were to have this reaction, it would occur moments after the test began while under the physician’s care. In most cases, these symptoms can be managed with an oral antihistamine tablet, such as Benadryl and the allergic reaction will cease within minutes.
Although only a small amount of dye is injected, since it is highly concentrated, it takes about a day to exit your system. The dye will pass through your urine and will be bright yellow in color. Drinking extra water will help flush it out quicker.