Fluorescein angiography, or fluorescent angiography, is a technique for examining the circulation of the retina using the dye tracing method. It involves injection of sodium fluorescein into the systemic circulation, and then an angiogram is obtained by photographing the fluorescence emitted after illumination of the retina with blue light at a wavelength of 490 nanometers. The fluorescein dye also reappears in the patient urine, causing a yellow-green appearance. It can also cause discolouration of the saliva.
Pathologic changes are recognized by the detection of either hyperfluorescence or hypofluroescence.
Causes of hyperfluorescence:
- leaking defects (i.e. capillary leakage, aneurysm, neovascularisation)
- pooling defects
- staining
- transmission (filling) defects
- abnormal vasculature
Causes of hypofluorescence:
- blocking defect (i.e. blood)
- filling defect (capillary blockage)
Among the common groups of ophthalmologic disease, fluorescein angiography can detect diabetic retinopathy, vein occlusions, retinal artery occlusions, edema of the optic disc, and tumors.
Tags:
Angiography,
Surgery
