Fluorescein Angiography
Fluorescein Angiography (FAG) is an examination technique used in ophthalmology. A fluorescein solution is administered into the cubital vein; approximately 10 seconds later, the substance appears in the retinal circulation, which we record using a digital retinal camera (or digital fundus camera). Under physiological conditions, fluorescein does not pass outside the vascular bed; it is gradually visualized in the pre-arterial, arterial, capillary, arteriovenous, venous and late phases. In conditions involving damage to the vessel wall, fluorescein passes outside the circulation and thus reveals hyperfluorescent pathological foci of microaneurysms, edema, or neovascularization. Hypofluorescence is seen in conditions with impaired vascular filling or loss of vascular tissue, as well as in hyperplasia of the pigment epithelium, hemorrhage and exudate.
FAG provides information about dynamic changes in the hemato-ocular barrier. The examination is used primarily for the diagnosis and assessment of diabetic retinopathy and maculopathy, as well as other vasculopathies, degenerative processes (age-related macular degeneration), arterial and venous occlusions, intraocular tumors, etc.
During the examination, adverse reactions to the administered substance may occur; in particular, attention must be paid to possible allergy to the contrast agent. In at-risk patients, premedication is administered (hydrocortisone, antihistamines). Fluorescein temporarily stains the skin, mucous membranes and urine. For 24 hours after the examination, the patient should not be exposed to direct light radiation (laser).
