What is FAF imaging?
Autofluorescence Imaging(FAF) is the concept of using naturally occurring fluorescence from the retina to provide an indicator of RPE (layer of the retina) health. Illuminating the retina with blue light causes certain cellular components to “glow” without injecting any dye.
What is FAF eye test?
FAF is used to record fluorescence that may occur naturally in the eye or accumulate as a byproduct of a disease process. The term “autofluorescence” is used to distinguish this type of fluorescence from that which occurs from administration of fluorescent dyes such as fluorescein or indocyanine green.
What causes autofluorescence?
Autofluorescence is the tissue-endogenous fluorescence caused by several different fluorophores. These include collagen and elastin as components of the connective tissue, tryptophan as a component of most proteins, and nicotinamide adenine dinucleotide (NAD), a coenzyme found in all living cells.
What causes autofluorescence in retina?
Abnormal regions of hypo-autofluorescence (AF) are a result of decreased levels of lipofuscin, decreased RPE density, or blockage of fluorescence. Some notable causes of hypo-AF include: Decreased RPE lipofuscin (eg RPE atrophy or RPE tears) Presence of naturally occurring macular pigments.
What is FAF used for?
FAF may detect abnormalities beyond those detected on funduscopic exam, fluorescein angiography, or optical coherence tomography, and can be used to elucidate disease pathogenesis, form genotype-phenotype correlations, diagnose and monitor disease, and evaluate novel therapies.
What is the difference between FA and FAF?
FAF Images The images produced are similar in appearance to those of fluorescein angiography images; however, unlike FA, FAF is not dependent on circulation as is fluorescein angiography.
How is FAF done?
Fundus autofluorescence (FAF) is a relatively new, non-invasive imaging modality that has been developed over the past decade. The FAF images are obtained through the use of confocal laser scanning ophthalmoscopy (cSLO).
How do I get rid of autofluorescence?
Use fluorophores that emit in a wavelength further from the autofluorescence compounds in your sample. Typically, far-red wavelength fluorophores such as CoralLite 647 are best for this. Commercially available reagents such as TrueVIEW (VectorLabs), have been shown to reduce autofluorescence from multiple causes.
Is luminescence a chemical or physical property?
Luminescence is the generic term for the emission of light which is not an effect of high temperature. So luminescence can be determined as an appearance of cold body radiation. This radiation can either be part of a chemical reaction or a cause of subatomic motions or stress on a crystal.
What is the difference between lipofuscin and drusen?
Macular Drusen The remaining damaged cells (called lipofuscin) from the oxidative stress accumulate in Bruch’s membrane and create drusen, which is the earliest visible sign of dry macular degeneration. The lipofuscin/drusen is a cluster of protein and oxidized lipids that do not degrade.
How does OCTA work?
OCTA works by detection of erythrocyte motion, so any extraneous movement during the image-capturing process may result in motion artifacts, which appear as white or black lines in the flow angiograms, and/or misalignment of the retinal vasculature.
How does fluorescein angiography work?
Fluorescein dye is injected into a vein in the arm/hand. As dye passes through the blood vessels of your eye, photographs are taken to record the blood flow in your retina. The photographs can reveal abnormal blood vessels or damage to the lining underneath the retina. The images will be captured in black and white.