What does fundus autofluorescence show?
Fundus autofluorescence (FAF), a relatively new imaging modality, focuses on the fluorescent properties of pigments in the retina to generate images that help us view various disease processes from a different perspective. It aids us in the understanding of the pathophysiology of different retinal disorders.
What is an FAF eye test?
The FAF measures the amount of Lipofuscin inside the cells of the retina. It produces images of the retina that show how much Lipofuscin is present in certain parts of the retina. This detects parts of the retina that are damaged or unhealthy. Several other compounds found inside the eye can also be measured using FAF.
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 bacterial autofluorescence?
Autofluorescence is the spontaneous fluorescence of materials without added dyes. Many people are responsible for this work but principal credit goes to Cindy Maddera, who just received her Master’s in my lab. Also contributing were Shelly Theiss, and Amy Huseby.
What is the difference between FA and FAF?
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. The intensity of the FAF signal corresponds to the accumulation or absence/reduction of lipofuscin and is compared to the surrounding retina.
How do I fix 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.
How do I reduce autofluorescence?
Historically, the main method that has been employed to lower autofluorescence has been to treat the tissue with solutions of Sudan Black or similar dyes. These hydrophobic dye molecules can bind to tissue sections and lower fluorescence through absorption of incident radiation.
What is cell autofluorescence?
Autofluorescence is the natural emission of light by biological structures such as mitochondria and lysosomes when they have absorbed light, and is used to distinguish the light originating from artificially added fluorescent markers (fluorophores).
What causes autofluorescence in cells?
Cellular autofluorescence can be due to the presence of collagen and elastin, cyclic ring compounds such as NADPH and riboflavin, aromatic amino acids and cellular organelles such as mitochondria and lysosomes.
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.
What is FAF (fundus autofluorescence)?
Fundus Autofluorescence (FAF) is a unique in vivo method of fundus imaging. Although it has been an area of active research over the last half a century, its only in the past decade that major advances have been made in its clinical application.
What causes fundus autofluorescence in the eye?
The major source of fundus autofluorescence (FAF) in the eye is the accumulated lipofuschin in the retinal pigment epithelium (RPE). This FAF depends upon the renewal of the outer segment of the photoreceptors and the resultant balance between accumulation and clearance of lipofuschin. [1]
What does the fundus photograph tell us about the retina?
While the surrounding retina appears mostly normal on the fundus photograph, FAF gives additional information by showing increased FAF intensity in a fine granular pattern extending beyond the geographic atrophy (GA) junctional zone. This pattern has been shown to increase the likelihood of GA progression.
What is the significance of autofluorescence (AF)?
Increased levels of autofluorescence typically indicates abnormal metabolism. Changes that are visible with FAF are often not visible clinically or with other imaging techniques such as conventional fundus photography.