NeuroVision Imaging, has developed a first of its kind, groundbreaking eye imaging system for measuring autofluorescence (AF) in the retina – Afina® Retinal Autofluorescence Measurement Software coupled with the Retia™ AF retinal camera. The Afina software is a medical device intended to import autofluorescence images of the retina from a qualified ophthalmic camera and then process those images to highlight areas of brighter autofluorescence relative to the background autofluorescence of the retina. The areas of brighter autofluorescence (spots) are counted as well as the total count of the pixels with brighter autofluorescence. Afina and Retia are market cleared by FDA in the United States.
Sources of autofluorescence in the fundus that can be detected:
- The main source of autofluorescence in the fundus is lipofuscin (LF) in the retinal pigment epithelium (RPE).17 LF is a byproduct of the visual cycle degradation pathway and is resistant to enzymatic degradation. Although a normal part of retinal metabolism, various physiological conditions or pathologies can accelerate the rate at which LF accumulates. This makes the presence of lipofuscin a potential early indicator of degenerative retinal diseases.
- Drusen, which consist primarily of lipofuscin, can be expected to produce hyperfluorescent spots. However, their location underneath the RPE means their signal is heavily modulated by the melanin in the RPE. As will be discussed below in more detail, the primary effect of drusen under an intact RPE is to physically distort the RPE layer, resulting in a distorted RPE AF signal.
- Amyloid beta is deposited in the inner retina and around the retinal vessels and exhibits fluorescence in the visible range.18 In particular, full-length amyloid beta (AB1-42) exhibits blue light (> 420) autofluorescence in senile plaques and cerebral amyloid angiopathy (truncated deposits do not).19
- Collagen and elastin proteins in the sclera and choroid can contribute to the AF signal of patients with geographic atrophy (GA), where the RPE has failed and is absent in places. The contribution of these proteins to AF can be around 6% for dark-pigmented humans and 15% for light-pigmented humans.20
- Vitelliform lesions form round yellow, retinal lesions consisting of shed outer segment debris in the extracellular space. They accumulate between the photoreceptor tips and the RPE. This is a lipofuscin-like material anterior to the RPE. 21
- Optic disc drusen consist of extracellular mitochondria in a protein matrix that if superficial, may produce AF. 21
Investigational Device(s). Limited by Federal (or United States) law to investigational use.