Quantitative Autofluorescence in Non-Neovascular Age Related Macular Degeneration

Abstract

Quantitative autofluorescence (qAF8) level is a presumed surrogate marker of lipofuscin content in the retina. We investigated the changes in the qAF8 levels in non-neovascular AMD. In this prospective cohort study, Caucasians aged ≥50 years with varying severity of non-neovascular AMD in at least one eye and Snellen visual acuity ≥6/18 were recruited. The qAF8 levels were analysed in the middle eight segments of the Delori pattern (HEYEX software, Heidelberg, Germany). The AMD categories were graded using both the Beckman classification and multimodal imaging (MMI) to include the presence of subretinal drusenoid deposits (SDD). A total of 353 eyes from 231 participants were analyzed. Compared with the age-matched controls, the qAF8 values decreased in the eyes with AMD (adjusted % difference = −19.7% [95% CI −28.8%, −10.4%]; p < 0.001) and across the AMD categories, (adjusted % differences; Early, −13.1% (−24.4%, −1%), p = 0.04; intermediate AMD (iAMD), −22.9% (−32.3%, −13.1%), p < 0.001; geographic atrophy −25.2% (−38.1%, −10.4%), p = 0.002). On MMI, the qAF8 was reduced in the AMD subgroups relative to the controls, (adjusted % differences; Early, −5.8% (−18.9%, 8.3%); p = 0.40; iAMD, −26.7% (−36.2%, −15.6%); p < 0.001; SDD, −23.7% (−33.6%, −12.2%); p < 0.001; atrophy, −26.7% (−39.3%, −11.3%), p = 0.001). The qAF8 levels declined early in AMD and were not significantly different between the severity levels of non-neovascular AMD, suggesting the early and sustained loss of function of the retinal pigment epithelium in AMD.

Advanced Research in Age-Related Macular Degeneration: Special Issue

“…The results showed that qAF8 is decreased during the early progression of AMD. qAF8 levels seem related more to the loss of function and integrity of RPE cells rather than being due to abnormalities in the visual cycle [9].…”

“…The quantitative autofluorescence (qAF8) level is a presumed surrogate marker of lipofuscin content in the retina [8]. Chandra et al [9] investigated changes in qAF8 levels in non-neovascular AMD in a prospective cohort study. The AMD categories were graded using both the Beckman classification and multimodal imaging, allowing for the deep phenotyping of AMD.…”

Fluorescence Lifetime Imaging of Human Retinal Pigment Epithelium in Pentosan Polysulfate Toxicity Using Adaptive Optics Scanning Light Ophthalmoscopy

“… 7 In age-related macular degeneration (AMD), quantitative fluorescence intensity decreases at an early stage of disease and remains reduced into late stage disease. 8 – 10 …”