Retinal imaging biomarkers of Alzheimer's disease: A systematic review and meta‐analysis of studies using brain amyloid beta status for case definition

Abstract

Introduction:We performed a systematic review and meta-analysis of the association between retinal imaging parameters and Alzheimer's disease (AD). Methods: PubMed, EMBASE, and Scopus were systematically searched for prospective and observational studies. Included studies had AD case definition based on brain amyloid beta (Aβ) status. Study quality assessment was performed. Random-effects meta-analyses of standardized mean difference, correlation, and diagnostic accuracy were conducted. Results: Thirty-eight studies were included. There was weak evidence of peripapillary retinal nerve fiber layer thinning on optical coherence tomography (OCT) (p = 0.14, 11 studies, n = 828), increased foveal avascular zone area on OCT-angiography (p = 0.18, four studies, n = 207), and reduced arteriole and venule vessel fractal dimension on fundus photography (p < 0.001 and p = 0.08, respectively, three studies, n = 297) among AD cases.Discussion: Retinal imaging parameters appear to be associated with AD. Small study sizes and heterogeneity in imaging methods and reporting make it difficult to determine utility of these changes as AD biomarkers.

Non-invasive in vivo imaging of brain and retinal microglia in neurodegenerative diseases

“…In recent years there has been significant interest in developing retinal imaging biomarkers for AD. Deposits of Aβ and tau protein have been found in the retina of AD patients, along with other retinal changes including vascular alterations, inflammation and thinning of retinal layers ( Ramirez et al, 2017 ; Snyder et al, 2021 ; Zhang et al, 2022 ; Ashraf et al, 2023 ). Interestingly, in the early stages of disease, preceding Aβ plaque formation in the brain, Aβ plaques were detected in the retina in AD mouse models ( Koronyo-Hamaoui et al, 2011 ; Koronyo et al, 2012 ), suggesting that retinal imaging may be useful as an early diagnostic tool.…”

Progress in mitochondrial and omics studies in Alzheimer’s disease research: from molecular mechanisms to therapeutic interventions

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