Retinal imaging biomarkers of Alzheimer’s disease: clinical evidence and perspectives

Abstract

AbstractA growing body of research is devoted to retinal imaging biomarkers of Alzheimer’s disease (AD). Imaging methods such as optical coherence tomography (OCT) provide qualitative and quantitative measures of retinal and optic nerve neurodegeneration, whereas OCT‐angiography yields depth‐resolved maps of the retinal microvasculature in exquisite detail. Similarly, conventional and widefield retinal photography enable measurements of the retinal vascular geometry. Other emerging technologies, including hyperspectral imaging, retinal curcumin‐fluorescence imaging and fluorescence lifetime imaging ophthalmoscopy, provide insights into retinal changes at the molecular level, such as the accumulation of amyloid beta.Navigating the evidence in this field is challenging. Of the many studies that have examined associations between retinal imaging findings and AD, most have been based on clinical case ascertainment in the absence of biomarker findings. In this presentation, we will provide an accessible overview of this rapidly evolving field, with an emphasis on studies of retinal imaging biomarkers of the disease that align with the NIA‐AA Research Framework. Underpinning this are the findings of a systematic review and meta‐analysis that we have recently conducted (in press). Drawing on the anatomical and pathological insights provided by fellow speakers in the symposium, we highlight opportunities for further clinicopathological correlation of key imaging biomarkers. Finally, as a prelude to the last talk in the symposium, we highlight gaps in the existing clinical literature and point to efforts to harmonise study methods to generate the evidence needed for adoption of retinal imaging biomarkers of AD in practice.