Retinal imaging think tank convened by the Alzheimer's Association to examine its promise in the early detection of Alzheimer's.

Abstract

Retinal changes are evident throughout the progression of Alzheimer's disease (AD), including the presence of amyloid plaques and neurofibrillary tangles, microvascular changes, evidence of inflammation, and other changes in retinal metabolism. Researchers have also found that retinal imaging may detect signs of underlying neurodegenerative disease even before cognitive impairment is present. Other studies show that non-invasive retinal imaging—including, but not limited to, optical coherence tomography—is a potential inexpensive and patient-friendly tool for screening for signs of AD. To help bring these potential new biomarkers to the forefront of research discussion, the Alzheimer's Association in collaboration with the editorial team from Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring (DADM) convened the “Retinal Imaging and Neurodegenerative Diseases” workshop in May 2019 in Washington, DC. This first-of-its-kind international event brought together 90 researchers from nine countries. The American Optometric Association (AOA) published a report from the workshop in its publication, Primary Care Optometry News.1 Workshop participants discussed multiple imaging modalities and methods, identified areas of data convergence, and explored gaps and potential areas to further advance application of these technologies for clinical trials and diagnostic uses. According to co-chairs Peter J. Snyder, PhD, editor-in-chief of DADM and vice president of research and economic development, University of Rhode Island, and Heather Snyder, PhD, vice president of medical science relations at the Alzheimer's Association, having this workshop is a critical step toward advancing research on retinal changes that may be uniquely amenable to non-invasive ocular imaging. The next step is to advance necessary research to further validate retinal/ocular non-invasive biomarkers. During the day-and-a-half meeting, researchers discussed a wide range of subjects including the quantification of amyloid beta and tau structures; advanced use of 3D macular scans and blood flow measurement; disease-related changes to the structure of retinal neuronal layers, vascular bed changes, and emerging imaging technologies (eg, cross-polarized light imaging, hyperspectral retinal imaging, and fluorescence lifetime imaging ophthalmoscopy); real-world trials of retinal imaging; microglia activation at the preclinical disease stage and imaging of neuroinflammation in the retina; the relationship between sleep disturbances and melanopsin-retinal ganglion cell degeneration; and how best to approach a consensus across research groups with respect to a “standard minimum dataset” to accelerate collaborative efforts. The AOA's chief public health officer, Michael Dueñas, OD, who participated in the workshop, said, “One day Alzheimer's disease could be another significant responsibility for optometry within team-based medical care. Pairing retinal imaging technology and our understanding of early cognitive decline is going to be essential in raising our patients’ health outcomes and preventing or slowing neurodegenerative disease.” A detailed white paper of the proceedings of this workshop is in process.