2022 Alzheimer's Association Research Grant to Promote Diversity (AARG-D)

Association of Retinal Vasculature with Alzheimer’s Neuroimaging Biomarkers

How are changes in blood flow in the retina associated with brain changes related to Alzheimer’s?

Sunu Mathew, M.D.
Indiana University
Bloomington, IN - United States

Background

Because Alzheimer's is a progressive disorder, researchers are working to develop methods for detecting at its earliest stages, before cognitive symptoms appear. One part of the body, the retina of the eye, may develop characteristic damage in individuals with Alzheimer's very early in the disease process. Past studies suggest such damage may include the thinning of a layer of cells in the retina and the build-up (accumulation) of beta-amyloid protein. Accumulation of beta-amyloid in the retina may lead to visual disorders associated with Alzheimer’s. It may also indicate similar accumulation in the brain, which is a hallmark of Alzheimer’s. 

There is a need for affordable, accessible, and reliable measures to help identify the earliest changes in Alzheimer’s.If changes in the retina and visual system are associated with the accumulation of beta-amyloid and/or tau in the earliest stages of Alzheimer’s, they could be used to quickly and easily identify individuals at risk for the disease.

Research Plan

Dr. Sunu Mathew and colleagues will study the relationship between changes in retinal blood flow and the deposition of retinal beta-amyloid, as well as the accumulation of beta-amyloid and tau in the brain, in stages of Alzheimer’s. The researchers will recruit 70 individuals aged 60 years and older through the Indiana Alzheimer’s Disease Research Center. The participants will include cognitively unimpaired individuals, individuals with subjective cognitive decline (self-reported memory problems), and individuals with mild cognitive decline (a subtle form of memory loss that may precede Alzheimer’s) or mild Alzheimer’s. 

The researchers will administer a comprehensive visual exam to the participants that includes structural and vascular (blood vessel) examination of the retina. They will also conduct brain scans (PET and structural magnetic resonance imaging, MRI) on all participants to measure levels of beta-amyloid and tau protein accumulated in the brain. 

Impact

If successful, the study results may help us understand the early changes in the retina in Alzheimer’s and may open new paths for possible detection of these changes. The findings may contribute to the use of tool related brain changes at risk for Alzheimer’s and dementia.