Retinal changes may serve as early indicator for Alzheimer's disease

A team of scientists at the Indiana University School of Medicine has identified that an eye condition affecting the retina, the light-sensing tissue in the back of the eye, may serve as an early indicator for Alzheimer's disease. Their findings, published in Alzheimer's & Dementia, offer new insights into the potential use of retinal changes as early biomarkers for Alzheimer's, which could improve diagnosis and treatment of neurodegenerative disease. 

The research was led by IU School of Medicine PhD Student Surabhi D. Abhyankar, MS, alongside colleagues from the school's departments of ophthalmology and biochemistry and molecular biology, the Stark Neurosciences Research Institute, and the Leslie Dan Faculty of Pharmacy at the University of Toronto. Their findings indicate that the presence of the APOE4 gene - known to increase the risk of Alzheimer's disease in humans - in mice impairs retinal function, suggesting a direct link between this genetic variant and visual processing deficits associated with Alzheimer's disease. 

The eye is a window to the brain reflecting changes associated with neurodegenerative conditions such as Alzheimer's disease. Nearly 7 million Americans are living with Alzheimer's disease, and our study will help provide ease of diagnosis and potential intervention for Alzheimer's disease, thus enhancing patient outcomes and quality of life in the future." 

Ashay Bhatwadekar, PhD, associate professor of ophthalmology and principal investigator of the study

The research team used advanced imaging techniques to assess retinal structure and function in the mice. Compared to control groups, they observed significant alterations in retinal thickness and electrical activity in biological tissues and cells. These findings align with clinical observations of retinal abnormalities in Alzheimer's patients, reinforcing the relevance of this model for studying triggers of the disease. 

"Our study demonstrates that retinal dysfunction occurs in the APOE4 mouse model, mirroring aspects of Alzheimer's pathology," Abhyankar said. "These results underscore the potential of retinal imaging as a non-invasive method to detect early neural changes in Alzheimer's disease."

Other study authors include Qianyi Luo, PhD; Gabriella D. Hartman, BS; Neha Mahajan, PhD; Timothy W. Corson, PhD; Adrian L. Oblak, PhD; and Bruce T. Lamb, PhD.

This research was supported by funding from the National Eye Institute and Research to Prevent Blindness.