Jackson Lab Explores Retinal Imaging as Non-Invasive Biomarker for Early Alzheimer's Detection
Key Insights
Jackson Lab (search) researchers are developing a retinal imaging test that examines the eye for vascular biomarkers linked to Alzheimer's disease (search), leveraging the retina as a "window into brain health."
Blood vessel deficits appear in as many as 80% of Alzheimer's cases, and the imaging approach aims to identify vascular changes before cognitive symptoms emerge.
The research combines human studies with mouse models to distinguish Alzheimer's-related retinal changes from eye diseases like glaucoma (search) and diabetic retinopathy (search).
Researchers at Jackson Lab (search) in Bar Harbor, Maine, are advancing a novel biomarker test that uses retinal imaging to detect Alzheimer's disease (search), offering a potentially simpler and more accessible alternative to current diagnostic methods. The approach capitalizes on the retina's unique biological connection to the brain, examining vascular changes that may signal the earliest stages of neurodegeneration.
"The reason the retina is a really great place to look is because it's essentially a piece of the brain that is sticking outside of the skull. It's the same tissue. We call it neural tissue," said Gareth Howell, principal investigator at Jackson Lab (search).
The diagnostic promise of retinal imaging lies in its practicality. While an MRI of the brain can be costly and difficult to access, retinal imaging can be performed as simply as a routine eye exam. This accessibility could prove transformative for early Alzheimer's screening, particularly in rural or underserved regions.
Vascular Biomarkers and Alzheimer's Pathology
Howell emphasized that blood vessel deficits represent a hallmark feature of Alzheimer's disease (search), appearing in a substantial proportion of cases. "In maybe as many as 80% of cases of Alzheimer's disease, you see blood vessel deficit of some kind, whether that be in the flow of the blood heading to that nerve cell, for instance. And so it's those markers that we're really trying to now work out. How can we visualize those? How do we find biomarkers for vessel health?" Howell said.
The research team aims to identify these vascular changes before patients exhibit cognitive symptoms, potentially opening a critical window for early intervention. However, distinguishing Alzheimer's-related retinal changes from other ocular conditions presents a significant scientific challenge.
"One of the challenges of this research is to actually see if we can determine early stages of dementia in a background of what might be early stages of an eye disease like glaucoma (search) or age related macular degeneration (search) or even diabetic retinopathy (search)," Howell noted.
Combining Human and Mouse Studies
To address the complexity of interpreting retinal changes in human subjects, Jackson Lab (search) is pursuing a dual-track research strategy that integrates human clinical studies with mouse model experiments.
"So that's why we're actually particularly excited to combine our human studies with our mouse studies. Because using mouse models of Alzheimer's disease (search), we can actually carefully uncover a particular disease state and whether it impacts the eye and brain at the same time or at different times," Howell explained.
Jackson Lab (search) has been investigating this retinal imaging method for approximately a decade. The ultimate objective, according to Howell, is to pinpoint individuals at the highest risk for the most consequential aspect of Alzheimer's disease (search): "What we're really trying to do is to identify the group of individuals that are most at risk of getting the parts of the Alzheimer's disease that we care about the most — which is ultimately cognitive decline. We want to stop cognitive decline."
Clinical Study Recruitment Underway
Jackson Lab (search) is currently seeking more than 800 participants for its retinal vasculature study, which is designed to track the early stages of dementia. The study protocol includes blood tests, eye examinations, and cognitive assessments, providing a comprehensive evaluation of each participant's neurological and vascular health.
The research comes at a time when interest in Alzheimer's biomarkers is intensifying. The FDA has approved two blood-based biomarker tests for Alzheimer's diagnosis in adults aged 55 and older who exhibit signs of cognitive decline, with accuracy rates of 90-95%. These blood tests are less invasive and less costly than PET scans or lumbar punctures. However, some clinicians urge caution regarding expanded testing in asymptomatic populations, noting that amyloid pathology can be present for decades before dementia develops.
Jackson Lab (search)'s retinal imaging approach represents a complementary strategy that focuses on vascular rather than amyloid biomarkers, potentially capturing a different dimension of Alzheimer's pathology that could enhance early detection and risk stratification.