Eye Test May Offer Early Diagnosis for Alzheimer’s
Eye Test May Offer Early Diagnosis for Alzheimer’s Disease
A new report published by researchers at Northwestern University offers the possibility of an early diagnostic test for Alzheimer’s disease – via an eye test. Using an infrared camera, the researchers were able to detect reduced blood capillaries in the back of the eye that appear linked to early Alzheimer’s. They published their research in the journal PLOS ONE.
“Once our results are validated, this approach could potentially provide an additional type of biomarker to identify individuals at high risk of progressing to Alzheimer’s,” stated Amani Fawzi, professor of ophthalmology at Northwestern University Feinberg School of Medicine and a physician at Northwestern Medicine. “These individuals can then be followed more closely and could be prime candidates for new therapies aimed at slowing down the progression of the disease or preventing the onset of the dementia associated with Alzheimer’s.”
Patients with Alzheimer’s have decreased blood flow to the retina as well as lower blood vessel density in the eye. It wasn’t known if those changes were also present in people with early Alzheimer’s or mild cognitive impairment.
Fawzi and colleague Sandra Weintraub recruited 32 patients whose cognitive testing was consistent with the forgetful type of cognitive impairment and matched them by way of age, gender and race to individuals who tested cognitively normal for their age. They all received eye imaging with OCT angiography, looking for changes in the vascular capillaries in the back of the eye.
The people who were cognitively impaired showed a statistically significant decrease in some measurements and not in others. The authors stated, “we found a significant positive correlation between MoCA scores for the entire study cohort and both the parafoveal SCP VD and peripapillary RPC VLD.” MoCA is the Montreal Cognitive Assessment Test for Dementia. VD stands for vessel density. SCP is parafoveal superficial plexus and RCP is radial peripapillary capillary. These refer to specific areas of the eye.
The test results are indicative, but aren’t rock solid and, as they note, the results need to be validated further. They plan to work further to correlate the results with other more standard, but also more invasive, types of Alzheimer’s biomarkers as well as look at the longitudinal changes in the eye parameters.
“Ideally the retinal findings would correlate well with other brain biomarkers,” stated Fawzi. “Long-term studies are also important to see if the retinal capillaries will change more dramatically in those who progressively decline and develop Alzheimer’s dementia.”
Early diagnosis of Alzheimer’s has gained a great of attention lately. Last week, Bill Gate’s The Bill & Melinda Gates Foundation and Amazon’s Jeff Bezos’ Day One Fund teamed to donate $15 million to the Diagnostics Accelerator, a project that is part of the Alzheimer’s Drug Discovery Foundation (ADDF). The Diagnostics Accelerator’s mission is fairly straightforward, although quite difficult—develop an easy and affordable test for Alzheimer’s disease.
On his blog, GatesNotes, Bill Gates outlined current advances in diagnosis Alzheimer’s, which is essentially via a spinal tap or a brain scan—invasive and expensive, respectively. And generally, people don’t look for diagnoses until they start showing symptoms. He wrote, “It’s hard to overstate how important finding a reliable, affordable, and easy-to-use diagnostic is for stopping Alzheimer’s.”
Part of Gates’s blog was related to the ADDF’s Diagnostic Accelerator’s announcement that it plans to fast-track digital tools for Alzheimer’s and related dementias. The Diagnostics Accelerator program itself was created in July 2018 with funding from co-founder Leonard Lauder, Gates, the Dolby family, and the Charles and Helen Schwab Foundation. Additional funds came from The Association for Frontotemporal Degeneration. Gates’ and Bezos’ funds bring the total program funding to almost $50 million.
The ADDF announced that funding for its Diagnostics Accelerator Digital Biomarker Initiative is now open to scientists and clinicians worldwide working in academic institutions, nonprofits, industry partnerships, and biotechnology companies, as well as new start-ups.
Funding priorities include portables, sensors, software, mobile and tablet apps, smart home systems, and virtual and augmented reality platforms.