Alzheimer’s Disease Diagnosis: Researchers Developing New Non-Invasive Eye Test To Detect Early Symptoms

A team of researchers is reportedly working on developing a non-invasive eye test that will help in Alzheimer’s disease diagnosis even before the symptoms appear.

Alzheimer’s is one of the most common forms of dementia. The cure to the disease has not yet been found. Around 50 million people are living with dementia around the globe, and the number is expected to increase in the coming decades as the population ages.

According to experts, brain damage due to Alzheimer’s disease begins two decades before the onset of symptoms such as memory loss and cognitive decline appear.

The type of technology used in the study is called optical coherence tomography angiography (OCT-A). The non-invasive optical coherence tomography angiography technique throws light into the eye that allows the doctor to measure retinal thickness and the thickness of fibers in the optic nerve.

The newly developed test detected evidence of Alzheimer’s in older patients who showed no symptoms of the disease. The researchers found that in patients with preclinical Alzheimer’s, the area at the center of the retina without blood vessels was significantly larger, suggesting less blood flow.

Rajendra S. Apte, Professor at Washington University in St. Louis, said the retina and central nervous system are interconnected, so changes in the brain gets reflected in cells in the retina.

“We found that this zone lacking blood vessels was significantly enlarged in people with preclinical Alzheimer’s disease,” Apte said.

“This technique has great potential to become a screening tool that helps decide who should undergo more expensive and invasive testing for Alzheimer’s disease prior to the appearance of clinical symptoms,” added study lead author, Bliss E. O’Bryhim. “Our hope is to use this technique to understand who is accumulating abnormal proteins in the brain that may lead them to develop Alzheimer’s.”

The researchers are hopeful that one day they can use the eye test to screen people as young as in their 40s or 50s to see whether they are at risk for the disease.

The study has been published in the Journal of the American Medical Association (JAMA) Opthalmology.