First signs of Alzheimer’s might appear in your eyes, study finds

 

First signs of Alzheimer’s might appear in your eyes, study finds

 

Research has been exploring how the eye could help diagnose Alzheimer’s disease before symptoms begin. The disease is well advanced by the time memory and behavior are affected.   If doctors are able to identify the disease in its earliest stages via non-invasive eye tests, people could make healthy lifestyle choices and control their “modifiable risk factors, like high blood pressure, high cholesterol and diabetes,” said Dr. Richard Isaacson, an Alzheimer’s preventive neurologist at the Institute for Neurodegenerative Diseases.   A recent study examined donated tissue from the retina and brains, over 14 years, from 86 people with Alzheimer’s disease and mild cognitive impairment.   The researchers then compared samples from donors with normal cognitive function to those with mild cognitive impairment and those with later-stage Alzheimer’s disease.   The study found significant increases in beta-amyloid, a key marker of Alzheimer’s disease, in people with both Alzheimer’s and early cognitive decline in both brain and retina tissue.   Microglial cells declined 80% in those with cognitive issues, the study found. These cells are responsible for repairing and maintaining other cells, including clearing beta-amyloid from the brain and retina.   It also found higher numbers of immune cells tightly surrounding amyloid beta plaques, as well as other cells responsible for inflammation and cell and tissue death.   Tissue atrophy and inflammation in cells in the far periphery of the retina were most predictive of cognitive status, the study found.   “The findings were also apparent in people with no or minimal cognitive symptoms, which suggests these new eye tests may be well-positioned to aid in early diagnosis,” said Isaacson, who did not work on the study.   While these tests don’t currently exist, Isaacson noted this work could help lead to these tests in the future.   “These findings may eventually lead to the development of imaging techniques that allow us to diagnose Alzheimer’s disease earlier and more accurately,” Isaacson said, “and monitor its progression noninvasively by looking through the eye.”