Cells along the outer edge of the retina begin to swell and multiply before memory problems appear. That subtle shift, visible only under specialized imaging, may signal the earliest stages of Alzheimer’s disease. Researchers at Houston Methodist report that these peripheral eye changes emerge before major failures occur in the brain’s waste-removal system, suggesting the eye could reveal risk years earlier than current diagnostics. The study, led by biomedical engineer Stephen Wong, Ph.D., examined how retinal support cells behave during the first phase of disease development in mice genetically engineered to develop Alzheimer’s pathology. Findings appear online in the Journal of Alzheimer’s Disease. “The eyes are indeed a window into the brain, but our study reveals that we have been looking at the wrong part of the window,” Wong said. “While most clinical eye exams focus on the central retina, the most critical early indicators of AD appear to be hidden at the periphery of the eye.” Biomedical engineer Stephen Wong, Ph.D. (CREDIT: Houston Methodist) A different part of the eye draws attention Most eye …