A study has concluded that the first sign of Alzheimer’s disease might first be apparent in a person’s eyes.
CNN reported on a study that examined retina and brain samples from 86 people who were experiencing a downward trend in mental efficiency.
The study was initially published in February in the Acta Neuropathologica journal, which found that inflammation and tissue atrophy were the earliest signs of the onset of Alzheimer’s disease.
“Our study is the first to provide in-depth analyses of the protein profiles and the molecular, cellular, and structural effects of Alzheimer’s disease in the human retina and how they correspond with changes in the brain and cognitive function,” Maya Koronyo-Hamaoui, senior author of the study and a professor of neurosurgery and biomedical sciences at Cedars-Sinai in Los Angeles, said in a statement to CNN.
“These changes in the retina correlated with changes in parts of the brain called the entorhinal and temporal cortices, a hub for memory, navigation and the perception of time,” Koronyo-Hamaoui said.
The authors said that the 86 different samples they took created the largest collection of retinal samples ever to be assembled for study.
Those researching the retina and brain samples compared samples from people experiencing no cognitive decline to samples from people experiencing mild to severe cognitive decline due to the later stages of Alzheimer’s disease.
“Markers of inflammation were (also) found, which may be an equally important marker for disease progression,” Dr. Richard Isaacson, a preventive neurologist in Alzheimer’s disease, said to CNN. “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.”
That the eyes provide a potential opportunity for early diagnosis might come as unsurprising to some. Experts have known that the eye is an effective means to look into the nervous system.
“The eye is the window into the brain,” Dr. Christine Greer, ophthalmologist and director of medical education at the Institute for Neurodegenerative Diseases in Boca Raton, said to CNN. “You can see directly into the nervous system by looking into the back of the eye, toward the optic nerve and retina.”