Researchers are investigating how the eye can aid in the early detection of Alzheimer’s disease. By the time memory and conduct are impacted, the disease has progressed significantly.
The researchers collected retinal and brain tissue samples from 86 human volunteers with the disease and mild cognitive impairment over 14 years – the biggest set of retinal samples ever analyzed, according to the authors.
Alzheimer’s Disease May Be Detected Through Eyes
The samples from donors with normal cognitive function were then compared to those with mild cognitive impairment and those with late-stage Alzheimer’s disease. The findings were published in the journal Acta Neuropathologica in February. They discovered large increases in beta-amyloid, a major hallmark of the disease, in persons with both Alzheimer’s and early cognitive impairment.
The researchers investigated the physical characteristics of these individuals’ retinas, measuring and mapping signs of inflammation and functional cell loss, and analyzing the proteins found in retinal and brain tissues.
What Researchers Discovered?
Researchers discovered the following in the retinas of people with mild cognitive impairment and Alzheimer’s disease:
- An excess of a protein called amyloid beta 42, clumps together in the brains of the patients to form plaques that impede brain function.
- Amyloid beta protein buildup in ganglion cells, which connect visual input from the retina to the optic nerve.
- A greater number of astrocytes and immune cells known as microglia surround amyloid beta plaques.
- There are up to 80% fewer microglial cells in the retina and brain cleaning amyloid beta proteins.
- Inflammation and cell and tissue death are caused by specific chemicals and biological mechanisms.