Cedars-Sinai Analysis Evaluates How Retinal Changes Correspond to Cognitive Changes in Alzheimer’s Disease

Cedars-Sinai investigators have produced an analysis evaluating how retinal changes correspond to brain and cognitive changes in Alzheimer’s disease patients. 

Investigators looked at retinal and brain tissue samples collected over 14 years from 86 human donors—the largest group of retinal samples from human patients with Alzheimer’s disease and mild cognitive impairment thus far studied. They compared samples from donors with normal cognitive function to those with mild cognitive impairment at the earliest stages of Alzheimer’s disease, and those with later-stage Alzheimer’s disease dementia.  

The investigators explored the physical features of the retinas of these patients, measuring and mapping markers of inflammation and functional cell loss, and analyzed the proteins present in retinal and brain tissues.  

Here is what investigators found in the retinas of patients with mild cognitive impairment and Alzheimer’s disease:

• An overabundance of a protein called amyloid beta 42, which in the brains of Alzheimer’s disease patients clumps together to form plaques that disrupt brain function
• Accumulation of amyloid beta protein in ganglion cells, the cells that bridge visual input from the retina to the optic nerve
• Higher numbers of astrocytes and immune cells, called microglia, tightly surrounding amyloid beta plaques
• As many as 80% fewer microglial cells clearing amyloid beta proteins from the retina and brain 
• Specific molecules and biological pathways responsible for inflammation, and cell and tissue death

The analysis was published in the peer-reviewed journal Acta Neuropathologica. Read the full Cedars-Sinai article here.