Ocular changes in Alzheimer’s disease

Scientists at Cedars-Sinai Medical Center in the US have described changes in the eye associated with Alzheimer’s disease and mild cognitive impairment.

The study, which was published in Acta Neuropathologica, involved the examination of the retinal and brain tissue from 86 human donors who had experienced Alzheimer’s disease or mild cognitive impairment, alongside a control group without signs of Alzheimer’s disease.

In donors with mild cognitive impairment or Alzheimer’s disease, the researchers found high levels of the amyloid beta 42 protein in the retina.

This protein clumps together in the brains of patients with Alzheimer’s disease and disrupts function.

Scientists also found higher numbers of astrocytes and immune cells, called microglia, tightly surrounding amyloid beta plaques in the retina.

Compared to the control group, there were as much as 80% fewer microglial cells clearing amyloid beta proteins from the retina and brain.

Dr Keith Black, of Cedars-Sinai, shared that the research provides a greater understanding of the effects of Alzheimer’s disease on the retina.

“Because these changes correspond with changes in the brain and can be detected in the earliest stages of impairment, they may lead us to new diagnostics for Alzheimer's disease and a means to evaluate new forms of treatment,” he said.