A test to identify protein deposits in the retina may inform doctors about increased risk of Alzheimer’s Disease.
The presence of amyloid protein spots in the retina may be an easy way for doctors to identify people who have an increased risk of developing Alzheimer’s disease, a new study suggest.
Accumulation of amyloid protein deposits in parts of the brain is a hallmark of Alzheimer’s disease (AD). These protein deposits, commonly called amyloid plaques, affect neuronal function, eventually leading to neuronal death, and are thought the be a key component of the AD pathology.
Now, this new study, led by Prof Robert Rissman, from the University of California, in San Diego, USA shows that people with early stages of AD are likely to have spots of amyloid protein in their retina.
The findings may point towards a non-invasive approach to identify people at high risk of developing AD.
In Australia, the exact number of people with AD is not known. However, data from the AIHW shows that in 2020 there were between 400,000 and 459,000 Australians with dementia. Most of these cases (about 70%) were diagnosed with AD.
Identifying patients who are at an early stage of AD is critical to inform potential therapeutic efforts. Currently, approaches to identify such patients involve the use of amyloid-ligand positron emission tomography (PET) and measuring cerebrospinal fluid (CSF) amyloid levels. Both techniques are effective, but not widely implemented, due to the cost and invasive nature of the procedures.
The findings of this new study may lead to the development of a quick, effective and inexpensive way to identify patients with early-stage AD.
About the study
Researchers analysed data from two previous studies that involved clinically normal individuals, who screened positive for high amyloid levels in the brain. A small number of patients were selected from these two studies, to establish if there was a correlation between levels of amyloid protein in the retina and levels of amyloid plaques in the brain.
Their analyses showed that the presence of amyloid retinal spots was correlated with brain scans showing high levels of cerebral amyloid plaques.
“This was a small initial dataset from the screening visit. It involved eight patients. But these findings are encouraging because they suggest it may be possible to determine the onset, spread and morphology of AD — a preclinical diagnosis — using retinal imaging, rather than more difficult and costly brain scans,” Dr Rissman said in a press release.
Now, the next step is to conduct a larger study to confirm these findings and provide support for the implementation of eye screening as a tool to identify patients with early-stage AD.