Early detection of Alzheimer’s may be as simple as detecting changes in the cells of the retina of the eye, according to a breakthrough study led by international researchers, including one of Indian origin. The study suggests that physical changes in retinal cells may occur at the same time as changes in the brain in the early stages of Alzheimer’s disease.
Researchers in Australia, Italy and the US investigated how two proteins – beta-amyloid and tau – known to build up in the brains of Alzheimer’s patients can also be found in the cellular tissue of the eye, often long before symptoms appear. first appeared.
The findings, published in the peer-reviewed journal Acta Neuropathol, could potentially contribute to the future development of an imaging technique with the potential to detect Alzheimer’s disease with a non-invasive eye test.
Professor Stuart Graham, Head of Ophthalmology and Visual Sciences, said: “Researchers have recognized in recent years that retinal changes can occur much earlier in the disease process, but trying to identify these in the eyes of living patients has proved difficult. Has happened.” Macquarie University.
“The accumulation of beta-amyloid and tau in the central nervous system may be an important early factor in the development of Alzheimer’s disease,” said Associate Professor Vivek Gupta, a visual neurobiologist who leads Macquarie’s Vision Neurodegeneration Research Group.
He added that while the specific cause of Alzheimer’s disease is unclear, “recent studies by our group and others have reported similar disease processes and changes in the retina.” The study analyzed donor brain and retinal tissue from 86 people.
The team developed a composite proteome map of the human retina and brains of people with Alzheimer’s disease, showing protein changes at the molecular, cellular and structural levels of both the eye and brain, and associated cell death and inflammation.
Donors included people with normal brain function, some with mild cognitive impairment, and others who had been diagnosed with Alzheimer’s disease; And 39 people had donated both retinal and brain tissue, so researchers could directly compare protein levels in each.
The results showed that people who had Alzheimer’s disease had nine times higher amounts of beta-amyloid protein in their retinas than people who had shown no signs of cognitive impairment during their lifetime.
The study also found that these markers were found at nearly five times the rate in people who were not diagnosed with Alzheimer’s disease during their lifetime but showed signs of mild cognitive impairment.
The researchers were also able to track patterns in the location of these markers within the retina, with higher levels found in the tissues of the inner layer of the retina.
“We don’t yet have a tool in the clinic to identify these changes in the living eye, but if we can label these proteins, then develop an imaging device that can detect changes in the earliest stages, we have There may be a way to clinically diagnose diseases like Alzheimer’s,” Graham said.
Graham said a range of degenerative diseases (including Alzheimer’s) share common cell degradation pathways, and identifying patterns in the types and locations of abnormal proteins in retinal cells could also help diagnose diseases such as glaucoma. .
“We can now easily diagnose advanced glaucoma by imaging the back of the eye, but we also know that changes are occurring at the molecular or cellular level, long before we can see the structural changes that occur when nerve damage occurs.” The fibers start coming out,” he said. ,