In a research conducted at the Gladstone Institutes and University of California, San Francisco, scientists have found that changes in a person's eye could predict changes in the brain. The study showed that a loss of cells in the retina or retinal thinning is one of the earliest signs of frontotemporal dementia (FTD) in people with a genetic risk for the disorder - even before any changes appear in their behavior.
Chief Investigator, Li Gan,PhD, of Gladstone Institutes, and UCSF associate professor of neurology Ari Green, MD, studied a group of individuals who were exposed to a genetic mutation that is known to result in FTD. They discovered that before any cognitive signs of dementia were present, these individuals showed a significant thinning of the retina compared with people who did not have the gene mutation.
Dr. Gan suggests that the retina acts as a type of 'window to the brain.' He added, "Retinal degeneration was detectable in mutation carriers prior to the onset of cognitive symptoms, establishing retinal thinning as one of the earliest observable signs of familial FTD. This means that retinal thinning could be an easily measured outcome for clinical trials."
For patients who suffer from FTD, the brain's frontal and temporal lobes shrink. The retina, comprised of light-sensitive neurons in the eye, connects directly to the brain through the optic nerve. Scientists consider it part of the central nervous system, where doctors can examine and track the change in neurons, and also identify the degradation of the brain in the retina.
Lead author Michael Ward, MD, PhD, a postdoctoral fellow at the Gladstone Institutes and assistant professor of neurology at UCSF, explained, that the retina may be used as a model to study the development of FTD in neurons. Follow-ups of these individuals over time could correlate a decline in retinal thickness with disease progression. In addition, doctors would be able to track the effectiveness of a treatment through a simple eye examination.
On the findings, Dr. Gan said, "we now not only know that retinal thinning can act as a pre-symptomatic marker of dementia, but we've also gained an understanding into the underlying mechanisms of frontotemporal dementia that could potentially lead to novel therapeutic targets."What is dementia?
Dementia refers to a group of degenerative mental diseases in which there is a serious loss of cognitive function which goes beyond normal ageing. Symptoms include confusion, mood swings, long-term memory loss and a gradual loss of bodily functions. Alzheimer's is the most common form of dementia. It is caused due to plaque deposition in the brain's neurons which affects its functioning and causes it to die. Why this happens is still not clear though research suggests it's linked to genetic susceptibility and mental age.
The finding was published in the Journal of Experimental Medicine