A Healthy Retina Could Be Indicative Of How Healthy Your Brain Is

A new study has found that changes in your retina can help indicate if you are at risk of brain disease like Alzheimer's disease. Read on to understand the link.

When you look in the mirror, you won't be able to see your retina. Your ophthalmologist can see into your eye using special devices, allowing you to see your healthy retina and everything it contains. The retina is a light-sensitive layer of tissue located near the optic nerve in the back of the eye. Light passes through the eye's lens, and the retina's duty is to convert that light into neural impulses that are sent to the brain via the optic nerve. The nerve that links your eyes to your brain is known as the optic nerve. The signals received by the brain will aid in the interpretation of the visuals you view. In simple words, it is like a window to your brain.

The Link Between Retina And Brain Health

A study published in the journal JAMA Ophthalmology found that the thinning of a person's retina in middle age is linked to cognitive performance in their early and adult life. Researchers believe that this study might be able to help predict a person's risk of medical problems such as Alzheimer's disease.

It is a brain disease characterised by a gradual mental loss that might go undiagnosed for decades before symptoms appear, however, concealed signals of the disease may exist far earlier. Visual deficits are common in people with Alzheimer's disease, which can lead to mental confusion, disorientation, and social withdrawal all symptoms that, along with memory loss, disturb the lives of millions of people living with the condition throughout the world.

Several other studies have found a link between thinner retinas and the onset of Alzheimer's. A study published in Neuroscience found that they found amyloid-beta proteins in the retinas of people suffering from Alzheimer's. Some other eye imaging studies found that Alzheimer's patients had thinner retinas.

Does Problems In Retina Lead To Alzheimer's?

For this study, researchers studied the data from the long-running Dunedin study of over a thousand babies born in the early 1970s in New Zealand. Barrett-Young and colleagues examined a subgroup of 865 adults who had undergone eye scans at the age of 45, as well as a battery of neuropsychology tests in adulthood and early childhood, as part of the Dunedin experiment. The scans were used to measure the thickness of two different regions of the retina (retinal nerve fibre layers and ganglion cell layers).

Participants in the study with thinner retinal layers performed worse on cognitive performance tests as adults and as children. However, no link was identified between retinal thinning and a general loss in cognitive function (from youth to middle age), which could imply that something is wrong with the brain.

While thinner retinal nerve fibre layers at 45 have been associated with a slowing of brain processing rates from childhood, this could simply be a characteristic of ageing and not necessarily Alzheimer's disease. Barrett-Young, who led the study said, "The findings suggest that [retinal thickness] could be an indicator of overall brain health."

Given what has been discovered thus far and the expanding burden of Alzheimer's disease, experts believe that examining retinal thinning as a biomarker of cognitive decline is worthwhile.