Early detection of diseases which cause dementia, such as Alzheimer’s disease and Parkinson’s disease, is one of the most important aspects of treatment. Although curing these diseases is, at present, not possible, catching them and beginning treatment early can significantly slow their progress, and have a huge impact on the ability of treatments to prevent cognitive impairment.
As a result, research that shows that the eyes can offer a potential early warning system for these diseases is an exciting development, and one that could be a real game changer for the treatment, prevention, and even future cure of neurodegenerative diseases.
According to various papers and studies, paying closer attention to eye health could help spot early signs of dementia, as various common eye conditions may be linked to a higher risk of neurodegenerative diseases. Similarly, changes in the eyes could show early indications of changes in the brain, allowing doctors to identify dementia or cognitive impairment far earlier.
In this article we are going to explore the link between the eyes and the brain, look at how the eyes might be able to give an early warning of dementia, and go over some common eye conditions which may be linked to these diseases.
The link between the eyes and the brain
There is a clear, tangible, and perceivable link between the eyes and the brain, and the connection between brain tissue and eye tissue is increasingly of interest to doctors and academics studying dementia, among other things.
The eyes are directly, physically linked to the brain via the optic nerve. The brain is, unsurprisingly, vital in our ability to see, to comprehend and analyze data taken in through the eyes, and transform it into the stimuli we think of as sight.
As well as being directly connected, the optic nerve and the retina themselves are made of brain tissue.
As a result of the physical connection, and the fact that the most important parts of the eye are actually brain tissue that extends beyond the cranium, diseases that affect the brain can also affect the eyes. Alzheimer’s disease and Parkinson’s disease, two of the many causes of dementia, are themselves caused by damage to brain tissue. While the signs of this in the brain itself are largely in the form of cognitive impairment and other symptoms of dementia, research indicates that there might be related yet different symptoms in the retina and optic nerve as well.
How eyes might act as early warning signs for dementia
An early diagnosis of dementia can be hugely valuable, allowing treatment to begin and slowing the progress of the condition. With an early diagnosis, people with dementia can live meaningful and productive lives for years, and avoid many of the worst aspects of the disease.
Early diagnosis lets the patient be more involved in their own care and treatment. Early treatment is more effective, and there are more choices that someone with dementia can make. It also helps caregivers and loved ones, by giving them more time to plan, and more options. As a result, identifying signs of dementia through the eyes is an exciting possibility.
Scientists have already identified links between the eyes and various other conditions, and eye exams are being used to help diagnose a number of other ailments, including cardiovascular disease, stroke, diabetes, and various cancers.
Given the links between the eyes and the brain explained above, it is perhaps unsurprising that signs of dementia may be able to be seen in the retina.
There are currently a number of different ways that neuroscientists and eye doctors are attempting to identify the relevant biomarkers and plaques associated with Alzheimer’s disease and Parkinson’s disease.
A quick and common test called optical coherence tomography (OCT) may be able to spot changes in the retina caused by degeneration of brain tissue. The equipment needed to do this test is cheap and readily available, as it is already in use by most opthamologists for other diagnoses.
Another more complex (yet at the same time delightfully simple) idea is called fluorescence lifetime imaging, a scan that lights up beta-amyloid, a biomarker of Alzheimer’s, in the retina. The technique is enhanced by the consumption of excess amounts of curcumin (turmeric) which is attracted to beta-amyloid, and conveniently glows yellow under fluorescent light!
A final technique is to take high-resolution photos of the microscopic blood vessels in the back of the eye, looking for thinning of the retina’s ganglion cell layer or changes to the blood vessels in the retina that might be mimicking similar changes in the brain.
Of course, these signs do not guarantee a diagnosis of dementia, and not everyone exhibiting the biomarkers will go on to suffer from Alzheimer’s or Parkinson’s. However, in the same way as something like high blood sugar, they offer a warning light, a yellow alert perhaps, and could be a catalyst for further, more definitive tests. And these cheap retinal scans could be transformational in an industry where current methods for identifying signs of dementia can cost upwards of $3,000!
Common eye conditions that could be linked to dementia
As well as the changes in the retina and biomarkers associated with dementia, there are a number of eye diseases and conditions that could occur as a result of Alzheimer’s or Parkinson’s, or could be associated with the neurodegeneration that comes with dementia.
Specifically, research indicates that older adults exhibiting age-related macular degeneration, cataracts, and diabetes-related eye disease are often more likely to suffer from dementia as well.
Further research shows that patients exhibiting age-related macular degeneration are 26% more likely to suffer from dementia, with cataracts showing an extra 11% likelihood, and diabetes-related eye disease indicating a huge 61% higher chance. Interestingly, glaucoma sufferers do not seem to show a link to Alzheimer’s or Parkinson’s, but do present a higher risk of vascular dementia, which usually occurs after a stroke.
Studies into the link between eye conditions and dementia are still in the early stages - we can’t categorically describe them as windows into the brain just yet! But as this article shows, there is plenty to be excited about and hopeful for in the future.
Whether biomarkers linked to the early stages of dementia, or eye disease caused by or leading to brain tissue degeneration, it seems extremely likely that the eyes do offer a far simpler way to get a head start on a dementia diagnosis. If progress continues and cheap, easy-to-administer eye tests can give an indication of an increased likelihood of dementia in the future, then we can significantly improve treatment and prevention, and make a vast improvement in the quality of life of people with dementia.
If you would like to find out more about what can be done to provide more effective support and care for a loved one with dementia, get in touch with Senior Helpers. We offer a wide variety of senior care services in the Orlando area, from in-home care to personalized care in an assisted living facility.
Our tailored services can provide family carers with the support and assistance they need to provide the best level of treatment for their loved ones suffering from dementia, from companionship to in-depth specialized medical care. Visit our website or get in touch directly, and we will do our best to help you provide all the care your loved ones need.