Eye tests may reveal more than we think

Jan 11: Information about the latest medications, theories, charities, new methods of diagnosis, causes of disease or after-care drops into my inbox daily and it is always fascinating to see how medical specialties cross over each other in research.

Charles Bonnet Syndrome is a little-known condition that produces silent visual hallucinations in some people who have lost 60 per cent of vision. It is a need for early diagnosis of potential sight loss and the importance of eye tests.

The eye is a useful organ to look at to not only check for signs of eye disease, but also for diseases elsewhere in the body.

It has been realized just how much information about a person’s health can be found in the eye and work by researchers from University College, London’s Institute of Ophthalmology.

The study points to yet another reason for regular eye tests. The researchers have been focusing not on the early diagnosis of eye disease but on a progressive disease of the nervous system, Parkinson’s.  Their discovery that changes in the retina may reveal the presence of Parkinson’s well in advance of the development of muscle stiffness and tremors may lead to a non-invasive and low cost eye test for early diagnosis, intervention and treatment.  If successful, this might also be a way to monitor patients’ responses to treatment.

Dr Susan Blakeney, clinical adviser for the College of Optometrists said: “This is exciting news.  Parkinson’s affects one in 500 people, so it would be great for optometrists to be able to play a part in its early diagnosis.  The eye is the only transparent part of the body and the retina is an extension of the brain, so the eye is a useful organ to look at to not only check for signs of eye disease, but also for diseases elsewhere in the body.  A regular sight test should form a part of everyone’s healthcare regime.”

Fruit flies – whose role in medical research I first encountered during a visit to Breakthrough Breast Cancer (now Breast Cancer Now’s) research centre in Fulham, west London – are also playing a part in helping to identify Parkinson’s disease. Researchers at York University detected that fruit flies – which share 60 per cent of the genes associated with humans – carrying different mutations of Parkinson’s have distinct patterns of visual responses. Reactions to visual patterns were registered and compared to fruit flies without mutations. The data collected allowed 85 per cent accuracy in detecting mutations in unknown flies. Dr Ryan West – the study’s lead author and a postdoctoral research scientist at York University’s Department of Biology – said: “We hope this may be translatable to the clinic where changes in vision may provide an early indication of early-onset Parkinson’s”.

There are, currently, no laboratory tests to identify Parkinson’s disease and diagnosis relies on medical history and neurological examinations. However, the charity Parkinson’s UK funds research and gives tremendous support to those with the disease.

It is evident that eye tests – too often overlooked – reveal so much more than simply the state of the eye and are as vitally important as any other health screening. AGENCIES