LONDON - An AI-powered eye scan could help to detect Parkinson's disease up to seven years before diagnosis, new research has found.
Researchers at University College Hospital and the Moorfields Eye Hospital used artificial intelligence to identify markers of Parkinson’s in eye scans.
It is the the largest study to date on retinal imaging in Parkinson’s disease, a neurodegenerative condition that affects 145,000 people in the UK.
In recent years this method has been used to detect other neurodegenerative conditions such as Alzheimer’s, multiple sclerosis and even schizophrenia.
"While we are not yet ready to predict whether an individual will develop Parkinson’s, we hope that this method could soon become a pre-screening tool for people at risk of disease," lead author Dr Siegfried Wagner said.
"Finding signs of a number of diseases before symptoms emerge means that, in the future, people could have the time to make lifestyle changes to prevent some conditions arising and clinicians could delay the onset and impact of life changing neurodegenerative disorders."
This news comes after a previous study found that thinking that somebody is standing behind you when they’re not could be an early sign of Parkinson’s disease.
Experiencing a strong sensation that a person is behind you, when no one really is, is known as a ‘presence hallucination’.
Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland, warned these hallucinations appear in a third of Parkinson’s patients before the onset of trembling and other motor symptoms begin. Once the motor symptoms have started, hallucinations affect half of all patients.
Writing in Nature Mental Health, experts discovered patients recently diagnosed with the disease who experience the hallucinations are more likely to have a rapid cognitive decline.
The disease is traditionally defined as a movement disorder, with typical motor symptoms including resting tremor, rigidity and slow movements, but it also leads to a wide variety of non-motor symptoms.
Celebrities with Parkinson's disease
Michael J. Fox, 61, recently shared the story behind his ongoing health battle with the condition in a Netflix documentary. He was first diagnosed with early onset Parkinson's in 1991.
Despite his acceptance of his diagnosis, he said honestly: "Parkinson’s is still kicking my ass. I won’t win at this. I will lose." But, he added, "There’s plenty to be gained in the loss."
Other celebrities who have spoken about living with Parkinson's disease include Jeremy Paxman, Ozzy Osbourne and Billy Connolly.
What is Parkinson's disease?
Parkinson's disease is a condition where parts of the brain become progressively damaged over many years, the NHS says.
It is caused by a loss of nerve cells in the substantia nigra (a part of the brain), which leads to a reduction in dopamine (known as one of the 'happy hormones').
More specifically, dopamine also helps to regulate the movement of the body, with a lack of it responsible for many of the symptoms of the disease.
Who is most at risk of Parkinson's disease?
It is unclear exactly what causes the loss of nerve cells that leads to Parkinson's, but many experts think it is a result of a combination of genetic and environmental factors.
While Parkinson's can run in families due to 'faulty genes' being passed on by a parent, it is rare for it to be inherited this way.
Parkinson's disease affects roughly one in 500 people in the UK. Most people with the condition start to develop symptoms when they're over 50. That said, around one in 20 people also first experience symptoms when they're under 40.
Men are slightly more likely to get the disease than women.
Parkinson's disease symptoms
There are three main symptoms of Parkinson's, which are:
- involuntary shaking of particular parts of the body (known as a tremor)
- slow movement
- stiff and inflexible muscles
Someone with Parkinson's disease can also experience a variety of other physical and psychological symptoms, including:
- depression and anxiety
- balance problems (this may increase the chances of a fall, which could help to explain Paxman's accident, for example)
- loss of smell (known as anosmia)
- sleeping problems (insomnia)
- memory problems.
The 'Parkinson's mask' – previously referred to by Paxman – is known as 'facial masking' or 'hypomimia', which links to the stiffness of muscles some people experience.
Nurse Linda, from the Parkinson's UK helpline, explains on the charity's website that the lack of dopamine in the brain can stop your facial muscles from working how they used to.
When this happens, people can look like they have a blank expression, even if they are experiencing a strong emotion. Having a Parkinson's mask is a common symptom and it doesn't mean someone with the condition is necessarily feeling low or depressed – they just can't use their facial muscles to correctly express themselves.
Many people with Parkinson's also report problems with apathy (lack of interest) and motivation, which means they might not respond to emotions like they used to.