Eye scans detect signs of Parkinson’s up to 7 years before diagnosis

The research, published in the journal Neurology, was carried out by a team at Moorfields Eye Hospital and UCL Institute of Ophthalmology.

They studied huge datasets of detailed eye scans using AI to identify subtle changes that indicate the presence of Parkinson’s, on average 7 years before clinical diagnosis.

This technique is not yet ready to predict whether an individual will develop Parkinson’s, but holds great potential to help identify people at risk of developing the condition in the future.

Are eye scans the key to early diagnosis?

Doctors have known for a long time that the eye can act as a ‘window’ to the rest of the body, giving a direct insight into many aspects of our health.

The use of data from eye scans has previously revealed signs of other neurodegenerative conditions, including Alzheimer’s, multiple sclerosis and, most recently, schizophrenia.

Eye scans and eye data have also been able to reveal if someone is prone to high blood pressure; cardiovascular disease including strokes; and diabetes.

High-resolution images of the retina are now a routine part of eye care. In particular, a type of 3D scan known as ‘optical coherence tomography’ (OCT),  is widely used in eye clinics and high-street opticians.

In less than a minute, an OCT scan produces a cross-section of the retina (the back of the eye) in incredible detail, down to a thousandth of a millimetre.

These images are extremely useful for monitoring eye health, but their value goes much further, as a scan of the retina is the only non-intrusive way to view layers of cells below the skin’s surface.

In recent years, researchers have started to use powerful computers to accurately analyse large numbers of OCTs and other eye images, in a fraction of the time it would take a human.

Using a type of AI known as ‘machine learning’, computers are now able to uncover hidden information about the whole body from these images alone.

A step towards preventing Parkinson’s in the future

Claire Bale, Associate Director of Research at Parkinson’s UK, comments:

"Parkinson’s is a condition that develops gradually over time and research suggests damage could begin many years before symptoms appear.

"Intervening earlier to stop the loss of precious brain cells is the key to preventing the condition. Parkinson’s UK and others are already funding clinical trials exploring medications and lifestyle approaches to investigate their potential for stopping, slowing or preventing Parkinson’s.

"This research offers hope that eye scans could be used to identify people at risk of developing Parkinson’s to enable early treatment. And because the eye scans analysed in this study are non-invasive, and already in routine use, this could be easily put into practice in the NHS."