The eyes are the window to the soul, so the saying goes, and to a doctor, the eyes can reveal a lot about what’s going on ­inside your body – good and bad.

Startling new research now reveals markers in the eyes can show up Parkinson’s seven years before ­symptoms appear. It’s the largest study to date on retinal imaging in Parkinson’s disease, and this is the first time such markers have been found.

Birmingham professor, Alastair Denniston, has used ­artificial ­intelligence to identify these markers in eye scans. To achieve this, his team analysed the AlzEye (eye scans) and Biobank databases to ­identify subtle markers of Parkinson’s, despite its relatively low ­prevalence in the ­population (0.1-0.2%).

This research has come up with a new word, oculomics, where eye scans reveal retinal biomarkers for conditions such as Alzheimer’s, multiple sclerosis and schizophrenia. Eye scans and eye data have also successfully pinpointed higher risks of high blood pressure, cardiovascular disease, strokes and diabetes.

Oculomics uses techniques like OCT, (optical coherence tomography), a type of 3D scan used in eye care. OCT is amazing. In less than a minute, it provides a detailed cross-section of the retina at the back of the eye, so researchers can examine layers of cells with incredible precision – down to a thousandth of a millimetre – in a non-invasive way.

This means the eyes can be monitored while gaining valuable insights into the overall health of the body. This project, led by Siegfried Wagner, principal investigator, and Pearse Keane of Moorfields Eye Hospital and UCL Institute of Ophthalmology, is an example of research collaboration between the NIHR (National Institute for Health and Care Research), Biomedical Research Centres at Moorfields, Birmingham University, Oxford University, University College Hospital and Great Ormond Street.

Study author Prof Denniston of Birmingham University, ­Moorfields and UCL says: “This project ­demonstrates the potential for eye data, harnessed by the technology, to pick up signs and changes too subtle for humans to see. We can now detect very early signs of Parkinson’s, opening up new possibilities for treatment.”

Siegfried Wagner added: “I continue to be amazed by what we can discover through eye scans. While we are not yet ready to predict whether an ­individual will develop Parkinson’s, we hope this method could soon become a pre-screening tool for people at risk. Finding signs 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.”