For the first time, scientists have identified a marker in the retina that may lead to the development of Parkinson’s disease, and it may be detected years prior to diagnosis.
Researchers out of Moorfields Eye Hospital and University College London (UCL) conducted the largest study to date looking at retinal imaging and Parkinson’s disease, using the AlzEye dataset, a retrospective cohort of 154,830 patients aged 40 years and over, and 67,311 volunteers aged 40-69 years from the UK Biobank.
Post-mortem scan studies of patients that had developed Parkinson’s disease revealed differences in the inner nuclear layer (INL) of the retina, as well as the previously noted thinner ganglion cell–inner plexiform layer (GCIPL) compared to healthy people.
This is the first time the INL has also been implicated as a Parkinson’s risk biomarker, and the first time the deterioration in those who would go on to develop the disease could be identified so early, at around seven years before official diagnosis.
“I continue to be amazed by what we can discover through eye scans,” said lead author Dr Siegfried Wagner (UCL Institute of Ophthalmology and Moorfields Eye Hospital). “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.”
Eye scans have been used to find signs of other neurodegenerative conditions, such as Alzheimer’s disease, multiple sclerosis and schizophrenia. More recent studies have looked at how artificial intelligence-assisted eye scans can assess stroke and heart disease risk.
High-resolution, 3D optical coherence tomography (OCT) scans offer an incredibly detailed view of the retina. They’re also the only non-intrusive way to view layers of cells beneath the skin. Using AI machine learning, these images can be quickly scanned for a wide range of health alerts.
This emerging field of “oculomics” is increasingly being looked to in order to assess early risk factors for degenerative diseases ahead of time, allowing for those aforementioned lifestyle changes and other interventions.
“This work demonstrates the potential for eye data, harnessed by the technology to pick up signs and changes too subtle for humans to see,” said Alastair Denniston, professor and consultant ophthalmologist at University Hospitals Birmingham. “We can now detect very early signs of Parkinson’s, opening up new possibilities for treatment.”
Future studies are needed to determine the interactions between GCIPL and INL, and if one triggers the other’s degrading.
“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,” said Dr Wagner.
The study was published in the journal Neurology.
Source: Moorfields Eye Hospital