OCTage: monitoring the ageing brain via Optical Coherence Tomography of the eyes

Age-related changes in the brain are one of the most important determinants of how our lives change with age. The only part of the brain that can be viewed directly and non-invasively is the retina at the back of the eye. The retina is actually an outgrowth of brain tissue, and thus changes in the brain due to age and disease are often reflected in the eyes.

Optical Coherence Tomography (OCT) is a relatively new technique which can image the 3D structure of living retinal tissue in near microscopic detail. OCT is already widely used to diagnose, assess and monitor eye conditions such as glaucoma, as well as monitor how systemic conditions such as diabetes are affecting the eyes. However, we believe that OCT imaging of the eyes has much greater potential to monitor brain health as well. We already know that retinal structure reflects demographic factors such as age, sex and ethnicity, and that particular neurodegenerative conditions, such as Alzheimer's and Parkinson's disease, are associated with changes in the thickness of the different tissue layers within the retina. We are excited by the possibility of using OCT scans to monitor brain health as people age.

Achieving this will require detecting and interpreting very subtle changes in retinal structure, far harder to detect than the gross changes caused by eye diseases like glaucoma or age-related macular degeneration. Changes of concern will have to be discriminated from normal variability within diverse populations. And there is already a shortage of ophthalmologists trained to make even relatively straightforward diagnoses from OCT images.

We propose to address this by using artificial intelligence (AI) techniques to recognise and characterise the changes that occur in the retina as people age, both in healthy ageing and in the presence of pathologies such as Parkinson's. Our vision is that one day, people could be offered an OCT scan as part of over-50s health check. These scans are cheap (around...