Heart condition detected from eye scans four years before diagnosis
Eye scans may reveal retinal changes linked to atrial fibrillation about four years before hospital diagnosis, a study of more than 90,000 people found.
Atrial fibrillation is the most common heart rhythm disorder and affects more than 1.5m people in the UK.
It raises the risk of stroke, heart failure and death. Because it can occur intermittently, it may be missed on a standard electrocardiogram (ECG).
Senior author Dr Siegfried Wagner, from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust, said: “This large-scale analysis shows that retinal imaging can pick up on structural changes within the eye that are clearly linked to atrial fibrillation.
“For patients, the value of this kind of eye imaging is that it is easy to access, quick and doesn’t involve any invasive procedures.
“Although not intended to replace ECG-based diagnosis, retinal imaging could act as a complementary tool, catching those most at risk of atrial fibrillation before it causes real harm.”
The study, led by researchers at University College London and Moorfields, examined whether retinal imaging used in optometry practices and hospital eye clinics could help identify people with the condition before a stroke or heart attack.
Researchers analysed optical coherence tomography scans and colour retinal photographs from two datasets.
The AlzEye dataset included more than 50,000 Moorfields Eye Hospital patients, of whom 5,735 already had atrial fibrillation. A UK Biobank cohort included around 40,000 participants, with 526 cases of the condition.
Across both datasets, people with atrial fibrillation consistently had a thinner macular ganglion cell and inner plexiform layer, or mGCIPL.
This layer at the back of the eye contains nerve cells connecting the eye to the brain. The thinner it was, the more likely a person was to have been diagnosed with atrial fibrillation.
Among people who did not have the condition when their retinal images were taken, those who later developed it had thinner mGCIPL layers on average four years before presenting to hospital.
The association remained after researchers accounted for age, sex, ethnicity, hypertension, diabetes, smoking and alcohol use.
The findings suggest retinal changes may be detectable before a clinical diagnosis, at a stage when atrial fibrillation has no symptoms.
The researchers propose that the thinning could reflect mini strokes in the brain that typically occur as a result of atrial fibrillation before diagnosis. They suggest reduced blood flow to retinal nerve cells following such strokes could contribute to the changes.
Lead author Dr Josef Huemer, from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust, said: “If confirmed in further research, our findings raise the possibility that routine eye examinations could, in future, help identify people who would benefit from closer cardiac assessment, potentially enabling earlier treatment with therapies known to reduce the risk of stroke.”
The study adds to research into oculomics, the use of high-resolution eye images to identify signs associated with diseases elsewhere in the body.
The UCL and Moorfields team has previously identified markers linked to conditions including Parkinson’s disease, Alzheimer’s disease, schizophrenia, cardiovascular disease and stroke.
