Eye scans detect atrial fibrillation up to 4 years before diagnosis

A routine eye scan might soon catch a dangerous heart condition years before it announces itself with a stroke or collapse. Researchers at University College London and Moorfields Eye Hospital have found that the retina—that thin tissue lining the back of the eye—bears structural marks of atrial fibrillation long before a patient or their doctor knows the condition exists. The discovery, published in PLOS Digital Health, analyzed retinal imaging from more than 90,000 people and found a consistent pattern: those with atrial fibrillation showed measurable thinning in a specific nerve layer at the back of the eye, compared with people without the condition.

Atrial fibrillation is the most common heart rhythm disorder in the UK, affecting more than 1.5 million people. The condition causes the heart's upper chambers to beat irregularly, substantially raising the risk of stroke, heart failure, and death. The problem is that it often comes and goes unpredictably. A standard electrocardiogram, the usual diagnostic tool, may miss it entirely if the heart happens to be beating normally at the moment of testing. As a result, many people live with undiagnosed atrial fibrillation until something catastrophic happens—a stroke, a heart attack, a medical emergency that forces the condition into the open.

The research team examined two large datasets of eye imaging. The first, from Moorfields Eye Hospital, included over 50,000 patients, of whom 5,735 had atrial fibrillation. The second, from the UK Biobank, contained around 40,000 participants, with 526 cases of atrial fibrillation. Using optical coherence tomography scans and color retinal photographs, the researchers measured the thickness of the macular ganglion cell and inner plexiform layer—a band of nerve tissue at the back of the eye that connects visual signals to the brain. In both datasets, people with atrial fibrillation consistently showed thinning in this layer. The thinner the layer, the more likely the person had the condition.

What made the finding more striking was its predictive power. Among patients who had no atrial fibrillation when their eye scans were taken, those who later developed the condition had already shown thinner nerve layers—on average four years before they presented to a hospital with symptoms. This held true even after researchers accounted for age, sex, ethnicity, high blood pressure, diabetes, smoking, and alcohol use. The retinal changes appeared to precede clinical diagnosis, suggesting they might flag the condition at a stage when a person feels nothing wrong.

The researchers propose that the thinning reflects mini strokes occurring in the brain as a consequence of atrial fibrillation—small clots that form when the heart beats irregularly and blood pools. These strokes may reduce blood flow to the retinal nerve cells, causing them to shrink. If that mechanism is correct, the eye scan would be detecting not just the heart condition itself but evidence of the damage it is already doing.

Dr. Siegfried Wagner, a senior author at the UCL Institute of Ophthalmology and Moorfields, emphasized the practical appeal of the approach. Eye imaging is accessible, quick, and non-invasive—no needles, no hospital admission, no waiting for results. It would not replace the electrocardiogram as a diagnostic tool, but it could work alongside it, flagging people at highest risk so they receive closer cardiac monitoring and earlier treatment with medications known to reduce stroke risk.

The human stakes became concrete in the story of John Brewer, a Moorfields patient who discovered his atrial fibrillation in the most jarring way possible: on the operating table during a cataract surgery. The surgical team noticed his heart rhythm was irregular, paused the procedure, and ran an ECG that confirmed atrial fibrillation. The discovery was distressing for him and his wife. A routine retinal scan at one of his regular eye appointments might have caught it years earlier, in a calm office setting rather than an operating theatre.

This research is part of a broader scientific movement called oculomics—the use of high-resolution eye imaging to detect systemic disease. The same team has already identified early markers for Parkinson's disease, Alzheimer's disease, schizophrenia, cardiovascular disease, and stroke. The work has been made possible by the INSIGHT Eye and Oculomics Health Data Research Hub at Moorfields, which holds over 30 million eye images linked to medical records, the world's largest collection of its kind. If these findings hold up in further research, the implication is clear: the eye exam you schedule for your vision might soon tell you something far more important about your heart.