Can your eye health predict heart problems later in life?
05 August 2021
Eyes are the window to your heart
Cardiovascular disease is the number one cause of death globally and, although you might not think it, your eyes actually hold a multitude of clues about your cardiovascular health. A routine eye examination can reveal underlying health problems with a simple glance at the blood vessels at the back of your eye.
When you have high blood pressure – a key risk factor for cardiovascular disease – the blood vessels in your eyes, specifically in the retina, change in ratio or shape, and there may even be small blood clots in the eye. Even while these issues are present, your vision can still be completely unaffected and, without an eye test, you may remain completely unaware of any cardiovascular problems developing.
Generally, the greater the curvature of the arteries in your retina, the higher your pulse pressure, which can indicate the development of cardiovascular disease. When the blood pushes too strongly against the artery walls, it can cause damage to the eye’s main blood supply, in turn leading to retinopathy. Symptoms of retinopathy include blurred vision, bleeding in the eye, or a retinal stroke. It’s clear that attending regular eye tests has benefits far beyond checking your vision.
High cholesterol and blocked arteries
Another condition caused by high blood pressure is blocked arteries. Blocked arteries are typically caused by high cholesterol, particles of which can build up on the walls of your arteries. The accumulation of cholesterol can prevent blood from flowing through to your brain or retina, damaging your vision. In some cases, this can lead to blindness and, in terms of issues unrelated to vision, it has also been known to cause tissue damage, strokes or death.
It is rare for a vascular problem in any part of the body to not be seen in the eye’s blood vessels. There was a case study featuring a Greek patient, with known high cholesterol levels, who experienced blurred vision. Upon examination, it was found that his right internal carotid artery was 80% blocked by cholesterol plaque build-up. This artery is in the neck and supplies blood to the brain, therefore affecting vision. For the majority of patients who have a severe carotid artery blockage, their only symptom might be visual loss. Again, this highlights the importance of regular eye tests as detecting these issues in a timely manner can save your vision.
The link between diabetes and eye health
While we’re discussing the effects of cardiovascular health on your eyes, we should also take a look at diabetes and as it is very often diagnosed following an eye test. Diabetes is a condition where the affected person has blood sugar levels higher than usual, impacting multiple organs including the eyes. Diabetes has a very slow onset so your blood sugar could be higher than the ideal level for an extended period before you start to feel the effects of the condition.
One of the most common complications of diabetes is diabetic retinopathy. High blood sugar levels can lead to issues with small blood vessels in the eyes. In turn, this can result in diabetic retinopathy which, in severe cases and if left untreated, can lead to blindness. Symptoms of diabetic retinopathy include:
- gradually worsening vision
- sudden vision loss
- shapes floating in your field of vision (floaters)
- blurred or patchy vision
- eye pain or redness
Predicting future cardiac events
In 2018, Google and Verily, its health tech subsidiary, published a study which demonstrated that their algorithm can accurately predict a patient’s risk for cardiovascular disease using retinal scans. Although the algorithm can’t detect actual heart disease, it can pick up on risk factors commonly associated with heart failure. The study was produced using 300,000 images of eyes and predicted which patients were likely to experience a cardiac event in the next five years with 70% accuracy. At the moment, this is usually predicted by using a blood test which has a 72% rate of accuracy. Perhaps these retinal scans are the future of predicting cardiac disease and detecting risk factors in patients?
Having regular eye tests is crucial to detect any issues with your vision and optical health, but also to discover any abnormalities that could point toward cardiovascular disease. The sooner these issues are detected and treated, the better the chance of saving your vision or, in more advanced cases, your life. Don’t delay your next eye test!
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