Behind your eyes: The link between eye and heart health

They say that your eyes are the window to your soul. While we can’t speak to the veracity of that, there is solid research to show that they are a window to your heart health. Problems and conditions that affect different parts of the body can manifest as vision and ocular health problems.

29th September is World Heart Day and, on this occasion, we wanted to highlight how you can unravel the mystery behind your eyes to detect, diagnose and prevent various heart diseases.

1. Eyes & heart: two separate organs with a strong link

Though the eyes and the heart are two very different organs, they have more in common than one might expect. Our eye’s blood vessels are closely connected to our hearts through our retina vasculature which are blood vessels arranged at the back of our eyes. This wonderful connection acts as the link between the eyes and the heart and helps detect heart problems during examinations of the different parts of the eyes.

During an eye examination, your ophthalmologist can use an ophthalmoscope to examine and analyse different parts of your eyes like the lens, pupil reflexes, retina, and optic nerve, which can reveal issues with your heart and blood vessels. In particular, arteriovenous nipping, narrowing of retinal arteries, and the dilatation of retinal veins are important signs of increased cardiovascular risk.

a) Shared risk factors & treatment

Some cardiovascular and eye diseases share underlying mechanisms. It’s no surprise that the risk factor for many heart diseases like arteriosclerosis & systemic hypertension and eye diseases such as retinal vein occlusions are common. What’s more, in addition to having a strong underlying pathological process, they may benefit from the same type of treatment.

Studies on links between carotid diseases and eye diseases show that patients with atherosclerosis detected in the carotid vessels were more likely to have AMD and diabetic retinopathy. Suggesting a strong link between cardiovascular functions and risk factors, and the occurrence and progression of various eye diseases, a study published in the European Heart Journal states that “Risk factors for arteriosclerosis, such as dyslipidemia, diabetes, or systemic hypertension, are also risk factors for eye diseases such as retinal arterial or retinal vein occlusions, cataracts, age-related macular degeneration, and increases in intraocular pressure (IOP).”

2. What can an eye exam reveal about your heart condition?

These common characteristics between the two can greatly benefit if your ophthalmologist looks at the bigger picture during an eye check-up and help detect the following heart diseases:

a) High blood pressure

Hypertension, more commonly known as high blood pressure, occurs when the weight of blood against the arteries is too high. Since patients with high blood pressure rarely have physical symptoms, they don’t discover the issue until they come for an eye exam which can prevent more serious issues like a stroke or a heart attack. An eye specialist can look at the blood vessels in your eyes to detect signs of high blood pressure. An irregular size ratio between the size of the retinal arteries to veins, which normally stands at 2 to 3, indicates high blood pressure or cardiovascular risk factors. Left undetected and untreated, this can cause blood clots, bleeding in the eye, blurry vision, and even blindness.

b) Blocked arteries

Another heart-related condition that can be detected in the eye is an arterial embolism. This occurs when an embolus gets stuck in and around the retina, resulting in restricted or blocked blood flow, which can result in tissue damage, stroke, blindness, or even death.

c) Diabetes

Diabetes, which has a damaging effect throughout the body, including the heart, can too be diagnosed through an eye exam. Small changes in the blood vessels (haemorrhage) or neovascularization in the eye (retina) caused by increased blood sugar levels cause damage to the eye and loss of vision. Early detection during an eye check-up gives patients the advantage of proper and timely treatment

d) Xanthelasma

People with high levels of cholesterol may develop soft, yellowish, cholesterol-filled bumps on the skin of their eyelids. Called xanthelasmas, these growths indicate a high level of cholesterol or other levels of fats in the blood. High cholesterol levels can increase your risk of a stroke and heart attack.

e) Age-related macular degeneration is linked to cardiovascular risk

Studies prove that patients with a specific subretinal drusenoid deposits form of age-related macular degeneration (AMD) are at significant risk for cardiovascular disease and stroke. Diagnoses of this by an ophthalmologist can lead to patients seeking timely treatment and evaluation from a cardiologist.

3. Steps you can take to keep both your heart and eyes healthy

The connection between heart and eye health is irrefutable. From shared risk factors, and shared treatments to shared diagnosis, it is evident that the same issues that can damage blood vessels in your heart can also harm the tiny blood vessels that supply blood to your eye. In this scenario, it becomes important to take care of your heart to prevent any damage to your eyes. Here are a few steps you can take to keep both your heart and your eyes healthy:

a) Stop smoking: Quitting at any age can significantly reduce your risk of a stroke and prevent damage to blood vessels including those in your eyes.

b) Exercise: It is easier for a strong healthy heart to pump blood throughout the body, including the eyes.

c) Maintain a healthy weight: Excess weight puts additional stress on the heart and increases blood pressure, which can create havoc with your vision.

d) Eat healthy foods: A healthy diet can prevent many heart diseases and lower cholesterol levels, aiding the prevention of related eye diseases in the process.

e) Know your family history: Share any heart-related family history with your ophthalmologist or optometrist to make them extra careful and watch out for signs of heart problems during an eye exam.

f) Get regular eye exams: A comprehensive annual eye exam is one of the most important steps you can take to preserve your sight and overall health.

4. Conclusion- There is more to your eyes than that which meets it

The eye is the only organ in which a doctor can see the live interplay of blood vessels, nerves, and connecting tissues without resorting to any invasive procedures. Google’s AI algorithm which uses machine learning to “extract new knowledge from retinal fundus images” and predict the risk of cardiovascular events, is a major medical breakthrough in using retinal exams to determine heart health.

2.2 billion people worldwide suffer from ocular diseases, half of which can be prevented with simple lifestyle changes. For people with heart disease — the number one cause of death worldwide — early diagnosis during an eye exam, and follow-up treatment with a cardiologist, could help stave off a heart attack or stroke.