On Sunday, 29 September the World Heart Federation’s World Heart Day shines a light on the international impact of cardiovascular disease (CVD), which remains the number one killer around the globe.
According to The Heart Research Institute CVD, which includes heart attack, stroke and heart failure, makes up almost 25 percent of deaths in Australia, with one person dying every 12 minutes from the disease.
However, 80% of premature deaths from CVD are preventable.
From an ocular perspective, the eye is the only place in the body where the live action of blood vessels, nerves and connecting tissue can be seen without relying on an invasive procedure.
This is why optometrists are often able to detect health conditions – like high blood pressure and high cholesterol – that are often linked to increased heart disease risk before any symptoms or, even worse, life-threatening events occur.
How early signs of heart disease can appear in the eyes
A recent study from UC San Diego Health and Shiley Eye Institute identified that people with heart disease tend to have their retinas marked by evidence of eye stroke.
This creates a mark (called a retinal ischemic perivascular lesion (RIPL) for those who are partial to scientific terminology) which can be spotted during a comprehensive eye examination by using an imaging tool called optical coherence tomography, or OCT.
What is an eye stroke?
An eye stroke, also called retinal artery occlusion, happens when blood flow to the retina is blocked or reduced.
The retina needs a constant supply of oxygen and nutrients to function properly, so when a blockage occurs, the tissue starts to die.
This can lead to sudden vision loss or the appearance of dark spots in your vision.
There are two main types of eye strokes:
- Central retinal artery occlusion (CRAO) is when the main artery supplying blood to the retina becomes blocked. It can cause severe and sudden vision loss in one eye.
- Branch retinal artery occlusion (BRAO) occurs when one of the smaller arteries branching from the main retinal artery is blocked. It typically causes partial vision loss.
The symptoms of an eye stroke can come on suddenly and may include:
- Sudden vision loss in one eye which might be partial or complete
- Blurry or distorted vision without any obvious cause
- Dark spots, shadows or a "curtain" appearing over part of the visual field (which can also be symptoms of an unrelated condition, retinal detachment)
- Loss of peripheral vision (the ability to see things out of the corners of your eyes)
These symptoms can develop over a few minutes to a couple of hours.
Since an eye stroke is an emergency, immediate medical attention is crucial to prevent permanent vision loss.
How does CVD affect the eyes?
Heart disease can impact the eyes in several ways, primarily by affecting blood flow.
Since the eyes rely on a network of tiny blood vessels, any issues with circulation or blood pressure can lead to eye problems.
Here’s how heart disease might affect your eyes.
Hypertensive retinopathy
Hypertensive retinopathy occurs when high blood pressure damages the small blood vessels in the retina, leading to issues like bleeding, swelling and narrowing of the vessels. This can impair vision, particularly if the swelling affects the macula.
In some cases, damaged vessels may leak fluid or burst, causing more severe problems like retinal haemorrhages or cotton wool spots (small white patches indicating poor blood supply).
Symptoms can range from blurred vision to sudden vision loss, but early stages may go unnoticed. Managing blood pressure and having regular eye exams are key to preventing or slowing its progression.
Diabetic retinopathy
Diabetic retinopathy is a complication of diabetes where high blood sugar damages the small blood vessels in the retina, leading to vision problems.
In the early stages, known as non-proliferative diabetic retinopathy (NPDR), these vessels may leak fluid or blood, causing swelling and blurred vision.
In more advanced stages, proliferative diabetic retinopathy (PDR), new abnormal blood vessels grow, which can bleed and cause severe vision loss or retinal detachment.
People with both diabetes and heart disease are at higher risk. Managing blood sugar, blood pressure, and cholesterol, along with regular eye exams, is essential to prevent or slow its progression.
Fluid build up
Fluid buildup from heart problems, such as congestive heart failure, can lead to swelling in the eyes, particularly in the macula, the part of the retina responsible for clear vision.
This condition, called macular oedema, occurs when fluid leaks into the retinal tissue, causing blurred or distorted vision.
People with heart issues that cause poor circulation or fluid retention may experience this as part of a broader swelling in the body.
Managing the underlying heart condition and fluid retention is key to reducing the risk of eye-related complications.
Treatment for macular oedema may include medications, laser therapy or injections to reduce swelling in the eye.
Regular eye exams are important to monitor any changes in vision that may be linked to heart or circulatory problems.
To book in an eye examination, use our Find an Optometrist search tool to locate your nearest optometrist today.
World Heart Day resources can be found here.
