From Monday 5th August until Sunday 11th of August, Stroke Foundation Australia's initiative, National Stroke Week will aim to save lives and enhance stroke recovery by raising awareness and creating conversation about stroke; one of the leading causes of adult disability and death nationally every year.
With close to 30,000 people suffering from stroke in Australia per annum, understanding the warning signs and effects of stroke can be crucial for early detection and prevention.
In this article we dive into what causes stroke and its aftereffects, how a stroke can impact vision and the signs your eyes might show that could help predict stroke risk.
What is a stroke?
A stroke occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting enough oxygen and nutrients. This causes brain cells to begin dying at a rate of around 1.9 million cells per minute.
Strokes can be broadly categorised into two main types:
- Ischaemic stroke is the most common type of all strokes. It occurs when a blood clot blocks or narrows an artery leading to the brain. The clot can form in the brain's arteries or travel from another part of the body to the brain's arteries
- Haemorrhagic stroke occurs when a blood vessel in the brain bursts, leading to bleeding in or around the brain. It can be caused by conditions such as high blood pressure, aneurysms, arteriovenous malformations (AVMs) or trauma
There are also transient ischaemic attacks (TIAs), sometimes called "mini strokes," which are temporary periods of decreased blood flow to the brain. TIAs are often early warning signs of a future stroke and should not be ignored.
Effects of a stroke
The effects of a stroke can vary widely depending on the severity and location of the stroke in the brain. Some people may recover completely, while others may live with disabilities; almost half a million Aussies live with the effects of stroke.
Common effects include:
- Paralysis or weakness often occurring on one side of the body affecting the face, arm, and leg
- Difficulty walking, loss of coordination and problems with balance
- Extreme tiredness and reduced stamina
- Difficulty remembering events, learning new information or recalling facts
- Difficulty focusing on tasks or sustaining attention
- Problems with planning, reasoning, problem-solving and decision-making
- Difficulty with speaking, understanding speech, reading or writing
- Slurred or slow speech due to weakness or lack of coordination in the muscles used for speaking
- Feelings of sadness, hopelessness or excessive worry
- Uncontrolled emotional responses such as laughing or crying inappropriately
- Altered behaviour, mood swings or changes in personality
- Chronic pain or unusual sensations (e.g., tingling, numbness) in affected areas
- Lack of awareness or attention to one side of the body (often the left side with right-brain strokes)
- Difficulty swallowing, which can lead to choking, aspiration and malnutrition
According to the Heart Research Institute, around one in five people will die within 28 days of a stroke and one in three people will die within a year. However, more than 80% of strokes can be prevented.
How stroke can affect vision
Not only can trouble seeing in one or both eyes be an indicator of stroke, but vision can also be significantly affected post-episode.
“Visual field loss is the most common visual problem after stroke. A person might lose sight in one half of their visual field, either in both eyes and in just one eye. Imagine looking straight ahead and only seeing what’s to your left or right – it’s disorienting and dangerous, especially when moving around or driving,” said Lyn Hsieh, optometrist and National Professional Services Advisor at Optometry Australia.
In addition to visual field loss, double vision (diplopia) can occur when a stroke affects the parts of the brain that control eye movements. This can make everyday tasks like reading or walking challenging.
A stroke can also affect the clarity of your vision, making things look blurry. This can happen if the stroke impacts the brain regions responsible for visual processing.
If you experience sudden vision loss, double vision, or any other severe symptoms of stroke call 000 immediately. Early intervention can make a significant difference in outcomes.
Signs your eyes might show in predicting stroke risk
While changes to your vision may typically occur after a stroke, your eyes can also give warning signs that you might be at risk for a stroke.
Here are some indicators to watch out for:
- Transient vision loss (TVL) is when you temporarily lose vision in one eye.
“The experience of TVL might feel like a curtain coming down over your eye. This can be a warning sign of a potential stroke, as it indicates a temporary lack of blood flow to your eye.”
- If the blood vessels in your retina become blocked, it can cause retinal blood vessel occlusions and result in sudden vision loss.
“This problem with blood flow indicate a potential stroke risk.”
- Hollenhorst plaques are tiny cholesterol deposits that can be seen in the blood vessels of your retina during an eye exam.
“The presence of cholesterol deposits can suggest a higher risk of stroke, as they may indicate that plaques are breaking off and traveling through your bloodstream.”
- High blood pressure, if left untreated can sometimes cause damage the blood vessels in your retina, leading to hypertensive retinopathy.
“This condition is a sign that your blood pressure is dangerously high, which significantly increases your risk of stroke.”
How to protect yourself against stroke
Without action, it is predicted that by 2050 the number of first-ever strokes experienced by Australians annually will increase to 50,600 – which is equivalent to one stroke every 10 minutes – and there will be 819,900 survivors of stroke living in the community.
Keeping conditions like high blood pressure, diabetes and high cholesterol under control can significantly reduce your risk of stroke.
Eating a balanced diet, exercising regularly and not smoking are lifestyle habits you can adapt to cut the likelihood of experiencing stroke as well.
Getting your eyes checked regularly by an optometrist can also mean early signs of problems that might indicate a stroke risk are spotted early; understanding the connections between strokes and vision can be a lifesaver.
It is recommended that every Australian, from the time they start primary school, pay their optometrist a visit at least every year until age 18, then every two years as an adult, and then yearly again after turning 65, unless otherwise directed, for a comprehensive eye examination.
To schedule an appointment with your local optometrist today, use our easy search tool here.
