Retinal Artery Occlusion (RAO)
Retinal Artery Occlusion (RAO) occurs when an artery supplying blood to the retina becomes blocked. Because the retina depends on a continuous supply of oxygen-rich blood, a blockage can cause sudden vision loss and requires urgent medical assessment.
Understanding Retinal Artery Occlusion
Retinal Artery Occlusion (RAO) is an acquired retinal vascular condition that occurs when an artery supplying blood to the retina becomes blocked. This interrupts the flow of oxygen-rich blood to retinal tissue and can cause sudden, potentially significant vision loss. The impact depends on the location and extent of the blockage.
There are two main types of RAO:
- Central Retinal Artery Occlusion (CRAO): A blockage of the main artery supplying the retina, which can affect a large area of retinal tissue and cause severe vision loss.
- Branch Retinal Artery Occlusion (BRAO): A blockage of a smaller retinal artery branch, affecting the area of the retina supplied by that vessel. The impact on vision depends on whether the macula, responsible for detailed central vision, is affected.
RAO is a medical emergency. Sudden vision loss requires immediate medical assessment, as prompt evaluation is also important to identify and manage any underlying vascular or cardiovascular causes.
Retina International works with people affected by retinal conditions, patient organisations, researchers, clinicians and healthcare partners worldwide to improve awareness, support access to care and ensure patient experiences inform research and innovation.
2 main types
RAO is generally classified as central or branch retinal artery occlusion.
Sudden onset
Vision loss can occur suddenly, often affecting one eye.
An eye emergency
Sudden vision loss from suspected RAO requires urgent medical assessment.
How Can RAO Affect Vision
Sudden vision loss
Vision may become significantly reduced over a short period of time, usually affecting one eye.
Missing areas of vision
A person may notice a dark or blank area where part of their vision is reduced or absent.
Reduced visual clarity
Vision may become less sharp, making it harder to see objects and details clearly.
Reduced contrast
Differences between light and dark areas may become harder to distinguish.
Changes in colour vision
Colours may appear less vivid or more difficult to distinguish.
Impact on daily activities
Vision loss may affect reading, mobility, recognising faces, driving and other everyday tasks.
Identifying Retinal Artery Occlusion
Retinal examination
An eye specialist examines the retina for signs of reduced blood supply and retinal damage.
OCT imaging
OCT provides detailed images of the retina and can help identify changes caused by reduced blood flow.
OCT Angiography
OCTA can provide information about blood flow and the retinal vascular network.
Fluorescein angiography
This imaging test can help identify areas where retinal blood flow is reduced or blocked.
Cardiovascular assessment
Blood pressure, diabetes, cholesterol and other vascular risk factors may be assessed to help identify possible causes and reduce future risk.
Urgent Assessment
Urgent eye assessment
Rapid evaluation is important because RAO can cause permanent retinal damage.
Vascular risk management
Conditions such as high blood pressure, diabetes and high cholesterol may need to be assessed and managed.
Cardiovascular assessment
Further medical evaluation may be recommended to identify underlying vascular problems and reduce the risk of future events.
Vision rehabilitation
Rehabilitation can help people adapt to lasting changes in vision and maintain independence.
Visual aids and support
Magnification, accessibility tools and other aids may help with everyday activities affected by vision loss.
Supporting independence
Vision loss following RAO can affect independence, mobility, work and daily activities. Vision rehabilitation and appropriate visual aids can help people adapt to changes in sight and maintain independence.
Advancing the future of RAO Treatment
Retinal protection — Research is investigating ways to protect retinal cells from damage caused by reduced oxygen and blood flow.
Restoring retinal function — New approaches are being explored to help restore or improve vision following retinal damage.
Earlier intervention — Better understanding and detection of RAO may help support faster assessment and treatment in the future.
Information and community support
Take the Next Step
Early recognition, prompt treatment, ongoing monitoring, and continued research are helping more people preserve their vision and maintain independence.
Through collaboration between patients, researchers, clinicians, and communities worldwide, Retina International continues to support progress towards a future where retinal conditions are better understood, better treated, and more effectively managed.
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