Retinal Vein Occlusion (RVO)
A retinal vascular condition that occurs when a vein carrying blood away from the retina becomes blocked.
Understanding Retinal Vein Occlusion
Retinal Vein Occlusion (RVO) is a retinal vascular condition that occurs when a vein carrying blood away from the retina becomes blocked.
The retina depends on a healthy blood supply to function properly. When a retinal vein becomes blocked, blood and fluid can build up within the retina, causing swelling, bleeding, and reduced retinal function. This can lead to blurred vision, distortion, and, in some cases, significant vision loss.
Retinal Vein Occlusion is one of the most common causes of vision loss related to retinal blood vessel disease, particularly among older adults. The severity and impact of vision changes depend on the location of the blockage and whether the macula—the central part of the retina responsible for detailed vision—is affected.
The two main types of Retinal Vein Occlusion are:
- Central Retinal Vein Occlusion (CRVO) – blockage of the main retinal vein as it leaves the eye.
- Branch Retinal Vein Occlusion (BRVO) – blockage of one of the smaller retinal vein branches within the retina.
Retina International works with people affected by retinal conditions, patient organisations, researchers, clinicians, and healthcare partners worldwide to improve understanding of retinal diseases, support access to care, and ensure patient experiences inform research and innovation.
What is Retinal Vein Occlusion?
Retinal Vein Occlusion occurs when a retinal vein becomes blocked, preventing normal drainage of blood from the retina.
When blood flow is interrupted:
- Pressure builds within retinal blood vessels
- Small blood vessels may leak fluid or blood
- The retina can become swollen
- Oxygen supply to retinal tissue may be reduced
The resulting damage can affect vision, particularly if the macula becomes involved.
Retinal Vein Occlusion does not usually cause complete blindness, but it can result in long-term visual impairment depending on:
- The location of the blockage
- The amount of retinal damage
- Whether macular oedema develops
- The effectiveness and timing of treatment
2 main types
RVO is classified as Central Retinal Vein Occlusion (CRVO) or Branch Retinal Vein Occlusion (BRVO).
Over 50
RVO is more common in people over age 50, although it can occur at younger ages.
Sudden vision changes
RVO often develops suddenly, causing blurred or distorted vision, dark spots, or loss of central vision.
How Retinal Vein Occlusion can affect vision
Blurred Vision
Vision may become unclear due to retinal swelling or bleeding.
Distorted Vision
Straight lines may appear:
- Bent
- Wavy
- Distorted
particularly when the macula is affected.
Loss of Central Vision
Macular involvement can cause difficulty with:
- Reading
- Recognising faces
- Seeing fine details
Dark Spots or Floaters
Bleeding inside the eye may cause:
- Spots
- Shadows
- Floating shapes
Sudden Vision Changes
RVO often develops suddenly and may be noticed upon waking or during daily activities.
Any sudden change in vision should be assessed promptly.
Identifying RVO
Comprehensive eye examination
An eye specialist examines the retina for:
- Retinal haemorrhages
- Swelling
- Blood vessel changes
Optical Coherence Tomography (OCT)
OCT provides detailed images of retinal layers and is essential for detecting and monitoring:
- Macular oedema
- Retinal swelling
- Treatment response
Fundus Photography
Retinal photographs document changes caused by the blockage and help monitor progression.
Fluorescein Angiography
This imaging test uses a dye to assess:
- Blood flow through retinal vessels
- Areas of leakage
- Blocked retinal circulation
OCT Angiography
OCTA provides detailed information about retinal blood vessels and may help assess vascular changes.
Systemic Health Assessment
Because RVO is associated with vascular risk factors, healthcare professionals may assess:
- Blood pressure
- Diabetes risk
- Cholesterol levels
- Cardiovascular health
How Central Retinal Vein Occlusion can affect vision
Widespread retinal haemorrhages
Blocked blood flow can cause blood to leak from retinal blood vessels, leading to bleeding across the retina.
Retinal swelling
Fluid can build up in the retina, causing swelling and affecting how well the retina functions.
Reduced oxygen supply
The blockage can limit normal blood flow and reduce the amount of oxygen reaching retinal cells.
Macular oedema
Fluid can collect in the macula, causing blurred or distorted central vision and making tasks such as reading and recognising faces more difficult.
Identifying Central Retinal Vein Occlusion
Comprehensive eye examination
An eye specialist examines the retina for:
- Retinal haemorrhages
- Swelling
- Blood vessel changes
Optical Coherence Tomography (OCT)
OCT provides detailed images of retinal layers and is essential for detecting and monitoring:
- Macular oedema
- Retinal swelling
- Treatment response
Fundus Photography
Retinal photographs document changes caused by the blockage and help monitor progression.
Fluorescein Angiography
This imaging test uses a dye to assess:
- Blood flow through retinal vessels
- Areas of leakage
- Blocked retinal circulation
OCT Angiography
OCTA provides detailed information about retinal blood vessels and may help assess vascular changes.
Systemic Health Assessment
Because RVO is associated with vascular risk factors, healthcare professionals may assess:
- Blood pressure
- Diabetes risk
- Cholesterol levels
- Cardiovascular health
How Branch Retinal Vein Occlusion (BRVO) can affect vision
Blurred vision
Vision may become unclear, particularly if swelling affects the macula.
Distortion
Straight lines or objects may appear bent, wavy or distorted.
Difficulty reading
Reduced central vision can make reading and other detailed tasks more challenging.
Missing areas of vision
A person may notice gaps, shadows or areas where vision is reduced.
Mild or moderate vision loss
Vision loss can vary depending on the location and severity of the blockage.
No noticeable symptoms
Some people may have no obvious symptoms if the affected area does not involve the central retina.
Identifying Branch Retinal Vein Occlusion (BRVO)
Comprehensive eye examination
An eye specialist examines the retina for:
- Retinal haemorrhages
- Swelling
- Blood vessel changes
Optical Coherence Tomography (OCT)
OCT provides detailed images of retinal layers and is essential for detecting and monitoring:
- Macular oedema
- Retinal swelling
- Treatment response
Fundus Photography
Retinal photographs document changes caused by the blockage and help monitor progression.
Fluorescein Angiography
This imaging test uses a dye to assess:
- Blood flow through retinal vessels
- Areas of leakage
- Blocked retinal circulation
OCT Angiography
OCTA provides detailed information about retinal blood vessels and may help assess vascular changes.
Systemic Health Assessment
Because RVO is associated with vascular risk factors, healthcare professionals may assess:
- Blood pressure
- Diabetes risk
- Cholesterol levels
- Cardiovascular health
Supporting individuals
Anti-VEGF Therapy
Anti-VEGF injections are commonly used when RVO causes macular oedema. They can help reduce fluid and swelling in the retina, which may improve or stabilise vision.
Steroid Treatments
Steroid injections or implants may be considered in selected people, particularly when macular oedema persists or when anti-VEGF treatment is not suitable or sufficiently effective.
Laser Treatment
Laser treatment may be used in specific situations, particularly when abnormal blood vessel growth develops or when persistent retinal swelling requires additional treatment.
Managing Health Risk Factors
Managing conditions that affect blood vessels can help reduce further vascular risk. This may include controlling:
- Blood pressure
- Diabetes
- Cholesterol
- Cardiovascular health
- Smoking
Regular Monitoring
Ongoing eye examinations and retinal imaging are important to monitor swelling, vision changes, treatment response, and potential complications. Some forms of RVO, particularly ischaemic CRVO, require close monitoring because of the increased risk of abnormal blood vessel growth and other complications.
Vision Rehabilitation
If vision loss remains despite treatment, low vision services and rehabilitation can help people adapt to changes in sight and maintain independence in daily activities.
Supporting independence, and participation
Living with RVO may involve adapting to changes in vision and managing ongoing eye care.
People may benefit from:
- Regular retinal monitoring
- Following treatment schedules
- Managing cardiovascular risk factors
- Using visual aids where needed
- Accessing rehabilitation support
Vision changes can affect:
- Independence
- Employment
- Mobility
- Emotional wellbeing
Support from healthcare professionals and patient communities can help people adjust and maintain quality of life.
Advancing the future of Retinal Vein Occlusion treatment
Improved Drug Delivery
Researchers are exploring new ways to deliver medicines to the retina more efficiently.
Artificial intelligence
AI technologies may support:
- Earlier detection
- Disease monitoring
- Prediction of progression
Research & Understanding Disease Mechanisms:
- Blood vessel biology
- Inflammation
- Retinal repair processes
Patient participation remains essential to developing treatments that address the needs of people living with RVO.
Learn About ResearchInformation and community support
Take the Next Step
Retinal Vein Occlusion can cause sudden changes in vision, but advances in diagnosis and treatment are helping many people preserve sight and maintain independence.
Through collaboration between patients, clinicians, researchers, and communities worldwide, progress continues towards better prevention, treatment, and support for people affected by retinal vascular conditions.
