WHAT WE TREAT
Central Retinal Vein Occlusion
CRVO is a blockage of the main retinal vein that causes swelling and vision loss.
About Central Retinal Vein Occlusion
Overview
The retina is a thin layer of nerve tissue at the back of the eye that captures light and sends visual signals to the brain. To function properly, it requires a constant supply of oxygen and nutrients provided by healthy blood circulation. Blood flows into the retina through the central retinal artery and out through the central retinal vein. When this vein becomes blocked, blood cannot drain properly, leading to fluid buildup, swelling, and retinal damage—a condition known as Central Retinal Vein Occlusion (CRVO).
The severity of the blockage determines the extent of vision loss. CRVO may be classified as either:
- Non-ischemic (partial)—limited obstruction with milder symptoms
- Ischemic (complete)—severe obstruction causing significant retinal injury and vision loss
Causes
When the central retinal vein becomes blocked, blood flow slows or stops, preventing oxygen and nutrients from reaching retinal tissue. This leads to:
- Swelling and leakage of blood and fluid into the retina
- Damage to the light-sensitive cells of the macula
- Reduced oxygen (ischemia) and potential vision loss
Treatment Options From LRR
Treatments
Although the visual prognosis for CRVO can be guarded, several treatments can help reduce swelling, control complications, and improve stability.
1. Addressing Systemic Risk Factors
Managing underlying health issues such as hypertension, diabetes, high cholesterol, and glaucoma is crucial to limit further vascular damage and prevent recurrence.
2. Intravitreal Injections
Medications injected into the eye can reduce macular swelling and help stabilize vision. These include:
Anti-VEGF agents: Aflibercept (Eylea®), Vabysmo® (faricimab), Ranibizumab (Lucentis®), and Bevacizumab (Avastin®)
Steroid injections or implants: Such as Ozurdex® (dexamethasone) for sustained release
While these treatments do not cure CRVO, they can significantly reduce fluid leakage and improve retinal health. Because steroids may increase intraocular pressure, patients are monitored carefully after each injection.
3. Laser Therapy
Pan-retinal photocoagulation (PRP) laser treatment may be used to prevent or regress abnormal blood vessel growth. In cases with extensive bleeding, vitrectomy surgery may be required to remove the blood and vitreous gel.
4. Glaucoma Surgery (if needed)
If neovascular glaucoma develops, surgical treatment may be necessary to lower eye pressure and preserve comfort and remaining vision.
More To Know
Complications
One of the most common complications of CRVO is macular edema—swelling in the central part of the retina that leads to blurry or distorted vision. In more severe or ischemic cases, abnormal new blood vessels can develop, a process known as neovascularization. Frequent monitoring—especially during the first six months—is essential for early detection and treatment of these complications.
These fragile vessels can cause:
- Vitreous hemorrhage (bleeding into the eye)
- Scar tissue formation and retinal detachment
- Neovascular glaucoma—dangerously high eye pressure leading to pain and vision loss
Diagnosis
RVO is diagnosed during a comprehensive retinal examination. Your retina specialist may perform several tests to confirm the diagnosis and assess severity, including:
- Pupil reflex testing
- Measurement of intraocular pressure (IOP)
- Slit-lamp and dilated retinal examination
- Color fundus photography
- Optical Coherence Tomography (OCT) for macular swelling
- Fluorescein angiography (FA) to evaluate circulation and detect ischemia
- Visual field and visual acuity testing
- Blood tests to identify systemic risk factors such as hypertension, diabetes, or clotting disorders
Who Is at Risk?
CRVO is more common in adults over 50, but it can occur at any age. Because CRVO is often linked to systemic vascular disease, patients are encouraged to have a complete medical evaluation by their primary care physician. Aspirin therapy or other blood-thinning measures may be recommended in select cases.
Risk factors include:
- Glaucoma
- High blood pressure (hypertension)
- High cholesterol (hyperlipidemia)
- Diabetes mellitus
- Atherosclerosis or cardiovascular disease
- Smoking
- Blood-clotting disorders
- Inflammatory or autoimmune conditions
- Use of oral contraceptives
Causes
When the central retinal vein becomes blocked, blood flow slows or stops, preventing oxygen and nutrients from reaching retinal tissue. This leads to:
- Swelling and leakage of blood and fluid into the retina
- Damage to the light-sensitive cells of the macula
- Reduced oxygen (ischemia) and potential vision loss
Symptoms
A CRVO usually causes sudden, painless vision loss or blurring in part or all of one eye. Some patients notice distorted or hazy vision, while others experience more dramatic loss of central vision.
Is CRVO Curable?
Unfortunately, there is no cure for central retinal vein occlusion. The long-term outlook largely depends on the degree of initial vision loss.
According to the Central Retinal Vein Occlusion Study, among patients with non-ischemic CRVO, only about 10% improved, 50% remained stable, and one-third worsened over time. In more severe ischemic CRVO, vision loss is often permanent, and spontaneous recovery is rare. However, with modern therapies, doctors can often reduce swelling, control complications, and preserve remaining vision.
Prepare For Your Visit
If you already have an appointment made, we look forward to providing your care! If you need an appointment or have questions, please reach out to the Lakes Region Retina care team.
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