Retinal Vein Occlusion: Risk Factors and Injection Treatments Explained

Stephen Roberts 3 December 2025 9 Comments

Imagine waking up one morning and noticing your vision is blurry-just in one eye. No pain, no redness, no headache. Just a sudden, unexplained fog over part of your sight. That’s how many people discover they have retinal vein occlusion (RVO). It’s not rare. Around 16 million people worldwide live with it. And while it sounds scary, treatment has come a long way-especially when it comes to injections.

What Exactly Is Retinal Vein Occlusion?

Your retina is like the film in a camera. It catches light and turns it into signals your brain reads as images. Blood flows through tiny veins in the retina to keep it alive. When one of those veins gets blocked, fluid leaks into the retina, swelling the macula-the part responsible for sharp central vision. That’s retinal vein occlusion.

There are two main types:

Central Retinal Vein Occlusion (CRVO): The main vein behind the eye gets blocked. Vision loss is usually more severe.
Branch Retinal Vein Occlusion (BRVO): A smaller branch gets blocked. You might lose vision in just one part of your eye, like the top or bottom.

The blockage doesn’t happen out of nowhere. It’s usually caused by a blood clot forming where a hardened artery presses on the vein-a common sight in older adults with high blood pressure or cholesterol.

Who’s Most at Risk?

Age is the biggest factor. Over 90% of CRVO cases happen in people over 55. More than half of all RVO cases are in those over 65. But it’s not just an older person’s disease. About 5-10% of cases occur in people under 45.

Here’s what raises your risk:

High blood pressure: Present in up to 73% of CRVO patients over 50. Uncontrolled hypertension is the #1 driver.
High cholesterol: About 35% of RVO patients have total cholesterol above 6.5 mmol/L.
Diabetes: Affects about 10% of patients over 50 and makes recovery harder.
Glaucoma: High pressure inside the eye increases risk, especially if the blockage is near the optic nerve.
Smoking: Found in 25-30% of cases. It damages blood vessels and thickens the blood.
Obesity and inactivity: Both contribute to poor circulation and artery hardening.
Blood disorders: In younger patients, conditions like polycythemia vera, leukemia, or inherited clotting disorders (like factor V Leiden) can trigger RVO.
Birth control pills: For women under 45, oral contraceptives are the most common link to CRVO.

If you have any of these, regular eye checkups aren’t optional-they’re essential. Many people don’t know they have high blood pressure or high cholesterol until they lose vision.

How Are Injections Used to Treat RVO?

There’s no way to unblock the vein. But we can treat the damage it causes: macular edema-the swelling that blurs your vision.

The go-to treatment? Injections into the eye. Yes, that sounds intense. But it’s quick, safe, and often life-changing.

Two main types of injections are used:

Anti-VEGF Injections

These block a protein called VEGF that causes leaking blood vessels and swelling. Three drugs are commonly used:

Ranibizumab (Lucentis): Approved for RVO in 2010.
Aflibercept (Eylea): Approved in 2012. Often more effective in severe cases.
Bevacizumab (Avastin): Originally a cancer drug, now used off-label. Costs about $50 per shot vs. $2,000 for the others.

Clinical trials show big results:

In the BRAVO trial, patients on ranibizumab gained an average of 16.6 letters on an eye chart after a year. The placebo group gained just 7.4.
Aflibercept in the COPERNICUS trial improved vision by 18.3 letters on average.

Most patients get monthly shots for 3-6 months, then switch to "as needed" based on scans. Real-world data shows people need 8-12 injections per year to keep vision stable.

Corticosteroid Injections

The dexamethasone implant (Ozurdex) is a tiny, dissolving pellet injected into the eye. It slowly releases steroid over 3-6 months.

It’s not first-line, but it helps when anti-VEGF doesn’t work:

In the GENEVA study, 27.7% of CRVO patients gained 15+ letters of vision with Ozurdex vs. 12.9% with placebo.
One patient on Reddit said: "After 8 Avastin shots with no change, Ozurdex gave me 10 lines back. Worth every penny."

But steroids have downsides:

60-70% of patients with natural lenses develop cataracts faster.
30% get elevated eye pressure, needing extra meds.

A doctor gently injecting a patient's eye, with glowing OCT scans floating like lanterns in a serene clinic.

What’s the Procedure Like?

You might be nervous. But here’s what actually happens:

You sit in a chair, head stabilized.
Your eye is numbed with drops.
The doctor cleans the surface with antiseptic.
A tiny speculum holds your eyelid open.
The needle goes in-quick, sharp pressure, then it’s over.
It takes less than 10 minutes.

You might see floaters or have a red spot on the white of your eye afterward. That’s normal. Subconjunctival hemorrhage happens in 25-30% of cases. It looks scary but clears up in days.

Serious infections (endophthalmitis) are rare-only 0.02-0.1% of injections.

How Do Doctors Know If It’s Working?

They use optical coherence tomography (OCT). This non-invasive scan shows the thickness of your retina.

Treatment starts when central subfield thickness (CST) is above 300 micrometers. The goal? Get it below 250. If CST stays high after 3 months, your doctor might switch drugs or add steroids.

Vision improvement takes time. Most patients see gains within 1-3 months. About 30-40% reach 20/40 vision or better after a year of treatment.

What Are the Real-Life Challenges?

The science works. But life doesn’t always cooperate.

Cost: Lucentis and Eylea cost $2,000 per shot. Even with insurance, copays can hit $150-$500. Avastin is cheaper, but not always covered.
Frequency: Monthly shots for months. That’s 12+ trips to the clinic a year. Many patients miss appointments because of anxiety, transportation, or work.
Emotional toll: "The waiting room is full of people who’ve been here before. I know the drill, but my heart still races every time," one patient wrote on Reddit.
Treatment fatigue: After 18 months of injections, some patients stop going-even when their vision is still improving.

A 2022 survey of 1,247 RVO patients found 78% had better vision-but 63% said cost was a burden, and 41% felt burned out by the process.

Diverse patients in a quiet clinic, each with half-blurred faces, holding medical journals and pill bottles.

What’s Next in RVO Treatment?

The future is about less frequent treatment and smarter choices.

Treat-and-extend: Start with monthly shots, then stretch the time between them if the eye stays stable. One 2023 study showed this works just as well as monthly, with 30% fewer injections.
Port Delivery System: A tiny implant (Susvimo) placed in the eye that slowly releases ranibizumab. Approved for AMD, now being tested for RVO. Could mean injections every 6 months instead of monthly.
Gene therapy: RGX-314 is in trials. It’s a one-time injection that makes your eye produce its own anti-VEGF protein.
Combination therapy: Some doctors now use anti-VEGF + steroid together for stubborn cases.

Doctors are also using new scans to predict who will respond best to which treatment. It’s no longer one-size-fits-all.

What Should You Do If You’re Diagnosed?

1. Get a full medical workup. Check your blood pressure, cholesterol, and blood sugar. Treat the root cause.

2. Start treatment fast. The sooner you begin injections, the better your vision outcome.

3. Ask about cost options. Ask if your clinic offers Avastin. Some safety-net hospitals use it for 90% of cases.

4. Track your progress. Keep a log of your vision changes and injection dates. Bring it to appointments.

5. Don’t skip follow-ups. Even if your vision feels fine, swelling can come back.

6. Speak up about anxiety or cost. Your doctor can help you find support programs or adjust your plan.

Final Thoughts

Retinal vein occlusion isn’t a death sentence for your vision. It’s a chronic condition-like high blood pressure or diabetes-but one you can manage.

Injections aren’t perfect. They’re expensive, frequent, and emotionally taxing. But they work. Most people regain usable vision. Many get back to driving, reading, and recognizing faces.

The key is early action and sticking with the plan. Your eyes won’t heal on their own. But with the right treatment, they can recover more than you think.