What is the initial treatment for Central Retinal Vein Occlusion (CRVO)?

Initial Treatment for Central Retinal Vein Occlusion (CRVO)

Intravitreal anti-VEGF agents are the preferred first-line therapy for CRVO with macular edema causing vision loss, with FDA-approved options including ranibizumab 0.5 mg and aflibercept 2 mg administered monthly initially. 1, 2

Primary Treatment Algorithm

When to Initiate Anti-VEGF Therapy

• Begin anti-VEGF therapy immediately for any vision-threatening macular edema documented on OCT in CRVO 2
• Do not delay treatment—patients receiving delayed therapy (after 6 months) never achieve the same visual gains as those treated immediately 1

FDA-Approved Anti-VEGF Options

• Ranibizumab 0.5 mg intravitreally: Demonstrated doubling of letters read compared to sham injections in the CRUISE trial, with 55-61% of patients gaining ≥15 letters at 6 months 1
• Aflibercept 2 mg intravitreally: Showed 15-letter gain in 56% of treated eyes versus 12% with sham in the COPERNICUS trial 1
• Bevacizumab 1.25 mg (off-label): Achieved 15-letter gain in 60% of treated eyes, with SCORE2 demonstrating similar efficacy to aflibercept at 6 months 1, 2

Initial Dosing Schedule

• Start with monthly injections for the first 6 months 1
• After 6 months, transition to pro re nata (PRN) or treat-and-extend protocols based on response 1
• Treat-and-extend protocols result in approximately 1-2 fewer injections compared to monthly dosing without compromising outcomes 1

Safety Considerations During Injection

Required Injection Protocol

• Use topical povidone iodine antiseptic before all intravitreal injections 1
• Use a lid speculum during injection 1
• Do not use routine prophylactic antibiotic eye drops—they are not recommended 1

Uncommon but Serious Risks

• Infectious endophthalmitis (0.0-0.9% incidence) 2
• Retinal detachment 1
• Elevated intraocular pressure 1
• No increased arterial thromboembolic events demonstrated in meta-analyses 1, 2

When to Consider Alternative Therapies

Intravitreal Corticosteroids (Second-Line)

• Reserve corticosteroids for inadequate response to anti-VEGF after 6 months of treatment 2
• Dexamethasone implant 0.7 mg: FDA-approved for CRVO, shows visual gains at 90 days but effect diminishes by 6 months; requires retreatment every 4 months 1
• Triamcinolone: Efficacious but carries significant risks of cataract formation and glaucoma 1
• Meta-analysis found no difference in visual improvement between bevacizumab, ranibizumab, aflibercept, and triamcinolone, but steroid-related IOP and cataract risks make anti-VEGF more favorable initially 1

Laser Photocoagulation

• Focal laser has no role for macular edema in CRVO—the CVOS study showed no benefit 1
• Dense peripheral panretinal photocoagulation (PRP) is indicated only for neovascular complications (iris or retinal neovascularization) 1
• Anti-VEGF may be used as adjunct for iris/angle neovascularization, though no phase 3 trial evidence exists for this indication 1

Critical Pitfalls to Avoid

Treatment Delay

• Delaying treatment beyond initial presentation results in permanently reduced visual outcomes—patients who received sham for 6 months before switching to ranibizumab never caught up to those treated from the start 1

Inadequate Follow-Up Documentation

• Document baseline and serial best-corrected visual acuity (BCVA) measurements 3
• Obtain baseline and follow-up OCT with quantitative central macular thickness measurements 3
• Failure to document objective response metrics is the most common reason for treatment authorization denial 3

Ischemic CRVO Considerations

• In ischemic CRVO (≥10 disc areas of nonperfusion on fluorescein angiography), anti-VEGF reduces macular edema but visual prognosis remains poor 4
• Monitor closely for neovascular complications requiring PRP 1
• Perform gonioscopy prior to dilation, especially when IOP is elevated or iris neovascularization risk is high 1

Expected Outcomes with Optimal Treatment

• Approximately 80% of treated eyes achieve visual acuity ≥20/40 with sustained anti-VEGF therapy 1
• About two-thirds of patients achieve resolution after 1-4 injections; one-third require continuous long-term injections 5
• Patients requiring sustained injections often establish a predictable rhythm for retreatment 5