What is the recommended treatment plan for a patient with existing central retinal vein occlusion?

Treatment of Existing Central Retinal Vein Occlusion

Anti-VEGF agents (ranibizumab, aflibercept, or bevacizumab) are the preferred first-line therapy for macular edema associated with central retinal vein occlusion (CRVO), with intravitreal corticosteroids reserved for inadequate responders. 1

Primary Treatment Approach

Initial Anti-VEGF Therapy

• Begin intravitreal anti-VEGF injections immediately for any vision-threatening macular edema documented on OCT imaging 2
• FDA-approved options include ranibizumab 0.5 mg or aflibercept 2 mg administered monthly initially 1
• Bevacizumab (off-label) demonstrates comparable efficacy, with 60% of treated eyes achieving 15-letter gains versus 20% with sham injections 1
• The SCORE2 trial confirmed aflibercept and bevacizumab have similar visual outcomes at 6 months 1

Evidence Supporting Anti-VEGF Superiority

• The CRUISE trial demonstrated doubling of letters read with ranibizumab compared to sham injections, with significant reduction in macular edema on OCT 1
• COPERNICUS showed 15-letter gain in 56% of aflibercept-treated eyes versus 12% with sham 1
• GALILEO confirmed similar findings for aflibercept efficacy 1
• Multiple systematic reviews confirm anti-VEGF efficacy with minimal side effects 1

Treatment Protocol

Loading Phase

• Administer 3-5 consecutive monthly intravitreal anti-VEGF injections as initial loading dose 3, 4
• Decision for re-injection should be based on OCT findings rather than visual acuity alone 3

Maintenance Regimen

• After loading phase, transition to pro re nata (PRN) or treat-and-extend protocols 3, 4
• The HORIZON trial showed approximately 50% of eyes achieved resolution of edema with PRN dosing at investigator discretion 1
• Delay in treatment is deleterious—patients starting anti-VEGF immediately achieve better visual outcomes than those with delayed treatment 1

Monitoring Requirements

• Monthly follow-up for first 6 months with gonioscopy to detect iris or angle neovascularization 1
• Continue monthly monitoring after discontinuing anti-VEGF in ischemic CRVO 1
• OCT imaging at each visit to assess macular edema response 1
• Fluorescein angiography before and during treatment to detect ischemic retinal areas 3

Second-Line and Adjunctive Therapies

Intravitreal Corticosteroids

• Consider dexamethasone implant or triamcinolone for inadequate response to anti-VEGF after 6 months 2
• Corticosteroids show efficacy but carry risks of cataract formation and elevated IOP 1
• May be reasonable alternative when considering side effect spectrum 3

Laser Photocoagulation

• The CVOS demonstrated no value of focal photocoagulation for macular edema in CRVO 1
• Complete peripheral panretinal photocoagulation (PRP) is recommended for iris or angle neovascularization 1
• Early targeted laser coagulation of ischemic retina may reduce injection frequency and improve edema response 3

Safety Considerations

Injection Technique

• Use topical povidone iodine before all intravitreal injections 1
• Routine antibiotic eye drops are not recommended 1
• Monitor IOP immediately following injection 1

Adverse Events

• Severe complications are uncommon: endophthalmitis, cataract formation, retinal detachment, elevated IOP 1
• Meta-analysis shows no evidence of increased arterial thromboembolic events with anti-VEGF treatment 1
• IOP elevations particularly common with corticosteroids 1

Documentation for Treatment Continuation

Required Evidence of Response

• Continuation requires demonstration of improvement in BCVA, maintenance of BCVA, reduction in macular edema on OCT, or reduction in rate of vision decline 5
• Submit baseline and current BCVA measurements 5
• Provide baseline and current OCT measurements with quantitative data 5
• Document treatment interval and response pattern 5
• Failure to document objective response metrics, particularly quantitative OCT data, is the most common reason for denial of continuation 5

Management of Non-Responders

Treatment Modification

• Switch between anti-VEGF agents or add dexamethasone implant for partial or non-responders 4
• Patients responding poorly to anti-VEGF tend to do so early in treatment course 6
• Consider adjuvant laser therapy when necessary 4

Ischemic CRVO Considerations

• All eyes in ischemic CRVO require laser treatment for peripheral ischemia 4
• Significant retinal ischemia may lead to proliferations, rubeosis iridis, and secondary glaucoma requiring laser 3

Common Pitfalls to Avoid

• Do not delay treatment initiation—early treatment correlates with better visual outcomes 1, 3
• Do not rely solely on visual acuity for re-treatment decisions; use OCT findings 3
• Do not use focal laser for macular edema in CRVO (ineffective per CVOS) 1
• Do not fail to monitor for neovascularization monthly for first 6 months 1
• Do not use corticosteroids as first-line when anti-VEGF is available due to favorable risk-benefit profile 1