Management of Retinal Vein Occlusion
Anti-VEGF intravitreal injections are the first-line treatment for macular edema associated with retinal vein occlusions, with intravitreal corticosteroids as second-line therapy and laser photocoagulation for specific indications. 1, 2
Classification and Diagnosis
Retinal vein occlusion (RVO) is classified based on the location of occlusion:
- Central Retinal Vein Occlusion (CRVO): Obstruction at or posterior to the optic nerve head
- Branch Retinal Vein Occlusion (BRVO): Obstruction at a branch or tributary of the central retinal vein
- Hemiretinal Vein Occlusion (HRVO): Occlusion affecting half of the retinal venous drainage
- Hemi-CRVO: Occlusion of one trunk of a hemicentral retinal vein
Diagnostic evaluation should include:
- Comprehensive ocular examination
- Optical Coherence Tomography (OCT) to assess macular edema
- Fluorescein angiography to evaluate retinal ischemia and neovascularization
- Pupillary assessment for relative afferent pupillary defect
- Gonioscopy to evaluate for neovascularization of the angle
- Intraocular pressure measurement
Treatment Algorithm
1. Management of Macular Edema
First-line therapy: Anti-VEGF intravitreal injections 1, 2
- FDA-approved: Ranibizumab, aflibercept
- Off-label: Bevacizumab
- Initial treatment: Monthly injections for 3 months (loading phase)
- Maintenance: PRN (as needed) or treat-and-extend regimen based on OCT findings
Second-line therapy: Intravitreal corticosteroids 1, 2
- Options: Triamcinolone, dexamethasone implant
- Consider when anti-VEGF response is inadequate
- Limitations: Risk of glaucoma and cataract formation
Alternative therapy for BRVO: Grid laser photocoagulation 1
- Consider for persistent macular edema after anti-VEGF therapy
- Particularly effective in BRVO cases
2. Management of Neovascularization
For BRVO with retinal neovascularization: 1
- Laser photocoagulation to areas of nonperfusion
For CRVO with retinal/iris neovascularization: 1
- Dense peripheral panretinal photocoagulation (PRP)
- Consider adjunctive anti-VEGF therapy if angiogenesis persists after PRP
3. Management of Systemic Risk Factors
- Hypertension
- Diabetes
- Hyperlipidemia
- Intraocular pressure (especially in patients with glaucoma)
Coordination with primary care physician to optimize management of systemic conditions and communicate end-organ damage
Follow-up Protocol
- Regular OCT imaging to monitor macular edema
- Careful examination for development of neovascularization
- Regular monitoring of intraocular pressure, especially with corticosteroid treatment
- Assessment of visual acuity at each visit
- Coordination with primary care for management of systemic risk factors
Special Considerations
- Timing: Early treatment initiation is associated with better visual outcomes 3
- Ischemic vs. Non-ischemic: Prognosis varies significantly between ischemic and non-ischemic RVO 1
- Neovascular Complications: CRVO and hemi-CRVO have higher risk of anterior segment neovascularization and neovascular glaucoma 1
- Pitfall: Delaying treatment can lead to irreversible vision loss; prompt referral to ophthalmology is essential
Treatment Efficacy
Multiple clinical trials have demonstrated the efficacy of anti-VEGF agents in improving visual acuity and reducing macular edema in patients with RVO. The prognosis for visual acuity depends on starting treatment early and continuing it consistently 3.
For patients with significant retinal ischemia, targeted laser coagulation of ischemic retina may reduce the frequency of necessary injections and improve the response of the edema to therapy 3.
While historical treatments such as ocular massage, anterior chamber paracentesis, and hemodilution have been used, they have not shown benefit for visual outcomes and are not recommended 2.
Conclusion
The management of RVO requires a systematic approach focusing on treating macular edema with anti-VEGF agents as first-line therapy, managing neovascular complications with appropriate laser treatment, and addressing underlying systemic risk factors. Regular monitoring and prompt intervention are essential to prevent vision loss and improve outcomes.