What is the current management plan for patients with retinal vein thrombosis?

Management of Retinal Vein Thrombosis

Anti-VEGF agents are the first-line treatment for macular edema associated with retinal vein occlusions, with panretinal photocoagulation reserved for cases with neovascularization. 1

Diagnosis and Classification

Retinal vein occlusion (RVO) is the most common retinal vascular disease after diabetic retinopathy 2. It is classified into two main types:

1. Branch Retinal Vein Occlusion (BRVO) - More common
2. Central Retinal Vein Occlusion (CRVO) - Less common but often more severe

Diagnostic Evaluation

Comprehensive evaluation should include:

• Thorough ocular examination to distinguish between BRVO and CRVO
• Retinal imaging (OCT, fluorescein angiography) to:
  • Evaluate for macular edema
  • Estimate degree of retinal ischemia
  • Detect retinal/iris neovascularization 1
• Assessment for relative afferent pupillary defect (indicates level of ischemia)
• Gonioscopy (especially important in ischemic CRVO)
• Examination of peripheral retina and vitreous 1

Treatment Approach

1. Management of Macular Edema

For BRVO with Macular Edema:

• First-line: Anti-VEGF injections (ranibizumab, aflibercept FDA-approved; bevacizumab off-label) 1
• Second-line: Intravitreal corticosteroids (triamcinolone, dexamethasone implant) - limited by side effects including glaucoma and cataract formation 1
• Alternative: Focal laser treatment in selected cases 1

For CRVO with Macular Edema:

• First-line: Anti-VEGF agents 1
• Second-line: Intravitreal corticosteroids 1

2. Management of Neovascularization

• For BRVO with retinal neovascularization: Retinal laser photocoagulation in areas of nonperfusion 1
• For CRVO with retinal/iris neovascularization: Dense peripheral panretinal photocoagulation (PRP) 1
• Anti-VEGF agents may be used adjunctively to provide immediate but temporary benefit and improve ability to deliver complete laser treatment 1

Evidence for Anti-VEGF Treatment

The BRAVO trial demonstrated that monthly intravitreal ranibizumab injections resulted in gains of 16-18 letters compared with 7.3 letters in the sham group at 6 months. Importantly, 55-61% of ranibizumab-treated eyes gained at least 15 letters compared with only 29% in the sham group 1.

Systemic Evaluation and Risk Factor Management

Most patients develop RVO at an elderly age, with more than half having associated systemic disorders 2:

• Hypertension (48% of RVO attributable)
• Hyperlipidemia (20% attributable)
• Diabetes mellitus (5% attributable) 1

Recommended Approach:

1. Involve primary care physician in management
2. Aggressively manage risk factors by optimizing control of:
   • Hypertension
   • Diabetes
   • Hyperlipidemia 1

Special Considerations

Young Patients (<45 years)

Consider thrombophilia workup in younger patients without typical risk factors, as studies show higher prevalence of coagulation disorders in this population 3. Potential factors include:

• Resistance to activated protein C
• Antiphospholipid antibodies
• Deficiency of anticoagulant proteins 3

Pregnancy Implications

In females with RVO and thrombophilia, there may be increased risk for pregnancy complications including spontaneous abortion and pre-eclampsia 4.

Monitoring and Follow-up

• Regular monitoring for development of neovascularization
• Assess treatment response with visual acuity testing and OCT
• Coordinate care with primary care physician for systemic risk factor management 1

Treatment Outcomes

Patient outcome goals include:

• Improvement or stabilization of visual function
• Improvement of vision-related quality of life
• Detection and treatment of neovascular complications
• Detection and treatment of macular edema
• Optimal control of systemic risk factors 1

Common Pitfalls to Avoid

1. Delayed treatment: Eyes receiving delayed treatment may not achieve the same level of vision gain as those treated promptly 1
2. Missing neovascularization: Failure to detect early neovascularization can lead to vitreous hemorrhage and neovascular glaucoma
3. Inadequate systemic evaluation: Not addressing underlying risk factors increases risk of recurrence and fellow eye involvement
4. Overlooking giant cell arteritis: In patients over 50 with retinal artery occlusion, always consider GCA as a potential cause requiring immediate corticosteroid treatment 1

By following this evidence-based approach to management, visual outcomes and quality of life can be optimized for patients with retinal vein thrombosis.