What is the treatment for Branch Retinal Vein Occlusion (BRVO) of the eye?

Treatment of Branch Retinal Vein Occlusion (BRVO)

For BRVO with macular edema causing vision loss, initiate intravitreal anti-VEGF therapy with ranibizumab 0.5 mg or aflibercept 2 mg monthly as first-line treatment, reserving intravitreal corticosteroids as second-line therapy due to significant risks of secondary glaucoma and cataract formation. 1, 2, 3

Initial Diagnostic Evaluation

Before initiating treatment, perform a comprehensive assessment focusing on four critical features that determine management decisions 1:

• Visual acuity testing is essential as baseline VA is the strongest prognostic factor for final visual outcome 1
• Pupillary assessment for relative afferent pupillary defect, which corresponds to ischemia severity and predicts neovascularization risk 4, 1
• Optical coherence tomography (OCT) to document macular edema and assess outer limiting membrane and photoreceptor integrity as prognostic biomarkers 5
• Fluorescein angiography or OCT angiography to evaluate the degree of retinal ischemia and differentiate perfused versus nonperfused BRVO 4, 5
• Gonioscopy and slit-lamp examination to detect iris neovascularization, particularly in ischemic cases 4

First-Line Treatment: Anti-VEGF Therapy

Anti-VEGF agents are the preferred first-line therapy for macular edema causing vision loss in BRVO, demonstrating superior visual outcomes compared to laser photocoagulation or observation. 1, 2, 3

FDA-Approved Options:

• Ranibizumab 0.5 mg intravitreally every 4 weeks initially, with the BRAVO trial demonstrating 16-18 letter gains at 6 months versus 7.3 letters with sham 2, 6
• Aflibercept 2 mg intravitreally every 4 weeks initially, with the VIBRANT trial showing 52.7% of patients gained ≥15 letters versus 26.7% with laser at 24 weeks 2, 7
• Bevacizumab (off-label) remains an effective alternative with comparable efficacy, though not FDA-approved for this indication 4

Treatment Initiation Criteria:

Initiate anti-VEGF therapy when visual acuity is ≤20/40 with documented macular edema on OCT 3. Early treatment is crucial, as delay leads to suboptimal visual outcomes 2.

Second-Line Treatment: Intravitreal Corticosteroids

Reserve corticosteroids for patients with inadequate response to anti-VEGF therapy after 6 months, contraindications to anti-VEGF, or as rescue therapy. 2, 3

Available options include 4:

• Triamcinolone acetonide (off-label)
• Dexamethasone intravitreal implant (FDA-approved)

Critical caveat: Corticosteroids carry significant risks of secondary glaucoma and cataract formation, particularly in younger patients, making them less favorable than anti-VEGF agents despite demonstrated efficacy 4, 5.

Laser Photocoagulation: Limited Current Role

Grid laser photocoagulation is no longer first-line therapy for macular edema in BRVO. 2

• The BRIGHTER and RETAIN trials demonstrated that adding laser to ranibizumab did not improve visual outcomes or reduce treatment burden 2
• Historically, the Branch Vein Occlusion Study (BVOS) showed benefit of grid laser over observation, but this has been superseded by anti-VEGF therapy 4, 2
• Sectoral laser photocoagulation to areas of nonperfusion remains indicated when retinal neovascularization develops to prevent vitreous hemorrhage 4, 1, 2

Management of Neovascular Complications

If retinal neovascularization develops 4, 1, 2:

• Sectoral panretinal photocoagulation (PRP) to areas of nonperfusion decreases vitreous hemorrhage risk 4, 1
• Anti-VEGF agents can be used adjunctively when PRP is insufficient to control angiogenesis or to facilitate complete laser delivery 4

Systemic Risk Factor Management

Immediate referral to an internist for cardiovascular risk factor optimization is essential 1, 2:

• Control hypertension, hyperlipidemia, and diabetes 4, 1
• Patients with RVO have higher risk of cardiovascular disease and cerebrovascular accidents 2
• Direct communication with the primary care physician is mandatory for coordinated care 4

Follow-Up Protocol

Monthly monitoring for the first 6 months is essential to detect complications 1:

• Visual acuity assessment
• Intraocular pressure measurement (especially with corticosteroid use)
• Undilated slit-lamp biomicroscopy and gonioscopy with careful iris examination
• Pupillary assessment for relative afferent pupillary defect
• OCT imaging to monitor macular edema
• Peripheral retina examination for neovascularization 2

Common Pitfalls to Avoid

• Delaying treatment: Early anti-VEGF therapy is crucial; delay results in poorer visual outcomes 2
• Using laser as first-line therapy: Anti-VEGF agents have superseded grid laser for macular edema 2
• Choosing corticosteroids first: Reserve these for anti-VEGF non-responders due to significant side effect profile 4, 3
• Neglecting systemic evaluation: Patients require cardiovascular risk assessment and management 1, 2
• Inadequate neovascularization surveillance: Monthly monitoring is critical in the first 6 months 1

Prognosis

Approximately 50-60% of BRVO eyes achieve final visual acuity of 20/40 or better, with initial visual acuity being the most important prognostic factor 8. The severity of occlusion and extent of ischemia are critical determinants of final visual outcome 4.