What is the recommended evaluation and management for central retinal vein occlusion (CRVO)?

Central Retinal Vein Occlusion: Evaluation and Management

Initial Diagnostic Evaluation

The first critical step is comprehensive ocular examination with systematic assessment of four key features: visual acuity, pupillary response, presence of macular edema, and degree of retinal ischemia. 1

Essential History Elements

• Duration and location of vision loss 1
• Current medications and cardiovascular risk factors including hypertension, diabetes, hyperlipidemia, cardiovascular disease, sleep apnea, and coagulopathies 1
• Prior ocular history including glaucoma, previous injections, or laser treatment 1

Required Physical Examination Components

• Visual acuity testing is mandatory as baseline VA is the strongest prognostic factor for final visual outcome 2
• Pupillary assessment for relative afferent pupillary defect (RAPD) - this corresponds directly to ischemia severity and predicts neovascularization risk 1, 2
• Slit-lamp biomicroscopy examining carefully for fine abnormal new iris vessels 1
• Intraocular pressure measurement 1
• Gonioscopy prior to dilation - essential in ischemic CRVO when IOP is elevated or iris neovascularization risk is high 1
• Dilated fundus examination of posterior pole and peripheral retina using indirect ophthalmoscopy 1

Diagnostic Imaging

• Optical coherence tomography (OCT) is essential for detecting and quantifying macular edema, guiding treatment decisions, and monitoring response 1, 3
• Fluorescein angiography to assess degree of retinal ischemia and capillary nonperfusion 1
• Color fundus photography to document severity of retinal findings, hemorrhages, and neovascularization 1

Treatment Algorithm for CRVO with Macular Edema

Anti-VEGF intravitreal injections are first-line treatment for macular edema causing vision loss in CRVO. 1, 3

First-Line Therapy: Anti-VEGF Agents

• FDA-approved agents include ranibizumab 0.5 mg or aflibercept (Eylea) 2 mg administered intravitreally 3, 4
• Ranibizumab demonstrated that 48% of CRVO patients gained ≥15 letters at Month 6 compared to 17% with sham treatment 4
• Monthly injections are typically given initially, with mean of 6 treatments in the first 6 months 4
• After initial monthly dosing, treatment can transition to pro re nata (PRN) protocol guided by OCT findings and visual acuity, which maintains visual gains with reduced injection burden 5

Second-Line Therapy: Intravitreal Corticosteroids

• Reserved for patients with contraindications to anti-VEGF therapy 1, 2
• Options include triamcinolone or dexamethasone implant 2
• Critical caveat: significant risk of secondary glaucoma and cataract formation with steroid use 1, 2

Management of Neovascular Complications

For CRVO patients who develop iris neovascularization, extensive and complete peripheral panretinal photocoagulation (PRP) is indicated immediately. 1

• PRP may decrease progression of iris neovascularization and prevent neovascular glaucoma 1
• Initial treatment with anti-VEGF agent may be helpful for immediate benefit and can improve ability to deliver complete laser treatment 1
• Monthly monitoring for first 6 months is essential to detect iris or angle neovascularization early 2

Systemic Evaluation and Risk Factor Management

Immediate referral to primary care physician or internist for cardiovascular risk factor optimization is mandatory. 2

• Control of hypertension, diabetes and blood glucose, and hyperlipidemia through direct communication with primary care 1
• Treatment of obesity and obstructive sleep apnea 6
• Smoking cessation counseling 6
• Most CRVO patients do not require extensive hematologic workup beyond routine systemic evaluation 7

Follow-Up Protocol

Monthly monitoring for the first 6 months is essential with assessment of: 2

• Visual acuity at each visit 2
• Intraocular pressure measurement 2
• Careful examination of iris and angle for neovascularization 2
• OCT imaging to monitor macular edema and guide re-treatment decisions 3

Key Clinical Pitfalls

• Do not use the conventional 10-disc area of retinal capillary obliteration as a parameter to differentiate ischemic from nonischemic CRVO - this is an invalid criterion 7
• Patients responding poorly to anti-VEGF tend to do so early in treatment course; consider switching to corticosteroids if inadequate response after 3-6 injections 5
• Real-world visual outcomes are often poorer than clinical trial results, particularly in ischemic CRVO where VA typically remains worse than 20/800 8
• Gonioscopy must be performed before dilation to avoid missing angle neovascularization 1