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Emergency: requires immediate attention
Branch retinal vein occlusion - External and Internal Eye
Other Resources UpToDate PubMed
Emergency: requires immediate attention

Branch retinal vein occlusion - External and Internal Eye

Contributors: Sid Schechet MD, D. Chimene Richa MD
Other Resources UpToDate PubMed


Retinal vein occlusion (RVO) is the second most common retinal vascular disorder after diabetic retinopathy. RVOs are divided into central (CRVO), hemi (HRVO), and branch retinal vein occlusions (BRVO). A BRVO is an occlusion of the central retinal vein at the secondary branches or further downstream, resulting in retinal hemorrhages, retinal nonperfusion, and possible subsequent macular edema. Ultimately, there is vision loss due to the nonperfused retina causing visual field defects, or loss of vision results from secondary macular edema.

BRVOs are further classified into ischemic (nonperfused) or nonischemic (perfused). An ischemic BRVO is defined as more than 5 disc diameters of nonperfusion on fluorescein angiography (FA). The ischemic variety portends a poorer prognosis.

A 2010 international meta-analysis by Rogers et al estimated the prevalence of any RVO to be 0.52%, BRVO 0.442%, and CRVO 0.08%. There was no association with sex, but BRVOs were associated with ethnicity with 0.282% of cases occurring in patients of Northern European descent, 0.353% in patients of African descent, 0.498% in patients of Asian descent, and 0.598% in patients of Hispanic descent.

A BRVO is painless and can cause symptomatic decreased vision or may in fact be asymptomatic. Vein occlusion occurs suddenly with resultant localized retinal hemorrhages and exudation. These occur most frequently in the superotemporal quadrant of the retina. With time, retinal neovascularization may occur due to the increased vascular-endothelial growth-factor (VEGF) drive with resultant vitreous hemorrhage and/or neovascular glaucoma. Macular edema, occurring in 90% of BRVO cases, is the main cause of vision loss and is a result of increased inflammatory and VEGF activity.

Risk factors for BRVOs include increased age, race, hypertension, hyperlipidemia, increased body mass index, and glaucoma. Interestingly, while diabetes mellitus is a risk factor for a CRVO, it has not been found to be a risk factor for a BRVO. Hypercoagulable disorders such as hyperhomocysteinemia may also predispose a patient to retinal vein occlusion.

The pathogenesis of a BRVO is multi-factorial and not completely understood. Possible mechanisms include mechanical compression of vessel walls, hypercoagulability, and arteriosclerotic changes.

Possible treatments for BRVOs include laser photocoagulation and anti-VEGF intravitreal injections.

BRVO cases have a good visual prognosis with 50%-60% of patients having a final visual acuity of 20/40 or better even without treatment.


H34.8390 – Tributary (branch) retinal vein occlusion, unspecified eye, with macular edema
H34.8391 – Tributary (branch) retinal vein occlusion, unspecified eye, with retinal neovascularization
H34.8392 – Tributary (branch) retinal vein occlusion, unspecified eye, stable

24596005 – Venous retinal branch occlusion

Look For

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Diabetic retinopathy
  • Hypertensive retinopathy
  • Retinal Vasculitis
  • Retinal arteriolar macroaneurysm
  • Radiation retinopathy
  • Macular telangiectasia
  • Age-related macular degeneration
  • Polypoidal choroidal vasculopathy
  • Commotio retinae

Best Tests

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Management Pearls

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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Last Reviewed:06/14/2017
Last Updated:09/30/2019
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Emergency: requires immediate attention
Branch retinal vein occlusion - External and Internal Eye
A medical illustration showing key findings of Branch retinal vein occlusion : Blurred vision, Cotton wool spots, Retinal hemorrhage, Retinal microaneurysm, Unilateral distribution, Vision loss, Visual field defect
Copyright © 2024 VisualDx®. All rights reserved.