Blood in the branch!

Retina
Written By Madhuvanthi Mohan

Acute Branched Retinal Vein Occlusion


Types:

Major BRVO: Occlusion of retinal vein that drains one of the quadrants

Macular BRVO : Occlusion of a venule within the macula



BRVO can also be ischemic/ non-ischemic- ischemic BRVO: Ischemic is >5-DD of non-perfusion on FFA



Risk factors: Hypertension, diabetes, hyperlipidemia, glaucoma etc

Young patients - High homocysteine, hypercoagulable states, use of oral contraceptive pills etc.



What is the most common site and why is it so?

The superotemporal quadrant is the most common to be involved as it has more number of arteriovenous crossings.



Retinal artery and vein share a common adventitial sheath - artery compresses the vein.

Venous obstruction→ Increased venous pressure→ Overloading of collateral draining capacity→ Macular edema and ischemia → Unrelieved venous pressure→ Rupture of vein wall and intraretinal hemorrhage



Fundus findings:

  • Dilatation and tortuosity of venous segment distal to the site of occlusion, proximal attenuation

  • Retinal hemorrhages confined to the distribution of a retinal vein are characteristic- wedge shaped pattern with apex towards site of obstruction

  • Flame-shaped hemorrhages and dot -blot hemorrhages predominate

  • Complete obstructions result in extensive intraretinal hemorrhages, cotton-wool spot formation, and widespread capillary nonperfusion

  • Macular edema

  • Neovascularisation can occur



Causes of visual loss in BRVO:

  • Macular edema

  • Macular ischemia

  • Hemorrhage over the fovea

  • Vitreous hemorrhage from neovascularization of the retina or the optic disc

  • Epiretinal membrane or vitreomacular traction

  • Retinal detachment - tractional/ rhegmatogenous/ combined




    Image from Rajan Eye Care Hospital


    #ophthalmology #ophthal #retina #brvo

Madhuvanthi Mohan
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