The most common cause of branch retinal vein occlusion is hypertension. Since retinal arteries and veins share a common adventitial sheath, the thickened artery compresses a retinal vein causing an occlusion, resulting in a retinal hemorrhage. Most patients present in their 60s with unilateral involvement. The patient may be asymptomatic if the macula is not involved. Visual complications of branch retinal vein occlusion include macular edema, retinal ischemia, and retinal and iris neovascularization. Argon laser photocoagulation is beneficial in patients with macu‐Photographed by Michael S. Stanley, Ophthalmic Photographer lar edema. If neovascularization develops, laser treatment reduces secondary vitreous hemorrhage and/or neovascular glaucoma.