Snapshot A 65-year-old man presents to the emergency department for progressive visual loss. He denies any photopsia or ocular pain. Medical history is significant for polycythemia vera. Physical examination is notable for engorged retinal veins with small retinal hemorrhages. Summary Occlusion of the retinal vein leading to retinal ischemia 3 types central retinal vein occlusion login to view 1 more bullet branch retinal vein occlusion login to view 1 more bullet hemiretinal vein occlusion login to view 1 more bullet Epidemiology Risk factors age hypertension diabetes smoking obesity hypercoagulability glaucoma retinal arteriolar abnormalities Pathophysiology Occlusion of the retinal vein leads to retinal ischemia the ischemia can result in neovascularization, resulting in complications such as glaucoma vitreous hemorrhage macular edema retinal detachment secondary to retinal traction Presentation Symptoms painless vision loss aymptomatic in certain cases of branch retinal vein occlusion Physical exam retinal edema retinal vein dilation retinal hemorrhage neovascular glaucoma chronic ischemia leads to neovascularization, which can encroach to the anterior chamber angle can cause pain eye due to increased intraocular pressure relative afferent pupillary defect severe cases Studies Fluorescein angiography indication confirms the diagnosis determines the degree of retinal nonperfusion Optical coherence tomography indication to quantify retinal thickening from fluid within the retina secondary to macular edema Differential Retinal artery occlusion differentiating factor pallor of optic disk and cherry red macula Treatment Medical observation indication login to view 1 more bullet intravitreal anti-vascular endothelial growth factor (VEGF) indication login to view 1 more bullet intravitreal glucocorticoids indication login to view 1 more bullet Surgical retinal laser photocoagulation indication login to view 1 more bullet Complications Neovascular glaucoma Vitreous hemorrhage Retinal traction Macular edema Prognosis Branch retinal vein occlusion typically has a better visual prognosis than central retinal vein occlusion