[Retinal vein occlusions]

Retinal venous occlusions comprise central retinal vein occlusion, hemiretinal vein occlusions, and branch retinal vein occlusions. They are associated with arterial hypertension and glaucoma. Retinal vein occlusions occur more frequently in males, at a median age of 55. The pathogenesis of retinal venous occlusions remains obscure. The clinical presentation of the disease is variable. In most cases, there is a unilateral visual loss over days with a painless, white and quiet eye. However, retinal venous occlusions may also present as an abrupt and profound loss of vision, or be asymptomatic. The course of the disease may be chronic, often with exacerbations. The most severe complication is the onset of extensive capillary non-perfusion, with a high risk of neovascular glaucoma. The most frequent complication is macular edema due to breakdown of the blood-retinal barrier, which can originate from the macula itself and/or from the disc. The treatment is symptomatic. Retinal venous occlusions may resolve either because of the recanalization of the affected vein, or because of the establishment of an efficient collateral circulation. Intravitreal anti-VEGF antibodies or steroids may transiently improve vision, as well as laser photocoagulation, focused or not on macroaneurysms. Visual sequelae are frequent.