Central retinal vein occlusion
With thanks to Yusuf.
Causes: thrombosis of the central retinal vein due to venous stasis secondary to diabetes / hypertension / cardiovascular disease; hypercoagulable states; vasculitis; glaucoma; compression of the central retinal vein in orbital pathology (tumour, thyroid exophtalmos)
– 2 types – perfused (nonischaemic) – 75%, and nonperfused (ischaemic) – 25%
Symptoms: monocular loss of vision that develops over minutes; painless; the degree of vision loss is variable, milder in non-ischaemic CRVO and severe in ischaemic CRVO
Examination: decreased VA; prominent afferent pupillary defect in ischaemic CRVO; fundoscopic exam: diffuse retinal hemorrhages and optic disc edema (the “blood and thunder” fundus) and tortuous retinal veins with cotton wool spots.
Complications are delayed and include neovascularization of the retina and iris and neovascular glaucoma.
There is no known effective medical treatment available. They all need urgent Ophtalmology referral and medical workup for the underlying cause.