​What is Medicine – What is Central Retinal Vein Occlusion?

​What is Medicine – What is Central Retinal Vein Occlusion? 
There are four branched veins which form the central retinal vein. The central retinal veins run through the optic nerve for draining blood from the retina.

Central retinal vein occlusion is due to the formation of thrombus / blood clot in the retinal veins. 

The thrombus or blood clot blocks the drainage of blood from the retina. 

The blockage of the central retinal vein causing problem to the whole retina.

The blockage of one the veins may cause problem in the area being drained by the branch of the veins. 

Blockage of the retinal vein cause pooling of blood in the retina. Retinal hemorrhages and macular edema may occur due to the leakage of the blood and fluid. 

Macular edema and retinal hemorrhages may result in the loss of vision due to the damage of the retinal tissue. A new blood vessel (neovascularization) may happen due to the release of VEGF. 

The risk factors of developing central retinal vein occlusion may include diabetes, smoking, hypertension, high cholesterol, glaucoma and systemic lupus erythematosus. 

Patient with central retinal vein occlusion may present with sudden painful loss of vision. 

The investigations that need to be considered are full medical history, full blood count ( leukemia) , ESR ( SLE), serum glucose and blood pressure. 

Fundoscopy of the examination may reveal the characteristic of retinal vein occlusion such as optic disc edema, macula edema and flame as well as blot hemorrhage 

In terms of management, referred the patient to the ophthalmologist. 

Laser photocoagulation, intravitreal steroids and anti VEGF therapies such as aflibercept or ranibizumab may be considered in treating macular edema and preventing the development of neovascularization.