Retinal Vein Occlusion
What is a Retinal Vein Occlusion?
Retinal veins are blood vessels that drain blood out from the retina. Occasionally a retinal vein blockage can develop leading to a back pressure in the blood vessels which can bleed. This will cause the vision to be blurry.
Are there different types of vein occlusion?
There are two types of retinal vein occlusions:
Central Retinal Vein Occlusion (CRVO) is where all areas of the retina are involved from the blockage of the main retinal vein. This is the most serious sort of vein occlusion.
Branch Retinal Vein Occlusion (BRVO) is a smaller part of the retina is affected by a blockage of a smaller retinal vein.
What are the risk factors?
High blood pressure
What is the treatment?
The vision is mainly affected by the development of a swelling in the central retina (macular oedema) with bleeding (haemorrhage).
Haemorrhage will slowly clear with time and at times may need laser on the retinal to stop it from further bleeding. Very occasionally, surgery may be needed to clear the blood away from the eye.
Macular oedema can be reduced by intravitreal anti-VEGF (vascular endothelial growth factors) injections (eg: Lucentis or Eylea) or steroid implant (Ozurdex). If the macular oedema resolves, the vision usually improves. However, in some occasions, the vision may not improve completely as there may be some underlying retinal cell damage.