What is retinal vein occlusion?

The retina is the area at the back of the eye that receives light and sends pictures of what the eye sees to the brain. Its blood supply is drained by tiny veins. A Retinal Vein Occlusion (RVO) occurs if the blood in one of them clots for some reason. This may affect the main vein (Central Retinal Vein Occlusion, CRVO), one of the two main branches (Hemi-Retinal Vein Occlusion, HRVO) or a smaller branch vein (Branch Retinal Vein Occlusion, BRVO). The patient may notice a sudden painless disturbance of vision.

A RVO is most likely to happen in older people, people with high blood pressure, a history of heart attack or stroke, diabetes, and in glaucoma, as well as in some rarer conditions. 

How is retinal vein occlusion managed?

How it affects the vision in the long term depends on which vessel is affected and whether this starves the retina of oxygen (‘ischaemic’ type) or does not (‘non-ischaemic’ type). The outlook for vision is better in the nonischaemic type. In the ischaemic type, new blood vessels grow into the retina and the iris, which sometimes results in glaucoma. This can be treated by closing the new vessels with the laser.

The main complication of RVO that affects vision is the gathering of fluid at the macula (the most sensitive part of the retina which gives the eye detailed colour vision). Hospital treatment usually includes injections of Anti-Vascular Endothelial Growth Factor (anti-VEGF) or steroids, which has been shown to be safe and effective. In addition, urgent referral to GP may be arranged for medical management and investigation of any underlying condition.