Branch Retinal Vein Occlusion

What's going on?

One of the branch veins within the eye has become occluded. This usually happens at a point where a retinal arteriole and retinal vein cross each other, as they share a sheath and pressure from the adjacent artery blocks venous flow. Back pressure causes rupture of the veins in that part of the retina. Usually a whole quadrant of the retina is involved and the vision in that field is reduced. If the blockage is close to the macula, the central vision will be impaired and visual acuity will drop. If the blockage involves the nasal retina, it may be completely clinically silent and the patient will not know that anything has occurred. Sometimes a single vein in the macula is affected, resulting in visual loss in that area and also problems in the surrounding area with exudates and oedema.

If I examine the patient, what will I find?

There will be retinal haemorrhages localised to one quadrant of the retina. There may also be some exudates around the damaged area.

What if I've diagnosed it?

Refer soon via letter.

What will the hospital do?

A fluorescein angiogram is sometimes done to assess the degree of ischaemia and damage. If the vision remains poor (worse than 6/12) at three months after the initial visual loss, the patient may be offered argon laser treatment to try to dry the leakage affecting the macula and thereby improve the vision.

What do I need to do?

Check for evidence of hypertension and treat as appropriate. Ensure the patient does not have some hypercoagulable condition.

Problems that may arise and how to deal with them

These patients may develop rubeotic glaucoma, although this is less likely than in those with central retinal vein occlusion.