Occlusion of a retinal vein is a common cause of sudden painless reduction in vision in older people. It occurs when a blood clot forms in a retinal vein. The retina is the thin membrane that lines the inner surface of the back of the eye. It is similar to the film of a camera. Blockage of one of the veins draining blood out of the eye causes blood and other fluids to leak into the retina causing bruising and swelling as well as lack of oxygen. This interferes with the light receptor cells and reduces vision. The condition is uncommon under the age of 60 but becomes more frequent in later life.There are two types of retinal vein occlusion
Branch Retinal Vein occlusions are due to obstruction of one of the four retinal veins. Each vein drains approximately a quarter of the retina.
Central Retinal Vein Occlusion is due to obstruction of the main vein formed from the four branches. In general, visual loss is more severe if the central retinal vein is occluded.
What causes Retinal Vein Occlusion?
A clot forming in the retinal vein results in complete obstruction of blood flow. The exact cause of this event is generally unknown but a number of common conditions increase the risk of retinal vein occlusion occurring.
• High blood pressure
• High cholesterol
• A number of rare blood disorders
It is essential to identify and treat any risk factors in order to minimise the risk to the other eye and prevent a further vein occlusion in the affected eye. Treatment of the risk factors dramatically reduces the risk of a further vein occlusion in both eyes. Without treatment there is a high risk of recurrence causing further damage to the sight of the affected eye and also damaging the sight of the other eye.
Mr. David will organise blood tests and retinal scans or a Fluorescein Angiogram ( a dye injection test) to identify the severity of the occlusion and offer appropriate treatment which may include any of the the following: