What is a retinal vein occlusion?

The retina is a structure within the eye that captures light and makes the picture. It consists of very fine blood vessels and nerves.

Sometimes there can be bleeding on the surface that involves either a branch of one of these blood vessels, or half the retina, or sometimes even the whole retina.

It is also associated with the slowing down of the blood flow within the veins as evidenced on an angiogram. During this process, the very fine blood vessels that supply the retina with oxygen can get damaged.

There can also be a swelling of the central part of the retina called the macula, and this is the part that we use for reading.

In a vein occlusion, there is an abnormality of the blood flow within the retina that results in these haemorrhages, and to a variable extent swelling of the macular.

What patients notice when they have a vein occlusion is that the eyesight can suddenly drop, especially if it involves the central macula. This may be a shadow that involves half the retina or a blurred patch in the middle of the retina, and generalised reduction vision throughout the one eye.

It is usually just the one eye that’s affected. It is very rare for both eyes to be affected at the same time. If you have a vein occlusion in one eye, you have a slightly higher risk of developing it in the other eye as well.

It can be a frightening experience but with early treatment and appropriate interventions much of the vision can be protected and to some extent restored.