Retinal vein occlusion

November 12, 2012

Retinal vein occlusion

The retina of the eye consists of light sensitive tissues which line the eye’s inner surface. This is where images are created by the optics of the eye – if the eye is the camera of the body then the retina is the camera film.

What happens during retinal vein occlusion?

A retinal vein occlusion is not dissimilar to a stroke in that it is the result of a blockage in the flow of blood from the retina which then causes damage; this blockage is very often due to atherosclerosis, or hardening of the arteries, and the resulting formation of a blood clot.

A retinal vein occlusion may cause nerve cells in the retina to die which in turn may result in vision loss – a blockage which develops in the main vein of an eye may affect the whole of that eye’s vision.

Causes and risk factors

Retinal vein occlusion is most often caused by narrowing or hardening of the arteries which, in turn, increases pressure on retinal veins. This means that individuals at risk of developing atherosclerosis are also at risk of developing retinal vein occlusion. Other risk factors include -

  • Age

  • Diabetes

  • High blood pressure

  • The presence of other optic disorders such as glaucoma, macular oedema or vitreous haemorrhage – these conditions may also be caused by retinal vein occlusion.

  • Health problems which affect blood circulation

Symptoms

The sudden onset of painless, blurring or loss of vision in one eye is the main symptom associated with a blockage in the retinal vein, and may affect all or part of the eye. The symptoms may appear to be very mild at first with only a slight loss of vision – however deterioration is likely to occur in the subsequent hours or days. Occasionally, complete vision loss may happen instantly.

Anyone experiencing loss of vision should seek medical attention straight away – retinal vein occlusion can cause permanent vision loss and may also lead to other eye problems.

Treatment

Treatment generally addresses the underlying health problems which have contributed to the retinal blockage – once it has happened there is no way of removing it.

Some patients, around 2/3, see an improvement in any vision loss in the following twelve months but for the remaining 1/3 there is usually no improvement.

Patients with an accumulation of fluid in the retina may be suitable candidates for focal laser photocoagulation treatment.

A known complication of blockage in the retinal vein is neovascular glaucoma which can cause extreme pain and physical deterioration in the eye as well as permanently destroying all vision in the affected eye. Patients who are affected by this complication may be advised to undergo panretinal laser photocoagulation.

New treatments involve the injection of microscopic quantities of drugs into the eye of affected patients in order to treat the abnormal blood vessels and fluid leak.

Laser photocoagulation

The laser photocoagulation procedure involves the focussing of a laser beam onto the growth of abnormal blood vessels on the retina – the cauterisation of these blood vessels will inhibit their growth and prevent further leaking of fluid, it will not, however, restore vision. This treatment is intended to prevent further damage to and possible loss of the eye.

Tags:

Category: Articles