What is it?
Diabetic retinopathy is an abnormality of blood vessels which supply the retina, the layer lining the inside of the eye which acts like a film in a camera.
These blood vessels leak fluid which causes a loss of reading vision, or abnormal blood vessels develop which can haemorrhage and lead to a more severe loss of vision.
Who gets it?
All diabetics are at risk of the condition which is largely related to the duration of the diabetes. In younger insulin dependent diabetics the onset of the condition is rapid whereas in older diabetics it comes on more slowly and the exact onset is therefore more difficult to pinpoint. After 10 years of the disease all diabetics will have some degree of retinopathy and about 40-50 percent will develop complications which can cause an effect on vision.
Can it be prevented?
Good control of the blood sugars will reduce the incidence of retinopathy and control of hypertension is also important. Smoking is associated with greater risk of the condition.
The most important preventative measure with regard to visual loss from diabetes is regular examinations by an eye specialist to detect the early changes of retinopathy. Special care needs to be taken in pregnant diabetic patients.
Can it be treated?
Laser treatment before symptoms is very effective in preventing loss of vision and is imperative, although may be less effective once symptoms have developed. Therefore, regular checks by an eye specialist to detect the changes before symptoms is absolutely mandatory and particularly so after 10 years of diabetes.
The laser treatment may need to be quite extensive and consists of multiple small burns on the surface of the retina. This is performed as an out patient sitting in front of a laser machine.
Following the laser treatment the vision is quite blurred for about a week and after that vision largely recovers but the eye remains less able to adapt to changes of light, particularly when going from light to dark conditions.
If the retinopathy progresses to haemorrhages and more damage to the retina, vitreoretinal surgery may be required.