High blood sugar leads to changes in the retina which can cause disturbance in vision.
Diabetic retinopathy is one of the most common causes of blindness in industrialised countries, affecting the retina of diabetic patients.
Diabetic retinopathy is related to the duration of the diabetes and the metabolic control of the patients; patients that control their diabetes poorly can develop retinopathy within a few years whilst patients that control their diabetes well may not develop retinopathy at all.
Diabetic retinopathy refers to the effect of diabetes on the retina. The retina needs a constant supply of blood, which it receives through a network of tiny blood vessels. Over time, a persistently high blood sugar level can damage these blood vessels in three main stages:
- Tiny bulges develop in the blood vessels, which may bleed slightly but don’t usually affect your vision – this is known as background retinopathy
- More severe and widespread changes affect the blood vessels, including more significant bleeding into the eye – this is known as pre-proliferative retinopathy
- Scar tissue and new blood vessels, which are weak and bleed easily, develop on the retina – this is known as proliferative retinopathy and it can result in some loss of vision
Blurred vision can develop if this leakage occurs in the central part of the retina known as the macula. This process is known as diabetic maculopathy or diabetic macular oedema (DMO). Diabetic maculopathy is one of the leading causes of blindness in the Western working population and early treatment can now reverse visual loss.
The main treatments for more advanced diabetic retinopathy are:
- laser treatment
- injections of medication into your eyes
- an operation to remove blood or scar tissue from your eyes
You can reduce your risk of developing diabetic retinopathy, or help stop it getting worse, by keeping your blood sugar levels, blood pressure and cholesterol levels under control.