Diabetic Retinopathy 

By Dr Alison Nankervis, Medical Adviser to DAV

‘You have diabetes so you will probably go blind’ – right? No way. Most people with diabetes will develop some degree of diabetic retinopathy if they have diabetes for long enough, but significant loss of vision is unusual. The whole point of proper eye care in diabetes is to maintain good vision. 

Let’s talk about what goes wrong with the eyes in people with diabetes, how it is detected and investigated and, most importantly, how it is treated. 

Diabetic retinopathy means that the retina in the eye has been damaged by diabetes. The retina is a thin layer of tissue which lines the back of the eye. It picks up visual messages which are then transferred to the brain along a special nerve. The central and most important part of the retina is called the macula. Damage to the macula causes severe loss of vision. 

Retinopathy can be classified as background (early) or proliferative (advanced). The signs of background retinopathy include small areas of bleeding (haemorrhages), or fatty deposits (exudates). Your doctor or optometrist will be able to detect these changes while you have completely normal vision. Usually no treatment is required, but careful observation (usually 6-12 monthly) is essential. 

Proliferative retinopathy develops after early changes. Fragile new blood vessels grow in the retina and these can bleed into the jelly-like substance at the back of the eye (the vitreous) causing clouded or decreased vision. This can take some weeks or months to clear. Leaking blood vessels near the macula must be treated early to prevent more severe damage. 

Detection and Investigation 

It is most important to have your eyes checked regularly, at the time of diagnosis and then every one-two years. This can be done by eye photographs or someone trained to examine eyes such as your GP, diabetes or eye specialist or optometrist. 

First they will test your vision and then will put drops in your eyes to dilate your pupils and get a good view of the retina. Your vision might be blurred for one-two hours afterwards, but sunglasses will help with the glare. Fluorescein angiography is where a yellow dye is injected into your arm or hand and photos taken of your eyes. This test is not usually necessary – only to check macular oedema or proliferative retinopathy. 
 

Early detection and treatment of retinopathy dramatically reduces the risk of loss of vision in diabetes.

Management of diabetic retinopathy  Laser therapy 

Cataracts in diabetes 

A cataract is a clouding of the lens in front of the eye, leading to less clear vision. Cataracts are more common in diabetes and are usually treated by removal of the cataract under local anaesthetic. A new, clear plastic lens replaces the clouded lens. 

Preventing diabetic retinopathy 

Anyone can get diabetic retinopathy and the longer you have diabetes the greater the risk. However tight control of your blood glucose markedly reduces the risk. Treatment of high blood pressure and cholesterol also helps. 

Looking after your eyes  

• Keep your blood glucose levels as well controlled as you can. 
• Have your eyes checked every one-two years.  
• See your doctor immediately if you notice any problems with your vision. 
• See your GP regularly to make sure your blood pressure and cholesterol are normal.