About one million Australians have diabetes, and unfortunately, this number is increasing by about 25,000 each year. Many people who have diabetes are at risk of eye problems, including retinal disease, cataracts and glaucoma.

Retinal disease
Disease of the retina (the light-sensitive layers at the back of the eye which enable us to see) occurs more often in people who have had diabetes for a long time, who are taking insulin, or whose diabetes is not controlled very well.

When a person is diagnosed with diabetes, it isn’t possible to predict at the time whether or not he or she will get retinal disease. However, about two-thirds of people with juvenile-onset diabetes (type 1 diabetes) will develop some significant retinal disease by 35 years after they’ve been diagnosed. One-third will develop swelling in their central area of vision. This is known as macular oedema.

Cataracts
A cataract is cloudiness in the lens of the eye and it leads to vision loss. Cataracts are more common in people with diabetes than the rest of the population and may also occur at an earlier age in people with diabetes than others.

Glaucoma
Doctors estimate that about 10 per cent of people with diabetes over the age of 40 have open-angle glaucoma, which is a condition where increased pressure within the eye causes damage to the optic nerve and so impairs vision or causes blindness. This compares to a figure of 3.3 per cent of people over the age of 40 who don’t have diabetes.

Diagnosis and treatment
Good control of diabetes is the best way of preventing complications.

Having your eyes checked regularly by a doctor is the most effective way of detecting any damage to your eyes. This should be at least every year if you are taking insulin, and every 2 years if you are not. However, if you are getting symptoms like blurred vision, especially if this comes on suddenly, then see a doctor without delay.

Treatment of retinal disease
If damage to the retina has already occurred, laser treatment (in which a laser beam is directed at the retina to repair damaged blood vessels) is very effective in preventing vision loss. Laser surgery works best if it isn’t done too early or too late—this is another reason why it is vital to detect eye damage promptly.

If you need this sort of laser treatment, your doctor will probably suggest you have this carried out before you have cataract surgery (if you need this). This lowers the risk of visual problems after surgery.

Cataract surgery
Cataract surgery usually has good results. It often involves removal of the lens of your eye which is replaced with a synthetic lens implant.

Additional risk factors
If you have other vascular diseases such as high blood pressure (hypertension), these should be treated as they can increase the damage to the eye in people with diabetes. Kidney disease also makes eye damage worse, particularly if you have high blood pressure as well. If you are pregnant, good control of diabetes is vital for both you and your baby.

Smoking
If you smoke, you should definitely stop. Nicotine constricts blood vessels, which can be harmful to a person with diabetes. In addition, doctors believe smoking undoes the good work that good blood sugar control has on the blood vessels. Talk to your doctor about giving up now. There are many methods available to help you.

The good news is that with regular eye checks and following your doctor’s recommendations, blindness from diabetes can be reduced just as effectively as it has been from other diseases such as trachoma, river blindness and vitamin A deficiency.