What is diabetic retinopathy?

Diabetic retinopathy

Diabetic retinopathy is the most common complication of diabetes. It is a leading cause of preventable blindness in New Zealand. Regular eye checks are vital to detect and enable the timely treatment of diabetic retinopathy to prevent vision loss.

What causes it?

Diabetic eye disease includes fluctuations in vision that can be related to changing blood glucose levels, as well as more sustained changes in vision from cataract and diabetic retinopathy.

Diabetic retinopathy is a term used to describe the changes that are seen in the retina of people with diabetes. The retina is the light sensitive structure inside the eye that is essential for vision.

High blood glucose levels cause damage to the small blood vessels in the retina, which can lead to bleeding and swelling of the retina (macular oedema), as well as the growth of abnormal new blood vessels and scar tissue. These changes develop over time, but are likely to develop sooner, or be more severe, if blood glucose levels are not well controlled and if other risk factors such as high blood pressure and raised blood lipids (like cholesterol) are present.

What are the symptoms?

In its early stages, diabetic retinopathy does not usually cause any symptoms, so you may not even know you have it.

Regular eye examinations are a key part of your diabetes care, so that diabetic retinopathy can be detected and treated before you notice any changes in your vision. Management of diabetic retinopathy is very effective and can often slow the progression of the disease. By the time diabetic retinopathy causes symptoms, it is often severe and more difficult to treat.

How to check for the condition

A full eye examination, including screening for diabetic retinopathy, should be performed at the time of diagnosis of diabetes and at least once every two years thereafter. More frequent eye checks may be needed for people with existing diabetic retinopathy and for people at high risk of progressive disease, including those who have had diabetes for many years or those with other complications of diabetes (such as kidney disease or neuropathy).

At Specsavers, all eye tests are bulk billed and all optometrists are qualified to perform diabetic eye examinations.

The optometrist will check your vision and then check the retina to look for any retinopathy. Your eye health will be comprehensively assessed. Your eye examination will include digital retinal photography, an important way to monitor any changes over time.

Eye drops may be used to examine your eyes in a diabetic eye examination – these can temporarily blur your vision. Please check when making the appointment if you will be able to drive shortly after the appointment.

If required, a referral will be made to an ophthalmologist for further treatment and management.

You may need to have a further assessment if:

  • You have retinopathy that could affect your sight.
  • Other eye conditions are detected, such as glaucoma (a group of eye conditions that affect vision) or cataracts (cloudy patches in the lens of the eye)


If you have sight problems in between appointments, such as sudden vision loss or a deterioration in your vision, seek immediate advice by contacting your optometrist, GP or ophthalmologist.