Diabetes and eye problems

If you have diabetes, you need regular eye checks because you have an increased risk of a number of eye problems. Keeping your diabetes as well controlled as possible delays or prevents diabetes-related eye disease.

Key points about diabetes and eye problems

  1. Diabetes can increase your risk of diabetic retinopathy, cataract and glaucoma.
  2. Diabetes eye checks every 2 years are an important part of your diabetes care, as treatment is possible if these conditions are found in the early stages.
  3. If you notice any changes in your vision, see your doctor or optometrist right away.
  4. If you have diabetes, you can take care of your eyes by having good blood sugar control, maintaining a healthy blood pressure, having regular diabetes eye checks and maintaining a healthy blood lipids level.

If you notice any changes in your sight, see an optometrist or your doctor right away. 

When do eye checks start?

  • For type 2 diabetes, eye checks start from the time of diagnosis. This is because some people may already have signs of diabetes eye disease by this time. 
  • For type 1 diabetes, eye checks tend to start 5 years after diagnosis, but this can vary depending on your age when first diagnosed. 
  • Pregnant women with known diabetes before should have eye checks in the first trimester.
  • If you have no damage to your retina (the innermost wall of your eye, which functions as its screen), you will be offered an eye screen every 2 years.

If there are any signs of eye disease, the eye team will explain what further tests, treatment and follow up is needed. You may also need eye checks more often than every 2 years.

How can diabetes affect my eyes?

Just like other parts of your body, diabetes affects your small blood vessels, in this case those on your retina. Diabetes can also affect the lens in your eyes, causing cataracts. In addition, diabetes can increase your risk of other eye problem such as glaucoma

Diabetes eye damage is sometimes called a ‘silent’ disease. This is because the damage may be happening for a long time before you notice any change in your sight. By the time your sight changes the damage is often very bad. Don't wait until you notice your vision is changing before you have your eyes properly checked.

Diabetic retinopathy (retina damage in diabetes)

Damage to your retina from diabetes is called ‘diabetic retinopathy’. This occurs when the blood supply to your retina is damaged from high blood glucose levels in your bloodstream over a long period of time. The blood vessels can become leaky, blocked or too small to let through enough blood.

Over time, this leads to your retina being damaged. This means only some of the information about an image can be transmitted via the eye nerve from your retina to your brain. If the damage is widespread, the whole of your retina can be wiped out and this results in total blindness.

Read more about diabetic retinopathy.

Cataracts

A cataract is when the lens of your eye becomes hazy or milky, making vision cloudy or blurry. Cataracts are common as people get older. However, for people with diabetes, the risk is doubled (two times more likely). Also you are likely to develop the condition at a younger age. If you notice any blurring or worsening of your vision, have your eyes tested.

Cataracts can usually be treated. In the early stages, you may find it helpful to wear sunglasses or glare control lenses in your glasses. As cataracts progress, less light gets through the lens and it is harder to see. Cataract surgery is a very common procedure. It removes the lens and replaces it with a new implanted lens. You will be able to see more clearly straight away and the surgery can usually be done on you as an outpatient during the day. 

Read more about cataracts.

Glaucoma

Glaucoma occurs when the pressure in your eye gets too high, causing damage to the optic eye nerve. When this happens, it can cause gradual loss of vision, usually starting at the sides (peripheral vision). This loss of side vision is often not noticed until it is well advanced, when treatment is more difficult. With regular eye checks, glaucoma can be found at an earlier stage and eye drops may be all that is needed to reduce the pressure. In some cases laser treatment or surgery are needed. 

Read more about glaucoma

What changes should I watch for?

If you notice any of these symptoms, see an optometrist or your doctor right away: 

  • you feel pressure in your eye
  • your vision becomes blurry
  • you have trouble reading or start to see double
  • one or both of your eyes hurt
  • you see spots or ‘floaters’
  • you can't see things at the side as you used to.

If you notice any changes in your sight, see an optometrist or your doctor right away. 

What is a diabetes eye check?  

A diabetes eye check looks at the back of your eyes (the retina or screen) rather than testing your vision for glasses or driving. It is done by a specially trained health professional either looking at, or photographing, the back of your eyes (retinas).

You will usually have drops put in your eyes to dilate your pupils (make them more open). This makes it easier to look at your retina.

Once your pupils are dilated, the eye care provider can either shine a light into your eyes to look at the retina themselves or take a photograph of the back of your eye. The photograph will then be checked by an eye specialist doctor and compared with previous photographs.

In New Zealand, every district health board has an eye screening service that is free for people with diabetes.

How do I get a diabetes eye check?

Usually your doctor or nurse will refer you to the local retinal screening service. However, you are the most invested in looking after your eyesight, so make sure to check each year whether your eye check is due and make sure you get to your appointment. 

  • If your last retinal eye check was normal, make sure it is done every 2 years. 
  • If you have early, mild or advanced diabetic eye disease, make sure you understand what treatment is needed and anything you can do to slow down the damage to your eyesight.

How can I delay or prevent eye damage?

If you have diabetes, you can take care of your eyes by:

  • having regular full diabetes eye checks every 2 years
  • working with your healthcare team to keep your blood sugar level well controlled
  • knowing what your blood pressure is and keeping to your target
  • quitting smoking – smoking damages the blood vessels in your eyes in addition to the damage caused by diabetes
  • maintaining healthy blood lipids (cholesterol).

Learn more

The following links provide further information about diabetes and eye problems. Be aware that websites from other countries may have information that differs from New Zealand recommendations.   

Diabetes and your eyes HealthInfo Canterbury, NZ
Diabetes and your eyes Save our Sight, Association of Optometrists, NZ
Diabetic retinopathy Fred Hollow's Foundation, Australia

References

  1. Management of diabetic retinopathy Ministry of Health, NZ and New Zealand Society for the Study of Diabetes

Reviewed by

Dr Divya Perumal works at the Eye Institute and Auckland public hospital. She has expertise in performing eye surgery, including advanced glaucoma surgery and cataract surgery. She is a senior lecturer at the University of Auckland and is actively involved in teaching junior doctors and research, as well as conducting public lectures. 

 

Credits: Health Navigator Editorial Team. Reviewed By: Dr Divya Perumal, Ophthalmologist, Auckland Last reviewed: 05 Feb 2021