Diabetes of the eye

Diabetic retinopathy is a diabetes complication that affects your eyes. It causes the blood vessels in the retina to become damaged, which over time, can lead to vision loss.

Diabetes is one of the leading causes of blindness in New Zealand, due to the damage it causes to the eyes. With new solutions to prevent and treat diabetes eye damage, the numbers of those affected is decreasing. Fortunately, existing damage to the eyes can often be stopped in its tracks, or at least prevented from getting any worse.

What is diabetic retinopathy?

Diabetes is a chronic medical condition where the level of glucose in the individual's blood is too high. Diabetes is one of the main causes of vision problems and blindness in New Zealand, due to the condition known as diabetic retinopathy. 

Diabetic retinopathy is a condition that results in the blood vessels in the retina to become damaged, more likely for those who have had diabetes for a substantial amount of time.

People who are diagnosed with diabetes have a higher risk of blindness and loss of vision due to the disease. Diabetic retinopathy has the ability to develop in those with either Type 1 or Type 2 diabetes, especially for those who have had the condition for a longer period of time.

Causes of diabetic retinopathy

Diabetic retinopathy is caused by the damage that occurs to the retina, from having diabetes. Damage to the small blood vessels in the retina occurs which then leads to fluid leaks in the macula (the part of the eye that is responsible for clarity of vision) which results in serious vision loss.

In response to the damaged blood vessels, new blood vessels try to form in the retina; however these abnormal vessels can leak and block vision in the back of the eye.

 Diabetic retinopathy 

Stages of diabetic retinopathy

Diabetic retinopathy is a progressive eye disease, classified by two different types: non proliferative and proliferative; and broken down into four stages. Nonproliferative refers to the early stages of the disease, while proliferative is the advanced stages.

Stage 1: Mild nonproliferative The first and earliest stage, characterized by tiny areas of the blood vessels (in the retina) sweling. At this stage, small amounts of fluid can leak into the retina, which triggers swelling of the macula - found near the middle of the retina.

Stage 2: Moderate nonproliferative The swelling of tiny blood vessels increases, which starts to interfere with the blood flow to the retina, meaning it’s not getting proper nourishment. This causes a gathering of blood and other fluids in your macula.

Stage 3: Severe nonproliferative More blood vessels in the retina become blocked, which prevents a significant amount of blood flowing through to the retina. To solve this, the body receives signals to begin growing new blood vessels in the retina.

Stage 4: Proliferative An advanced stage of the disease, where the new blood vessels form in the retina. The new blood vessels are often fragile, so there’s a higher risk of fluid leakage. Different vision problems such as reduced field of vision, blurriness and even sometimes blindness, are now triggered.

Symptoms of a silent disease

Symptoms for diabetic retinopathy can vary for everyone. Many people don’t experience any symptoms, until the disease progresses to stage 4 (proliferative). This is how diabetic retinopathy can go unnoticed, sometimes being referred to as a ‘silent’ disease. 

Fortunately, an eye examination can detect diabetic retinopathy in its earliest stages, even before you experience symptoms. Which is why it’s important people with diabetes get regular eye checks, we’d recommend at least once a year, your Optometrist will advise you on this.

Book an appointment with one of our optometrists here.

Symptoms of stage 4 (proliferative) diabetic retinopathy include:

  • Changes in vision, i.e. vision loss or decreased field of vision

  • More eye floaters

  • Blurry or distorted vision

  • Poor night vision

  • Sensitivity to glare

  • Change in colours

Symptoms usually affect both eyes and don’t always show themselves in the stages 1-3 (nonproliferative) of diabetic retinopathy, so it’s possible to have it and not know it. This is because the blood vessels don’t always leak in these earlier stages.


Treatment options for diabetic retinopathy can vary for each individual depending on the severity of the case. If you think you may be suffering from diabetic retinopathy, book an appointment with one of our specialised optometrists. 

Treatment starts with managing your diabetes and blood sugar levels, including taking your prescribed medication as directed, eating well and exercise regularly. Keeping your blood sugar within a healthy range, can slow down the progression of vision loss.

If you have a non proliferative stage (stages 1-3) of diabetic retinopathy, treatment options could include:

- Laser surgery: reducing the drive for abnormal blood vessels and swelling in the retina.

- Eye medications: a steroid injection in the eye can stop inflammation and prevent new blood vessels forming.

- Vitrectomy: if you have stage 4 diabetic retinopathy, you may need a type of an eye surgery called Vitrectomy. Used to treat problems with the retina and vitreous, an ophthalmologist (eye surgeon) removes the vitreous (jelly type liquid that fills the middle of your eye) and replaces it with another liquid solution.


At OCULA, we believe in prevention as the first line of defence; which is why anyone with diabetes needs to ensure they get an eye examination at least once a year, or more regularly if advised by their optometrist. Our specialised optometrists will work with you to create a tailor made vision plan, so you can maintain good eye health. 

If you’ve been diagnosed with diabetes, it’s important to maintain a healthy lifestyle; including keeping those glucose levels under control. 


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How does diabetes affect my vision? Diabetes affects two main parts of your eyes: the lens and the retina. Damage to your retina (the back of your eye) is usually serious and more common for those who already have diabetes.

We like Diabetes NZ’s analogy. Similar to when you project an image onto a screen, your retina is a light sensitive disc that picks up the image (like a screen), coming through your lens (like a projector). 

If the lens (or projector) is damaged, the image on the screen (your retina) won’t be displayed correctly. Usually you can fix this by refocusing the lens (wearing prescription glasses) or putting a new lens onto the projector (which in the case of your eyes, would mean surgery to remove the old news and implant a new lens).

If you’re trying to project an image onto a screen that’s twisted, has holes or black spots in it, for example, the image won’t look as it should. Your retina acts like the screen and unfortunately if it’s damaged in this way, it can be quite hard to fix. 

What can go wrong with my retina if I have diabetes? Damage to your retina through diabetes, is an eye condition called diabetic retinopathy. It’s a process, with 4 different stages (see above for more info). Fortunately, the first few stages can often be treated successfully, or at least prevented from getting any worse.

Unlike a projector screen, your retina is a living tissue and it needs a steady blood supply to keep it happy and healthy. If something happens to the blood supply, it can damage parts of the screen. If the damage is too bad, the whole of the screen can be wiped out completely - resulting in total vision loss (blindness).


I have diabetes, should I get an eye test? Yes, it’s important that your eye health is closely monitored by regular eye examinations. We’d recommend every 2 years, or sooner if advised by your optometrist. 

There is also the national diabetic retinal screening program, which your GP can refer you to. It enables you to be screened using retinal photography on a regular basis and if a problem is detected, you’ll be referred to the public health system for treatment. Speak to your GP for more info.

How long does it take to go blind from diabetic retinopathy? As it is a slow progressing disease, vision loss can begin as early as 5 years from the diagnosis of diabetes.

Is everyone with diabetes likely to get diabetic retinopathy? While diabetes leads to diabetic retinopathy, there are factors that can increase the progression; such as: 

  • If you don't manage your diabetes well and have an unhealthy lifestyle

  • If you have had diabetes for a long time

  • If you have high blood pressure

Is there one type of diabetes that’s more closely linked with diabetic retinopathy? No, both types of diabetes (1 and 2), have a high chance of developing diabetic retinopathy.


Book an appointment

If you have been diagnosed with diabetes, it is important that you get regular eye examinations as your risk of developing diabetic retinopathy is higher. 

Book an appointment with one of our specialised optometrists to ensure you keep an eye on your general eye health.