Diabetic Retinopathy

What is diabetic retinopathy?

Diabetic retinopathy is an eye condition that can happen if you have diabetes. Over time, high blood sugar levels can damage the tiny blood vessels at the back of your eye, affecting how well you see.

At first, you might not notice any changes to your vision. But if it’s left untreated, diabetic retinopathy can get worse and may lead to permanent sight loss. Your optometrist will be able to spot signs of diabetic retinopathy during an eye test – and treatment is available if needed. Whether you’ve just been diagnosed with diabetes or you’ve had it for a while, keeping up with your eye tests is one of the best ways to protect your sight.

Types of diabetic retinopathy

Diabetic retinopathy is usually described in two main types, depending on how advanced the condition is and what changes are happening inside the eye.

Non‑proliferative diabetic retinopathy (NPDR): This is the earlier form of the condition. Tiny blood vessels in the retina become damaged and start to leak fluid or blood. In mild cases, only a few vessels are affected. In moderate to severe cases, there’s more widespread swelling, bleeding and damage. NPDR doesn’t always cause noticeable symptoms, but it can progress over time, especially without regular eye tests.
Proliferative diabetic retinopathy (PDR): This is the more advanced stage. The body tries to make up for the damage by growing new blood vessels, but these are fragile and prone to leaking. This bleeding can lead to scar tissue, which may pull on the retina and cause a retinal detachment. If left untreated, PDR can lead to serious sight loss or even permanent blindness.
Diabetic Maculopathy: Diabetic macular oedema (DMO) can develop alongside either type. It’s when fluid builds up in the macula – the part of the retina you use for sharp, central vision. It can cause blurred vision and needs monitoring or treatment.

What are the symptoms of diabetic retinopathy?

In the early stages, diabetic retinopathy might not affect your sight at all. That’s why many people don’t realise there’s a problem until the condition has progressed.

When symptoms do appear, they can vary depending on which part of the eye is affected. You might notice:

Blurred vision
Floaters and flashes or cobweb‑like shapes in your line of sight
Patchy or missing areas in your vision
Cloudy vision
Tunnel vision, where your side vision starts to narrow
Difficulty seeing at night
Halos around lights
Colours looking faded or washed out

These symptoms may come and go, or slowly get worse over time.

In advanced cases, sudden loss of vision can happen, especially if there’s bleeding inside the eye or the retina becomes detached. This is rare, but serious.

If you’re experiencing any of these changes, it’s important to book an eye test as soon as you can. Early treatment can help protect your sight.

What causes diabetic retinopathy?

Diabetic retinopathy happens when high blood sugar levels damage the small blood vessels in the retina – the part of your eye that detects light and sends signals to your brain.

Over time, raised blood sugar can make these vessels swell, leak or block up. This stops the retina from getting the oxygen it needs, which can lead to vision problems. You’re more likely to develop diabetic retinopathy if your blood sugar isn’t well controlled. But other things like high blood pressure, high cholesterol and how long you’ve had diabetes also play a role.

How is diabetic retinopathy diagnosed?

At your eye test, your optometrist will talk with you about your eye health, any changes you’ve noticed, and how your diabetes is being managed. This helps us understand your risk and decide which checks are right for you. We’ll carry out a series of painless tests to look for early signs of diabetic retinopathy:

Visual acuity test

You’ll read letters on a chart, known as a Snellen chart, so we can check how clearly you’re seeing and spot any changes since your last visit.

Tonometry

This test measures the pressure inside your eye.

Dilated eye exam

We may use special drops to widen (dilate) your pupils, so we can get a clearer view of your retina and optic nerve. Learn more about the dilated eye exam.

Digital retinal photography

A quick, painless scan that takes high‑resolution images of the back of your eye to help spot even tiny blood vessel changes.

OCT scan (optical coherence tomography)

This advanced scan captures 3D images of your retina to check for swelling or damage in greater detail. Learn more about the OCT scan.

If we find signs of diabetic retinopathy or diabetic macular oedema (DMO), we’ll explain what’s happening, recommend next steps, and refer you for diabetic eye screening or specialist care if needed.

These checks are quick, straightforward, and one of the best ways to help protect your sight.

How is diabetic retinopathy treated?

If diabetic retinopathy is caught early, you may not need treatment straight away, but you’ll need regular eye tests to keep an eye on things. If you’ve noticed changes to your sight, like blurriness, floaters or struggling to see clearly, take a look at our guide to why your eyesight might be getting worse. The right treatment depends on the stage and type of retinopathy you have. Your eye specialist will explain your options and answer any questions. You might be referred to an eye specialist for one of the following:

Laser treatment

Laser treatment seals leaking blood vessels and stops new ones from growing to help protect the retina and prevent further vision loss. There are two main types:

Focal laser photocoagulation – targets a specific affected area
Pan‑retinal photocoagulation – treats the wider peripheral retina

Laser treatment is done under local anaesthetic at an outpatient clinic. Your pupils will be widened with drops, and a special lens will keep your eye open. You may feel a mild pricking sensation in some areas, but most people don’t find it painful. The whole procedure usually takes 20–40 minutes.

After treatment, your vision may be blurry for a few hours, and you’ll be sensitive to light, so bring sunglasses and arrange for someone to drive you home. It may take several sessions and a few months to see the full benefit.

Eye injections

Injections, known as anti‑VEGF drugs, help reduce swelling in the macula and stop abnormal blood vessel growth. Sometimes steroids are used instead.

The injection is given under local anaesthetic, using a fine needle. You may need monthly injections at first, with fewer as your condition stabilises.

Side effects can include floaters, mild irritation, or watery eyes, but the treatment is safe and can improve vision in many people.

Eye surgery (vitrectomy)

In more advanced cases, surgery may be needed to remove blood or scar tissue from inside the eye. This is called a vitrectomy.

It’s usually done under local anaesthetic and sedation. You’ll go home the same day or the next, wearing an eye patch for a few days. It can take several months for your vision to settle afterwards.

While risks like infection or retinal detachment are rare, the surgery is considered safe and helps improve or stabilise vision in most patients.

Book an eye test

Can diabetic retinopathy be prevented?

You can’t always prevent diabetic retinopathy, but there’s a lot you can do to lower your risk and slow it down. Managing your diabetes well and having regular eye checks makes a real difference. Here are six things that help protect your eyes:

Keep your blood sugar in check. The better your control, the lower the risk of damage to the blood vessels in your eyes.
Manage your blood pressure. High pressure puts extra strain on the delicate vessels in the retina.
Watch your cholesterol. Raised cholesterol can affect blood flow to your eyes.
Don’t smoke. Smoking reduces circulation and speeds up damage to blood vessels.
Go to all your diabetes check‑ups. This includes foot checks, blood tests and other health reviews.
Get regular eye checks. A yearly diabetes eye screening or eye test helps spot any changes early, when treatment works best.

Even if you already have early signs of diabetic retinopathy, these steps can still help stop it from getting worse.