Diabetic eye problems

Diabetic eye problems include a range of symptoms such as floaters, blurred vision or sudden loss of vision caused by damage to the eye from diabetes, called diabetic retinopathy.

Around one-third of people with diabetes have diabetic retinopathy, and it's a leading cause of blindness in working-age adults (Source: Eye and Vision). However, the UK's diabetic screening programme has shown that early detection and intervention can reduce the impact of diabetic retinopathy and associated eye problems (Source: BMJ).

If you have diabetes, it's essential that you attend your annual diabetic eye screening and regular ophthalmology check-ups to identify and treat any diabetic eye problems early on.

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Diabetic eye screening

Diabetic eye screening is an annual test for all people with diabetes over the age of 12. People with both type 1 diabetes and type 2 diabetes are eligible. The test looks for any eye problems due to diabetes. Sometimes, the signs of diabetic eye disease go unnoticed, so a diabetic eye test checks for problems before they affect your sight. If eye problems are left undetected and untreated, they can lead to further complications and even sight loss.

Gestational diabetes generally resolves once the baby is born, so diabetic eye screening is unnecessary for this type of diabetes.

What does a diabetic eye exam consist of?

A dilated eye exam allows your optometrist or eye doctor to get a very detailed view of any changes in the eye caused by diabetes so that they can identify issues early on. First, your eyesight will be checked by asking you to read some letters on a chart before eye drops are put in to dilate the pupil of your eye. The eye drops may sting and cause blurry vision. Once the eye drops have taken effect, a camera will be used to take photographs of the back of your eye. Your vision may remain blurry for a few hours after the exam, so you might need someone to drive you home.

Diabetes and eye tests

People diagnosed with diabetes are eligible for yearly eye tests as part of the diabetic eye screening programme. Eye tests can pick up on changes in your vision, check overall eye health and identify anything of concern that might need further investigation.

All adults, even those not experiencing eye problems, are advised to get an eye test at least every two years (Source: NHS). Sometimes, routine eye tests detect early changes that are a sign of undiagnosed diabetes.

How does diabetes affect the eyes?

High blood sugar levels can damage the tiny blood vessels in the back of the eyes, causing a range of problems collectively known as diabetic eye disease. As a result of this damage, your eyes create abnormal new blood vessels on the retina of the eye, but these are weak and can cause bleeding and other problems in a condition called proliferative diabetic retinopathy.

In the early stages, these changes can go unnoticed, but they can cause eye floaters, blurred vision and even blindness as they progress. Damaged blood vessels can leak and bleed, and this can collect at the back of the eye, affecting central vision (macular oedema).

Eventually, the blood supply to the retina is compromised, and scar tissue develops, leading to loss of vision. If caught early, lifestyle changes and careful control of blood sugar can prevent the damage from getting worse. If your eyesight is at risk, possible treatments include laser therapy, medication injections or surgery.

Diabetes eye symptoms

Diabetes can affect your eyes and vision in many ways. The most common symptoms of diabetic eye disease include:

Blurry or fuzzy vision, sometimes changing during the day
Eye floaters
Poor colour vision
Double vision

If you have diabetes and are experiencing any of these symptoms, see your optometrist for advice.

Diabetic eye conditions

Diabetes-related eye complications can all lead to loss of vision if left untreated. Different parts of the eye can be affected, including the retina, macula, optic nerve and lens. Your optometrist will check for each of these conditions during your diabetic eye exam.

The retina is a delicate part of the eye that senses light and sends information to your brain to convert the light signals into vision. High blood sugars damage the tiny blood vessels that feed the retina, leading to a condition called diabetic retinopathy.

There are different stages of diabetic retinopathy:

The very early stage of diabetic retinopathy is known as background retinopathy. The tiny blood vessels start to bulge (microaneurysms) or begin to leak (dot and blot haemorrhages), but eyesight is unaffected.

At the next stage, called pre-proliferative diabetic retinopathy, blood vessels become weaker and start to leak and bleed into the retina. There is a higher risk that eyesight will be affected.

In advanced stage diabetic retinopathy, known as proliferative diabetic retinopathy, new, abnormal blood vessels grow on the retina, causing severe damage to the eye. This stage can cause retinal detachment and vision loss.
The macula is a part of your retina responsible for your central vision and helps you see fine detail and colour. Diabetic macular oedema occurs when leaky blood vessels cause a build-up of fluid at the back of the eye that damages the macula and affects your central vision. Damage to the macula is known as maculopathy.
Cataracts occur when proteins in the eye's lens break down, causing clouding. The exact link between diabetes and cataracts remains somewhat unclear, but studies suggest that people with diabetes are three or four times more likely to develop cataracts (Source: World Journal of Diabetes). Your ophthalmologist will look for any signs of cataracts during your diabetic eye screen.
Glaucoma is an eye condition caused by damage to the optic nerve at the back of the eye. Having diabetes increases the likelihood of developing glaucoma (Source: International Journal of Ophthalmology). Abnormal new blood vessels in advanced diabetic eye disease can also lead to sight-threatening glaucoma (neovascular glaucoma).

How long does it take for diabetes to damage the eyes?

There is no set timeline for how long it takes for diabetes to damage the eyes, but the longer someone has diabetes, the greater the chance of developing eye problems. Early detection is the key to reducing the risk.

Is eye damage from diabetes reversible?

Diabetic retinopathy cannot be reversed, but careful blood sugar control can help minimise any damage, and treatment can sometimes prevent further deterioration.

Diabetic eye disease treatment

The treatment for diabetic eye disease depends on the cause and severity of the problem.

Regular eye exams can detect early changes. If damage does occur, treatment options include laser eye surgery, eye injections and eye vitamins.

In an attempt to repair the damage to the blood vessels in the back of the eye, your body creates new blood vessels that are often weak and can bleed into the eye, causing further problems. A type of laser eye surgery called laser photocoagulation is used to treat these new blood vessels.

Laser treatment can also reduce the cause of the fluid build-up in the eye that causes macular oedema.

In some advanced cases, where laser therapy is unsuccessful, surgery may be necessary to remove blood in the vitreous (vitrectomy) or treat retinal detachment or scarring.
In some cases, eye injections are used to stop the production of weak, abnormal blood vessels in the back of the eyes. The procedure involves numbing the eye with anaesthetic before injecting a medication called anti-VEGF or a steroid medication. To start with, you may need injections once a month until your condition stabilises.

Frequently asked questions

Yes, with good diabetes care from specialist healthcare professionals, you can:

Keep your blood glucose levels under control

Maintain normal blood pressure and cholesterol level

Eat a healthy diet

Take regular exercise

Try and stop smoking

Conclusion

Diabetes and eye health are closely linked. Diabetic retinopathy is a common complication of diabetes and can damage eyesight and cause vision loss. Other diabetic eye problems include cataracts, glaucoma and diabetic macular oedema.

People with diabetes should attend regular eye screening, practice good eye care, and take advice from specialist healthcare professionals to quickly identify and treat any eye changes.

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Medically reviewed by: The Royal College of Ophthalmologists on 06/09/2022

Edited by: Nick Astbury FRCS FRCOphth FRCP
Clinical Associate Professor
LSHTM

The Royal College of Ophthalmologists champions excellence in the practice of ophthalmology and is the only professional membership body for medically qualified ophthalmologists. The RCOphth is unable to offer direct advice to patients. If you’re concerned about the health of your eyes, you should seek medical advice from your GP, optometrist or ophthalmologist.