Diabetic eye screening

July 21, 2018

Diabetic eye screening is a key part of diabetes care. People with diabetes are at risk of damage from diabetic retinopathy, a condition that can lead to sight loss if it's not treated.

Diabetic retinopathy is one of the most common causes of sight loss among people of working age.

It occurs when diabetes affects small blood vessels, damaging the part of the eye called the retina. When the blood vessels in the central area of the retina (the macula) are affected, it's known as diabetic maculopathy.

People with diabetes should also see their optician every two years for a regular eye test. Diabetic eye screening is specifically for diabetic retinopathy and can't be relied upon for other conditions.

Why eye screening is needed

Screening is a way of detecting the condition early before you notice any changes to your vision. Diabetic retinopathy doesn't usually cause any noticeable symptoms in the early stages.

If retinopathy is detected early enough, treatment can stop it getting worse. Otherwise, by the time symptoms become noticeable, it can be much more difficult to treat. This is why the NHS Diabetic Eye Screening Programme was introduced.

Everyone aged 12 and over with diabetes is offered screening once a year. Diabetic retinopathy is extremely unusual in children with diabetes who are under the age of 12.

The check takes about half an hour and involves examining the back of the eyes and taking photographs of the retina.

When diabetic eye screening is offered

Everyone with diabetes who is 12 years of age or over should be invited to have their eyes screened once a year.

You should receive a letter from your local Diabetic Eye Screening Service inviting you to attend a screening appointment. The letter will include a leaflet about diabetic eye screening.

People with diabetes can opt out of the screening programme if they choose. They should confirm this decision in writing to the screening service that has invited them for diabetic eye screening

Contact your local screening service or your GP if you haven't received a letter and your appointment is overdue. You can look up your local screening service here – your service will be the one nearest to your GP surgery.

The invitation will say where you need to go. This may be your GP surgery, your local hospital, a local optician's practice, or another nearby clinic.

Bring all the glasses and contact lenses you wear, along with lens solution for contacts.

If you have sight problems in between screening appointments, such as sudden vision loss or a deterioration in your vision, seek immediate medical advice. Don't wait until your next screening appointment.

Diabetic eye screening in pregnancy

If you have diabetes and become pregnant, you'll need special care as there are risks to both mother and baby associated with the condition.

You'll be offered additional tests for diabetic retinopathy at or soon after your first antenatal clinic visit, and also after 28 weeks of pregnancy.

If the early stages of retinopathy are found at the first screening, you'll also be offered another test between 16 and 20 weeks of pregnancy.

If serious retinopathy is found at any screening, you'll be referred to an eye specialist.

Some women who don't have diabetes can develop hyperglycaemia (high blood sugar) during pregnancy. This is known as gestational diabetes.

Pregnant women who develop gestational diabetes aren't offered screening for diabetic retinopathy.

What happens during diabetic eye screening

The screening appointment should last about 30 minutes.

When you arrive, the procedure will be explained to you. If you have any questions, ask the healthcare professional who is treating you.

You'll be given eye drops to enlarge your pupils, which takes between 15 and 20 minutes, and photographs of your retina will be taken.

There will be a flash of light each time a photograph is taken, but the camera won't touch your eye. Although the light is bright, it shouldn't be uncomfortable.

The eye drops may cause your eyes to sting slightly, and after about 15 minutes your vision will be blurred. You may find it difficult to focus on objects that are close to you.

Depending on the type of eye drops used, the blurring can last between two and six hours. You won't be able to drive home from your appointment, so you may want to bring someone with you.

After the screening procedure, you may also find that everything looks very bright. You may want to take a pair of sunglasses to wear afterwards.

Side effects

In very rare cases, the eye drops can cause a sudden pressure increase within the eye. This requires prompt treatment at an eye unit.

The symptoms of a pressure increase are:

pain or severe discomfort in your eye
redness of the white of your eye
constantly blurred vision, sometimes with rainbow halos around lights

If you experience any of these symptoms after screening, go back to the screening centre or your nearest accident and emergency (A&E) department.

Your screening results

Within six weeks, both you and your GP should receive a letter letting you know your results.

You won't get the results immediately as the photographs need to be studied by a number of different healthcare professionals, including someone who is trained in identifying and grading retinopathy.

The screening results may show either:

no retinopathy
background retinopathy – also called stage one retinopathy
degrees of referable retinopathy – this means retinopathy that requires referral to an eye specialist for further assessment and treatment

You may need to have a further assessment if:

the photographs aren't clear enough to give an accurate result
you have retinopathy that could affect your sight and follow-up treatment is needed
you have retinopathy that needs to be checked more than once a year
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 your results show no retinopathy or background retinopathy, you'll be invited back for another screening appointment a year later.

You can also reduce your risk of developing diabetic retinopathy in the future by controlling your blood sugar levels and blood pressure.

Read more about preventing diabetic retinopathy.

If screening detects signs that diabetic retinopathy or maculopathy is threatening your sight, you'll be given information about how far the condition has progressed. This will determine the type of treatment you receive.

Read about the treatment options for diabetic retinopathy and maculopathy.

If you have questions about your results, contact your local diabetic eye screening service. Their details should be on the letter you received from them. Alternatively, you can find your local screening service here.

Private screening for diabetic retinopathy

Eye checks for diabetic retinopathy are available privately but they won't necessarily be quality-assured in the same way as the NHS Diabetic Eye Screening Programme.

If you're considering private screening, check that the company is properly regulated and ask for clear written information about the benefits as well as the risks of any tests offered.

Find further information in the UK National Screening Committee's leaflet on private screening.