Eye screening is a key part of your diabetes care. If you have diabetes, your eyes are at risk of damage from diabetic retinopathy, a condition that can lead to sight loss if it's not treated.
Diabetic retinopathy 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 is known as diabetic maculopathy.
Diabetic retinopathy is one of the most common causes of sight loss among people of working age.
However, you may not know that you have diabetic retinopathy as it does not usually cause any noticeable symptoms in the early stages.
Screening is a way of detecting the condition early before you notice any changes to your vision.
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.
The check takes about half an hour and involves examining the back of the eyes and taking photographs of the retina.
Read on to find out when screening is offered, what happens at your screening appointment, and what you'll learn from your screening results.
When is diabetic eye screening 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.
Contact your local screening service or your GP if you have not received a letter and your appointment is overdue.
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. Do not wait until your next screening appointment.
Diabetic eye screening in pregnancy
If you have diabetes and become pregnant, you will 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 will also be offered another test between 16 and 20 weeks of pregnancy.
If serious retinopathy is found at any screening, you will be referred to an eye specialist.
Some women who do not have diabetes can develop hyperglycaemia (high blood sugar) during pregnancy. This is known as gestational diabetes.
Pregnant women who develop gestational diabetes are not offered screening for diabetic retinopathy.
Other eye checks
Diabetic eye screening is not covered as part of your normal eye examination with an optician.
Screening does not look for other eye conditions, so you should continue to visit your optician regularly for an eye examination as well.
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 will 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 will not touch your eye. Although the light is bright, it should not 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.
In very rare cases, the eye drops can cause a sudden pressure increase within the eye.
This will require 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 will not get the results immediately as the photographs will 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 are not 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 will 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.
If screening detects signs that diabetic retinopathy or maculopathy is threatening your sight, you will be given information about how far the condition has progressed. This will determine the type of treatment you receive.
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.
For more information on diabetic eye screening, see our diabetic eye screening FAQs.