Diabetic Screening at Classic Eyes
Dorset Diabetic Screening Programme
The Dorset Diabetic Eye Screening Programme serves the diabetic population of Dorset and is available for patients aged 12 and over.
Patients are referred to the programme by their General Practice for screening, grading & referring to the Hospital Eye Services as required.
More information about the Dorset Diabetic Screening Programme is available from their website: despdorset.co.uk/
What is diabetic retinopathy?
Diabetic retinopathy is a complication of diabetes and a leading cause of blindness. It occurs when diabetes damages the tiny blood vessels inside the retina, the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision. If you have diabetic retinopathy, at first you may not notice changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.
What are the stages of diabetic retinopathy?
Diabetic retinopathy has four stages:
1. Mild non-proliferative retinopathy — At this earliest stage, microaneurysms occur, which are small areas of balloon-like swelling in the retina’s tiny blood vessels.
2. Moderate non-proliferative retinopathy — As the disease progresses, some blood vessels that nourish the retina are blocked.
3. Severe non-proliferative retinopathy — Many more blood vessels are blocked, depriving several areas of the retina with their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment.
4. Proliferative retinopathy — At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye. By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can result.
Who is at risk for diabetic retinopathy?
All people with diabetes — both type 1 and type 2 — are at risk. That is why everyone with diabetes should get a comprehensive eye exam at least once a year. Between 40-45% of people diagnosed with diabetes have some stage of diabetic retinopathy. If you have diabetic retinopathy, we can recommend treatment to help prevent its progression. During pregnancy, diabetic retinopathy may be a problem for women with diabetes. To protect vision, every pregnant woman with diabetes should have a comprehensive eye exam as soon as possible. Your doctor may recommend additional exams during your pregnancy.
How does diabetic retinopathy cause vision loss?
Blood vessels damaged from diabetic retinopathy can cause vision loss in two ways:
- Fragile, abnormal blood vessels can develop and leak blood into the center of the eye, blurring vision. This is proliferative retinopathy and it is the fourth and most advanced stage of the disease.
- Fluid can leak into the center of the macula, the part of the eye where sharp, straight-ahead vision occurs. The fluid makes the macula swell, blurring vision. This condition is called macular edema. It can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses. About half of the people with proliferative retinopathy also have macular oedema.
Does diabetic retinopathy have any symptoms?
Diabetic retinopathy often has no early warning signs. Don’t wait for symptoms. Be sure to see us at least once a year for a comprehensive dilated eye exam.
What are the symptoms of proliferative retinopathy if bleeding occurs?
At first, you will see a few specks of blood, or spots, “floating” in your vision. If spots occur, see us as soon as possible. You may need treatment before more serious bleeding occurs. Haemorrhages tend to happen more than once, often during sleep. Sometimes, without treatment, the spots clear, and you will see better. However, bleeding can re-occur and cause severely blurred vision. You need to be examined at the first sign of blurred vision, before more bleeding occurs. If left untreated, proliferative retinopathy can cause severe vision loss and even blindness. Also, the earlier you receive treatment, the more likely treatment will be effective.
How are macular oedema and diabetic retinopathy detected?
Macular oedema and diabetic retinopathy are detected during a comprehensive eye exam. We check your retina for early signs of the disease, including:
- Leaking blood vessels.
- Retinal swelling (macular edema).
- Pale, fatty deposits on the retina—signs of leaking blood vessels.
- Damaged nerve tissue.
- Any changes to the blood vessels.
The images from the Optomap allow us to monitor changes to your retina from year to year so it is vital to see us regularly.
How is macular oedema treated?
Macular edema is treated with laser surgery. This procedure is called focal laser treatment. The ophthalmologist places up to several hundred small laser burns in the areas of retinal leakage surrounding the macula. These burns slow the leakage of fluid and reduce the amount of fluid in the retina. The surgery is usually completed in one session. Further treatment may be needed. A patient may need focal laser surgery more than once to control the leaking fluid. If you have macular oedema in both eyes and require laser surgery, generally only one eye will be treated at a time, usually several weeks apart.
Focal laser treatment stabilises vision. In fact, focal laser treatment reduces the risk of vision loss by 50%. In a small number of cases, if vision is lost, it can be improved.
How is diabetic retinopathy treated?
During the first three stages of diabetic retinopathy no treatment is needed, unless you have macular oedema. To prevent progression of diabetic retinopathy, people with diabetes should control their levels of blood sugar, blood pressure, and blood cholesterol. Proliferative retinopathy is treated with laser surgery. This procedure is called scatter laser treatment, which helps shrink the abnormal blood vessels. The ophthalmologist places 1,000 to 2,000 laser burns in the areas of the retina away from the macula, causing the abnormal blood vessels to shrink. Because a high number of laser burns are necessary, two or more sessions usually are required to complete treatment. Although you may notice some loss of your side vision, scatter laser treatment can save the rest of your sight. Scatter laser treatment may slightly reduce your color vision and night vision. It works better before the fragile, new blood vessels have started to bleed. That is why it is important to have regular, comprehensive eye exams. Even if bleeding has started, scatter laser treatment may still be possible, depending on the amount of bleeding.
If the bleeding is severe, you may need a surgical procedure called a vitrectomy. During a vitrectomy, blood is removed from the center of your eye.
What can I do if I already have lost some vision from diabetic retinopathy?
If you have lost some sight from diabetic retinopathy, we have a low vision clinic that can provide devices that may help you make the most of your remaining vision.
What can I do to protect my vision?
Everyone with diabetes should have a comprehensive eye exam at least once a year. In some cases you may need an eye exam more often.
People with proliferative retinopathy can reduce their risk of blindness by 95% with timely treatment and appropriate follow-up care. A major study has shown that better control of blood sugar levels slows the onset and progression of retinopathy.
The people with diabetes who kept their blood sugar levels as close to normal as possible also had much less kidney and nerve disease. Better control also reduces the need for sight-saving laser surgery. This level of blood sugar control may not be best for everyone, including some elderly patients, children under age 13, or people with heart disease.
Be sure to ask your doctor if such a control program is right for you. Other studies have shown that controlling elevated blood pressure and cholesterol can reduce the risk of vision loss. Controlling these will help your overall health as well as help protect your vision.
Optomap image showing diabetic retinopathy
Text, images and photographs taken from www.optos.com