What is diabetic retinopathy?

Posted on 1 November 2021

Specialist ophthalmologist Dr Steve Steyn is based at Mediclinic Welkom and Mediclinic Stellenbosch. He provides information on how diabetes can affect your eyesight.

If you live with diabetes, it’s vital to understand the effects of fluctuating blood sugar (high or very low) on your body, including your eyes and kidneys. We look at potential effects as well as potential treatments for these conditions.

It can damage the walls of the small blood vessels in these organs, altering their structure and function. The blood vessels may thicken, leak, develop clots, close off, or grow balloon-like defects in your eyes called micro aneurysms. Frequently, fluid accumulates in the part of the retina used for reading; this condition is called macular oedema.

In advanced cases, the retina has poor blood supply – causing it to grow new, but defective, blood vessels – a process called neovascularisation. These fragile vessels can bleed, creating vision-impairing haemorrhages, scar tissue, and retinal detachment (separation of the retina from the back of the eye). The new vessels can also block fluid flow within the eye, increase pressure, and ultimately cause glaucoma.

Everyone living with diabetes should have an annual eye examination at an ophthalmologist to ensure diabetic retinopathy is detected early and treated. Some signs of diabetic retinopathy can’t be seen during a refraction eye test and require special examinations. To get a better look at the inside of the eye, your doctor might administer drops to dilate your pupils and then view the retina with lenses and a special light called a slit lamp. The eye examination will likely also include a check for glaucoma and cataracts. These conditions occur more frequently in people with diabetes, and both can cause severe vision problems.

Treatment for diabetic retinopathy

Treatment for diabetic retinopathy should involve both a medical doctor and an ophthalmologist. Your medical doctor can help you better control blood sugar and can treat other complications of diabetes that may worsen diabetic retinopathy, such as impaired kidney or heart function. Your ophthalmologist can treat retinopathy directly with a laser or a surgical procedure called vitrectomy. This will prevent further vascular changes and preserve vision. Don’t be surprised if your doctor recommends one of these treatments as a preventative measure even before you notice any vision problems.


New eye treatment options include injections into the back of the eye to treat diabetic retinopathy and its vision-threatening causes. The injections are safe, painless and have the greatest potential to maintain your vision. We encourage you to discuss these potential treatments with your ophthalmologist.

Photocoagulation (laser treatment)

This works in part by creating tiny, painless retinal burns that seal off leaking vessels and reduce swelling. The number of burns and the number of treatments you need depend on the type and extent of your retinopathy and how well it responds to treatment. You may have to wait several months to find out how much effect the treatment is having.

Vitrectomy surgery

Your doctor may recommend this if:

  • You have haemorrhage/ bleeding that doesn’t clear
  • Retinal detachment
  • Laser treatment doesn’t sufficiently halt the growth of new vessels. During vitrectomy, your doctor drains the gel-like substance inside the back of the eye, allowing the clearing of any lingering blood and removal of scar tissue.

Treatments can be very effective, but your expectations should be realistic; talk to your treating ophthalmologist. Typically, laser or surgical treatment will not restore lost vision – however, treatment can prevent any additional loss of eyesight. If you already have vision loss, your doctor can counsel you about treatment options for visual rehabilitation.

Prevention of diabetic retinopathy

Studies have shown that maintaining near-normal or stable blood sugar can decrease the chance of developing retinopathy and help keep existing retinopathy from getting worse. Your GP/physician can provide guidelines that may include insulin and other medications, diet changes, and exercise. Intensive insulin therapy, which may require frequent blood sugar testing and use of an insulin pump, may be an option. It’s not always easy to stick to the disciplined lifestyle necessary to control your blood sugar. We encourage you to speak to your doctor if you need extra support with this.

Pregnancy can precipitate or worsen retinopathy in women with diabetes who take insulin, so if you’re considering pregnancy, discuss the risks with your doctor. They’ll usually recommend an eye examination before pregnancy, a second examination during the first trimester, and additional examinations at intervals based on the status of your retinopathy. Women who suddenly develop diabetes during a pregnancy (gestational diabetes) are not at risk of developing retinopathy during the pregnancy.

High blood pressure, high blood cholesterol, and obesity can all promote diabetic retinopathy and should be treated. Smoking is a major culprit, so consult your doctor about methods to assist in quitting. Never ignore the symptoms of infection, which can worsen diabetic retinopathy. Cataract surgery can affect existing retinopathy, too; talk to your doctor about the timing of treatments for retinopathy and cataracts.

Researchers continue to investigate new drugs that may prevent or slow diabetic retinopathy – your doctor can provide information about this. Depending on the severity of your diabetes and related complications, you may also want to discuss the options of pancreas and kidney transplants, which can protect against retinopathy.


Published in Diabetes

In the interest of our patients, in accordance with SA law and our commitment to expertise, Mediclinic cannot subscribe to the practice of online diagnosis. Please consult a medical professional for specific medical advice. If you have any major concerns, please see your doctor for an assessment. If you have any cause for concern, your GP will be able to direct you to the appropriate specialists.