Diabetic retinopathy

What is diabetic retinopathy?

Diabetic retinopathy is the most common diabetic eye disease and the leading cause of blindness. It is caused by changes to the small blood vessels of the retina (light-sensitive tissue at the back of the eye).

What are the stages of diabetic retinopathy?

There are 3 main stages:

  • Background diabetic retinopathy

This is very common in people who have had diabetes for a long time. At this early stage, small blood vessels of the retina are mildly damaged causing mild retinal swelling and leakage of blood and fluid. Vision is usually normal at this stage.

  • Diabetic maculopathy

Damaged blood vessels can swell and leak fluid leading to swelling of the centre of the retina (the macula). When this happens, central vision will be affected.

  • Proliferative diabetic retinopathy

As the disease progresses, new blood vessels can grow on surface of the retina. These blood vessels are abnormal and fragile. They can rupture, causing bleeding within the eye (vitreous haemorrhage) and sudden visual loss. Scarring can also occur which pulls on the retina, causing further damage and more severe visual loss.

What symptoms will I experience if I have diabetic retinopathy?

Patients with early diabetic retinopathy are asymptomatic and usually have good vision. However, as the disease progresses, they may complain of:

  • Blurring of central vision
  • Sudden visual loss
  • Seeing floaters and flashes
  • Fluctuation in vision

How can I prevent diabetic retinopathy?

Regular screening and early detection is the key to management of diabetic retinopathy. All diabetic patients should have their eyes examined at least once a year. There are often no symptoms in the early stages of the disease, so don’t wait till the onset of symptoms before seeking help.

Many studies have demonstrated that good control of blood sugar can slow the onset and progression of diabetic retinopathy. Other studies have shown that controlling high blood pressure and raised cholesterol can also reduce the risk of vision loss.

How are diabetic retinopathy treated?

During the early stages of the disease, no treatment is needed. Patients will be advised to control their levels of blood sugar and attend regular follow-up. For more advanced disease, different treatments are available. These are:

  • Laser treatment

Laser treatment aims to reduce retinal swelling by sealing the damaged blood vessels. It can also cause a regression of abnormal blood vessels, thus reducing the risk of bleeding.

  • Surgery

In patients with advanced disease, intraocular surgery such as a vitrectomy may be needed to remove blood clot and scar tissue.

  • Injection of medication into the eye

Many recent studies have demonstrated the benefits of injecting some medications (such as steroid and anti-VEGF) into the eye. These may help to improve vision in some patients.