What is diabetic retinopathy?

Diabetic retinopathy is one of the leading causes of preventable blindness in Australia. According to the Centre for Eye Research Australia, one in three people with diabetes are diagnosed with diabetic retinopathy.

There are two different types of diabetic retinopathy:

1. Non-proliferative diabetic retinopathy (NPDR) is the more common form and occurs gradually over time. When you have NPDR, the walls of the blood vessels in your retina weaken due to increased blood glucose levels. Smaller blood vessels can develop tiny bulges n their walls which can sometimes leak fluid and blood into the retina or become blocked. Some of the larger vessels may begin to dilate and become irregular.

As NPDR worsens, it may progress to proliferative diabetic retinopathy and lead to more severe vision loss.

2. Proliferative diabetic retinopathy (PDR) is the more severe form of diabetic retinopathy and can lead to blindness if not treated early. PDR occurs when a reduced oxygen supply to the retina stimulates the growth of new blood vessels (neovascularisation). These new fragile blood vessels tend to leak and bleed and can create scar tissue.

Other complications you may experience due to diabetic retinopathy may include:

Macular oedema, which can occur in both NPDR and PDR when fluid leaking from either the damaged or new retinal blood vessels builds up in the macula, causing swelling.

The macula is a small oval shaped area, about 5.5 mm in diameter, responsible for your sharp central vision and most of your colour vision. The macula is used for looking at fine detail of objects at all distances, near and far.

Retinal detachment can occur in PDR where scar tissue from the growth of new blood vessels can cause the retina to detach from the back of the eye. Symptoms include spots floating in your vision and/or flashes of light, often in your peripheral/side vision.

Glaucoma can occur in PDR if the new blood vessels interfere with the normal flow of fluid out of the eye, leading to increased pressure inside the eye. Read this article for more information on glaucoma.