The retina is a layer of special light-sensitive tissue at the back of the eye that sends nerve impulses up the optic nerve to the brain. This process is responsible for vision. If the retina becomes damaged by disease,
Then the quality of vision is affected or even lost. In people with diabetes, tiny blood vessels in the retina may become diseased and damaged due to the effects of diabetes. Diabetes can cause the blood vessels to swell and leak blood or fluid around the retina. As they heal, scar tissue forms on the retina. These problems can damage the retina so badly that the retina functions less effectively and vision is impaired.
This disease process is called diabetic retinopathy. It usually affects the retina slowly, over months or years. The longer a person has diabetes, the greater the risk of diabetic retinopathy occurring.
The area of the retina that provides the sharpest vision is called the macula.
Leaking blood or fluid can cause the macula to swell, which is called macular oedema. This causes blurred vision and is a common result of diabetic retinopathy.
Blood vessels can grow and eventually bleed. This can cause a less common but more damaging form of retinopathy that can lead to blindness.
Diabetic retinopathy is the leading cause of new cases of blindness in adults in Australia, New Zealand and most Western countries. All people with diabetes are at risk of developing retinopathy to some degree.