Everyone with diabetes is at risk of developing diabetic eye disease. Most people consider sight to be their most precious sense so it is critical to be aware of the risk of diabetic eye disease and to understand how to prevent its onset. For those who already have diabetic eye disease, there are steps to take to reduce the risk of further vision loss.
Managing diabetes can be difficult. Living with diabetic retinopathy and the potential impact it can have on vision can be challenging. Providing it is diagnosed early and all steps are taken to keep it under control, most people with diabetic retinopathy should keep most, if not all, of their vision.
IMPORTANT: When you see your eye care professional make sure you explain that you have diabetes and how long you have had it.
- If you have diabetes you will need to visit an eye specialist (ophthalmologist) or an optometrist at least every two years for a comprehensive, dilated eye exam.
- People with diabetes at high risk, including indigenous people, need to have an eye check at least every 12 months. Even if vision appears to be perfect.
- People with existing diabetic eye disease need to have an eye check every 12 months, or more frequently if disease is advanced.
- Be guided by the eye care professional and do not cancel or delay appointments unless absolutely essential.
- The longer you have had diabetes the more important it is to have regular eye tests, even if the tests have always been clear in the past. This is because the risk of eye disease is strongly related to the duration of diabetes.
Diabetes is a very serious condition. It requires daily self-management and personal responsibility including the management of blood glucose levels, blood pressure and blood lipids through the maintenance of a healthy weight, healthy diet and healthy activity. Access to a multidisciplinary health professional team will support diabetes care in an individual manner.
Three main types of diabetes
- Type 1 diabetes is an autoimmune condition in which the immune system is activated to destroy the cells in the pancreas, which produce insulin. It is not known what causes this autoimmune reaction.
- Type 1 diabetes is not linked to modifiable lifestyle factors and cannot be prevented.
- Type 1 diabetes can occur at any age though onset is commonly in children, adolescents and young adults.
- All people with type 1 diabetes need insulin therapy to survive.
- Type 2 diabetes is a chronic condition in which the body becomes resistant to the normal effects of insulin and/or gradually loses the capacity to produce enough insulin in the pancreas. It is not known what causes type 2 diabetes.
- Type 2 diabetes is associated with modifiable lifestyle risk factors (overweight/obesity, unhealthy diet, physical inactivity, stress). Type 2 diabetes also runs in families.
- Type 2 diabetes commonly develops in adults, although it is becoming more common among children and young adults.
- Gestational diabetes is a type of diabetes that occurs during pregnancy and affects 5-10% of pregnancies in Australia. This condition normally disappears after the baby is born, however both the mother and the baby have a higher chance of developing type 2 diabetes later in life.
Over time high blood glucose levels can lead to damage of the small, specialised blood vessels in the retina at the back of the eye. The vessels become weaker and may leak clear fluid and/or become blocked. This is called non-proliferative diabetic retinopathy and normally does not affect vision.
Leakage of fluid from damaged retinal blood vessels can result in swelling of the retina (edema) and disrupt its normal function. If this swelling is in the central macular area (causing diabetic macular edema or DME) it can cause progressive loss of detailed, central vision and even legal blindness, although it won't cause "black" or total blindness. DME is the most common cause of vision loss in people with diabetic retinopathy and frequently affects both eyes at the same time.
Blockage of small retinal blood vessels can disrupt macular function and can cause potentially blinding proliferative diabetic retinopathy (PDR). If sufficient blockage occurs there is a reduction in the supply of oxygen (ischaemia) to the retina. Nature tries to fix this by growing new blood vessels from the retina. Unfortunately, these new vessels are abnormal and are very fragile. They grow forward into the central gel cavity of the eye where they tend to break and bleed, obstructing vision.
The process is progressive and without any symptoms until the vessels bleed. These vessels then scar and may pull on the retina, possibly causing the retina to detach. If proliferative diabetic retinopathy is not treated early, it can result in total blindness.
With time, the majority of people with diabetes will develop retinopathy, however the severity of disease is greatly influenced by how well diabetes is controlled.