Why do diabetics need an eye screening?
The most serious eye condition is diabetic retinopathy. It occurs when the high blood glucose in diabetes damages the small blood vessels of the retina, the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision. About 22% of diabetics in Singapore are affected by diabetic retinopathy, making it the most common type of visual impairment in the country. This condition is generally painless condition with no obvious symptoms in its early stage. However, sudden loss of vision may occur when the condition worsens. For this reason, most of these cases go undetected until its very advanced stage, where the structural damage is no longer reversible.
Diabetic patients develop cataract (clouding of the natural crystalline lens in the eye) at earlier age compared to those without diabetes.
For more information about cataract, click here.
People with diabetes are 40% more likely to suffer from glaucoma (a condition where the nerves in the eye are damaged due to increase in high pressure) than people without diabetes. The longer someone has had diabetes, the more common glaucoma is. Moreover, glaucoma is also termed as the ‘silent thief of sight’, as there may be no symptoms at all until the disease is very advanced and leads significant vision loss.
For more information about glaucoma, click here.
Regular eye screening is therefore the key to early detection of diabetic eye diseases, a term that is used to describe the group of eye diseases associated with diabetes, hence reduce the risk vision loss and preserve good vision.
Normal clear vision versus vision disturbance in severe diabetic retinopathy
How does Diabetic Retinopathy cause vision loss?
There are 3 types of diabetic retinopathy:
Non-proliferative diabetic retinopathy is the earliest stage of diabetic retinopathy. In this stage, the damaged tiny blood vessels in the retina may begin to leak fluid and small amounts of blood hence causing the retina to swell or forming yellowish deposits at the back of your eye.
This is the most severe type of diabetic retinopathy. It occurs when new blood vessels begin to grow in the inner part of the retina. As these vessels are mostly abnormal and fragile, they may eventually lead to bleeding in the eye and in severe cases, form scar tissue that may cause the retina to wrinkle or detach.
This condition occurs when the damaged blood vessels allow fluid to leak into the most visually important part of the retina called the macula that is responsible for sharp central vision. Dr Cheryl Lee’s analogy is that if the retina is Singapore, the macula is Orchard road.
Non-proliferative diabetic retinopathy.
Are you at risk?
All individuals with diabetes are at risk. The longer you have diabetes, the more likely it is for you to develop diabetic retinopathy. Studies have shown that 60% of diabetics on tablets and 100% of diabetics on injection have some form of diabetic eye disease over time. Diabetic retinopathy may be a problem for women with diabetes during pregnancy. Pregnant woman with diabetes should have a comprehensive eye examination even before family planning.
How is Diabetic Retinopathy detected?
Diabetic eye disease can be detected through a comprehensive eye examination that includes visual acuity test, dilated retinal examination with colour retinal photography, and a high-definition scan of the retina if necessary.
What are the treaments available?
Diabetic retinopathy is treated with laser treatment that can be performed in the clinic with no hospitalization stay. Focal laser is usually done in non-proliferative cases to slow down the leakage of fluid and reduce the amount of fluid in the retina while scatter laser shrinks the abnormal blood vessels in proliferative cases. Multiple sessions may be required to complete the treatment. This treatment has been shown to reduce risk of severe vision loss by 50%. In addition, patients with proliferative retinopathy have less than 5% chance of losing their vision within the next 5 years if they receive timely and appropriate treatment.
Surgery is only needed if there is a retinal detachment or if bleeding does not resolve spontaneously.