By Dr Ajeet Madhav Wagle
MBBS(India), FRCS(Edinburgh), FAMS(Singapore)
Medical Director and Senior Consultant
Diabetes mellitus, commonly referred to as diabetes, is a systemic condition characterised by high blood sugar levels over a prolonged period. Diabetes is a major public health problem as the number of people afflicted by it is fast approaching epidemic proportions in many countries around the world.
If you or your loved ones have diabetes, here are 5 important facts about diabetic eye disease that you should know:
1. Diabetes causes blindness
Diabetes causes a potentially blinding eye condition called diabetic retinopathy. Diabetic retinopathy often affects working-age adults and thus has huge socioeconomic implications.
Diabetic retinopathy affects the blood vessels in the retina, the light-sensitive nerve layer lining the internal back surface of the eye. The damaged retinal blood vessels bleed or leak fluid, causing blurred or distorted vision. Scar tissues can also form in the eye, leading to retinal detachment and blindness. Increased awareness of diabetic retinopathy and a robust eye screening programme for diabetics can reduce the burden of blindness from diabetes.
2. Diabetic retinopathy is relatively common
Diabetic retinopathy affects about one in every three diabetics and about a third of those who have diabetic retinopathy have serious sight-threatening disease. The longer an individual has diabetes, the higher the likelihood of developing diabetic retinopathy. In fact, more than 90% of those with diabetes for more than 30 years have some form of diabetic retinopathy.
3. No eye symptom does not mean no diabetic retinopathy
While many diabetic patients know that diabetes can affect their eyes, some are unaware that diabetic retinopathy can be present even in the absence of visual symptoms. It is very important to understand that in the early stages of diabetic retinopathy, there is usually no visual symptom at all. Often when symptoms start to appear, it is already too late and the disease is usually fairly advanced.
Doctors strongly recommend that all diabetics have a detailed retinal evaluation at least annually even if they do not have any visual symptom so that diabetic retinopathy can be detected early and treated if necessary.
4. Diabetic retinopathy vision loss may be irreversible
Diabetic retinopathy, if not treated promptly, can result in severe permanent damage to the vision. Hence, preventing the development of diabetic retinopathy by adopting a healthy lifestyle is very important. Good control of the diabetes alone is not sufficient. One should also optimise his/her blood pressure, body weight and blood cholesterol levels. Going for regular eye screening to pick up any diabetic retinopathy early is also very critical.
5. Prompt diabetic retinopathy treatment saves sight
Fortunately, recent medical advances have improved the treatment outcomes of diabetic retinopathy. New treatments such as intravitreal injection therapy with anti-vascular endothelial growth factor (anti-VEGF) agents (eg, Eylea, Lucentis) and sustained-release steroid implants (eg, Ozurdex) have significantly improved vision outcomes for patients with retinal swelling (macular oedema) due to leakage from damaged retinal blood vessels. Compared to traditional retinal laser treatments, these newer modalities give better visual recovery. In some patients with advanced diabetic retinopathy, these newer treatments may have to be combined with laser treatment to effectively control the disease.
For some diabetic patients with advanced retinal disease, newer small-gauge instruments can be used in a complex surgery, called vitrectomy, to salvage some useful vision. However, a proportion of such patients may still end up with blindness despite treatment.
In conclusion, all diabetics should be aware that diabetes can cause blindness. This blindness is potentially preventable by adopting a healthy lifestyle and by having regular eye examinations. Early detection and prompt treatment of diabetic retinopathy saves sight.