Diabetes is a condition, in which the body has difficulty metabolizing sugar, leading to an excess sugar in the blood. According to the World Health Organization, over 425 million people around the world have diabetes.
Diabetes is caused by an autoimmune disease which affects the islets of Langerhans (type 1) leading to little or no production of insulin (which helps in mopping up excess sugar in the bloodstream); or by the inability of insulin to do its job of mopping up excess insulin due to resistance of insulin at the cells (usually common in obese people) or even during pregnancy (gestational diabetes).
Whatever the cause of diabetes, if it is left unmanaged, it can cause complications in the body, including kidney failure, stroke, non healing sores or even diabetic eye disease, which can lead to blindness or severe visual impairment.
Diabetic eye disease is a group of potentially blinding conditions associated with long standing diabetes with poorly controlled blood sugar. Two main conditions are of importance when we talk about diabetic eye disease viz: diabetic retinopathy and diabetic cataracts.
When an individual has had diabetes for a long period of time, it may lead to damage of blood vessels in the body over time. The damage of blood vessels then leads to a poor supply of blood to tissues of the body, including the retina in the eye (ischaemia). The lack of blood supply to the retina triggers the formation of new blood vessels via the vascular endothelial growth factor (VEGF). This leads to the formation of small weak blood vessels (neo-vascularisation). These new blood vessels being very fragile, frequently leak, releasing blood and other fluid into the eyes (exudates). If you look into the eye of a person who has had poorly controlled diabetes for a long period of time, you may see white spots (cotton wool spots), bleeding (seen as dot and blot haemorrhage or severe pre-retinal or intra-retinal bleeding etc), new weak vessels (neo-vascularisation) in sensitive places of the eye, or even leaking fluids (exudates). All of these signs and more is defined as RETINOPATHY, and work together to cause blindness or severe visual impairment.
Due to the high sugar levels in the blood, there is usually a change in thickness of the lens over time, leading to frequent blurriness even with your eyeglasses, or in some cases, frequent changes of glasses over a short period of time. This occurs due to the swelling of the natural lens within the eye, causing blurriness.
If this swelling of the lens persists, it may lead to a change in the metabolism of the natural lens within the eye, and if this change in metabolism continues unabated, it may lead to the formation of cataracts within the eyes. This is called a diabetic cataract.
Other eye conditions resulting from diabetes
Studies have shown that people with diabetes are at a greater risk of having glaucoma- a potentially blinding disease.
What to do about your diabetes
So what do you do when you have diabetes or you have diabetes and are now experiencing changes in your vision?
Firstly, if you are diabetic, whether you are experiencing visual disturbances or not, see your eye doctor at least once a year for a comprehensive eye examination.
Second, work with your general medical practitioner to ensure good control of your blood sugar. You can make this work better by monitoring your blood glucose daily and taking your medications daily.
Eat a healthy diet daily, made up mainly of fruits and vegetables.
Exercise regularly, avoid alcohol consumption.
What will my eye doctor do for me?
Your eye doctor will:
- Conduct a dilated funduscopy at least once a year for you to ensure you do not develop diabetic retinopathy, or that it isn’t progressing rapidly.
- Monitor the signs within your eyes to ensure you they do not progress to become vision threatening.
- Consider using lasers to treat your retina or give anti-VEGF medications (as injections) if you have serious diabetic retinopathy that is vision threatening.
- Consider conducting a cataract surgery for you if you have developed a visually significant cataract.