We are in the most "diabetogenic" era of all times. Cases of diabetes increase daily. The most common cause of blindness in the first world is Diabetes. When one looks at studies done in Iceland for instance this is entirely preventable if glucose levels are well controlled.
"The eyes are the window to the soul" (famous English proverb)
Similarly the eyes of a diabetic tell a story that relates quite closely to their diabetes control. The crux of the matter is: CONTROL. Once you have diabetes you have to manage it in such a way that you prevent macro and microvascular complications that occur if you walk around with high sugars.
Microvascular complications: Heart disease and heart attacks, strokes, limb disease that results in the need for amputation. Microvascular complications: kidney, eye and nerve disease otherwise known as nephropathy, retinopathy and peripheral neuropathy. This article concentrates on retinopathy – pathology (abnormality or disease of the back of the eye).
Previously (in years before the advent of laser and good control of glucose studies) nearly all type 1 diabetics had moderate to severe retinopathy after 20 years of having disease. Currently, especially with good control, although your risk for developing retinopathy increases as the years of having the disease does, certainly the risk of developing blindness has reduced dramatically , also the degree of damage to the back of the eye can be drastically reduced with early laser therapy.
The "pathology" that happens at the back of the eye can be explained by 3 mechanisms: the small vessels (blood vessels) leak, they start to make growth substance that causes "new vessels" to grow and eventually the vessels close and block. If you can imagine that walking around with a high blood sugar level is like pouring out a "sticky drink" inside your body and if you can realize that the blood vessels in your eyes are extremely small (smaller than a millimeter) then you can understand that "pouring out a sticky drink into an already tight space" is bad and causes damage.
So, how do you prevent damage at the back of the eye? Control. As a type1 or type 2 diabetic you need to aim for a good HbA1C and a good value would be 7. (Different international organizations have different values and one's age is also important in setting a target- so generally older patients should rather aim for 8/8.5)
HbA1c is a blood test that measures your sugar value on average over the previous 8-12 weeks. There are other values that are also of importance like fasting glucose, post-prandial (2 hours after a meal) and generally what your sugar runs at. In landmark trials done internationally: DCCT and EDIC (Diabetes control and complications trial and Epidemiology of Diabetes Intervention and Complications) the intensively controlled group had a decrease in risk of retinopathy of 76% and a slowing of progression of 54 % in patients who already had eye disease. In EDIC there was a 42 % decrease in any cardiovascular (heart) disease in the well controlled group.
So how does one achieve control? Simply put: healthy diet, exercise, correct medication, regular (once a year) eye checks. Studies show that the simple intervention of having your eyes checked once a year reduces your risk of developing eye disease dramatically – partly because early disease can be treated quickly and easily and partly because a greater awareness is created.
Exercise is one of the most underrated therapies in this modern time. It is truly an elixir far underutilized. In the Finnish Diabetes Prevention Programme, in subjects who exercised regularly (and properly – actually breaking a sweat) there was a 43% risk reduction in developing diabetes. In all exercise related studies done it shows massive benefit in controlling glucose, releasing stress, general wellness but greatly improved outcome for diabetes complications including eye disease. The bottom line is that exercising decreases your HbA1c and in so doing reflects in less diabetic retinopathy and protection for eyes. Very importantly, depending on the type of eye disease you as the individual have, you need advice on what type of exercise to do – for example : if you have proliferative diabetic retinopathy you should not bungi jump or do contact types of sports. Thus seeing your eye care specialist once a year is very important in terms of advice regarding exercise too.
There is also a direct correlation between lipids – like cholesterol and triglycerides and eye disease. In a large recent study participants with high
Triglycerides started on a medication called a fibrate (to lower triglycerides) showed a 30 – 40 % reduction in retinopathy. This is both interesting in the correlation and the efficacy of the medication. We have long known the link between cholesterol and heart attacks so this is interesting to see this same link with eye disease. If you are a diabetic make sure you know what your triglyceride level is, if it is high you will definitely benefit from a fibrate to lower your level which will protect your eyes at the same time.
In both the long and the short term, diabetics will greatly benefit from glucose control. Without a doubt – and proven by Iceland – good control of diabetes leads to no blindness at the end of the day.
In summary : aim for a glucose level of 7 by eating correctly, using medication to keep the sugars well controlled, exercising regularly and in the right way for you specifically and have your eyes checked once a year. You will see the benefits!
Written by Dr Claudine Lee – GP 26 Hilton Avenue 033 343 2243 (Family practitioner with an interest in diabetes and eye conditions as well as women's health, botox and general ailments).