A Diabetic's Role In Preventing Blindness From Diabetes

By Lionel Chisholm, MD, FRCS(C)

Complications of diabetes in the eyes, kidneys, and blood vessels occur more frequently when the condition is of longer duration and poorly controlled.

With diabetes, the incidence of blindness is 25 times greater than in non-diabetics and is the most common cause of blindness in the working age population. The burden of vision loss falls more heavily on those with poorly controlled diabetes, where blood sugar levels are elevated and hemoglobin A1C, which measures control over a longer term, is chronically above the accepted norm of 5 to 6.5%.

The most common eye complication of diabetes is diabetic retinopathy, in which retinal swelling and abnormal blood vessel proliferation results in impaired retinal function and bleeding within the eye causing blurry vision and ultimately blindness.

There are good treatments for this disorder, and others, that ophthalmologists can employ to limit the damage and restore vision. However, the outcomes are sometimes imperfect, and often function is limited, thereby restricting an individual's visual efficiency.

Maintenance of good health with diabetes is crucial to limiting the bad effects of the disease on the eyes and other important organs. This includes control of blood sugar, blood pressure, serum lipid levels, and cholesterol. This is where patients can play a critical role in treating their condition with the advice and guidance of a physician.

The Diabetes Control and Complications Trial found that, in type 1 diabetics, good control reduced diabetic retinopathy overall by 76%. The United Kingdom Prospective Diabetic Study examined type 2 diabetics and found that with each percentage lowering of hemoglobin A1C, the measure of long-term blood sugar control, there were 18% fewer heart attacks and 25% fewer diabetic deaths.

The Fenofibrate Intervention and Event Lowering in Diabetes Study (FIELD) found that the progression of diabetic retinopathy was reduced when serum lipid levels were under 200 mgm. Lastly, the Action to Control Cardiovascular Risks in Diabetes Study (ACCORD) examined the effects of controlling blood sugar, lipid levels and blood pressure in patients who already had cardiovascular risks, and found that the progression of diabetic retinopathy was decreased from 10.4% to 7.3% over four years by intensive blood sugar control and by 10.2% and 6.5% on either of two regimens of lipid lowering medication.

The critical factor is the patient's own compliance in controlling their diabetes, with the help and guidance of a physician. As the clinical trials demonstrate, it is possible for patients, through their own efforts, to reduce the ravages of diabetic retinopathy and lower the chance of blindness.

There are wonderfully successful treatments for diabetic eye disease available, such as the use of lasers, surgery and growth factor injections, but these are more effective when the diabetes is kept under control.

If you are diabetic, have a family history of diabetes, or think you may have symptoms of diabetes, working closely with your physician can set you on an enlightened path to protect your eyesight and overall health.