[Goals of blood glucose regulation in prevention of diabetic retinopathy].

In several studies a correlation between blood glucose levels and HbA1 (A1c) and the prevalence of retinopathy was documented. Minimal risk for the onset of retinopathy was observed when HbA1 was below 9% from the beginning of diabetes mellitus. This HbA1 (A1c) value corresponds with values above 7 mmol of blood glucose. In intervention trials with near normal values of blood glucose, initially i.e. during the first months of treatment, an increase of microaneurysm was observed. However, in the next 7 years (as was observed in the Oslo Study) the grade of retinopathy in patients was less severe than in patients with HbA1 > 10%. Only 20% of patients treated conventionally can reach the aim of optimal blood glucose regulation. Obviously, in patients with diabetes beginning before the age of 30, this is the reason why the prevalence for the diabetic retinopathy is 40-98% after 15 years of diabetes. Only the functional insulin therapy allows the achievement of optimal blood glucose control in about 40% of patients without increased risk of hypoglycemia. Therefore, this kind of therapy should be the therapy of choice in a great number of type 1 diabetes patients.