The effect of short-term near-normal blood glucose control on oscillatory potential and macular recovery time in insulin-dependent diabetic patients with long-standing metabolic dysregulation

Seven insulin-dependent diabetic patients (mean age 36 years and mean duration of diabetes 19 years) underwent intensified treatment with continuous subcutaneous insulin infusion (CSII) for one week. The patients were selected for the study due to long-standing hypergycemia in an endeavour to determine possible influence on retinal neurosensory function by even short-term near-normalization of blood glucose concentrations. During CSII treatment, near-normalization of the blood glucose levels was obtained (mean blood glucose concentration before treatment; 13.7 +/- 1.6 mmol/l-during treatment; 6.3 +/- 0.4 mmol/l. Recording of the oscillatory potentials by electroretinography and the macular recovery by nyctometry remained about the same in the course of this short-term treatment. Our study suggests that short-term strict metabolic control does not reverse the retinal neural abnormalities in long-standing insulin-dependent diabetes. Consequently; this regimen does not enable prediction of possible beneficial effect of sustained near-normoglycemic treatment.