Effect of treatment on retinal circulation, platelet aggregation and blood viscosity in insulin-dependent and noninsulin-dependent diabetics.

In order to investigate the influence of diabetic treatment, especially insulin treatment on diabetic retinopathy, disc-to-macula circulation time, platelet aggregation and blood viscosity were observed before and after treatment for 5 years in 42 diabetics (17 insulin-dependent diabetics [IDD] and 25 noninsulin-dependent diabetics [NIDD]). The disc-to-macula circulation time was significantly correlated with the mean blood glucose level. The platelet aggregation in IDD was enhanced significantly as compared with that in NIDD, however after treatment with insulin, the platelet aggregation revealed a significant decrease in IDD. The inter-period changes in the disc-to-macula circulation time before and after treatment in IDD were correlated with those of platelet aggregation, but not with those of blood viscosity. These results suggested that although the blood glucose level was considered to be one of the important factors influencing the retinal circulation, insulin had a direct effect on the platelet function in improving the retinal circulation in addition to lowering the blood glucose level.