Abstract
Purpose:
To compare the retinal circulation in patients with type 1 diabetes mellitus (T1DM) with no or early-stage diabetic retinopathy (DR) with that in healthy young subjects.
Methods:
Thirty-seven eyes of 37 patients with T1DM (T1DM group, mean age ± standard deviation, 29.8 ± 10.6 years) and 37 eyes of healthy age-matched young subjects (control group, 28.8 ± 10.1 years) were enrolled in this study. We simultaneously measured the vessel diameter (D) and blood velocity (V) using a Canon Laser Doppler Flowmeter (CLBF Model 100, Canon, Tokyo, Japan) and calculated the retinal blood flow (RBF) and wall shear rate (WSR), which is an index of wall shear stress, in a temporal retinal arteriole.
Results:
The patients with T1DM had no DR (n=27) or background DR (n=10). Although there were no significant differences in D, V, and RBF between the two groups, the group-averaged WSR value in the T1DM group was significantly (P<0.05) lower than in the control group.
Conclusions:
We confirmed for the first time that the WSR in the retinal arterioles decreased in T1DM without DR and mild DR, suggesting that retinal arteriolar endothelial function may be impaired in patients with T1DM with minimal DR.