Abstract
Purpose: :
To study the relationship between retinal circulation and renal function in patients with type 2 diabetes mellitus.
Methods: :
Using a laser Doppler velocimetry system (CLBF Model 100; Canon, Tokyo, Japan), we measured the retinal vessel diameter and blood velocity and calculated the retinal blood flow (RBF) in 169 eyes of 169 patients (mean age±SD, 59.0±11.1 years). The patients with type 2 diabetes had no diabetic retinopathy (n=122) or background diabetic retinopathy (n=47). To determine if RBF is affected in the presence of renal dysfunction, we evaluated the renal function using the estimated glomerular filtration rate calculated by age and serum creatinine level. We divided the patients into four groups based on the stage of chronic kidney disease (CKD) (non-CKD group, n=99; CKD groups stage 1, n=22; stage 2, n=27; stage 3, n=21).
Results: :
There were no differences in the retinal arteriolar blood velocity among the groups. We found significant decreases in vessel diameter (P<0.02) and RBF (P<0.035) in CKD stage 3 compared with those in the non-CKD group. Multiple regression analysis showed that the stage of the CKD was significantly and independently associated with decreased RBF (P=0.02).
Conclusions: :
Our results indicated that the RBF decreases in patients with type 2 diabetic with CKD stage 3, suggesting that impaired renal function may be associated with decreased RBF in the early phase of diabetic retinopathy.
Keywords: diabetic retinopathy • diabetes • blood supply