Evaluation of Factors on Retinal Circulation in Patients With Type 2 Diabetes Using a Laser Doppler Velocimetry (LDV) System

Abstract

Abstract: : Purpose: To investigate the relation between retinal circulation and traditional risk factors in patients with type 2 diabetes mellitus. Methods: Using a LDV system (CLBF model 100; Canon, Tokyo, Japan), we measured retinal blood flow (RBF) in retinal arteriole in 98 eyes of 98 patients (age; mean±SD: 60.0±10.3 years, male:female=49:49). The patients with type 2 diabetes had no diabetic retinopathy (n=73) or background diabetic retinopathy (n=25). We assessed the relationship between RBF and traditional risk factors, including age, duration and treatment of diabetes, hemoglobin A1c (HbA1c), hypertension, hyperlipidemia, smoking, and obesity. Results: There were no differences in RBF between the patients with presence and absence of hypertension and hyperlipidemia. On the other hands, there were significantly decrease in RBF in patients with insulin therapy and current smoking compared with non–insulin therapy and non–smokers, respectively. In a simple regression analysis, there were no relations between RBF and age, duration of diabetes, HbA1c, and body mass index. In multiple regression analysis, smoking(r=–0.31, P=0.01) and insulin therapy (r=–0.29, P=0.01) showed independent correlation with RBF. Conclusions: Our results indicate that the smoking and insulin therapy may be associated with the decrease in RBF in patients with type 2 diabetes, especially in early stage of diabetic retinopathy.

Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: risk factor assessment • clinical research methodology