Impaired retinal circulation in patients with type 2 diabetes mellitus: retinal laser Doppler velocimetry study.
OBJECTIVE
To evaluate the differences in retinal circulation in eyes of patients with type 2 diabetes with no or early-stage diabetic retinopathy compared with control eyes.


METHODS
Seventy-five nondiabetic eyes and 194 eyes with type 2 diabetes mellitus were evaluated. The type 2 diabetic eyes were classified into two groups: 139 eyes (139 patients) without diabetic retinopathy (NDR) and 55 eyes (55 patients) with mild nonproliferative diabetic retinopathy (NPDR). The retinal circulatory parameters were measured with laser Doppler velocimetry, and the factors that affect retinal hemodynamics were determined in a cross-sectional population of patients with type 2 diabetes.


RESULTS
The group-averaged blood velocity (V) and retinal blood flow (RBF) in the NDR and mild NPDR groups were significantly (P < 0.01) lower than in the non-DM group. The diameter and wall shear rate were also significantly (P < 0.05) lower in the NDR group than in the nondiabetic control eyes. Multiple regression analysis showed that the RBF was independently and negatively correlated with serum low-density lipoprotein and creatinine. HbA1c was significantly (P < 0.05) higher in participants in the lowest RBF quartile than in the highest quartiles.


CONCLUSIONS
The results indicate that the RBF may decrease in patients with type 2 diabetes without retinopathy and in those with mild retinopathy.
Nagaoka
Taiji
T
Department of Ophthalmology, Asahikawa Medical College, Asahikawa, Japan. nagaoka@asahikawa-med.ac.jp
Sato
Eiichi
E
Takahashi
Atsushi
A
Yokota
Harumasa
H
Sogawa
Kenji
K
Yoshida
Akitoshi
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001775:Blood Circulation / Q000502:physiology; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D012161:Retinal Artery / Q000503:physiopathology*
D001786:Blood Glucose; D003404:Creatinine; D006442:Glycated Hemoglobin; D008077:Lipoproteins, LDL; C517652:hemoglobin A1c protein, human