Impaired retinal artery blood flow in IDDM patients before clinical manifestations of diabetic retinopathy.
OBJECTIVE
To determine whether hemodynamic changes in retinal arteries precede clinical manifestations of diabetic retinopathy and to examine the effects of control of hyperglycemia on retinal artery blood flow.


METHODS
We assessed blood flow in bilateral central retinal arteries in 50 insulin-dependent diabetes mellitus (IDDM) patients without retinopathy and 20 sex- and age-matched control subjects using duplex Doppler sonography. We determined the peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged velocity (TAV), resistance index (RI), and pulsatility index (PI).


RESULTS
PSV, EDV, and TAV were significantly lower in IDDM patients than in control subjects (P < 0.05, P < 0.01, and P < 0.01, respectively). The RI was significantly higher in IDDM patients than in control subjects (P < 0.01) and was significantly correlated with plasma levels of glucose in IDDM patients (r = 0.0.310, P = 0.0248). Multiple regression analysis identified the plasma levels of glucose as a significant determination of RI in IDDM patients. After 14 days of intensive insulin therapy in 7 IDDM patients, the RI and plasma levels of glucose showed significant decreases (P = 0.018, P = 0.001, respectively).


CONCLUSIONS
Our results showed that changes in retinal hemodynamics were present before the clinical detection of overt diabetic retinopathy and suggest that the presence of short-term hyperglycemia partly contributes to impaired retinal circulation.
Kawagishi
T
T
Second Department of Internal Medicine, Osaka City University Medical School, Japan.
Nishizawa
Y
Y
Emoto
M
M
Konishi
T
T
Maekawa
K
K
Hagiwara
S
S
Okuno
Y
Y
Inada
H
H
Isshiki
G
G
Morii
H
H
D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D003971:Diastole; D005260:Female; D019270:Fructosamine; D006442:Glycated Hemoglobin / Q000032:analysis; D006439:Hemodynamics; D006595:Hexosamines / Q000097:blood; D006801:Humans; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000502:physiology / Q000503:physiopathology; D012016:Reference Values; D012039:Regional Blood Flow; D012044:Regression Analysis; D012161:Retinal Artery / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology*; D013599:Systole; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance
D001786:Blood Glucose; D002784:Cholesterol; D008076:Cholesterol, HDL; D019270:Fructosamine; D006442:Glycated Hemoglobin; D006595:Hexosamines