RT Journal Article
SR Electronic
T1 Retinal haemodynamics in patients with early diabetes mellitus.
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 327
OP 331
DO 10.1136/bjo.80.4.327
VO 80
IS 4
A1 J E Grunwald
A1 J DuPont
A1 C E Riva
YR 1996
UL http://bjo.bmj.com/content/80/4/327.abstract
AB AIMS/BACKGROUND: The retinal circulation was investigated in a group of 19 patients with insulin dependent diabetes mellitus with less than 4 years of disease duration and no evidence of diabetic retinopathy. Results of these patients were compared with those of 16 age-matched normal controls. METHODS: Venous diameter (D) was measured from monochromatic fundus photographs. Maximum erythrocyte velocity (Vmax) was assessed by bidirectional laser Doppler velocimetry in the major retinal veins of one eye of each subject. Total volumetric blood flow rate (QT) was calculated by adding the flow rates of the major retinal veins. RESULTS: Average QT was 12% larger than normal in diabetic patients (one tailed, non-paired Student's t test, p < 0.05). A statistically significant correlation was observed between QT and disease duration (r = 0.35, p < 0.04). Patients with longer disease duration tended to have somewhat larger QT. The average retinal vascular regulatory responses to hyperoxia were not significantly different from normal in diabetic patients. In these patients, however, higher blood glucose levels were associated with decreased regulatory responses to hyperoxia. CONCLUSIONS: Patients with diabetes mellitus of relatively short duration have mildly increased QT, suggesting that increased blood flow may play an early role in the development of diabetic retinal microangiopathy.