Abstract
Purpose: :
To study the effect of different physiological conditions on retinal vessel function in a healthy population, utilizing a recently developed Retinal Function Imager (RFI) that implements a new, non-invasive diagnostic approach to measuring blood flow velocity
Methods: :
59 healthy volunteers were recruited for this study. If eligible, both eyes of each subject were used (98 eyes). All patients had a detail ophthalmic evaluation, blood pressure measurements and RFI scanning. The blood flow velocity was quantified for secondary and tertiary branches of arteries and veins. Correlation between physiological parameters and velocity were studied with pearson and spearman correlation tests and comparisons were performed using Students t-test and Kolmogorov-Smirnov test.
Results: :
The mean age was 45.7±15.7 (19-81) years. In subjects older than 40 years, we found a negative correlation between age and venular velocity (R2=0.28, p<0.01) with an average decrease of 0.48±0.05mm/sec (15.8±0.4%) per decade. In subjects younger than 40 there was no significant effect of age, and there was no significant correlation between age and arterial velocity. Mean arterial pressure (MAP) ranged between 74 to 128 mm Hg. There was a correlation between MAP and arterial velocity (R2=0.18, p<0.01), with an average increase of 0.16±0.1mm/sec for 10mmHg increase (3.9±2.3%). Velocities were higher in females (n=37) compared to males (n=22) both in the veins (3.48±0.9 vs 3.02±0.7mm/sec, respectively, p<0.05) and in the arteries (4.61±1.1 vs 4.0±0.8mm/sec, respectively, p<0.05) when age and MAP matched.
Keywords: blood supply • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • aging