Effects of Aging on the Main Infero–Temporal Retinal Artery in Healthy Women Using the Canon Laser Blood Flow System(CLBF): Preliminary findings.

Abstract

Abstract: : Purpose:Non–invasive technologies have been developed over the last years to measure blood flow in the retinal vessels by independently quantifying the blood column width and the center line blood velocity in vivo. The Canon Laser Doppler Flowmeter 100 system (CLBF, Canon, Japan) is the first technology of its kind that measures simultaneously the blood column width of a retinal vessel and its corresponding center line blood velocity using a dual laser system. The blood flow is then calculated by the CLBF software. In the present study, were are reporting the preliminary findings of the effects of aging on the diameter (D) of the blood column width, blood velocity (Vel) and blood flow (BF) of the main infero–temporal retinal artery using the CLBF system. Methods: This study was approved by the Maisonneuve–Rosemont Hospital Research Ethics Committee. Seventeen healthy women (46–62 yrs old) were tested. CLBF measures (D, Vel and BF) were performed on the main infero–temporal retinal artery in one eye. Measures were obtained from the average of three reproducible recordings. Systolic (BPsys) and diastolic blood pressure (BPdias), and heart rate (HR) were documented. Results:In our small study population, there was a significant positive correlation between Vel and age (r=0.49, p=0.04), while D decreased and BF increased non–significantly (r=–0.18, p=0.50; r=0.18, p=0.50). We also found a strong negative relationship between D and BPsys (r=–0.46, p=0.06), and a significant positive correlation between the BPsys with age (r=0.61, p=0.01). There was no relationship between BPdias, HR and D, with Vel, BF and age. Conclusions:Aging is known to induce thickening and stiffening of the arterial wall, and decreasing of the arterial lumen size leading to an increased blood velocity. In our small study population, we demonstrated the consequences of aging on the main infero–temporal retinal artery as observed by a significant increase in blood velocity with age, accompanied by a small reduction in the diameter of the blood column width using the CLBF system. Moreover, it is known that BPsys increases with age while DPdias and HR remained unaffected. In our study population there was also a significant increase on BPsys with age, as well as a strong negative relationship between BPsys and diameter of the infero–temporal retinal artery.

Keywords: aging • blood supply • retina