Abstract
Purpose :
Remote ischemic conditioning (RIC) induced by transient episodes of ischemia in the arm causes hemodynamic changes in the larger vessels, which have shown to protect against ischemic insults in other organs and to affect the reactivity of retinal arterioles in normal persons. However, retinal diseases with ischemia predominantly affect the retinal periphery. Therefore, there is a need to investigate whether the effect of RIC on peripheral vessels differs from that on other retinal vessels.
Methods :
In twenty normal persons aged 20-31 years the Dynamic Vessel Analyzer (DVA) was used to measure the diameters of macular and peripheral arterioles, during rest, isometric exercise and flicker stimulation. Diameter measurements were obtained before, immediately after, and one hour after RIC induced by transient ischemia in the left arm.
Results :
The baseline diameter of peripheral retinal arterioles was reduced significantly immediately after (p=0.009) but not 1 hour after RIC (p=0.5). In the peripheral arterioles constriction induced by isometric exercise was significantly reduced immediately after (p=0.005), but not one hour after RIC (p>0.99). Flicker stimulation caused vasodilation in both macular and peripheral arterioles, but the response was unaffected by the intervention. Simultaneous flicker stimulation and exercise caused a significantly larger dilation in the peripheral arterioles than in the macular arterioles (p<0.016 for all comparisons). The macular arterioles ware unaffected by RIC.
Conclusions :
Remote ischemic conditioning affects the reactivity of peripheral but not macular arterioles in normal persons. The potential of remote ischemic conditioning as an intervention on retinal ischemic diseases should be investigated.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.