Effects of Isometric Exercise on Subfoveal Choroidal Blood Flow in Smokers and Nonsmokers

Little is known about potential effects of smoking on ocular blood flow regulation. In the present study, the hypothesis was that choroidal blood flow (CBF) changes during an increase in ocular perfusion pressure induced by isometric exercise are altered in chronic smokers. The study was performed in 24 (12 smokers and 12 nonsmokers) healthy male volunteers in an observer-masked, two-cohort study design. The difference in CBF regulation between smokers and nonsmokers was tested during isometric exercise over a period of 6 minutes. CBF was assessed with laser Doppler flowery (LDF), and ocular perfusion pressure (OPP) was calculated from mean arterial pressure (MAP) and intraocular pressure (IOP). Six minutes of isometric exercise induced a significant increase in MAP, pulse rate (PR), OPP, and CBF in smokers and nonsmokers (each P