[Effects of cigarette smoking on ocular circulation chronic effect on choroidal circulation]

The effects of long-term smoking on choroidal circulation were studied. For this purpose, Wistar rats were made to inhale mainstream smoke for 30 minutes daily. After periods of inhalation (16 weeks and 25 weeks), choroidal blood flow (CBF) was measured by the hydrogen clearance method and the index of choroidal vascular resistance (systolic tail arterial pressure/CBF) was calculated. There was no significant difference in CBF between either smoking group (16 weeks and 25 weeks) and controls. However the index of choroidal vascular resistance increased significantly after inhalation of smoke for 25 weeks. No histopathological abnormalities were detected in the choroid and outer layer of the retina. The results suggested that long-term smoking might induce disturbance of choroidal circulation.