The acute effect of cigarette smoking on macular capillary blood flow in humans.

The acute effect of cigarette smoking on retinal macular blood flow was studied in 14 healthy habitual smokers using the blue field simulation technique. This technique provides a method for quantifying the velocity of leukocytes flowing in one's own macular capillaries. Subjects adjusted the mean velocity of computer simulated leukocytes moving on a CRT screen to match that of their own entoptically perceived leukocytes before, during, and immediately after smoking a cigarette. Smoking resulted in a 12 +/- 5% (SEM) increase in macular leukocyte velocity and presumably blood flow. Possible mechanisms for this increase are discussed.