The practice of cigarette smoking is extremely widespread; nicotine is probably the most frequently used drug in the world, and yet the effect of smoking on the intraocular vascular system is very poorly understood. There are two broad reasons why our knowledge is so limited: First, the action of nicotine is diverse and complicated; second, the methods of studying the effects of drugs on the intraocular circulation are inaccurate, limited, difficult, or disturbing to the physiology. It is a widespread assumption that smoking causes a generalized constriction of intraocular blood vessels, but, as we will discuss, this is not necessarily true.
We will consider first some pharmacological effects of smoking and nicotine, then the actions of the drug nicotine on the vascular tree, and finally our own experimental findings concerning the effect of smoking and nicotine on the intraocular circulation.
A normal-sized commercial American cigarette weighs approximately 1 gm. and