Marihuana Smoking and Intraocular Pressure

Abstract

<h3>To the Editor.—</h3> It is accepted widely that the physiologic effects of smoking marihuana are not well known, despite an acknowledged high incidence of usage. Even the President of the United States has called for a major effort to study drug effects in a scientific manner. In an attempt to investigate the effects of marihuana smoking upon the human visual system, complete ocular examinations were performed in a group of youthful subjects, before and one hour after smoking. Selection of subjects, medical and other safeguards utilized, and details of the protocol will be presented in a later publication. The purpose of this letter is to present preliminary data concerning the most impressive change observed so far, namely, a substantial decrease in intraocular pressure observed in a large percentage of subjects. Applanation tonometry was performed by the same experienced examiner, using the same tonometer for each pair of observations. Marihuana was