I. Response of Iris Sphincter and Ciliary Muscle to Greatly Diluted Solutions of Drugs
Drug tests by means of conjunctival instillation have been used in patients with pupillotonia firstly for the purpose of differential diagnosis and secondly in order to determine the site of the underlying disturbance. Whereas some drugs have, when used in the usual concentrations, no influence on the normal pupil (epinephrine, methacholine [Mecholyl]), others (cocaine, pilocarpine, eserine, etc.) are, as a rule, employed in concentrations considerably above threshold. A priori it should be possible, by making use of greatly diluted solutions of the latter drugs, to detect differences of reactivity between normal and abnormal pupils not sufficiently great to be apparent if stronger concentrations are employed. As the effect on the tonic pupil of such greatly diluted solutions has but exceptionally been investigated, it seemed a matter of interest to study the question more systematically. For this