Digoxin-induced decrease in intraocular pressure in the cat.

A constant intravenous infusion of digoxin (2 micrograms/kg/min) to alpha-chloralose-anesthetized cats produced a progressive decrease in intraocular pressure with increasing doses of digoxin between 60 micrograms/kg and drug-induced ventricular arrhythmia which occurred at a mean dose of 172 micrograms/kg. Digoxin elicited a 40% decrease in intraocular pressure just prior to ventricular arrhythmia compared to a decrease of only 10% with a control infusion of diluent in the same animal (P less than 0.05). There was no significant difference (P less than 0.1) between changes in blood pressure and heart rate observed in the experimental versus the control infusions. The decrease in intraocular pressure may result from inhibition of the Na-K-ATPase in the ciliary body.