Terbutaline stimulates aqueous humor flow in humans during sleep
N. Z. Gharagozloo, R. S. Larson, L. J. Kullerstrand and R. F. Brubaker
Department of Ophthalmology, Mayo Clinic, Rochester, Minn.
A randomized, double-masked study of the effect of terbutaline sulfate, a
selective beta 2-agonist, on the rate of aqueous humor formation was
performed in awake and sleeping normal human subjects. The rate of aqueous
formation was measured by fluorophotometry. Both the drug- and
placebo-treated eyes showed a statistically significant nocturnal reduction
of the flow rate (36% suppression in the terbutaline-treated eyes and 43%
suppression in the placebo-treated eyes). Terbutaline had no effect on
daytime aqueous flow rates, but stimulated flow by 15% during sleep. The
drug had no significant effect on intraocular pressure. This study confirms
past observations that beta-agonists exert their maximal effects during
sleep, when endogenous adrenergic stimulation is at a minimum.
