Kazemi A, et al. - Researchers examined how timolol, an aqueous humor flow suppressant, influences outflow facility in healthy eyes. In this prospective, before-and-after multicenter study, 113 healthy participants over 40 years of age were evaluated for intraocular pressure (IOP) with the participant in the sitting position by using a pneumatonometer and for outflow facility with the participant in the supine position by 2-minute pneumatonography. The evaluation was conducted before and after self-administration of drops of timolol 0.5% for 1 week, twice daily in each eye. A decrease in outflow facility in healthy human eyes was noted following timolol administration. Eyes with higher baseline outflow facility displayed this effect in greater intensity. Lower outflow facility was observed in correlation to older age.