Purpose: The purpose of the study was to determine the 24-h effects of pilocarpine 2% ophthalmic solution on intraocular pressure (IOP) and ocular perfusion pressure (OPP) when used in addition to prostaglandin analog (PGA) therapy.
Methods: Twenty-seven patients with ocular hypertension (OHTN) or open angle glaucoma who were receiving stable monotherapy with a PGA were admitted to an inpatient sleep laboratory for 24-h monitoring of IOP, blood pressure (BP), and heart rate over 2 separate visits. The first baseline visit was performed under PGA monotherapy only. During the second 24-h visit, pilocarpine 2% was administered four times daily in addition to their normal PGA dosing. For each study visit, measurements of all study metrics were performed every 2 h in the habitual position. OPP was calculated as 2/3[diastolic BP +1/3(systolic BP - diastolic BP)] - IOP.
Results: During the diurnal period, pilocarpine significantly reduced IOP from a baseline of 18.2 ± 0.5 mmHg on PGA monotherapy to 17.1 ± 0.4 mmHg, P < 0.01. Similarly, pilocarpine significantly lowered IOP during the nocturnal period from 21.1 ± 0.7 to 20.0 ± 0.6 mmHg, P < 0.01. Mean OPP was unchanged from baseline levels after the addition of pilocarpine in both the diurnal and nocturnal periods. Mean systolic BP was significantly reduced during the nocturnal period only (-3.16 ± 1.5 mmHg, P = 0.03).
Conclusions: In patients taking PGA monotherapy, the addition of pilocarpine can significantly lower IOP throughout the diurnal and nocturnal periods, but has no effect on OPP.
Keywords: 24-h; intraocular pressure; nocturnal; ocular perfusion pressure; pilocarpine; prostaglandin analog.