Effects of a dorzolamide/timolol fixed combination on diurnal intraocular pressure, heart rate, blood pressure, and ocular perfusion pressure in normal-tension glaucoma

The aim of this study was to evaluate the effects of a dorzolamide-timolol fixed combination (DTFC) on intraocular pressure (IOP), heart rate (HR), blood pressure (BP), ocular perfusion pressure (OPP), and diastolic ocular perfusion pressure (DOPP) in patients with normal-tension glaucoma (NTG). A prospective, interventional, single-blind, single-center study was conducted. Newly diagnosed NTG patients that had not been treated with a glaucoma medication in the most recent 4 weeks were included. Patients were examined at baseline (without medication) and week 4 (under medication). Baseline IOP, HR, systolic and diastolic BP, OPP, and DOPP were measured at 8 am, 12 pm, and 4 pm. At week 4, IOP, HR, systolic and diastolic BP, OPP, and DOPP were measured at 10 am and 8 pm as well. After 4 weeks of DTFC treatment, IOP was significantly reduced at all time points (1.6-2.6 mmHg, P < 0.001), and the average IOP reduction was 14.4 %. HR and systolic BP showed no statistically significant difference at all time points; however, diastolic BP was decreased significantly at 12 pm and 4 pm (P = 0.004 and 0.001). OPP and DOPP showed no statistical significant difference after DTFC. DTFC has favorable effects on IOP and can be used without concerns of DOPP in patients with NTG.