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

Purpose: 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). Methods: 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. Results: 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. Conclusions: DTFC has favorable effects on IOP and can be used without concerns of DOPP in patients with NTG.