Twenty-four-hour intraocular pressure and blood pressure levels with bimatoprost versus latanoprost in patients with normal-tension glaucoma

Aim: To evaluate 24 h intraocular pressure (IOP) and blood pressure (BP) with bimatoprost or latanoprost in patients with normal-tension glaucoma. Design: Prospective, randomised, crossover, active-controlled, observer-masked study. Methods: After a 6-week medicine-free period, we randomised patients to either latanoprost or bimatoprost for 8 weeks and then to the opposite medicine for 8 weeks. At baseline, and at the end of each treatment period, we evaluated IOP and BP at 08: 00 and then every 2 h over the 24 h day. Diastolic ocular perfusion pressure (DOPP) was calculated from the above parameters. Results: Forty completed patients had a 24 h untreated baseline IOP of 15.5 (2.3) mm Hg, and a DOPP of 59.2 (6.1) mm Hg. Both treatments lowered IOP at each time point (p < 0.006), and over the 24 h curve (p < 0.001, both medicines 13.1 mm Hg, 16% decrease). No difference existed between treatments in absolute IOP, at each time point, and over the 24 h curve (p >= 0.26). Additionally, no differences were found between treated 24 h systolic (p >= 0.29) and diastolic BP (p >= 0.12). The mean 24 h DOPP for latanoprost was increased from baseline (3%, p = 0.031) but not for bimatoprost (2%, p = 0.21). However, no difference in DOPP existed between treatments at any time point or over the 24 h curve (p >= 0.17). No difference was observed between treatments for any adverse event (p > 0.05). Conclusions: In patients with normal-tension glaucoma, both bimatoprost and latanoprost reduce the 24 h intraocular pressure from untreated baseline to a similar extent. Latanoprost is associated with slightly improved ocular diastolic perfusion pressure over 24 h but similar absolute perfusion levels to that of bimatoprost.