To compare the therapeutic efficacy and safety of dorzolamide/timolol fixed-combination (Cosopt) in primary open angle glaucoma patients.

: In this prospective, interventional study ,newly diagnosed primary open angle glaucoma (POAG) patients that had not been treated with a glaucoma medication in the most recent 4 weeks underwent 24h IOP, blood pressure (BP) and heart rate (HR) measurements and were treated with Cosopt two times daily(BID) .After 4 weeks of treatment a second 24h assessment of IOP, BP and HR was performed and then subjects switched to Cosopt three times daily (TDS)treatment for additional 4 weeks when a third 24h assessment was performed. Throughout the study, all adverse events were recorded and monitored by the investigators.

In 31 POAG patients that completed the study ,Mean untreated 24h IOP was 23.09 mmHg (19.0 to 21.6). Mean 24h IOP was significantly lower after 4 weeks of treatment with Cosopt TDS than after 4 weeks of treatment with Cosopt BID(13.1 vs 16.54 mmHg, p = 0.0006). Cosopt BID and TDS significantly reduced the mean 24h diastolic BIP and mean 24h HR from baseline but (P < 0.0001), whereas mean 24-hour diastolic BP and HR were unchanged compared to cosopt two times daily after treatment with cosopt TDS . One patient reported episodes of bradycardia during cosopt three times daily and not completed the study.

Cosopt three times daily has a superior IOP-lowering effect than Cosopt two times daily in POAG patients and can be used with caution in patients with POAG.