A 12-week comparison of bimatoprost 0.03% and a fixed combination of latanoprost 0.005% and timolol 0.5% in reducing the 24-hour IOP in glaucoma patients. A European multi-centre, randomised, double-masked trial

Purpose: To compare the 24–h mean IOP between bimatoprost and the fixed combination of latanoprost and timolol when switched from a non–fixed combination of latanoprost and timolol. Methods: This randomised, double masked trial was carried out in 7 centres throughout Europe. Included were patients who were controlled (IOP <22 mmHg) on the unfixed combination of latanoprost and timolol for at least 3 months prior to the baseline visit or patients on monotherapy either with latanoprost or timolol who were eligible for dual therapy being uncontrolled. The last group of patients underwent a 6 weeks wash–in phase with the non–fixed combination of latanoprost and timolol before baseline IOP determination and inclusion into the study. Supine and sitting positions IOPs were recorded at 8 pm, midnight, 5 am, 8 am, noon, and 4 pm at baseline, week–6 and week–12 visits. At each time point IOP was measured twice by well–trained evaluators, and then averaged. Holter 24–hour blood pressure was also recorded. An ANCOVA model was used for the primary efficacy variable, with mean area under the IOP curve after 12 weeks of treatment as response variable, and treatment, centre and baseline as factors. The interaction between treatment and centre was investigated. A secondary analysis was performed on the within treatment change from baseline. Results: Mean baseline IOP was 16.3 (sd, 3.3) and 15.5 (2.9) in bimatoprost and the fixed combination of latanoprost and timolol groups respectively. At week 12, mean IOPs were respectively 16.1 (2.5) and 16.3 (3.7). Mean daytime and nighttime IOPs were similar and no statistical significant difference between the 2 groups could be found. Mean IOP changes from baseline were 0.3 (3.6) during daytime and –0.8 (3.8) during nighttime in bimatoprost group and 1.43 (2.6) and 0.14 (3.2) in the fixed combination of latanoprost and timolol respectively. Conclusions: Bimatoprost is at least as good as the fixed combination of latanoprost and timolol in maintaining the IOP on a controlled level.