Purpose
To measure the effect on intraocular pressure (IOP) for 24 hours after repeated administration of the fixed combination of latanoprost 0.005% and timolol 0.5%.
Methods
A randomized, double-masked placebo-controlled crossover study including 20 patients with ocular hypertension was carried out. Patients were randomized to treatment with the fixed combination of latanoprost and timolol or with placebo. The eyedrop was taken at 8 am. After 2 weeks of treatment, the patients were hospitalized, and the IOP was measured at 8 am, and thereafter every other hour until midnight, and also at 3 am, 6 am, and 8 am. After a washout period of 4 weeks, they switched to the other eyedrop, and after 2 weeks of treatment were hospitalized and the IOP measurements were repeated at the same intervals.
Results
The mean 24-hour IOP was 14.7 ± 0.3 mm Hg (mean ± standard error of the mean) for latanoprost and timolol and 19.4 ± 0.3 mm Hg for placebo. This corresponds to a significant IOP difference of 4.7 ± 0.4 mm Hg (95% confidence interval 3.8–5.8;P < 0.001) between the two treatments in favor of the combination. At all measured time points, except at 3 am, the mean IOP was lower with latanoprost and timolol than with placebo. During daytime measurements the mean IOP was 13.9 ± 0.7 mm Hg for the fixed combination and 19.5 ± 0.7 mm Hg for the placebo. Corresponding figures at nighttime were 16.1 ± 0.7 mm Hg and 19.2 ± 0.7 mmHg, respectively.
Conclusions
The fixed combination of latanoprost and timolol significantly reduced IOP after administration once daily for 2 weeks in patients with ocular hypertension. A reduction of IOP during a 24-hour period was seen, with a greater IOP reduction during daytime compared with nighttime. The fixed combination applied once daily could be a convenient alternative to concomitant therapy with its individual components.
