Intraocular pressure over 24 hours after repeated administration of latanoprost 0.005% or timolol gel-forming solution 0.5% in patients with ocular hypertension.

PURPOSE

To compare the effect on intraocular pressure (IOP) over 24 hours after 4 weeks of treatment with latanoprost 0.005% and timolol gel 0.5%.

DESIGN

Randomized, open, crossover single-center study.

PARTICIPANTS

Twenty-seven patients with ocular hypertension.

METHODS

The patients were randomly assigned to 4 weeks of latanoprost 0.005% once daily or timolol gel 0.5% once daily, with a 4-week washout period before switching therapy.

MAIN OUTCOME MEASURES

Measurement of IOP during 24 hours of hospitalization. Blood pressure and heart rate were also measured repeatedly over the 24 hours. Daytime mean IOP, nighttime mean IOP, and 24-hour mean IOP were calculated as IOP area under the curve (AUC) divided by time in hours.

RESULTS

The mean IOP during daytime (7 AM to 10 PM) was 13.5 +/- 0.4 mmHg (daytime IOP, AUC/15 hours, least square mean +/- standard error of the mean [SEM]) in the latanoprost group, and 14.8 +/- 0.4 mmHg in the timolol gel group. This difference of 1.3 +/- 0.3 mmHg was statistically significant in favor of latanoprost (P < 0.001; 95% confidence interval [CI], 0.7, 2.0). The mean IOP at night (10 PM to 7 AM) was 13.7 +/- 0.4 mmHg for latanoprost (nighttime IOP, AUC/9 hours, least square mean +/- SEM) and 15.9 +/- 0.5 mmHg for timolol gel, with a difference of 2.2 +/- 0.3 mmHg (P < 0.001; 95% CI, 1.5, 2.8). At every measured time point during the 24 hours, latanoprost reduced IOP more than timolol. There was no difference between the two treatment groups regarding blood pressure and heart rate.

CONCLUSIONS

Latanoprost reduced mean 24-hour IOP, mean daytime IOP, and mean nighttime IOP statistically significantly more than timolol. Also, latanoprost reduced IOP more effectively at every measured time point over the 24 hours compared with timolol gel.