Abstract
Abstract: :
Purpose. To compare the effects of 0.5% timolol and 0.005% latanoprost in lowering intraocular pressure (IOP) at night in patients with open-angle glaucoma or ocular hypertension. Methods. Sixteen patients with open-angle glaucoma or ocular hypertension (ages 41-79 years) were treated with topical timolol (Timoptic-XE), latanoprost (Xalatan), or no drug for at least 4 weeks. Timolol was given once in the morning and latanoprost once in the evening. At the end of each treatment period, IOP was measured using a pneumatonometer every 2 hours for a consecutive 24 hours in a sleep laboratory. During the 16-hour diurnal/wake period, IOP and blood pressure in both sitting and supine positions were measured. During the 8-hour nocturnal period, IOP and blood pressure were measured supine. Average IOP and blood pressure in relevant body positions were calculated for the diurnal and the nocturnal periods. Results. Reductions of diurnal IOP, either sitting or supine, were not different with the treatments of timolol and latanoprost. However, the nocturnal supine IOP without treatment (23.6 ± 0.9 mmHg, mean ± SEM) was significantly reduced only with the treatment of latanoprost (21.6 ± 0.9 mmHg), not with the treatment of timolol (23.4 ± 0.8 mmHg). For the treatment with latanoprost, the reduction of supine IOP was less during the nocturnal period than during the diurnal period despite administration in the evening. There was no significant reduction of mean blood pressure by either the treatment with timolol or latanoprost. Conclusions. There was little reduction of IOP during the nocturnal period after the treatment with timolol. Treatment with latanoprost caused a significant reduction of IOP at night. However, this reduction of IOP was less than the reduction during the diurnal period. Both timolol and latanoprost were effective in lowering IOP during the day.
Keywords: intraocular pressure • pharmacology • eicosanoids