Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198-5840, USA.
J Glaucoma. 2010 Aug;19(6):356-64. doi: 10.1097/IJG.0b013e3181d12dd8.
To investigate whether the intraocular pressure (IOP) reduction and mechanism of action of timolol and latanoprost change between 1 and 6 weeks of treatment.
Thirty participants on no ocular medications completed this double-masked, 6-visit, crossover study. At each visit IOP was determined by pneumatonometry, aqueous flow by fluorophotometry, and outflow facility by fluorophotometry and tonography. Separate values of uveoscleral outflow were calculated using the Goldmann equation, an episcleral venous pressure of 11 mm Hg, and each of the 2 outflow facility values. In a randomized fashion, both eyes were treated for 6 weeks with latanoprost 0.005% once daily or timolol 0.5% twice daily. Measurements were repeated at 1 and 6 weeks of dosing. After 6 weeks of washout, the second drug was administered in a crossover manner. One and 6 weeks of treatment were compared with appropriate baselines using 1-way analyses of variance (ANOVA).
Timolol reduced aqueous flow by 27% at week 1 (P<0.001) and 16% at week 6 (P=0.03). Latanoprost increased uveoscleral outflow several fold at each visit (P<0.05). Neither drug altered outflow facility. Neither drug showed a detectable change in aqueous humor dynamics at week 6 compared with week 1. Both drugs significantly (P<0.001) reduced IOP at 1 and 6 weeks of treatment.
Timolol and latanoprost significantly reduce IOP by different mechanisms. Timolol reduces aqueous flow whereas latanoprost increases uveoscleral outflow. Continued treatment with timolol or latanoprost for 6 weeks did not alter effects on aqueous humor dynamics. Outflow facility changes sometimes reported with prostaglandin analogues were not detected in this study.
研究噻吗洛尔和拉坦前列素在治疗 1 至 6 周期间眼压（IOP）降低和作用机制是否发生变化。
30 名未使用眼部药物的参与者完成了这项双盲、6 次就诊、交叉研究。每次就诊时，通过气动眼压计确定 IOP，通过荧光光度法确定房水流量，通过荧光光度法和眼压描记术确定流出道通畅性。使用 Goldmann 方程、眼上静脉压 11mmHg 和 2 个流出道通畅性值，分别计算葡萄膜巩膜流出道的单独值。以随机方式，双眼分别用拉坦前列素 0.005%每日一次或噻吗洛尔 0.5%每日两次治疗 6 周。在剂量 1 和 6 周时重复测量。在洗脱 6 周后，以交叉方式给予第二种药物。使用单向方差分析（ANOVA）将 1 周和 6 周的治疗与适当的基线进行比较。
噻吗洛尔在第 1 周（P<0.001）和第 6 周（P=0.03）时将房水流量降低了 27%。拉坦前列素在每次就诊时将葡萄膜巩膜流出量增加数倍（P<0.05）。两种药物均未改变流出道通畅性。与第 1 周相比，第 6 周时两种药物均未检测到房水动力学的明显变化。两种药物在治疗 1 周和 6 周时均显著（P<0.001）降低 IOP。
噻吗洛尔和拉坦前列素通过不同的机制显著降低 IOP。噻吗洛尔降低房水流量，而拉坦前列素增加葡萄膜巩膜流出量。连续使用噻吗洛尔或拉坦前列素治疗 6 周不会改变房水动力学的影响。本研究未检测到前列腺素类似物有时报道的流出道通畅性变化。
