Campbell S H, Hickey-Dwyer M, Harding S P
St. Paul's Eye Unit, Royal Liverpool Hospital, UK.
Eye (Lond). 1993;7 ( Pt 1):105-8. doi: 10.1038/eye.1993.22.
Forty patients with an intraocular pressure (IOP) between 30 and 49 mmHg in either eye (57 eyes) were recruited into a trial of timolol 0.25% versus timolol 0.5%. Patients were randomised to receive the two concentrations of drug in the order ABA or BAB. The study period was 12 weeks for each patient, with changes in drug concentration at 4 and 8 weeks. IOPs were measured at the same time every 2 weeks. Mean IOP of both eyes was used, excluding any eyes with initial IOPs of less than 30 mmHg. There was no difference between the 2-week and 4-week pressure readings, which were therefore combined. There was no statistically significant difference in the initial IOPs of the two groups (0.5%, 33.45 mmHg; 0.25%, 32.63 mmHg) nor in the initial fall in IOP with either concentration (0.5%, 12.03 mmHg; 0.25%, 11.31 mmHg). Furthermore, changing from one concentration to the other had no significant effect on IOP. Mean IOPs over the whole study period averaged 21.12 mmHg for timolol 0.25% and 20.75 mmHg for timolol 0.5%. Again these differences were not statistically significant. The statistical power of the study was estimated to exceed 85%. The authors suggest that there is no justification for use of the 0.5% strength, which is more expensive and has no advantages.
40例单眼眼压（IOP）在30至49 mmHg之间的患者（共57只眼）被纳入一项比较0.25%噻吗洛尔与0.5%噻吗洛尔的试验。患者被随机按ABA或BAB顺序接受两种浓度的药物。每位患者的研究期为12周，在第4周和第8周改变药物浓度。每2周在同一时间测量眼压。使用双眼的平均眼压，排除初始眼压低于30 mmHg的任何眼睛。2周和4周的眼压读数无差异，因此将其合并。两组的初始眼压（0.5%组为33.45 mmHg；0.25%组为32.63 mmHg）以及使用任一浓度时眼压的初始下降幅度（0.5%组为12.03 mmHg；0.25%组为11.31 mmHg）均无统计学显著差异。此外，从一种浓度换为另一种浓度对眼压无显著影响。在整个研究期间，0.25%噻吗洛尔的平均眼压为21.12 mmHg，0.5%噻吗洛尔的平均眼压为20.75 mmHg。同样，这些差异无统计学显著意义。该研究的统计效能估计超过85%。作者认为使用0.5%浓度没有依据，其价格更高且无优势。
