APR 08, 2011
This study evaluated the ability of a fixed combination of brimonidine-timolol to reduce IOP spikes after phacoemulsification in at-risk patients. Using a double-masked design, the authors randomized patients scheduled for surgery to receive one drop of brimonidine-timolol fixed combination immediately after surgery or no treatment. They found that a single drop of brimonidine-timolol fixed combination effectively reduced IOP six, 12 and 24 hours postoperatively, while the mean IOP among controls increased at all three postop measurement times.
Subjects in the study were 58 patients (58 eyes) scheduled to undergo surgery with the same surgeon at one hospital in Greece. They underwent IOP measurement preoperatively and at six, 12, and 24 hours postoperatively.
Mean IOP was significantly lower in the treatment group than the control group at all three postoperative measurement times (P = 0.01, P = 0.004 and P = 0.002, respectively). The mean IOP change between the two groups was also statistically significantly different at six, 12 and 24 hours after surgery (P = 0.015, P = 0.006 and P = 0.003, respectively). Overall, mean IOP increased by 0.14 mmHg ± 3.88 in the treatment group and by 2.8 ± 5.01 mmHg in the control group.
The authors hypothesize, based in part on the results of previous studies, that the ocular hypotensive effect of the brimonidine-timolol fixed combination can be attributed primarily to timolol. They say that further studies are needed to clarify whether the brimonidine-timolol fixed combination provides a greater IOP-lowering effect than either of its individual components administered as monotherapy postoperatively.
This study provides important evidence favoring the use of brimonidine-timolol fixed combination instead of Diamox, which until now has been the best choice to blunt pressure spikes in at-risk patients.