PURPOSE. Timolol maleate is one of the most widely used anti-glaucoma agent. Different publications have stated that timolol once daily (qd) is just as effective as taken twice daily (bid). However, at least one other study has shown that timolol bid more effectively lowered intraocular pressures (IOP) than qd, when IOPs were measured in the 23rd hour. Since compliance is often an issue with glaucoma patients, it is important to consider a once a day formulation at this critical point. The purpose of this study was to evaluate the mean IOP drop at the 23rd hour, between those treated with Timoptic-XE 0.5% (TXE) qd versus timolol maleate 0.5% solution (TS) bid. METHOD. A total of 13 Glaucoma/Glaucoma Suspects participated in an open-label, cross-over study comparing TXE qd and TS bid. Patients were randomly assigned to a treatment regimen and eye. IOPs were measured two weeks later prior to their morning drop. Treatment regimen and eye were switched and patients returned in two weeks. This was repeated until each eye received both treatments.
RESULTS. Mean reduction of IOP was 2.75 mm Hg (sd = 2.38) when the patients were on TXE. Alternatively, when the patient was on TS, the reduction was 2.92 mm Hg (sd = 2.97), when IOPs were measured in the 23rd hour. The mean lowering effect when compared to the baseline and control eye was 2.75 and 1.67 mm Hg, and 2.92 and 1.75 mm Hg, for TXE and TS respectively.
CONCLUSIONS. There was no statistical significance in IOP lowering effect at the 23rd hour. Therefore, TXE could be a drug of choice if beta-blockers were indicated for the treatment of glaucoma based on its effectiveness and easier compliance. However, it is important to notice that some patients responded with greater IOP control with TXE, and some with TS, and mean IOPs for those treated with TS bid showed a greater reduction than TXE qd when measured in the 23rd hour.