Abstract
Abstract: :
Purpose: To compare the intraocular pressure (IOP) lowering effect of concomitant administration of topical beta-blocker and topical carbonic anhydrase inhibitor (tCAI) versus fixed-combination timolol 0.5%-dorzolamide 2% (Cosopt®). To expand upon previous work comparing the intraocular pressure(IOP) lowering effect of fixed combination 2% dorzolamide and 0.5% timolol (Cosopt) therapy to that observed with concomitant administration of a topical beta-blocker and dorzolamide. Method: In a national multi-site study involving 16 investigators, 365 consecutive glaucoma patients were changed from a regimen including topical beta-blocker and dorzolamide to regimen involving Cosopt® in the eye with the higher IOP. In 106 patients, contralateral eyes were used as controls and remained on the concomitant therapy. Average IOP before and 1 month after changeover were compared. Analysis involved a student-t test for change in IOP along with an evaluation of the percent of successfully treated patients (IOP equivalent or better reduction). Results: Baseline IOP was 19.09 mmHg for study eyes and 17.40 mmHg for control eyes. Four weeks after initiation of treatment on the fixed combination, a mean additional IOP reduction of 1.74 mmHg was observed (9.1 % reduction) (p<.0001). Overall, 82% of eyes exhibited equal or lower IOP on the fixed combination compared to concomitant therapy. In the group of 106 fixed combination eyes paired with contralateral controls, the mean IOP reduction was 1.80 mmHg in the fixed combination eyes (9.4% reduction) (p=.002), compared to a statistically insignificant IOP reduction of .36 mmHg in the control eyes (p=.48). Therapy was well tolerated and without side effects. Conclusion: These observations appear to indicate that changeover to fix-combination therapy from concomitant administration of individual components was successful and might offer additional IOP reduction. This benefit may be due to increased compliance of one bid medication versus one bid and one tid medication, or to a decrease in the washout effect seen when using two or more medications.
Keywords: 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 514 pharmacology