Experience with Cosopt, the fixed combination of timolol and dorzolamide, after switch from free combination of timolol and dorzolamide, in Swiss ophthalmologists' offices.

PURPOSE: To analyse a response to the therapy switch from the concomitant application of beta-blocker and topical carbonic anhydrase inhibitor to the fixed combination of timolol and dorzolamide (Cosopt) in glaucoma/ocular hypertensive patients under everyday, office-practice conditions. PATIENTS AND METHODS: The data source was a survey among practising ophthalmologists in Switzerland assessing their experience with glaucoma patients/ocular hypertensives put for the first time on the fixed combination of timolol and dorzolamide. A total of 98 patients underwent the therapy switch in at least one eye. The intraocular pressure (IOP) change between the baseline visit before switch to the timolol-dorzolamide fixed combination occurred, and the first follow-up control after the switch, served as an indicator of compliance.
RESULTS: The IOP decreased on average from 19.43 +/- 5.64 mmHg to 17.97 +/- 3.58 mmHg (p < 0.01). The time to the follow-up visit ranged from 4 to 354 days, and the magnitude of IOP change demonstrated a significant dependence on the time to the follow-up visit, also when corrected for baseline IOP level. A total of 87 (85.3%) continued on the timolol-dorzolamide fixed combination therapy after the first control visit. In 68 of these 98 patients the contralateral eyes underwent the same therapy switch, and their IOP followed an identical pattern of behaviour.
CONCLUSION: The average IOP decrease of 1.5 mmHg upon therapy switch to the timolol-dorzolamide fixed combination suggests a better efficacy due to improved compliance. Short-term compliance benefit seems to be more pronounced. The high timolol-dorzolamide fixed combination therapy continuation rate reflects an improvement in compliance and subjectively-perceived convenience.