A CONTROLLED CLINICAL-TRIAL OF DORZOLAMIDE - A SINGLE-CENTER SUBSET OF A MULTICENTER STUDY

Purpose: To assess the safety and intraocular pressure (IOP)-lowering activity of 2% dorzolamide (topical carbonic anhydrase inhibitor), com pared to 0.5% timolol and 0.5% betaxolol eyedrops. Methods: A parallel , masked, randomised one-year clinical trial was conducted in 16 patie nts with open-angle glaucoma or ocular hypertension, being a subset of a multicentre study which enrolled 523 subjects. Patients had IOP > 2 2 mmHg in one eye at baseline following washout of ocular hypotensive medications and were then randomised in a 3:1:1 ratio to receive 2% do rzolamide thrice daily, 0.5% timolol twice daily or 0.5% betaxolol twi ce daily respectively. IOP was measured at Hour 2 (morning peak), Hour 5 and Hour 8 (afternoon trough for dorzolamide) at baseline, Weeks 2 and 4 and Months 2, 3, 6, 9 and 12. Results: Topical dorzolamide 2% so lution was well tolerated and safe. Mean IOP for dorzolamide at Hour 2 was 29.1 mmHg at baseline and 20.8 mmHg on treatment at one year, a 2 8.5% change. Mean IOP for dorzolamide at Hour 8 was 24.5 mmHg at basel ine and 20.2 mmHg on treatment at one year, a 17.6% change. Comparable percent changes for timolol and betaxolol were 43.2/25.7 mmHg at Hour 2 and 21.9/13.5 mmHg at Hour 8 respectively. Conclusions: Dozolamide 2% given thrice daily was well tolerated and safe, with a clinically s ignificant effect on IOP comparable to betaxolol 0.5% twice daily, but not as great as timolol 0.5% twice daily.