Tolerability and effectiveness of preservative-free dorzolamide–timolol (preservative-free Cosopt^®) in patients with open-angle glaucoma or ocular hypertension

Cindy Hutnik¹, David Neima², Fahim Ibrahim³, Robert Scott⁴, Julie Vaillancourt⁵, Denis Haine⁵, John S Sampalis⁵, Natacha Bastien⁶, Sylvain Foucart⁶

¹Ivey Eye Institute, St Joseph Healthcare, London, Ontario, Canada; ²New Westminster, British Columbia, Canada; ³Point Edward, Ontario, Canada; ⁴Kentville, Nova Scotia, Canada; ⁵JSS Medical Research, Westmount, Quebec, Canada; ⁶Merck Frosst Canada Ltd, Kirkland, Quebec, Canada

Purpose: To assess the effect of preservative-free dorzolamide–timolol on nonvisual symptoms and intraocular pressure (IOP) in newly diagnosed and untreated patients with open-angle glaucoma or ocular hypertension.

Methods: This was a prospective, 8-week, open-label, Canadian multicenter study. All patients were treated with preservative-free dorzolamide–timolol formulation. The primary outcome was the change in the nonvisual symptom score of the Glaucoma Symptom Scale (GSS-SYMP-6) from baseline to 8 weeks. Secondary effectiveness outcome measures were absolute and percent changes in IOP from baseline to 4 and 8 weeks.

Results: One hundred and seventy-eight patients were enrolled. Mean (SD) age was 65.6 (12.1) years and 90 (50.6%) were females. There were 92 patients diagnosed with open-angle glaucoma, 62 with ocular hypertension, and 23 with both diseases (diagnosis was missing for one patient). The mean (SD) GSS-SYMP-6 score increased from 73.6 (21.8) at baseline to 76.1 (20.7) at 8 weeks (P = 0.097). Mean (SD) IOP significantly decreased by 11.7 (5.1) mmHg at 4 weeks (P < 0.001) and by 11.5 (5.3) mmHg at 8 weeks (P < 0.001), representing reductions of -38.5% (P < 0.001) and -38.0% (P < 0.001), respectively.

Conclusion: Preservative-free dorzolamide–timolol does not increase eye discomfort while significantly reducing IOP in patients with open-angle glaucoma or ocular-hypertension.

Keywords: open-angle glaucoma, ocular hypertension, GSS-SYMP-6, intraocular pressure, dorzolamide–timolol, preservative-free

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