The Ocular Hypertension Treatment Study and the Collaborative Initial Glaucoma Treatment study, have reported that about 50-75% of patients will need combination therapy at any stage of the disease and may require 2 or more drugs to reach their target pressure. In such cases a fixed combination rather than separate drugs has a number of potential advantages including no risk of drug washout, reduced exposures to preservatives with reduced side effects, reduced costs of treatment, and ultimately better patient compliance and quality of life.Brinzolamide1%/Timolol0.5% fixed combination is a twice daily eye drops suspension comprising the carbonic anhydrase inhibitor (CA-II) brinzolamide and β-adrenergic receptor antagonist timolol.