- Following requirements for intention-to-treat analyses, we will measure mean intraocular pressure at 12 months comparing the two groups and adjusting for baseline intraocular pressure, including all subjects who accepted and refused treatment (primary analysis, unadjusted). We will also measure intraocular pressure as above, adjusting for cataract surgery, age, gender, prior use of medication, degrees of open angle in study eye at baseline, and severity of glaucoma (Cup to disk ratio) in study eye at baseline (primary analysis, adjusted). Both of the above analyses will be repeated using a per protocol approach (including only patients who accepted their assigned therapy, or secondary analysis).