Comparative Effectiveness of Treatment Strategies for Primary Open-Angle Glaucoma

The primary objectives of the study are: 1. To compare the proportion of patients who achieve a successful response to treatment (reduction in Intraocular Pressure (IOP) of \>15%) between patients treated with laser surgery (including argon laser trabeculectomy, and selective laser trabeculoplasty) with patients receiving additional medications, at 1-year post-treatment initiation. 2. To compare the proportion of patients who achieve a successful response to treatment (reduction in IOP of \>15%) between patients treated with other procedures (including incisional surgery, drainage device procedures, and other glaucoma procedures) with patients receiving additional medications, at 1-year-post-treatment initiation. The study is a prospective, observational cohort study and will not provide or recommend any treatment. Patients who have failed initial medical therapy with two glaucoma medications will be identified and enrolled at the time of scheduling of a laser surgery procedure or other procedure such as incisional surgery or drainage device, or initiation of an additional course of therapy with medication as determined by their physician. This inception cohort of new initiators of laser surgical treatment, other procedures, or additional medical therapy will be followed for 12 months. All decisions regarding treatment are solely at the discretion of the physician in accordance with their usual practice. Enrollment is expected to begin in February 2011 and continue through 12 months of follow-up after enrollment targets have been reached.