This is an application for support for our organization to become a participating Clinical Center in the Ocular Hypertension Treatment Study (OHTS). The OHTS is a multicenter random assignment clinical trial designed to test the hypothesis that medical reduction of intraocular pressure prevents or delays the onset of glaucomatous visual system damage in ocular hypertensive patients. The complete details of the OHTS rationale, design, and methods are in the OHTS lead application and Manual of Procedures. This proposal provides documentation of the ability of the Principal Investigator and the Coinvestigators to screen sufficient numbers of ocular hypertensive individuals to enroll at least 100 patients over a 24-month period. We shall organize for this effort under sponsorship of the University Ophthalmic Consultants Research and Educational Foundation of Washington. We are committed to the need and justification of the OHTS. We include with this application documentation of the capabilities of our organization to conduct the study in accord with the details of the OHTS Manual of Procedures. Most of our enrolled patients will come from our private, glaucoma subspeciality practices. We have already functioned successfully for the Advanced Glaucoma Intervention Study (AGIS). We bring that functioning organization to our proposed participation in the OHTS. In our Research Plan we list organizations in our area as potential outside referral sources for patients for enrollment and randomization to treatment in the OHTS. Our relationship with these organizations is established; they have been productive sources in our AGIS activity.