Recruitment for the study has been completed. The 255 patients were identified by an extensive, population-based screening of successive age cohorts as well as by clinical referral. The diagnosis was confirmed through Humphrey perimetry at two postscreening visits to the Clinical Center or Satellite Center. Eligible patients who agreed to participate had two additional visits for collection of baseline data. They were randomized to treatment with the beta blocker Betaxolol and argon laser trabeculoplasty (treated group) or to no initial treatment (control group) with close followup of both groups.