Forty-two young patients (age 29 to 60) had one eye randomized to ALT (n = 22) or SLT (n = 20). Intraocular pressure was measured prior to laser and 1 hour, 1 day, 6 weeks, 3 months, every 3 months until 2 years, and then yearly post-laser. χ2 analysis and student's t-test were used to determine statistical significance.