Factors associated with long-term progression or stability in primary open-angle glaucoma

PURPOSE: To evaluate long term risk factors for progression or stability in patients with primary open-angle glaucoma. METHOD: We retrospectively included consecutively reviewed patients who had primary open-angle glaucoma for at least 5 years in this multicenter trial. Historical and clinical factors in these patients were evaluated for their association with stability or progression of the glaucoma. RESULTS: We included 218 patients in this study; of these, 34 progressed over an average length of follow-up of 45.5 +/- 30.0 months, and 184 were stable over an average of 72.8 +/- 18.3 months. The mean intraocular pressure over the follow-up period for the progressed group was 19.5 +/- 3.8 mm Hg and for the stable group 17.2 +/- 3.1 mm Hg (P = .001). The average standard deviation of individual intraocular pressures was greater in the progressed group (5.1 mm Hg) than the stable group (3.9 mm Hg, P = .012), Baseline characteristics indicating a greater potential to progress were a larger cup-to-disk ratio (P < .001), a greater number of medications (P = .02), older age (P .007), and worse visual acuity (P = .003). However, no difference was observed in pressure levels that prevented progression in these subpopulations compared with the total sample size. CONCLUSIONS: This study suggests that lowering the intraocular pressure is important in the treatment of primary open-angle glaucoma to help prevent long-term progression. Lowering the pressure, however, is not uniformly effective in preventing progression. Additionally, risk factors for progression do not further help identify pressure levels that prevent worsening of glaucoma. (C) 2000 by Elsevier Science Inc, All rights reserved.