To determine the current place of argon laser trabeculoplasty (ALT) in the therapeutic armamentarium of primary open-angle glaucoma (POAG), 211 photocoagulated phakic eyes were analyzed. 159 eyes had a 5-year follow-up, 147 eyes had an 8-year follow-up and 127 eyes had a minimal 10-year follow-up. These eyes came from an initial group of 151 patients, 76 women and 75 men, with a mean age of 67 years. We decided, to judge trabeculoplasty results according to three combined criteria of failure--insufficient or transient intraocular pressure drop (< or = 3 mm Hg), progression in visual field loss and need for filtrating surgery--and according to various expected goals: prevent an increase of drugs with their subsequent side effects, taper a nontolerated medical treatment, and try to cease all medical treatment in noncompliant patients. According to these criteria, during the first 5 years, the cumulative failure rate in the 159 eyes rose steadily from 19% (31 eyes) in the 1st year to 52% (82 eyes) in the 5th year. In the 147 eyes with an 8-year follow-up, 25 eyes (17%) were successful and in the 127 eyes with a 10-year follow-up 14 eyes (11%) were still controlled. At the 10-year follow-up the surgical failure rate (35%; 40 eyes in 113) was similar to the rate at 5 years (33%; 27 in 82). 30 eyes, which were excluded from the study, despite being still controlled, belonged to patients who had died during the follow-up. Their mean age at the time of ALT was 76 years. The low success rate at 10 years was predictable from the 10% new failure cases per year encountered in the 5-year data.(ABSTRACT TRUNCATED AT 250 WORDS)