The Advanced Glaucoma Intervention Study (AGIS): 9. Comparison of glaucomaoutcomes in black and white patients within treatment groups

PURPOSE: To compare in eyes of black and white patients the progression of glaucoma after failure of medical therapy and upon start of surgical interv ention. DESIGN: Cohort study analysis of data from a randomized clinical trial. METHODS: This multicenter study included open,angle glaucoma patients who h ad failed medical therapy: 451 eyes of 332 black patients, 325 eyes of 249 white patients. Eyes were randomly assigned to an argon laser trabeculoplas ty (ALT),trabeculectomy-trabeculectomy (ATT) sequence or a trabeculectomy,A LT trabeculectomy (TAT) sequence; they had been followed for 7 to 11 years at database closure. Main outcome measures were decrease of visual field (D VF), sustained decrease of visual field (SDVF), decrease of visual acuity ( DVA), sustained decrease of visual acuity (SDVA), and failure of first surg ical glaucoma intervention. Statistical methods included logistic regressio n to obtain average adjusted black-white odds ratios for binary outcomes, a nd Cox regression to estimate adjusted black-white risk ratios for time-to- event outcomes. RESULTS: In the ATT sequence blacks were at lower risk than whites of failu re of first intervention (ALT, RR = 0.68, P = 0.040). In the TAT sequence b lacks were at higher risk than whites of failure of the first intervention (trabeculectomy, RR = 1.79, P = 0.033), of intraocular pressure = greater t han or equal to 18 mm Hg (average OR = 1.41, P = 0.026), and of DVF (averag e OR = 1.78, P = 0.007). In both treatment sequences, the average number of prescribed medications was greater for blacks than whites (P less than or equal to 0.002). CONCLUSIONS: The results support the hypothesis that after failure of medic al therapy and upon initiation of surgical intervention, an initial interve ntion with trabeculectomy retards the progression of glaucoma more effectiv ely in white than in black patients. The data provide a weak suggestion tha t an initial surgical intervention with ALT retards the progression of glau coma more effectively in black than in white patients. (Am J Ophthalmol 200 1;132:311-320. (C) 2001 by Elsevier Science Inc. All rights reserved.).