title: The Advanced Glaucoma Intervention Study (AGIS): 11. Risk factors for failure of trabeculectomy and argon laser trabeculoplasty.
abstract: OBJECTIVE
  To investigate the association of pre-intervention and post-intervention patient and eye characteristics with failure of argon laser trabeculoplasty (ALT) and trabeculectomy.
  
  
  METHODS
  Cohort study of participants in the Advanced Glaucoma Intervention Study.
  
  
  METHODS
  This multicenter study took place between 1988 and 2001. Between 1988 and 1992, 789 eyes of 591 patients aged 35 to 80 years with advanced glaucoma were randomized into one of two surgical treatment sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy or trabeculectomy-ALT-trabeculectomy. Upon study-defined failure (based on maximum medications, sustained intraocular pressure (IOP) elevation, visual field defect, and disk rim deterioration) of each intervention, patients were offered the subsequent intervention. Potential follow-up was 8 to 13 years. This report is based on data from 779 eyes that had at least 3 months of follow-up. The main outcome measures are failure of ALT and trabeculectomy, whether as first or second interventions. Effect size is measured by the hazard ratio (HR) and its corresponding 95% confidence interval (CI) obtained from Cox multiple regression analysis, where HR corresponds to the coefficient of change in risk associated with a unit increase in a factor. For binary factors, this corresponds to the change in risk in eyes with the factor relative to the risk in eyes without the factor.
  
  
  RESULTS
  Pre-intervention factors associated with failure of ALT are younger age (HR = 0.98, CI = 0.96-0.99, P =.009) and higher IOP (1.11, 1.08-1.15, P <.001). Pre-intervention factors associated with failure of trabeculectomy are younger age (HR = 0.97, CI = 0.95-0.99, P =.005) and higher IOP (1.04, 1.01-1.06, P =.002), as well as diabetes (2.86, 1.88-4.36, P <.001) and any postoperative complication (1.99, 1.35-2.93, P <.001). Individual postoperative complications significantly associated with increased risk of failure of trabeculectomy are elevated IOP (3.4, 1.9-6.1, P <.001) and marked inflammation (2.4, 1.3-4.6, P =.006).
  
  
  CONCLUSIONS
  In this study, ALT failure was associated with younger age and higher pre-intervention IOP. Trabeculectomy failure was associated with younger age, higher pre-intervention IOP, diabetes, and one or more postoperative complications, particularly elevated IOP and marked inflammation.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D015331:Cohort Studies; D048909:Diabetes Complications; D005260:Female; D005902:Glaucoma, Open-Angle / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000150:complications; D016016:Proportional Hazards Models; D012307:Risk Factors; D012720:Severity of Illness Index; D014130:Trabeculectomy / Q000009:adverse effects*; D017211:Treatment Failure