title: Validation of a predictive model to estimate the risk of conversion from ocular hypertension to glaucoma.
abstract: OBJECTIVE
  To develop and validate a predictive model to estimate the risk of conversion from ocular hypertension to glaucoma.
  
  
  METHODS
  Predictive models for the 5-year risk of conversion to glaucoma were derived from the results of the Ocular Hypertension Treatment Study (OHTS). The performance of these models was assessed in an independent population of 126 subjects with ocular hypertension from a longitudinal study (Diagnostic Innovations in Glaucoma Study [DIGS]). The performance of the OHTS-derived models was assessed in the DIGS cohort according to equality of regression coefficients, discrimination (c-index), and calibration.
  
  
  RESULTS
  Thirty-one patients (25%) developed glaucoma during follow-up. Hazard ratios for DIGS- and OHTS-derived predictive models were similar for age, intraocular pressure, central corneal thickness, vertical cup-disc ratio, and pattern standard deviation but were significantly different for the presence of diabetes mellitus. When applied to the DIGS population, the OHTS-derived predictive models had reasonably good discrimination (c-indexes of 0.68 [full model] and 0.73 [reduced model]) and calibration.
  
  
  CONCLUSIONS
  The OHTS-derived predictive models performed well in assessing the risk of glaucoma development in an independent population of untreated subjects with ocular hypertension. A risk scoring system was developed that allows calculation of the 5-year risk of glaucoma development for an individual patient.
authors.affiliation: Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA 92093, USA. fmedeiros@eyecenter.ucsd.edu
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Sample
authors.forename: Cintia F
authors.initials: CF
authors.lastname: Gomi
authors.forename: Christopher
authors.initials: C
authors.lastname: Bowd
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Crowston
authors.forename: Linda M
authors.initials: LM
authors.lastname: Zangwill
mesh_terms: D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009798:Ocular Hypertension / Q000175:diagnosis / Q000503:physiopathology*; D018570:Risk Assessment