title: Comparison of HRT-3 glaucoma probability score and subjective stereophotograph assessment for prediction of progression in glaucoma.
abstract: OBJECTIVE
  To assess whether baseline Glaucoma Probability Score (GPS; HRT-3; Heidelberg Engineering, Dossenheim, Germany) results are predictive of progression in patients with suspected glaucoma. The GPS is a new feature of the confocal scanning laser ophthalmoscope that generates an operator-independent, three-dimensional model of the optic nerve head and gives a score for the probability that this model is consistent with glaucomatous damage.
  
  
  METHODS
  The study included 223 patients with suspected glaucoma during an average follow-up of 63.3 months. Included subjects had a suspect optic disc appearance and/or elevated intraocular pressure, but normal visual fields. Conversion was defined as development of either repeatable abnormal visual fields or glaucomatous deterioration in the appearance of the optic disc during the study period. The association between baseline GPS and conversion was investigated by Cox regression models.
  
  
  RESULTS
  Fifty-four (24.2%) eyes converted. In multivariate models, both higher values of GPS global and subjective stereophotograph assessment (larger cup-disc ratio and glaucomatous grading) were predictive of conversion: adjusted hazard ratios (95% CI): 1.31 (1.15-1.50) per 0.1 higher global GPS, 1.34 (1.12-1.62) per 0.1 higher CDR, and 2.34 (1.22-4.47) for abnormal grading, respectively. No significant differences (P > 0.05 for all comparisons) were found between the c-index values (equivalent to area under ROC curve) for the multivariate models (0.732, 0.705, and 0.699, respectively).
  
  
  CONCLUSIONS
  GPS values were predictive of conversion in our population of patients with suspected glaucoma. Further, they performed as well as subjective assessment of the optic disc. These results suggest that GPS could potentially replace stereophotograph as a tool for estimating the likelihood of conversion to glaucoma.
authors.affiliation: Hamilton Glaucoma Center, Department of Ophthalmology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Alencar
authors.forename: Christopher
authors.initials: C
authors.lastname: Bowd
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.forename: Linda M
authors.initials: LM
authors.lastname: Zangwill
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Sample
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
mesh_terms: D018450:Disease Progression; D005500:Follow-Up Studies; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis; D009887:Ophthalmoscopy / Q000379:methods*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D010781:Photography / Q000379:methods*; D011336:Probability; D011446:Prospective Studies; D014054:Tomography / Q000379:methods; D014786:Vision Disorders / Q000175:diagnosis*; D014794:Visual Fields