title: Test-retest reproducibility of optic disk deterioration detected from stereophotographs by masked graders.
abstract: OBJECTIVE
  To assess the reproducibility of determining whether an eye has developed optic disk deterioration by the Optic Disc Reading Center (ODRC) in the Ocular Hypertension Treatment Study (OHTS).
  
  
  METHODS
  Test-retest reproducibility study.
  
  
  METHODS
  Masked, certified graders at the ODRC determine the occurrence of optic disk deterioration in OHTS by comparing baseline with follow-up stereoscopic optic disk photographs. To assess reproducibility, re-gradings were obtained annually by inserting masked "quality control" photographs into the usual ODRC reading stream.
  
  
  RESULTS
  Agreement (kappa) ranged from 0.65 to 0.83 over 5 years. Specificity ranged from 98% to 100%, and sensitivity ranged from 64% to 81%.
  
  
  CONCLUSIONS
  The kappa statistic for test-retest agreement in OHTS is in the range considered good to excellent over 5 years. Consistency (specificity) in re-grading optic disks that did not develop deterioration was particularly high. The sensitivity results show that detecting subtle deterioration of optic disks is challenging.
authors.affiliation: Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Parrish
authors.forename: Joyce C
authors.initials: JC
authors.lastname: Schiffman
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Anderson
authors.forename: Donald L
authors.initials: DL
authors.lastname: Budenz
authors.forename: Maria-Cristina
authors.initials: MC
authors.lastname: Wells-Albornoz
authors.forename: Ruth
authors.initials: R
authors.lastname: Vandenbroucke
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kass
authors.forename: Mae O
authors.initials: MO
authors.lastname: Gordon
mesh_terms: D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D009798:Ocular Hypertension / Q000175:diagnosis; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity