title: Reproducibility of the Heidelberg Retina Tomograph III Glaucoma Probability Score.
abstract: OBJECTIVE
  To evaluate the intrasession reproducibility of the Heidelberg Retina Tomograph III (HRT III) Glaucoma Probability Score (GPS) and analyze the factors that may affect it.
  
  
  METHODS
  Twenty normal subjects and 20 glaucomatous patients underwent 10 HRT III examinations of 1 randomly selected eye during the same session. The reproducibility of the GPS and its parameters was assessed by calculating the intraclass correlation coefficients (ICCs) and 95% confidence intervals of the study population as a whole, and of the 2 subgroups. The factors influencing individual reproducibility were evaluated by means of regression analysis.
  
  
  RESULTS
  The reproducibility of the GPS parameters (at a confidence level of 95%) was almost perfect in the population as a whole (ICCs 0.964-0.856) and in the normal subjects (ICCs 0.976-0.897), but decreased in the glaucoma patients in whom it ranged from almost perfect to substantial (ICCs 0.922-0.705). The parameters were mainly influenced by image quality, but also by diagnosis and age, although the probability of glaucoma did not seem to depend on these variables.
  
  
  CONCLUSIONS
  GPS is a highly reproducible diagnostic tool, especially in the case of "good" or better quality images as evaluated by the HRT software; moreover, the reproducibility of the GPS parameters was significantly better in normal subjects than in glaucoma patients.
authors.affiliation: San Paolo Hospital, University of Milan, Italy. giotaibbi@libero.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: Taibbi
authors.forename: Paolo
authors.initials: P
authors.lastname: Fogagnolo
authors.forename: Nicola
authors.initials: N
authors.lastname: Orzalesi
authors.forename: Luca
authors.initials: L
authors.lastname: Rossetti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011336:Probability; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D014054:Tomography / Q000295:instrumentation; D055815:Young Adult