title: Can an inexperienced observer accurately plot disc contours using Heidelberg retinal Tomograph?
abstract: OBJECTIVE
  To examine the reliability of inexperienced observers in plotting optic disc contours on Heidelberg retinal tomography images before and after training.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  One hundred eyes that were randomly selected from the Singapore Indian Eye Study.
  
  
  METHODS
  Both eyes of subjects were imaged with Heidelberg Retina Tomograph 3 (HRT-3; Heidelberg Engineering, Heidelberg, Germany). Optic disc contours were plotted on the same images by 2 new observers on 2 separate occasions, before and after 2-hour standardized training on the skills and tools available to accurately identify and delineate optic disc contours. These plottings were compared with an experienced, trained glaucoma expert (gold standard). Agreement and variability were analyzed by interclass correlation tests and Bland-Altman plots.
  
  
  RESULTS
  A total of 182 images (18 excluded because of poor quality) from 89 Indian subjects were included. The mean age was 53.27 ± 7.25 years and 54.8% were male. There was moderate-to-high agreement between pretraining (both new observers) and experienced observer's results (interclass correlation values range, 0.76-0.99). The interclass correlation improved for all the HRT-3 parameters after the 2 new observers were adequately trained. Comparing the interclass correlation values before and after training, the differences for mean retinal nerve fibre layer thickness for Observer 1 and all the HRT-3 parameters for Observer 2 were statistically significant.
  
  
  CONCLUSIONS
  This study shows that it is easy to train a new inexperienced observer to plot optic disc contours on HRT images, which translates into improved and acceptable interobserver variability and agreement.
authors.affiliation: Department of Ophthalmology, National University Health Systems.
authors.forename: Victor
authors.initials: V
authors.lastname: Koh
authors.affiliation: Department of Ophthalmology, National University Health Systems.
authors.forename: Sheila
authors.initials: S
authors.lastname: Wee
authors.affiliation: Department of Ophthalmology, National University Health Systems.
authors.forename: Monica
authors.initials: M
authors.lastname: Lim
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre.
authors.forename: Wan-Ling
authors.initials: WL
authors.lastname: Wong
authors.affiliation: Department of Ophthalmology, National University Health Systems; Singapore Eye Research Institute, Singapore National Eye Centre; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Tien-Yin
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Department of Ophthalmology, National University Health Systems; Singapore Eye Research Institute, Singapore National Eye Centre; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.affiliation: Department of Ophthalmology, National University Health Systems. Electronic address: ploonsc@yahoo.com.
authors.forename: Seng-Chee
authors.initials: SC
authors.lastname: Loon
mesh_terms: D002983:Clinical Competence; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000208:ethnology; D006801:Humans; D007194:India / Q000208:ethnology; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D009885:Ophthalmology / Q000193:education*; D019721:Ophthalmoscopes; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000208:ethnology; D010780:Photogrammetry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012846:Singapore / Q000453:epidemiology; D014054:Tomography; D044465:White People / Q000208:ethnology