title: Reproducibility of anterior chamber angle analyses with the swept-source optical coherence tomography in young, healthy Caucasians.
abstract: OBJECTIVE
  To assess the reproducibility of iridocorneal angle (ICA) analysis in young, healthy Caucasian subjects using swept-source optical coherence tomography (SS-OCT) by determining variability and interobserver agreement between expert and nonexpert observers.
  
  
  METHODS
  Thirty-one healthy volunteers (nonexperts) acquired three consecutive SS-OCT images of the right eyes of their peer nonexperts. Images were analyzed by 31 nonexperts and additionally by three experts, whereby the angle opening distance (AOD) and the trabecular iris space area (TISA) at 500 and 750 μm were calculated. A random intercept model was used to determine the amount of variation between observers. In addition, the intra-observer variability between nonexperts and experts was calculated by determining the coefficient of variation (CV).
  
  
  RESULTS
  A significant difference was found in the expert analysis for the nasal and temporal angle in the AOD500 (P = 0.002), AOD750 (P < 0.01), and TISA750 (P < 0.01), and the values AOD500 (P = 0.025), AOD750 (P = 0.012), and TISA500 (P = 0.010) were significantly larger if nonexperts analyzed SS-OCT images. The CV was only significant larger for nonexperts for AOD500 (11.1% vs. 8.7%, P < 0.01).
  
  
  CONCLUSIONS
  This study demonstrated high reproducibility of angle analysis in young, healthy Caucasian subjects using SS-OCT. Nevertheless, nonexperts obtained significant larger values compared with experts, implying that training is a necessary requirement before analyzing SS-OCT images in ophthalmic practice.
authors.affiliation: University Eye Clinic, Maastricht, The Netherlands.
authors.forename: Hellen C S
authors.initials: HC
authors.lastname: Römkens
authors.affiliation: University Eye Clinic, Maastricht, The Netherlands.
authors.forename: Henny J M
authors.initials: HJ
authors.lastname: Beckers
authors.affiliation: Zuyd University of Applied Sciences, Heerlen, The Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Frusch
authors.affiliation: University Eye Clinic, Maastricht, The Netherlands.
authors.forename: Tos T J M
authors.initials: TT
authors.lastname: Berendschot
authors.affiliation: University Eye Clinic, Maastricht, The Netherlands.
authors.forename: John
authors.initials: J
authors.lastname: de Brabander
authors.affiliation: University Eye Clinic, Maastricht, The Netherlands.
authors.forename: Carroll A B
authors.initials: CA
authors.lastname: Webers
mesh_terms: D000867:Anterior Chamber / Q000033:anatomy & histology*; D003315:Cornea / Q000033:anatomy & histology*; D005260:Female; D005583:Fourier Analysis; D064368:Healthy Volunteers; D006801:Humans; D007498:Iris / Q000033:anatomy & histology*; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence; D044465:White People; D055815:Young Adult
keywords: anterior chamber angle; reproducibility; swept-source optical coherence tomography