title: Reproducibility and repeatability of ganglion cell-inner plexiform layer thickness measurements in healthy subjects.
abstract: OBJECTIVE
  To assess the reproducibility and repeatability of macular ganglion cell-inner plexiform layer (GC-IPL) thickness measurements in healthy subjects.
  
  
  METHODS
  In this observational study, 60 healthy eyes were subjected to macular GC-IPL thickness measurements by means of Cirrus™ high-definition optical coherence tomography (Cirrus version 6.0; Carl Zeiss Meditec, Dublin, Calif., USA) by two examiners in two sessions. Average, minimum and 6 sectoral GC-IPL thicknesses were measured. Inter- and intraobserver reproducibility was tested and analyzed by means of the concordance correlation coefficient (CCC). The repeatability of measurements was assessed by the coefficient of repeatability (CR).
  
  
  RESULTS
  Mean age (±SD) was 29.63 (±5.1) years. The CRs for average GC-IPL thickness were 2.1 and 2.2 µm for the first and the second operator, respectively. Inter- and intraobserver CCCs ranged from 0.91 (95% CI: 0.89-0.93) to 0.98 (95% CI: 0.96-0.99) and from 0.92 (95% CI: 0.88-0.94) to 0.98 (95% CI: 0.97-0.99), respectively.
  
  
  CONCLUSIONS
  GC-IPL thickness measurements in young healthy subjects showed excellent reproducibility and repeatability, especially for average and sectoral GC-IPL thickness measurements.
authors.affiliation: Ophthalmology Clinic, University 'G. d'Annunzio' Chieti-Pescara, Chieti, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Carpineto
authors.forename: Agbeanda
authors.initials: A
authors.lastname: Aharrh-Gnama
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ciciarelli
authors.forename: Alessandra
authors.initials: A
authors.lastname: Mastropasqua
authors.forename: Luca
authors.initials: L
authors.lastname: Di Antonio
authors.forename: Lisa
authors.initials: L
authors.lastname: Toto
mesh_terms: D000328:Adult; D005260:Female; D006068:Gonioscopy; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009929:Organ Size; D011446:Prospective Studies; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology; D012165:Retinal Ganglion Cells / Q000166:cytology*; D055351:Retinal Neurons / Q000166:cytology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult