title: Repeatability and Reproducibility of Retinal Nerve Fiber Layer Parameters Measured by Scanning Laser Polarimetry with Enhanced Corneal Compensation in Normal and Glaucomatous Eyes.
abstract: OBJECTIVE
  To assess the intrasession repeatability and intersession reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness parameters measured by scanning laser polarimetry (SLP) with enhanced corneal compensation (ECC) in healthy and glaucomatous eyes.
  
  
  METHODS
  One randomly selected eye of 82 healthy individuals and 60 glaucoma subjects was evaluated. Three scans were acquired during the first visit to evaluate intravisit repeatability. A different operator obtained two additional scans within 2 months after the first session to determine intervisit reproducibility. The intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) were calculated for all SLP parameters in both groups.
  
  
  RESULTS
  ICCs ranged from 0.920 to 0.982 for intravisit measurements and from 0.910 to 0.978 for intervisit measurements. The temporal-superior-nasal-inferior-temporal (TSNIT) average was the highest (0.967 and 0.946) in normal eyes, while nerve fiber indicator (NFI; 0.982) and inferior average (0.978) yielded the best ICC in glaucomatous eyes for intravisit and intervisit measurements, respectively. All COVs were under 10% in both groups, except NFI. TSNIT average had the lowest COV (2.43%) in either type of measurement. Intervisit TRT ranged from 6.48 to 12.84.
  
  
  CONCLUSIONS
  The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.
authors.affiliation: Department of Ophthalmology, Miguel Servet University Hospital, Aragon Health Sciences Institute, 50009 Zaragoza, Spain.
authors.forename: Mirian
authors.initials: M
authors.lastname: Ara
authors.affiliation: Department of Ophthalmology, Miguel Servet University Hospital, Aragon Health Sciences Institute, 50009 Zaragoza, Spain ; Department of Surgery, Gynecology and Obstetrics, University of Zaragoza, 50009 Zaragoza, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ferreras
authors.affiliation: Department of Family Medicine, Seminario Primary Health Care Center, 50009 Zaragoza, Spain.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Pajarin
authors.affiliation: Department of Ophthalmology, Miguel Servet University Hospital, Aragon Health Sciences Institute, 50009 Zaragoza, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Calvo
authors.affiliation: Department of Neurosciences, University of Pisa, 56100 Pisa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Figus
authors.affiliation: Department of Ophthalmology, University of Siena, 53100 Siena, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Frezzotti
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003315:Cornea / Q000473:pathology; D005901:Glaucoma / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009900:Optic Nerve / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D055351:Retinal Neurons / Q000473:pathology*; D057109:Scanning Laser Polarimetry / Q000379:methods*; D012680:Sensitivity and Specificity