title: Assessing the relationship between central corneal thickness and retinal nerve fiber layer thickness in healthy subjects.
abstract: OBJECTIVE
  To determine the relationship between central corneal thickness (CCT) and retinal nerve fiber layer (RNFL) thickness obtained by scanning laser polarimetry (GDx-VCC; Carl Zeiss Meditec, Dublin, California, USA), confocal scanning laser ophthalmoscopy (HRT II; Heidelberg Engineering, Heidelberg, Germany), and optical coherence tomography (Stratus OCT; Carl Zeiss Meditec).
  
  
  METHODS
  Multicenter clinical trial, retrospective cross-sectional study.
  
  
  METHODS
  One hundred and nine healthy subjects from the Advanced Imaging in Glaucoma Study were enrolled in this study. All subjects had a standard clinical examination, including visual field (VF) and good-quality scans from all three imaging devices. CCT was measured using an ultrasonic pachymeter. A linear mixed-effects model was used to assess the relationship between RNFL thickness and CCT, accounting for clustering of eyes within subjects, testing site, ethnicity, family history of glaucoma, axial length intraocular pressure, and VF global indices.
  
  
  RESULTS
  For OCT and GDx, there was a slight nonstatistically significant positive relationship between CCT and RNFL thickness. For HRT, there was a slight nonstatistically significant negative relationship between CCT and RNFL thickness. Relationships for each device were found to differ between sites.
  
  
  CONCLUSIONS
  CCT was not statistically significantly related to RNFL thickness in healthy eyes.
authors.affiliation: UPMC Eye Center, Ophthalmology and Visual Science Research Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Tarkan
authors.initials: T
authors.lastname: Mumcuoglu
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Townsend
authors.forename: Gadi
authors.initials: G
authors.lastname: Wollstein
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bilonick
authors.forename: Kyung Rim
authors.initials: KR
authors.lastname: Sung
authors.forename: Larry
authors.initials: L
authors.lastname: Kagemann
authors.forename: Joel S
authors.initials: JS
authors.lastname: Schuman
mesh_terms: D001837:Body Weights and Measures; D003315:Cornea / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D006068:Gonioscopy; D006801:Humans; D007368:Interferometry / Q000379:methods; D007429:Intraocular Pressure; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers; D009887:Ophthalmoscopy / Q000379:methods; D012165:Retinal Ganglion Cells / Q000166:cytology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods; D014463:Ultrasonography