title: The influence of eccentric scanning of optical coherence tomography on retinal nerve fiber layer analysis in normal subjects.
abstract: OBJECTIVE
  To investigate the influence of eccentric scanning on retinal nerve fiber layer (RNFL) analysis using Stratus optical coherence tomography (OCT) in normal Koreans when the eccentricity of scanning occurs in 4 different directions.
  
  
  METHODS
  Thirty-one eyes of 31 persons underwent 1 concentric disk-centered and 4 superiorly, inferiorly, nasally and temporally eccentric RNFL OCT scans.
  
  
  RESULTS
  The average RNFL thickness measured by temporally eccentric scanning (115.1 microm) was significantly greater when compared with that found by concentric scanning (107.1 microm; p < 0.0001). The proportions of eyes outside normal limits on the RNFL analysis map using the criterion of >or=1 clock hour abnormal at the <1% level in superiorly (12/31, 38.7%), nasally (16/32, 51.6%) and temporally (12/31, 38.7%) eccentric scans were significantly different in comparison with the concentric (4/31, 12.9%) scan (p < 0.05).
  
  
  CONCLUSIONS
  An off-centered OCT scan affected RNFL thickness measurement and its interpretation.
authors.affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Chungkwon
authors.initials: C
authors.lastname: Yoo
authors.forename: Il Hoon
authors.initials: IH
authors.lastname: Suh
authors.forename: Yong Yeon
authors.initials: YY
authors.lastname: Kim
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology; D009900:Optic Nerve / Q000033:anatomy & histology*; D012016:Reference Values; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014065:Tonometry, Ocular; D014794:Visual Fields / Q000502:physiology