title: Reproducibility of spectral-domain optical coherence tomography RNFL map for glaucomatous and fellow normal eyes in unilateral glaucoma.
abstract: OBJECTIVE
  To compare the reproducibility of the optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness map between glaucomatous and fellow normal eyes of unilateral glaucoma patients.
  
  
  METHODS
  In this prospective case-control study, Cirrus HD-OCT was performed for 79 unilateral glaucoma patients 3 times on the first visit and on 3 subsequent visits within a 2-month period. Test-retest standard deviation (TRT-SD) and tolerance limit based on the 1.645×√2×TRT-SD formula were derived for RNFL thicknesses at the respective superpixels of the RNFL thickness map.
  
  
  RESULTS
  The TRT-SDs and tolerance limits of the glaucomatous eyes (TRT-SD: 2.75 to 20.25 μm; tolerance limits: 6.40 and 47.11 μm) were significantly smaller than those of the fellow normal eyes (TRT-SD: 2.73 to 26.49 μm; tolerance limits: 6.35 and 61.63 μm) in the superotemporal, inferotemporal, and superonasal areas (P <0.05). The TRT-SDs in most areas showed a significant positive correlation with the RNFL thicknesses (P<0.05).
  
  
  CONCLUSIONS
  The test-retest variabilities of the Cirrus HD-OCT RNFL thickness map of the glaucomatous eyes were lower than those of the fellow normal eyes, especially in areas of high diagnostic importance. Moreover, variability was positively correlated with the baseline RNFL thicknesses. Therefore, adjusting the tolerance limits on the basis of the baseline RNFL thickness values might help improve the ability to recognize progression. Further prospective studies on this issue are warranted.
authors.affiliation: *Department of Ophthalmology, Haeundae Paik Hospital †Department of Ophthalmology, Inje University College of Medicine, Busan ‡Interdisciplinary Program, Graduate School, Seoul National University §Department of Ophthalmology, Seoul National University Hospital ∥Department of Ophthalmology, Seoul National University College of Medicine ¶Department of Applied Statistics, Yonsei University #Department of Biomedical Engineering, College of Medicine and Institute of Medical & Biological Engineering, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Suh
authors.forename: Byeong Wook
authors.initials: BW
authors.lastname: Yoo
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Hyunjoong
authors.initials: H
authors.lastname: Kim
authors.forename: Hee Chan
authors.initials: HC
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*