title: The measurement repeatability using different partition methods of intraretinal tomographic thickness maps in healthy human subjects.
abstract: OBJECTIVE
  To determine the repeatability and profiles with different partition methods in intraretinal thickness layers in healthy human subjects, using optical coherence tomography (OCT).
  
  
  METHODS
  A custom-built ultrahigh-resolution OCT was used to acquire three-dimensional volume of the macula in 20 healthy subjects. The dataset was acquired twice using the macular cube 512×128 protocol in an area of 6×6 mm2centered on the fovea. Commercially available segmentation software (Orion™) was used to segment the dataset into thickness maps of six intraretinal layers. The coefficient of repeatability and intraclass coefficient of correlation (ICC) were analyzed using hemispheric zoning and sectors defined by the Early Treatment Diabetic Retinopathy Study (ETDRS).
  
  
  RESULTS
  All datasets were successfully segmented to create six thickness maps of individual intraretinal layers. Coefficients of repeatabilities of these layers in hemispheric zones ranged from 0.9 to 6.6 µm, with an average of 3.6 µm (standard deviation [SD] 1.4), which was not significantly different compared to ETDRS sectors (P>0.05). ICCs of these layers in hemispheric zones ranged from 0.68 to 0.99, with an average of 0.91 (SD 0.07). There were no significant differences in ICCs between two zoning methods (P>0.05). Significant variations of tomographic intraretinal thicknesses were found between the inner and outer annuli and among the quadrantal sectors within the inner and outer annuli (P<0.05). Significant variations of the quadrantal sectors including both inner and outer annuli were evident in intraretinal layers (P<0.05) except for the outer plexiform layer.
  
  
  CONCLUSIONS
  The measurement repeatabilities of tomographic thicknesses of intraretinal layers are comparable using both hemispheric and ETDRS partitions in volumetric data combined with the commercially available segmentation software. In keeping with known, normal anatomical variation, significant differences in tomographic thickness in various intraretinal layers were apparent in both hemispheric and ETDRS sectors.
authors.affiliation: Department of Ophthalmology, Xiangya Hospital, Changsha, Hunan, People's Republic of China; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Tan
authors.affiliation: Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA; Department of Neurology, University of Miami, Miami, FL.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
authors.forename: Che
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Xiangya Hospital, Changsha, Hunan, People's Republic of China; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
authors.forename: Byron L
authors.initials: BL
authors.lastname: Lam
authors.affiliation: School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Hu
authors.affiliation: Voxeleron LLC, Pleasanton, CA, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Oakley
authors.affiliation: Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
keywords: healthy subject; intraretinal layer; thickness variation; tomography