title: Impact of retinal pigment epithelium pathology on spectral-domain optical coherence tomography-derived macular thickness and volume metrics and their intersession repeatability.
abstract: BACKGROUND
  To determine the impact of retinal pigment epithelium (RPE) pathology on intersession repeatability of retinal thickness and volume metrics derived from Spectralis spectral-domain optical coherence tomography (Heidelberg Engineering, Heidelberg, Germany).
  
  
  METHODS
  Prospective cross-sectional single centre study.
  
  
  METHODS
  A total of 56 eyes of 56 subjects were divided into three groups: (i) normal RPE band (25 eyes); (ii) RPE elevation: macular soft drusen (13 eyes); and (iii) RPE attenuation: geographic atrophy or inherited retinal diseases (18 eyes).
  
  
  METHODS
  Each subject underwent three consecutive follow-up macular raster scans (61 B-scans at 119 μm separation) at 1-month intervals.
  
  
  METHODS
  Retinal thicknesses and volumes for each zone of the macular subfields before and after manual correction of segmentation error. Coefficients of repeatability (CR) were calculated.
  
  
  RESULTS
  Mean (range) age was 57 (21-88) years. Mean central subfield thickness (CST) and total macular volume were 264 and 258 μm (P = 0.62), and 8.0 and 7.8 mm3(P = 0.31), before and after manual correction. Intersession CR (95% confidence interval) for CST and total macular volume were reduced from 40 (38-41) to 8.3 (8.1-8.5) and 0.62 to 0.16 mm3after manual correction of segmentation lines. CR for CST were 7.4, 23.5 and 66.7 μm before and 7.0, 10.9 and 7.6 μm after manual correction in groups i, ii and iii.
  
  
  CONCLUSIONS
  Segmentation error in eyes with RPE disease has a significant impact on intersession repeatability of Spectralis spectral-domain optical coherence tomography macular thickness and volume metrics. Careful examination of each B-scan and manual adjustment can enhance the utility of quantitative measurement. Improved automated segmentation algorithms are needed.
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Daren
authors.initials: D
authors.lastname: Hanumunthadu
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.|Department of Neurology, The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, China.
authors.forename: Jin Ping
authors.initials: JP
authors.lastname: Wang
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.|Department of Neurology, The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Evan N
authors.identifier: http://orcid.org/0000-0002-5466-1176
authors.initials: EN
authors.lastname: Wong
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.|Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.|Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: William H
authors.initials: WH
authors.lastname: Morgan
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Praveen J
authors.initials: PJ
authors.lastname: Patel
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), University of Western Australia, Perth, Western Australia, Australia.|Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Fred K
authors.initials: FK
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D015593:Retinal Drusen / Q000175:diagnosis*; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence; D055815:Young Adult
keywords: age-related macular degeneration; inherited retinal disease; optical coherence tomography; repeatability; segmentation error