title: Spectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration.
abstract: OBJECTIVE
  To determine the intrasession repeatability of spectral-domain OCT (SDOCT)-derived macular retinal and choroidal metrics in patients with neovascular age-related macular degeneration (nAMD) in the Distance of Choroid Study (DOCS).
  
  
  METHODS
  Validity and reliability analysis.
  
  
  METHODS
  Enrolled patients underwent repeated SDOCT imaging using the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). A single technician certified for clinical trials took 3 macular volume scans. Retinal thicknesses were calculated for each of the 9 Early Treatment Diabetic Retinopathy Study (ETDRS) macular subfields. Center point thickness and total macular volume were also included in the analysis. Manual subfoveal choroidal thickness measurements were made by a masked observer.
  
  
  RESULTS
  A total of 40 eyes of 40 patients were included in this analysis (mean [± standard deviation] age: 74.1 [± 7.2] years, 60% male). The coefficient of repeatability (CR) of the central macular subfield was 30.6 μm (95% confidence interval [CI] 29.8-1.4 μm). The CR for the other macular subfields ranged from 7.0 μm to 38.2 μm. The CR for the total macular volume was 0.212 mm(3) (95% CI 0.206-0.217 mm(3)) and the CR for the center point was 47.5 μm (95% CI 46.2-48.7 μm). Images were also reviewed for the presence of segmentation error in the central macular subfield, and after exclusion of these eyes the revised CR for this subfield was 13.7 μm (95% CI 13.3-14.1 μm). The intrasession CR of subfoveal choroidal thickness was 34.7 μm (95% CI 33.7-35.7 μm).
  
  
  CONCLUSIONS
  This study suggests that a change of greater than 31 μm in Spectralis SDOCT-derived retinal thickness measurement of the central macular subfield and 35 μm in subfoveal choroidal thickness is necessary to detect true clinical change associated with disease progression or improvement in nAMD with a revised figure of 14 μm for central macular retinal subfield thickness in the absence of segmentation error.
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Daren
authors.initials: D
authors.lastname: Hanumunthadu
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Tomas
authors.initials: T
authors.lastname: Ilginis
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Marie
authors.initials: M
authors.lastname: Restori
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Sagoo
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Adnan
authors.initials: A
authors.lastname: Tufail
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Kamaljit S
authors.initials: KS
authors.lastname: Balaggan
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom. Electronic address: praveen.patel@moorfields.nhs.uk.
authors.forename: Praveen J
authors.initials: PJ
authors.lastname: Patel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009929:Organ Size; D011446:Prospective Studies; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D057135:Wet Macular Degeneration / Q000175:diagnosis*