title: Reproducibility of retinal and choroidal thickness measurements in enhanced depth imaging and high-penetration optical coherence tomography.
abstract: OBJECTIVE
  Two optical coherence tomography (OCT) modalities can visualize the choroid: high-penetration OCT (HP-OCT) using a long wavelength, and enhanced depth imaging technique using Heidelberg OCT (EDI-OCT). The purpose of this study was to compare and investigate the agreement among the retinal/choroidal thickness parameters.
  
  
  METHODS
  Twenty-four eyes of 12 healthy volunteers were examined simultaneously using the prototype swept-source HP-OCT and EDI-OCT. Six independent examiners measured the central retinal/choroidal thicknesses on horizontal B-scan images. The reliability was evaluated by intraclass correlation coefficient (ICC). Intervisit reproducibility was assessed by examining 10 of the volunteers 4 months later.
  
  
  RESULTS
  Using HP-OCT, the average of all measurements was 209.1 ± 12.9 μm in the retina and 292.7 ± 77.3 μm in the choroid, and using EDI-OCT, 212.5 ± 13.3 μm in the retina and 283.7 ± 84.1 μm in the choroid. An intersystem comparison showed that the ICCs were 0.661 (95% confidence interval [CI], 0.535-0.754) for the retina and 0.921 (95% CI, 0.875-0.948) for the choroid. Using HP-OCT, the interexaminer ICC reproducibility values were 0.630 (95% CI, 0.447-0.791) for the retinal thickness and 0.912 (95% CI, 0.835-0.958) for the choroidal thickness; using EDI-OCT, the values for the retinal and choroidal thicknesses were 0.788 (95% CI, 0.607-0.898) and 0.970 (95% CI, 0.948-0.985), respectively. The intervisit ICC values for the retinal and choroidal thicknesses were 0.504 (95% CI, 0.376-0.609) and 0.893 (95% CI, 0.864-0.916).
  
  
  CONCLUSIONS
  The retinal and choroidal thicknesses were well-correlated between the instruments. Higher reliability and reproducibility are expected for the choroidal thickness measurements despite with higher morphologic interindividual variations.
authors.affiliation: Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan. ikuno@ophthal.med.osaka-u.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ikuno
authors.forename: Ichiro
authors.initials: I
authors.lastname: Maruko
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yasuno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miura
authors.forename: Tetsuju
authors.initials: T
authors.lastname: Sekiryu
authors.forename: Kohji
authors.initials: K
authors.lastname: Nishida
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Iida
mesh_terms: D000328:Adult; D001837:Body Weights and Measures; D002829:Choroid / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence; D055815:Young Adult