title: Reproducibility of spectral-domain optical coherence tomography total retinal thickness measurements in mice.
abstract: OBJECTIVE
  To test the reproducibility of spectral-domain optical coherence tomography (SD-OCT) total retinal thickness (TRT) measurements in mice.
  
  
  METHODS
  C57Bl/6 mice were anesthetized, and three repeated volumetric images were acquired in both eyes with SD-OCT (250 A-scans × 250 frames × 1024 samplings), centered on the optic nerve head (ONH). The mice were repositioned between scans. TRT was automatically measured within a sampling band of retinal thickness with radii of 55 to 70 pixels, centered on the ONH by using custom segmentation software. The first volumetric image acquired in a given eye was used to register the remaining two SD-OCT images by manually aligning the en face images with respect to rotation and linear translation. Linear mixed-effects models were fitted to global and quadrant thicknesses, taking into account the clustering between eyes, to assess imprecision (measurement reproducibility).
  
  
  RESULTS
  Twenty-six eyes of 13 adult mice (age 13 weeks) were imaged. The mean global TRT across all eyes was 298.21 μm, with a mouse heterogeneity standard deviation (SD) of 4.88 μm (coefficient of variation [CV] = 0.016), an eye SD of 3.32 μm (CV = 0.011), and a device-related imprecision SD of 2.33 μm (CV = 0.008). The superior quadrant had the thickest mean TRT measurement (310.38 μm) and the highest (worst) imprecision SD (3.13 μm; CV = 0.010), and the inferior quadrant had the thinnest mean TRT (291.55 μm). The quadrant with the lowest (best) imprecision SD was in the nasal one (2.06 μm; CV = 0.007).
  
  
  CONCLUSIONS
  Good reproducibility was observed for SD-OCT retinal thickness measurements in mice. SD-OCT may be useful for in vivo longitudinal studies in mice.
authors.affiliation: UPMC Eye Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Gabriele
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Joel S
authors.initials: JS
authors.lastname: Schuman
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bilonick
authors.forename: Jongsick
authors.initials: J
authors.lastname: Kim
authors.forename: Larry
authors.initials: L
authors.lastname: Kagemann
authors.forename: Gadi
authors.initials: G
authors.lastname: Wollstein
mesh_terms: D000818:Animals; D000886:Anthropometry; D001699:Biometry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*; D000090324:Tumor Protein, Translationally-Controlled 1