Repeatability and Reproducibility of Spectral-Domain Optical Coherence Tomography Measurements of Retinal Thickness in Rats.

ABSTRACTPurpose: To evaluate the in vivo repeatability and reproducibility of spectral-domain optical coherence tomography (SD-OCT) measurements of total retinal thickness (TRT) and retinal nerve fiber layer (RNFL) thickness in rats.Methods: Retinal thickness was measured using an RNFL circular scan with AutoRescan and TruTracking modes in 20 eyes of Long-Evans Tokushima Otsuka rats. Three RNFL circular scan images were acquired with a brief rest between measurements to evaluate intra-session repeatability. Three additional RNFL circular scans were acquired 1 day later to evaluate intersession repeatability. Two experienced examiners independently measured TRT using automatic alignment and RNFL thickness using manual alignment according to the same procedure to evaluate inter-examiner reproducibility 1 week later. The correlation of measurements by OCT and histology was determined.Results: For TRT, the intra-session and inter-session intraclass correlation coefficient (ICC) with SD-OCT was between 0.85 an...