Purpose. The clinical utility of new optical coherence tomography (OCT) instruments strongly depends on measurements reproducibility. The aim of this study was to assess retinal nerve fiber layer (RNFL) thickness reproducibility using six different spectral-domain OCTs (SD-OCTs) and one time-domain OCT. Methods. RNFL thickness (average and four quadrant) from six SD-OCTs (Spectral OCT/SLO OPKO/OTI, 3D-OCT 2000 Topcon, RS-3000 NIDEK, Cirrus HD-OCT Zeiss, RTVue-100 Optovue, and Spectralis Heidelberg) and one time-domain OCT (Stratus OCT Zeiss) was measured twice in 38 right eyes of 38 randomly chosen healthy volunteers by two masked operators. Inter- and intraoperator reproducibility was evaluated by ...