Abstract
Abstract: :
Purpose: To evaluate the reproducibility of measurements of the retinal nerve fiber layer and rim length by the optical coherence tomography (OCT3) in healthy subjects. The authors also assessed the variance of measurements between separate operators. Methods: Two independent circular scans (R=1,73mm)of the peripapillary retina and optic nerve head (ONH) analysis of 32 normal eyes, were acquired by two experienced operators two times successively. For each operator reproducibility of OCT RNFL thickness (average, inferotemporal and superotemporal of thickness values) and of rim length was expressed in term of coefficient of variance and intraclass correlation coefficients (ICC). Using multivariate analysis of variance the authors determined the variance of measurements between the two operators. Results: The reproducibility of RNFL measurements varied for each operator. Coefficients of variance were respectively for operator 1 and 2: 8% and 6,5% in superotemporal area, 6,6% and 6,6% in inferotemporal and of 4,6% and 3,4% for average thickness.Rim length measurements were 13,7% and 11,6% in superotemporal and 9,8% and 12,3% in inferotemporal. Between the two operators coefficients of variance of RNFL measurement were 6,3% in superotemporal, 5,9% in inferotemporal and 3,7% for average thickness. For rim length, there were 10,8% in superotemporal and 10,8% in inferotemporal. For all this parameters there was not statistically significant intra or inter observer difference. Reproducibility was good with intra and inter operator ICC variations between 0,51 and 0,85. Conclusions: These results suggest that OCT3 provides reproductible measurements in healthy subjects. Measurements obtained by separate operators are similar.
Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer