Abstract
Purpose: :
To assess the reproducibility of a new spectral domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec Inc, Dublin, CA) to analyze peripapillary retinal nerve fiber layer (RNFL) thickness in healthy eyes.
Methods: :
Thirty healthy volunteers were enrolled. For each studied eye, three Optic disc cube 200 x 200 scans of Cirrus HD OCT were taken on the same day in discontinuous sessions by the same operator. The reproducibility of the calculated thickness and the probability code for peripapillary RNFL thickness were determined using the intraclass correlation coefficient (ICC), coefficient of variation (COV), test-retest variability, and Fleiss’ generalized kappa (Κ).
Results: :
For average RNFL thickness measurements, the ICC was 0.970, the COV was 2.38%, and test-retest variability was 4.5 µm. For quadrants except nasal one, the ICCs were 0.972 or higher and the COVs were 4.26% or less. Overall test-retest variability ranged from 5.8 to 8.1 µm. Also for clock-hour sectors, the ICCs and the COVs showed the worst values in nasal areas when compared to other areas. Regarding probability codes for the average RNFL thickness, the Κ value was 0.690. For quadrants and for clock-hour sectors, the Κ values were lowest at the nasal areas compared to other areas.
Conclusions: :
The reproducibility of Cirrus HD OCT to analyze the peripapillary RNFL thickness in healthy eyes is excellent. For the calculated RNFL thickness and for the probability code, variability is relatively higher in the nasal area, and more cautious analyses are needed.
Clinical Trial: :
www.clinicaltrials.gov NCT00742378
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • ganglion cells