Abstract
Purpose: :
Different scan circle location of peripapillary retinal nerve fiber layer thickness (RNFL) measurement may be a source of test-retest variability in conventional time-domain OCT. The purpose of this study was to test the reproducibility of RNFL thickness measurement with retest mode of Spectral OCT SLO tracking system.
Methods: :
27 glaucomatous and 30 healthy eyes were scanned three times with 10 minutes interval using retest mode of RNFL thickness measurement in Spectral OCT SLO at same visit by well-trained single operator (Intra-session reproducibility). All healthy subjects were scanned 3 days later with same protocol (Inter-session reproducibility). Standard deviation (SD), coefficient of variation (CV), intraclass correlation coefficient (ICC) of RNFL thickness were calculated in average and 4 quadrants.
Results: :
Intra-session SD, CV and ICC of average RNFL thickness were 2.0microns, 1.9% and 0.98 in glaucoma group, 2.4microns, 2.0% and 0.89 in healthy group. Inter-session SD, CV and ICC of average RNFL thickness were 2.6microns, 2.2% and 0.87 in healthy group. Nasal quadrants showed the least reproducibility among 4 quadrants.
Conclusions: :
RNFL thickness assessed by retest mode of Spectral OCT SLO showed excellent intra- and inter-session reproducibilities. Retest mode of RNFL thickness measurement in spectral domain OCT employing SLO tracking system may be helpful for reducing test-retest variability originated from operator scan circle placement.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer