Reproducibility of retinal nerve fiber layer and macular thickness measurement with the RTVue-100 optical coherence tomograph

Abstract

Purpose: To evaluate the reproducibility of peripapillary retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex (GCC) measurements made with the RTVue-100 Fourier-domain optical coherence tomography (OCT) device (Optovue, Inc., Fremont, CA) and to determine the influence of 4 factors: pupil dilation, subject age, experience in imaging examinations, and glaucoma severity.

Design: Prospective study for evaluation of a diagnostic test.

Participants: Thirty-seven hospital-based participants (14 normal and ocular hypertensive subjects, 11 patients with moderate and 12 with severe glaucoma), all experienced in imaging examinations, and 40 consecutive screening trial participants lacking such experience.

Methods: One eye of all participants was imaged 5 times. For the hospital-based participants, on the same day the measurement series was repeated after pupil dilation. For determination of intersession reproducibility, measurements were performed again 3 months later.

Main outcome measures: Intrasession and intersession coefficient of variation (CV), intraclass correlation coefficient (ICC), intratest variability, and test-retest variability.

Results: For the average and quadrant RNFLT parameters and the GCC parameters, intrasession ICC varied between 93.9% and 99.0%, intrasession CV between 1.95% and 5.69%, and intratest variability varied between 3.11 and 9.13 microm. Most thickness values, all intrasession CV and intratest variability values, and the signal strength index were not changed significantly after pupil dilation. Intrasession CV of the 16 peripapillary RNFLT sectors varied between 4.90% and 11.66%. Most intrasession CV values increased significantly with increased disease severity, but intratest variability for average RNFLT and the quadrant RNFLT parameters, which are used for statistical comparison with the normative database, were unaffected by the severity of glaucoma. Patient age and experience in imaging examinations had no influence on intrasession CV. Intratest variability and intrasession CV represented 79.1% to 98.6% and 77.1% to 95.0% of test-retest variability and intervisit CV, respectively, for the average and quadrant RNFLT and the GCC parameters.

Conclusions: Intrasession and intersession reproducibility of RNFLT and GCC measurements with the RTVue-100 OCT are satisfactory for diagnostic purposes, both in normals and in patients with different glaucoma severity. Pupil dilation, age, and experience in imaging examinations did not influence reproducibility in a clinically significant manner.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.