Reproducibility of corneal, macular and retinal nerve fber layer thickness measurements using the iVue-100 optical coherence tomography.

Khathutshelo P Mashige
University of KwaZulu-Natal, Discipline of Optometry.

Abstract
Purpose: To determine the intra-session and inter-session reproducibility of corneal, macular and retinal nerve fber layer thickness (RNFL) measurements with the iVue-100 optical coherence tomography in normal eyes.

Methods: These parameters were measured in the right eyes of 50 healthy participants with normal vision. Six scans each for
corneal thickness, macular and optic nerve head were taken on one day (intra-session), followed by similar repeated measures
on fve separate days (inter-session). Reproducibility was computed using intra-class correlation coeffcient (ICC), coeffcient of
variation (COV), and test-retest variability (TRV).

Results: For intra-session reproducibility, the ICC, COV and TRV values for mean corneal thickness were 0.924, 2.82%, and
3.06 µm respectively. For the mean macular thickness, they were 0.978, 4.64% and 4.51 µm respectively, while for mean RNFL
thickness they were 0.946, 3.19%, and 5.66 µm respectively. Inter-session values for mean corneal thickness were 0.926, 2.65%
and 3.48 µm, and 0.916, 2.24% and 2.03 µm for mean macular thickness. For mean RNFL thickness, they were 0.962, 2.21%,
and 4.72 μm respectively.

Conclusion: There was good reproducibility of all measured parameters. However, mean RNFL thickness measurements were
the most reproducible, suggesting that this may be the best parameter to use to determine measured changes over time.

Keywords: Corneal thickness, macular thickness, retinal nerve fber layer thickness, iVue-100, reproducibility