Reliability of Intra-Retinal Layer Thickness Estimates

Abstract

PurposeMeasurement of intra-retinal layer thickness using optical coherence tomography (OCT) has become increasingly prominent in multiple sclerosis (MS) research. Nevertheless, the approaches used for determining the mean layer thicknesses vary greatly. Insufficient data exist on the reliability of different thickness estimates, which is crucial for their application in clinical studies. This study addresses this lack by evaluating the repeatability of different thickness estimates.MethodsStudies that used intra-retinal layer segmentation of macular OCT scans in patients with MS were retrieved from PubMed. To investigate the repeatability of previously applied layer estimation approaches, we generated datasets of repeating measurements of 15 healthy subjects and 13 multiple sclerosis patients using two OCT devices (Cirrus HD-OCT and Spectralis SD-OCT). We calculated each thickness estimate in each repeated session and analyzed repeatability using intra-class correlation coefficients and coefficients of repeatability.ResultsWe identified 27 articles, eleven of them used the Spectralis SD-OCT, nine Cirrus HD-OCT, two studies used both devices and two studies applied RTVue-100. Topcon OCT-1000, Stratus OCT and a research device were used in one study each. In the studies that used the Spectralis, ten different thickness estimates were identified, while thickness estimates of the Cirrus OCT were based on two different scan settings. In the simulation dataset, thickness estimates averaging larger areas showed an excellent repeatability for all retinal layers except the outer plexiform layer (OPL).ConclusionsGiven the good reliability, the thickness estimate of the 6mm-diameter area around the fovea should be favored when OCT is used in clinical research. Assessment of the OPL was weak in general and needs further investigation before OPL thickness can be used as a reliable parameter.

The measurement repeatability using different partition methods of intraretinal tomographic thickness maps in healthy human subjects

“…We reported the details of segmentation repeatability in annuli and sectors using two partition methods and found that they were comparable. In addition, the repeatabilities in annuli and section were comparable to those reported in previous studies 24,26,40,41. Oberwahrenbrock et al reviewed the reliability of intraretinal thickness measurements and estimated the ICCs and CoRs from previously published data 40.…”

MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 4: Afferent visual system damage after optic neuritis in MOG-IgG-seropositive versus AQP4-IgG-seropositive patients

“…Automatic segmentation results were carefully checked for errors and corrected if necessary by an experienced rater masked for the diagnosis of the subjects. Combined ganglion cell and inner plexiform layer volume (GCIP), inner nuclear layer volume, and outer retinal layers volume including the outer plexiform and nuclear layer, inner and outer photoreceptor segments, and retinal pigment epithelium, were extracted from a 6-mm-diameter cylinder around the fovea [32]. Furthermore, all scans were examined for macular microcysts [19] and other retinal pathologies.…”

Retinal ganglion cell loss in neuromyelitis optica: a longitudinal study

“…The combined ganglion cell and inner plexiform layer volume (GCIP), inner nuclear layer volume (INL) and total macular volume (TMV) was calculated as a 3 mm diameter cylinder around the fovea from a macular volume scan ( Berlin : 25°×30°, 61 vertical B-scans, 11≤ART≤18; Munich : 20°×20°, 25 vertical B-scans, 21≤ART≤49; Oxford : 69% 30°×25° 61 vertical B-scans, 27% 30°×15° 37 horizontal B-scans, 2% 30°×25° 61 horizontal B-scans, 2% 30°×15° 19 horizontal B-scans, 7≤ART≤22) 20. The fovea thickness (FT) was defined as mean thickness of the 1 mm diameter cylinder around the fovea from the same scan 16.…”