Repeatability and Reproducibility of Pachymetric Mapping with Visante Anterior Segment Optical Coherence Tomography

Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, 00, Hong Kong
Investigative Ophthalmology & Visual Science (Impact Factor: 3.4). 01/2008; 48(12):5499-504. DOI: 10.1167/iovs.07-0591
Source: PubMed


To determine the repeatability and reproducibility of central and peripheral corneal pachymetry mapping with anterior segment-optical coherence tomography (AS-OCT).
An observational cross-sectional study involving two groups: 27 healthy eyes and 20 eyes with keratoconus. Each subject underwent scanning sessions with AS-OCT to determine intraobserver repeatability, interobserver reproducibility, and additionally for healthy eyes, intersession reproducibility for different regions of the cornea up to a 10-mm diameter. Main outcome measures were reproducibility and repeatability coefficients, intraclass correlation coefficients, and coefficients of variation of the average central (0-2 mm), pericentral (2-5 mm), transitional (5-7 mm), and peripheral (7-10 mm) corneal thicknesses generated by the Visante AS-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) pachymetric mapping protocol.
The coefficients of repeatability were less than 2% in healthy subjects and less than 3% in patients with keratoconus. The reproducibility coefficients were less than 2% and 4% in healthy subjects and patients with keratoconus, respectively. There was no significant difference between scans obtained by different observers or during different visits. The intraclass correlation coefficients were greater than 0.99 and 0.97 in healthy subjects and patients with keratoconus, respectively.
With the pachymetric mapping protocol of Visante AS-OCT, these results suggest that central and peripheral corneal thickness measurements in healthy subjects and in eyes with keratoconus are repeatable and reproducible.

  • Source
    • "Agreement between the RTVue FD-OCT measurements and the 3 Scheimpflug camera measurements was even lower than for central measurements. The lower level of agreement for the 5-mm measurements (with respect to central and 2-mm measurements) may be explained by the larger variability of peripheral corneal thickness measurements, as shown by previous studies [17], [26]–[28]. We also believe that agreement of the three Scheimpflug cameras for CT5mm is high enough to consider the differences not clinically significant. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To compare corneal thickness measurements using Pentacam (Oculus, Germany), Sirius (CSO, Italy), Galilei (Ziemer, Switzerland), and RTVue-100 OCT (Optovue Inc., USA). Methods Sixty-six eyes of 66 healthy volunteers were enrolled. Three consecutive measurements were performed with each device. The mean value of the three measurements was used for subsequent analysis. Central corneal thickness (CCT), thinnest corneal thickness (TCT), and midperipheral corneal thickness (MPCT; measured at superior, inferior, nasal, and temporal locations with a distance of 1 mm (CT2mm) or 2.5 mm (CT5mm) from the corneal apex) were analyzed. Differences and agreement between measurements were assessed using the repeated-measures analysis of variance (ANOVA) and Bland-Altman analyses, respectively. Results Statistically significant differences (p<0.001) among the four devices were revealed in CCT, TCT and CT2mmmeasurements. The CCT, TCT, and CT2mm values were ranked from the thickest to the thinnest as follows: Galilei>Sirius>Pentacam>RTVue OCT. For these measurements, agreement between measurements by Sirius and Pentacam was good, whereas Galilei overestimated and RTVue underestimated corneal thickness compared to Sirius and Pentacam. As regards CT5mm measurements, Pentacam provided the largest values, whereas RTVue OCT yielded the smallest values. Agreement of the CT5mm measurements was good between the Pentacam, Sirius, moderate between Galilei and the other two Scheimpflug systems, and poor between the RTVue OCT and the remaining devices. Conclusions The Pentacam and Sirius can be used interchangeably for CCT measurements, while the Galilei and RTVue systematically over- and underestimate CCT, respectively. The three Scheimpflug cameras, but not the RTVue, may be used interchangeably for MPCT measurements.
    Full-text · Article · May 2014 · PLoS ONE
  • Source
    • "To assess intra-observer repeatability and inter-observer reproducibility of 3D-based indices, ten randomly chosen patients and five controls were measured a second time, after a time interval of more than one month by the same observer and, at that time, also by a second observer blinded to the measurements of the first observer. Repeatability and reproducibility coefficients, intra-class correlation coefficients (ICC) between intra-observer and inter-observer measurements were calculated as previously published.[13],[14] "
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess the regional diastolic function in patients with hypertrophic cardiomyopathy (HCM) by using single-beat, real-time, three-dimensional echocardiography (RT-3DE). Sixty-five patients with HCM in sinus rhythm together with fifty age- and gender-matched normal controls were studied by two dimensional echocardiography (2DE) and RT-3DE. The parameters analyzed by RT-3DE included: left ventricular (LV) volumes, left ventricular ejection fraction (LVEF), end diastolic sphericity index (EDSI), diastolic dyssynchrony index (DDI), dispersion end diastole (DISPED), and normalized 17 segmental volume-time curves. Evaluated by RT-3DE, LVEF was slightly lower compared with 2DE (63.2 ± 6.8% vs. 59.1 ± 6.4%, P < 0.0001). Normal subjects had relatively uniform volumetric curves for all LV segments. In HCM patients, the segmental volumetric curves were dyssynchronous. Increased DDI and DISPED in end diastole were observed in patients with HCM (9.95 ± 3.75, 41.76 ± 17.19, P < 0.0001), and not all abnormal volumetric segments occurred in the hypertrophic regions. Patients with HCM have presented regional diastolic dyssynchrony in the diastole phase, and this preclinical lesion can be recognized by single-beat RT-3DE.
    Full-text · Article · Sep 2012 · Journal of Geriatric Cardiology
  • Source
    • "Moreover, all corneal thickness measurements derived from pachymetric maps obtained with AS-OCT demonstrated excellent repeatability. The resulting CR were comparable with previously reported data for pachymetric maps obtained with spectral-domain OCT (Li et al. 2008a,b, 2010) and were lower than previously reported for time-domain OCT (Mohamed et al. 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess accuracy and repeatability of central corneal thickness (CCT) measurements obtained by swept-source anterior segment optical coherence tomography (AS-OCT), spectral-domain retinal OCT with corneal module and ultrasound pachymetry (USP), and to assess repeatability of pachymetric mapping with AS-OCT. 50 healthy volunteers were recruited. A single, experienced operator analysed the right eye of each participant twice in the same session with AS-OCT ('corneal map' routine), retinal OCT and USP. CCT measurements were compared using repeated-measures analysis of variance, Bonferroni test, Pearson correlation and Bland-Altman plots. Repeatability of thickness maps and CCT measurements were assessed using Alpha of Cronbach, intraclass correlation coefficient (ICC) and coefficient of repeatability. Mean CCT±SD was 540±28.9 μm for AS-OCT, 544±29.5 μm for retinal OCT and 549.3±31.7 μm for USP; the differences were statistically significant (p<0.01). CCT measurements obtained with the three instruments were highly correlated: r was 0.965 for AS-OCT/USP, 0.962 for retinal OCT/USP and 0.984 for AS-OCT/retinal OCT comparison. The repeatability of CCT measurements was higher for AS-OCT than for the other devices (p<0.001). Repeatability of pachymetric maps was excellent (ICC=0.999). Pachymetric maps by swept-source AS-OCT showed excellent repeatability. CCT measurements obtained by AS-OCT, USP and retinal OCT were highly correlated although not identical.
    Full-text · Article · Jun 2012 · Acta ophthalmologica
Show more