The Experts below are selected from a list of 233733 Experts worldwide ranked by ideXlab platform
Qinmei Wang - One of the best experts on this subject based on the ideXlab platform.
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measurement of central corneal thickness by high resolution scheimpflug imaging fourier domain optical coherence tomography and ultrasound pachymetry
Acta Ophthalmologica, 2012Co-Authors: Shihao Che, David Huang, Jinhai Huang, Wuhe Che, Qinmei WangAbstract:. Purpose: To compare the repeatability and Reproducibility of central corneal thickness (CCT) measurements by high-resolution (HR) rotating Scheimpflug imaging and Fourier-domain optical coherence tomography (FD-OCT). CCT measurements were compared to those determined by ultrasound pachymetry (UP). Methods: In 35 healthy eyes, intra-observer repeatability for HR Scheimpflug (Pentacam) and FD-OCT (RTVue) systems was determined in consecutive images taken by an observer in the shortest time possible. Imaging was repeated again by a second observer to evaluate inter-observer Reproducibility. The CCT measurements were compared among Scheimpflug, FD-OCT and UP images. Results: Mean coefficients of repeatability were 0.48% for Scheimpflug and 0.26% for FD-OCT. For Scheimpflug, the coefficient of inter-operator Reproducibility was 0.87%. For FD-OCT, the coefficient of inter-operator Reproducibility was 0.45%. The CCT measurements by Scheimpflug, OCT and UP images were (mean ± standard deviation) 521.7 ± 27.6 μm, 510.8 ± 28.6 μm and 516.5 ± 27.6 μm, respectively. The differences between instruments were statistically significant. The 95% limits of agreement in CCT were −0.7 to 22.5 μm for Pentacam-OCT, −13.4 to 24.0 μm for Pentacam-UP and −26.7 to 15.4 μm for OCT-UP. There was a high degree of correlation between CCT measured by all 3 methods. Conclusion: Noncontact measurements of CCT with HR Scheimpflug and FD-OCT systems yielded excellent repeatability and Reproducibility and can be used interchangeably. Although both devices were comparable with UP; in clinical practice, the measurements acquired by optical modalities are not directly interchangeable with UP measurements.
Jost B Jonas - One of the best experts on this subject based on the ideXlab platform.
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Reproducibility of subfoveal choroidal thickness measurements with enhanced depth imaging by spectral domain optical coherence tomography
Investigative Ophthalmology & Visual Science, 2013Co-Authors: Lei Shao, Liang Xu, Chang Xi Chen, Lihong Yang, Kui Fang Du, Shuang Wang, Jin Qiong Zhou, Ya Xing Wang, Jost B JonasAbstract:PURPOSE: To measure the interobserver Reproducibility and intra-observer Reproducibility of subfoveal choroidal thickness measurements performed by enhanced depth imaging of spectral-domain optical coherence tomography (EDI-OCT) in a population-based setting. METHODS: The Beijing Eye Study 2011 was a population-based study performed in rural and urban regions of Greater Beijing. The study included 3468 individuals with a mean age of 64.6 ± 9.8 years (range, 50-93 years). The participants underwent EDI-OCT and the subfoveal choroidal thickness (SFCT) was measured. To examine the interobserver variability, all images were assessed by two examiners independently of each other within 2 months. To examine the intra-observer Reproducibility, a smaller study sample consisting of 21 eyes of 21 healthy subjects from the Tongren Eye Center was included in the study. These latter subjects were scanned 10 times with 1 minute breaks between each examination. The SFCT was measured by the same observer within 2 weeks. The intrasession within subject SD, the coefficient of variation, and the intraclass correlation coefficient (ICC) were calculated. RESULTS: EDI-OCTs were performed for 3233 subjects. Mean SFCT measured by grader one and grader two were 254.6 ± 107.3 μm and 253.8 ± 107.4 μm, respectively, with a mean difference of 3.14 ± 13.1 μm (95% confidence interval, 0.0, 24.0). Bland-Altman plot showed 1.9% (61/3233) points outside the 95% limits of agreement. For the assessment of the intra-observer Reproducibility, the ICC was 1.00 (P < 0.001, and the mean coefficient of variation was 0.85% ± 1.48%). CONCLUSIONS: Under routine examination conditions, SFCT measurements by EDI-OCT showed a high intra-observer Reproducibility and interobserver Reproducibility.
James G Fujimoto - One of the best experts on this subject based on the ideXlab platform.
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retinal nerve fibre layer thickness measurement Reproducibility improved with spectral domain optical coherence tomography
British Journal of Ophthalmology, 2009Co-Authors: Jong S Kim, Hiroshi Ishikawa, Kyung Rim Sung, Gadi Wollstei, Richard A Ilonick, M L Gabriele, Larry Kagema, Jay S Duke, James G Fujimoto, Joel S SchumaAbstract:Background/aims: To investigate retinal nerve fibre layer (RNFL) thickness measurement Reproducibility using conventional time-domain optical coherence tomography (TD-OCT) and spectral-domain OCT (SD-OCT), and to evaluate two methods defining the optic nerve head (ONH) centring: Centred Each Time (CET) vs Centred Once (CO), in terms of RNFL thickness measurement variability on SD-OCT. Methods: Twenty-seven eyes (14 healthy subjects) had three circumpapillary scans with TD-OCT and three raster scans (three-dimensional or 3D image data) around ONH with SD-OCT. SD-OCT images were analysed in two ways: (1) CET: ONH centre was defined on each image separately and (2) CO: ONH centre was defined on one image and exported to other images after scan registration. After defining the ONH centre, a 3.4 mm diameter virtual circular OCT was resampled on SD-OCT images to mimic the conventional circumpapillary RNFL thickness measurements taken with TD-OCT. Results: CET and CO showed statistically significantly better Reproducibility than TD-OCT except for 11:00 with CET. CET and CO methods showed similar Reproducibility. Conclusions: SD-OCT 3D cube data generally showed better RNFL measurement Reproducibility than TD-OCT. The choice of ONH centring methods did not affect RNFL measurement Reproducibility.
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Reproducibility of nerve fiber thickness macular thickness and optic nerve head measurements using stratusoct
Investigative Ophthalmology & Visual Science, 2004Co-Authors: L A Paunescu, Hiroshi Ishikawa, Joel S Schuman, Lori Lyn Price, Paul Stark, S Beaton, Gadi Wollstein, James G FujimotoAbstract:PURPOSE: The measurement Reproducibility of the third generation of commercial optical coherence tomography, OCT-3 (StratusOCT, software ver. A2, Carl Zeiss Meditec Inc., Dublin, CA) was investigated. The nerve fiber layer (NFL) thickness, macula thickness map, and optic nerve head (ONH) parameters in normal eyes were studied. METHODS: Ten normal subjects were imaged six times (three before and three after dilation) per day, and the series was repeated on three different days. The order of the scans before pupil dilation was randomized in each of the 3 days of scanning. After pupil dilation, the scans were also randomized in each of the 3 days of scanning. Each series was performed separately for standard-density (128 A-scans per macular and ONH image and 256 A-scans per NFL image) and high-density (512 A-scans per image for all three scan types) scanning. RESULTS: The mean macular thickness was 235 +/- 9.8 micro m. A-scan density (or image acquisition speed) had a statistically significant effect (P < 0.05) on the Reproducibility of the mean macular thickness, macular volume, and a few sectors of the macular map. No significant dilation effect was found for any of the macular parameters. The best intraclass correlation coefficient (ICC; 94%) for macular scans was found for dilated high-density scanning, with an intervisit SD of 2.4 micro m and an intravisit SD of 2.2 micro m. The mean NFL thickness for standard scanning was 98 +/- 9 micro m. NFL Reproducibility showed mixed results and had interactions between scan density and dilation for some parameters. For most of the NFL parameters, Reproducibility was better with dilated standard-density scanning. The mean NFL thickness ICC for dilated standard scanning was 79%, with an intervisit SD of 2.5 micro m and an intravisit SD of 1.6 micro m. For the ONH analysis, the Reproducibility was better for dilated standard-density scanning for almost all the parameters, except for disc area, horizontal integrated rim volume, and vertical integrated rim area, which were better before dilation. The best Reproducibility was found for cup-to-disc ratio (ICC = 97%, with intervisit SD of 0.04 micro m and intravisit SD of 0.02 micro m). CONCLUSIONS: StratusOCT demonstrated reproducible measurements of NFL thickness, macular thickness, and optic nerve head parameters. The best Reproducibility was found for dilated standard scanning for NFL and ONH parameters and for dilated high-density scanning for macular parameters.
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Reproducibility of nerve fiber layer thickness measurements using optical coherence tomography
Ophthalmology, 1996Co-Authors: Joel S Schuman, James G Fujimoto, Tamar Pedutkloizman, Ellen Hertzmark, J R Wilkins, Jeffery G Coker, Carmen A Puliafito, Eric A SwansonAbstract:Purpose: Optical coherence tomography (OCT) is a new technology that uses near-infrared light in an interferometer to produce approximately 10-µm resolution crosssectional images of the tissue of interest. The authors performed repeated quantitative assessment of nerve fiber layer thickness in individuals with normal and glaucomatous eyes, and they evaluated the Reproducibility of these measurements. Methods: The authors studied 21 eyes of 21 subjects by OCT. Each subject underwent five repetitions of a series of scans on five separate occasions within a 1-month period. Each series consisted of three circular scans around the optic nerve head (diameters, 2.9, 3.4, and 4.5 mm). Each series was performed separately using internal (fixation with same eye being studied) and external (fixation with contralateral eye) fixation techniques. The eye studied and the sequence of testing were assigned randomly. Results: Internal fixation (IF), in general, provides a slightly higher degree of Reproducibility than external fixation (EF). Reproducibility was better in a given eye on a given visit than from visit to visit. Reproducibility as measured by intraclass correlation coefficients were as follows: circle diameter (CD), 2.9 mm, 0.51/0.57 (normal/glaucoma) (IF), 0.43/0.54 (EF); CD, 3.4 mm, 0.56/0.52 (IF), 0.43/0.61 (EF); CD, 4.5 mm, 0.53/0.43 (IF), 0.42/0.49 (EF). Conclusions: Nerve fiber layer thickness can be reproducibly measured using OCT. Internal is superior to external fixation; each circle diameter tested provides adequate Reproducibility.
Jinhai Huang - One of the best experts on this subject based on the ideXlab platform.
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measurement of central corneal thickness by high resolution scheimpflug imaging fourier domain optical coherence tomography and ultrasound pachymetry
Acta Ophthalmologica, 2012Co-Authors: Shihao Che, David Huang, Jinhai Huang, Wuhe Che, Qinmei WangAbstract:. Purpose: To compare the repeatability and Reproducibility of central corneal thickness (CCT) measurements by high-resolution (HR) rotating Scheimpflug imaging and Fourier-domain optical coherence tomography (FD-OCT). CCT measurements were compared to those determined by ultrasound pachymetry (UP). Methods: In 35 healthy eyes, intra-observer repeatability for HR Scheimpflug (Pentacam) and FD-OCT (RTVue) systems was determined in consecutive images taken by an observer in the shortest time possible. Imaging was repeated again by a second observer to evaluate inter-observer Reproducibility. The CCT measurements were compared among Scheimpflug, FD-OCT and UP images. Results: Mean coefficients of repeatability were 0.48% for Scheimpflug and 0.26% for FD-OCT. For Scheimpflug, the coefficient of inter-operator Reproducibility was 0.87%. For FD-OCT, the coefficient of inter-operator Reproducibility was 0.45%. The CCT measurements by Scheimpflug, OCT and UP images were (mean ± standard deviation) 521.7 ± 27.6 μm, 510.8 ± 28.6 μm and 516.5 ± 27.6 μm, respectively. The differences between instruments were statistically significant. The 95% limits of agreement in CCT were −0.7 to 22.5 μm for Pentacam-OCT, −13.4 to 24.0 μm for Pentacam-UP and −26.7 to 15.4 μm for OCT-UP. There was a high degree of correlation between CCT measured by all 3 methods. Conclusion: Noncontact measurements of CCT with HR Scheimpflug and FD-OCT systems yielded excellent repeatability and Reproducibility and can be used interchangeably. Although both devices were comparable with UP; in clinical practice, the measurements acquired by optical modalities are not directly interchangeable with UP measurements.
Wuhe Che - One of the best experts on this subject based on the ideXlab platform.
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measurement of central corneal thickness by high resolution scheimpflug imaging fourier domain optical coherence tomography and ultrasound pachymetry
Acta Ophthalmologica, 2012Co-Authors: Shihao Che, David Huang, Jinhai Huang, Wuhe Che, Qinmei WangAbstract:. Purpose: To compare the repeatability and Reproducibility of central corneal thickness (CCT) measurements by high-resolution (HR) rotating Scheimpflug imaging and Fourier-domain optical coherence tomography (FD-OCT). CCT measurements were compared to those determined by ultrasound pachymetry (UP). Methods: In 35 healthy eyes, intra-observer repeatability for HR Scheimpflug (Pentacam) and FD-OCT (RTVue) systems was determined in consecutive images taken by an observer in the shortest time possible. Imaging was repeated again by a second observer to evaluate inter-observer Reproducibility. The CCT measurements were compared among Scheimpflug, FD-OCT and UP images. Results: Mean coefficients of repeatability were 0.48% for Scheimpflug and 0.26% for FD-OCT. For Scheimpflug, the coefficient of inter-operator Reproducibility was 0.87%. For FD-OCT, the coefficient of inter-operator Reproducibility was 0.45%. The CCT measurements by Scheimpflug, OCT and UP images were (mean ± standard deviation) 521.7 ± 27.6 μm, 510.8 ± 28.6 μm and 516.5 ± 27.6 μm, respectively. The differences between instruments were statistically significant. The 95% limits of agreement in CCT were −0.7 to 22.5 μm for Pentacam-OCT, −13.4 to 24.0 μm for Pentacam-UP and −26.7 to 15.4 μm for OCT-UP. There was a high degree of correlation between CCT measured by all 3 methods. Conclusion: Noncontact measurements of CCT with HR Scheimpflug and FD-OCT systems yielded excellent repeatability and Reproducibility and can be used interchangeably. Although both devices were comparable with UP; in clinical practice, the measurements acquired by optical modalities are not directly interchangeable with UP measurements.
