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N J L Sheen - One of the best experts on this subject based on the ideXlab platform.
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mapping choroidal and Retinal Thickness variation in type 2 diabetes using three dimensional 1060 nm optical coherence tomography
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Marieh Esmaeelpour, Boris Považay, B Hermann, Bernd Hofer, Vedran Kajic, Sarah L Hale, R V North, Wolfgang Drexler, N J L SheenAbstract:Purpose. To map choroidal (ChT) and Retinal Thickness (RT) in healthy subjects and patients with diabetes with and without maculopathy using three dimensional 1060-nm optical coherence tomography (3D-1060nm-OCT). Methods. Sixty-three eyes from 42 diabetic subjects (41–82 years of age; 11 females) grouped according to a custom scheme using Early Treatment Diabetic Retinopathy Study definitions for pathology within 1 disc-diameter of fovea (without pathology [NDR], microaneurysms [M1], exudates [M2], clinically significant macular edema [CSME]) and 16 eyes from 16 healthy age matched subjects (38–79 years of age; 11 females) were imaged by 3D-1060nm-OCT performed over a 36° × 36° field of view. Axial length, 45° fundus photographs, body mass index, plasma glucose, and blood pressure measurements were recorded. The ChT at the subfoveal location and ChT maps between RPE and the choroidal–scleral interface were generated and statistically analyzed. Results. RT maps show thinning in the NDR group but an increase in Thickness with increasing maculopathy in the temporal and central regions (unpaired t-test; P < 0.05). ChT mapping of all diabetic patients revealed central and inferior thinning compared to healthy eyes (unpaired t-test; P < 0.001). Subfoveal ChT (mean ± SD) for healthy eyes was 327 ± 74 μm, which was significantly thicker than all diabetic groups (214 ± 55 μm for NDR, 208 ± 49 μm for M1, 205 ± 54 μm for M2, and 211 ± 76 μm for CSME (ANOVA P < 0.001; Tukey P < 0.001).
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mapping choroidal and Retinal Thickness variation in type 2 diabetes using three dimensional 1060 nm optical coherence tomography
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Marieh Esmaeelpour, Boris Považay, B Hermann, Bernd Hofer, Vedran Kajic, Sarah L Hale, R V North, Wolfgang Drexler, N J L SheenAbstract:Purpose. To map choroidal (ChT) and Retinal Thickness (RT) in healthy subjects and patients with diabetes with and without maculopathy using three dimensional 1060-nm optical coherence tomography (3D-1060nm-OCT). Methods. Sixty-three eyes from 42 diabetic subjects (41–82 years of age; 11 females) grouped according to a custom scheme using Early Treatment Diabetic Retinopathy Study definitions for pathology within 1 disc-diameter of fovea (without pathology [NDR], microaneurysms [M1], exudates [M2], clinically significant macular edema [CSME]) and 16 eyes from 16 healthy age matched subjects (38–79 years of age; 11 females) were imaged by 3D-1060nm-OCT performed over a 36° × 36° field of view. Axial length, 45° fundus photographs, body mass index, plasma glucose, and blood pressure measurements were recorded. The ChT at the subfoveal location and ChT maps between RPE and the choroidal–scleral interface were generated and statistically analyzed. Results. RT maps show thinning in the NDR group but an increase in Thickness with increasing maculopathy in the temporal and central regions (unpaired t-test; P < 0.05). ChT mapping of all diabetic patients revealed central and inferior thinning compared to healthy eyes (unpaired t-test; P < 0.001). Subfoveal ChT (mean ± SD) for healthy eyes was 327 ± 74 μm, which was significantly thicker than all diabetic groups (214 ± 55 μm for NDR, 208 ± 49 μm for M1, 205 ± 54 μm for M2, and 211 ± 76 μm for CSME (ANOVA P < 0.001; Tukey P < 0.001).
K V Chalam - One of the best experts on this subject based on the ideXlab platform.
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Retinal Thickness measurement obtained with spectral domain optical coherence tomography assisted optical biopsy accurately correlates with ex vivo histology
PLOS ONE, 2014Co-Authors: Lee R Ferguson, Sandeep Grover, James M Dominguez, Sankarathi Balaiya, K V ChalamAbstract:Background This study determines ‘correlation constants’ between the gold standard histological measurement of Retinal Thickness and the newer spectral-domain optical coherence tomography (SD-OCT) technology in adult C57BL/6 mice. Methods Forty-eight eyes from adult mice underwent SD-OCT imaging and then were histologically prepared for frozen sectioning with H&E staining. Retinal Thickness was measured via 10x light microscopy. SD-OCT images and histological sections were standardized to three anatomical sites relative to the optic nerve head (ONH) location. The ratios between SD-OCT to histological Thickness for total Retinal Thickness (TRT) and six sublayers were defined as ‘correlation constants’. Results Mean (± SE) TRT for SD-OCT and histological sections was 210.95 µm (±1.09) and 219.58 µm (±2.67), respectively. The mean ‘correlation constant’ for TRT between the SD-OCT and histological sections was 0.96. The Retinal Thickness for all sublayers measured by SD-OCT vs. histology were also similar, the ‘correlation constant’ values ranged from 0.70 to 1.17. All SD-OCT and histological measurements demonstrated highly significant (p<0.01) strong positive correlations. Conclusion This study establishes conversion factors for the translation of ex vivo data into in vivo information; thus enhancing the applicability of SD-OCT in translational research.
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reproducibility of spectral domain optical coherence tomography Retinal Thickness measurements and conversion to equivalent time domain metrics in diabetic macular edema
JAMA Ophthalmology, 2014Co-Authors: Susan B Bressler, K V Chalam, Neil M Bressler, Adam R Glassman, Allison R Edwards, Glenn J Jaffe, Michele Melia, David D Saggau, Oren Z PlousAbstract:Importance Understanding measurement variability and relationships between measurements obtained on different optical coherence tomography (OCT) machines is critical for clinical trials and clinical settings. Objective To evaluate the reproducibility of Retinal Thickness measurements from OCT images obtained by time-domain (TD) (Stratus; Carl Zeiss Meditec) and spectral-domain (SD) (Cirrus; Carl Zeiss Meditec, and Spectralis; Heidelberg Engineering) instruments and formulate equations to convert Retinal Thickness measurements from SD-OCT to equivalent values on TD-OCT. Design, Setting, and Participants A cross-sectional observational study was conducted in private and institutional practices. Persons with diabetes mellitus who had at least 1 eye with central-involved diabetic macular edema, defined as Stratus central subfield Thickness (CST) of 250 μm or greater, participated. An additional normative cohort (individuals with diabetes but without diabetic macular edema) was enrolled. Each study eye underwent 2 replicate Stratus scans followed by 2 replicate Cirrus or Spectralis scans (real-time image registration used) centered on the fovea. Main Outcomes and Measures Optical coherence tomography CST and macular volume. Results The Bland-Altman coefficient of repeatability for relative change in CST (the degree of change that could be expected from measurement variability) was lower with Spectralis (7%) compared with Cirrus (14%) and Stratus (12% and 15% within Cirrus/Stratus and Spectralis/Stratus groups, respectively). For each cohort, the initial Stratus CST was within 10% of the replicate Stratus measurement nearly all of the time; the conversion equations predicted a Stratus CST within 10% of the observed Thickness 86% and 89% of the time for Cirrus/Stratus and Spectralis/Stratus groups, respectively, which is similar to the agreement on Stratus test-retest. The Bland-Altman limits of agreement for relative change in CST between machines (the degree of change that could be expected from measurement variability [combining within and between instrument variability]) were 21% for Cirrus and 19% for Spectralis when comparing predicted vs actual Stratus measurement. Conclusions and Relevance Reproducibility appears to be better with Spectralis than with Cirrus and Stratus. Conversion equations to transform Cirrus or Spectralis measurements to Stratus-equivalent values, within 10% of the observed Stratus Thickness values, appear feasible. Central subfield Thickness changes beyond 10% when using the same machine or 20% when switching machines, after conversion to Stratus equivalents, are likely due to a change in Retinal Thickness rather than measurement error.
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comparison of Retinal Thickness in normal eyes using stratus and spectralis optical coherence tomography
Investigative Ophthalmology & Visual Science, 2010Co-Authors: Sandeep Grover, Ravi K Murthy, Vikram S Brar, K V ChalamAbstract:PURPOSE. Spectral-domain optical coherence tomography (SDOCT) is an advancement over time-domain OCT (TD-OCT) in the imaging of Retinal disorders. Retinal Thickness measured by SD-OCT differs from that measured by TD-OCT because the delineation of the outer boundary of the retina differs in the two instruments. The present study aims to evaluate this difference by comparing macular Thickness, as obtained by Stratus and Spectralis OCT, in subjects without any known Retinal disease. METHODS. Thirty-six subjects with no history of Retinal disease and with normal vision and normal intraocular pressure were enrolled in the study. Both Stratus and Spectralis OCT scanning were performed by the same operator on all subjects in one eye. Central point Thickness (CPT) and Retinal Thickness in nine ETDRS subfields, including central subfield (CSF), were measured. Student’s t-test was used to determine statistical significance. RESULTS. Mean CPT, as measured by the Stratus and Spectralis OCT, was 166.9 20.9 m and 225.1 17.1 m( P 0.0001), and mean CSF was 202.3 19.6 m and 271.4 19.6 m( P 0.0001), respectively. Although the mean difference in CSF Thickness was 69.1 m, it ranged from 61.9 to 74 mi n the other eight ETDRS subfields. CONCLUSIONS. An increased measurement in Retinal Thickness of approximately 65 to 70 m, as measured by Spectralis OCT compared with Stratus OCT, is consistent with the extent of axial Retinal Thickness measured by the two instruments. This increased measurement corresponds to the inclusion of the outer segment-RPE-Bruch’s membrane complex by Spectralis OCT, which is relevant to studies using the newer SD-OCT for assessment of Retinal Thickness. (Invest Ophthalmol Vis Sci. 2010;51:2644‐2647) DOI:10.1167/iovs.09-4774
Neil M Bressler - One of the best experts on this subject based on the ideXlab platform.
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reproducibility of spectral domain optical coherence tomography Retinal Thickness measurements and conversion to equivalent time domain metrics in diabetic macular edema
JAMA Ophthalmology, 2014Co-Authors: Susan B Bressler, K V Chalam, Neil M Bressler, Adam R Glassman, Allison R Edwards, Glenn J Jaffe, Michele Melia, David D Saggau, Oren Z PlousAbstract:Importance Understanding measurement variability and relationships between measurements obtained on different optical coherence tomography (OCT) machines is critical for clinical trials and clinical settings. Objective To evaluate the reproducibility of Retinal Thickness measurements from OCT images obtained by time-domain (TD) (Stratus; Carl Zeiss Meditec) and spectral-domain (SD) (Cirrus; Carl Zeiss Meditec, and Spectralis; Heidelberg Engineering) instruments and formulate equations to convert Retinal Thickness measurements from SD-OCT to equivalent values on TD-OCT. Design, Setting, and Participants A cross-sectional observational study was conducted in private and institutional practices. Persons with diabetes mellitus who had at least 1 eye with central-involved diabetic macular edema, defined as Stratus central subfield Thickness (CST) of 250 μm or greater, participated. An additional normative cohort (individuals with diabetes but without diabetic macular edema) was enrolled. Each study eye underwent 2 replicate Stratus scans followed by 2 replicate Cirrus or Spectralis scans (real-time image registration used) centered on the fovea. Main Outcomes and Measures Optical coherence tomography CST and macular volume. Results The Bland-Altman coefficient of repeatability for relative change in CST (the degree of change that could be expected from measurement variability) was lower with Spectralis (7%) compared with Cirrus (14%) and Stratus (12% and 15% within Cirrus/Stratus and Spectralis/Stratus groups, respectively). For each cohort, the initial Stratus CST was within 10% of the replicate Stratus measurement nearly all of the time; the conversion equations predicted a Stratus CST within 10% of the observed Thickness 86% and 89% of the time for Cirrus/Stratus and Spectralis/Stratus groups, respectively, which is similar to the agreement on Stratus test-retest. The Bland-Altman limits of agreement for relative change in CST between machines (the degree of change that could be expected from measurement variability [combining within and between instrument variability]) were 21% for Cirrus and 19% for Spectralis when comparing predicted vs actual Stratus measurement. Conclusions and Relevance Reproducibility appears to be better with Spectralis than with Cirrus and Stratus. Conversion equations to transform Cirrus or Spectralis measurements to Stratus-equivalent values, within 10% of the observed Stratus Thickness values, appear feasible. Central subfield Thickness changes beyond 10% when using the same machine or 20% when switching machines, after conversion to Stratus equivalents, are likely due to a change in Retinal Thickness rather than measurement error.
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comparing Retinal Thickness measurements from cirrus spectral domain and stratus time domain optical coherence tomography
Retina-the Journal of Retinal and Vitreous Diseases, 2010Co-Authors: W Geitzenauer, Christopher Kiss, Mary K Durbin, Maria Teresa A Abunto, Thomas Callan, Paul F Stetson, M Wieland, Neil M Bressler, Giovanni Gregori, Ursula SchmidterfurthAbstract:Purpose: The purpose of this study was to compare Retinal measurements obtained using spectral domain-optical coherence tomography with measurements obtained using time domain-optical coherence tomography. Methods: Three hundred and seventy subjects were recruited at three university-based and one community-based retina practice for a cross-sectional observational study. For each subject, one eye was enrolled as the study eye. A Stratus Fast Macular scan was performed, and a Cirrus 200 × 200 Macular Cube scan was performed. Both instruments segment the acquired images to generate Retinal Thickness values and report averages measured in nine subfields defined by the Early Treatment Diabetic Retinopathy Study. These average values were compared with each other quantitatively using linear regression and Bland-Altman plots. Results: Of the recruited subjects, 283 had acceptable images taken on the same day with both the Cirrus and Stratus devices. Mean differences between the instruments were noted in all subfields for all disease categories and ranged from 29 μm (outer superior subfield) to 54 μm (central subfield). Conclusion: Differences between time domain and spectral domain measurements of Retinal Thickness depend on pathology and location. Comparisons across instruments should be made with caution.
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Retinal Thickness on stratus optical coherence tomography in people with diabetes and minimal or no diabetic retinopathy
American Journal of Ophthalmology, 2008Co-Authors: Neil M Bressler, Ronald P Danis, David J Browning, Roy W Beck, Allison R Edwards, Andrew N Antoszyk, Antonio P Ciardella, Michael J Elman, Scott M Friedman, Adam R GlassmanAbstract:Purpose To evaluate optical coherence tomography (OCT) Thickness of the macula in people with diabetes but minimal or no retinopathy and to compare these findings with published normative data in the literature from subjects reported to have no Retinal disease. Design Cross-sectional study. Methods In a multicenter community- and university-based practices setting, 97 subjects with diabetes with no or minimal diabetic retinopathy and no central Retinal thickening on clinical examination and a center point Thickness of 225 μm or less on OCT (Stratus OCT; Carl Zeiss Meditec, Dublin, California, USA) were recruited. Electronic Early Treatment of Diabetic Retinopathy Study best-corrected visual acuity, seven-field stereoscopic color fundus photographs, and Stratus OCT fast macular scan were noted. Main outcome measures were central subfield (CSF) Thickness measured on Stratus OCT. Results On average, CSF Thickness was 201 ± 22 μm. CSF Thickness was significantly greater in retinas from men than retinas from women (mean ± standard deviation, 209 ± 18 μm vs 194 ± 23 μm; P P > .10). Conclusions CSF Thicknesses on Stratus OCT in people with diabetes and minimal or no retinopathy are similar to Thicknesses reported from a normative database of people without diabetes. CSF Thickness is greater in men than in women, consistent with many, but not all, previous reports. Studies involving comparisons of Retinal Thickness with expected norms should consider different mean values for women and men.
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relationship between optical coherence tomography measured central Retinal Thickness and visual acuity in diabetic macular edema
Ophthalmology, 2007Co-Authors: David J Browning, Ronald P Danis, Neil M Bressler, Adam R Glassman, Lloyd Paul Aiello, Roy W Beck, David M Brown, Donald S Fong, James L Kinyoun, Quan Dong NguyenAbstract:Objective To compare optical coherence tomography (OCT)-measured Retinal Thickness and visual acuity in eyes with diabetic macular edema (DME) both before and after macular laser photocoagulation. Design Cross-sectional and longitudinal study. Participants Two hundred ten patients (251 eyes) with DME enrolled in a randomized clinical trial of laser techniques. Methods Retinal Thickness was measured with OCT and visual acuity was measured with the electronic Early Treatment of Diabetic Retinopathy procedure. Main outcome measures Optical coherence tomography-measured center point Thickness and visual acuity. Results The correlation coefficients for visual acuity versus OCT center point Thickness were 0.52 at baseline and 0.49, 0.36, and 0.38 at 3.5, 8, and 12 months after laser photocoagulation. The slope of the best fit line to the baseline data was approximately 4.4 letters (95% confidence interval, 3.5-5.3) of better of visual acuity for every 100-mum decrease in center point Thickness at baseline with no important difference at follow-up visits. Approximately one third of the variation in visual acuity could be predicted by a linear regression model that incorporated OCT center point Thickness, age, hemoglobin A1C, and severity of fluorescein leakage. The correlation between change in visual acuity and change in OCT center point thickening 3.5 months after laser treatment was 0.44, with no important difference at the other follow-up times. A subset of eyes showed paradoxical improvements in visual acuity with increased center point thickening (7%-17% at the 3 time points) or paradoxical worsening of visual acuity with a decrease in center point thickening (18%-26% at the 3 time points). Conclusions There is modest correlation between OCT-measured center point Thickness and visual acuity, and modest correlation of changes in Retinal thickening and visual acuity after focal laser treatment for DME. However, a wide range of visual acuity may be observed for a given degree of Retinal edema. Thus, although OCT measurements of Retinal Thickness represent an important tool in clinical evaluation, they cannot substitute reliably as a surrogate for visual acuity at a given point in time. This study does not address whether short-term changes on OCT are predictive of long-term effects on visual acuity.
Peter K Kaiser - One of the best experts on this subject based on the ideXlab platform.
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comparison of Retinal Thickness measurements between three dimensional and radial scans on spectral domain optical coherence tomography
American Journal of Ophthalmology, 2009Co-Authors: Kaori Sayanagi, Sumit Sharma, Peter K KaiserAbstract:Purpose To compare Retinal Thickness (RT) measurements between traditional 6 radial line scans and three-dimensional (3D) scans using spectral-domain optical coherence tomography (SD-OCT). Design Prospective, consecutive case series. Methods Twenty eyes of 17 patients with macular diseases and 8 healthy subjects were scanned using 2 different methods (3D scan and 6 radial line scan) using 2 different SD-OCT devices (Topcon OCT-1000 [Topcon Inc, Paramus, New Jersey, USA] and Canon SPOCT [(Canon/Optopol Inc, Depew, New York, USA]) by an experienced OCT operator. In 16 eyes, the data of TD-OCT were also obtained for comparison. The RT in 9 regions based on Early Treatment Diabetic Retinopathy Study areas were analyzed and compared. Bland-Altman plots were used to evaluate agreement. Results In the eyes with macular diseases, there was no significant difference in the RT between 3D and 6 radial line scans except the center subfield ( P = .011) on the Topcon OCT-1000, and inner inferior ( P = .031) and outer nasal ( P = .014) areas on the Canon SPOCT. In the healthy subjects, there was no significant difference between the different scans on both SD-OCT devices. The 95% limit of subjects was 3.2 to 30.6 μm and 16.7 to 28.3 μm in the eye with macular diseases on OCT-1000 and SPOCT, respectively, and 6.7 to 13.6 μm and 10.8 to 32.3 μm in healthy subjects on OCT-1000 and SPOCT, respectively. Conclusions Preliminary results suggest the RT obtained by the 2 different scan patterns, 3D scan and 6 radial line scan, did not differ significantly on SD-OCT.
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comparing Retinal Thickness measurements using automated fast macular Thickness map versus six radial line scans with manual measurements
Ophthalmology, 2009Co-Authors: Mehran Taban, Sumit Sharma, Dawn R Williams, Nadia K Waheed, Peter K KaiserAbstract:Purpose To compare automated Retinal Thickness values generated by the fast macular Thickness maps (FMTM) and customized 6-radial line scans (RLS) versus manual Retinal measurements on Stratus optical coherence tomography (OCT) (Carl Zeiss Meditec, Dublin, CA). Design Prospective, observational case series. Participants Patients with subfoveal choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD), diabetic macular edema (DME), or branch/central Retinal vein occlusion (RVO). Methods Patients were prospectively imaged using the FMTM and customized RLS patterns on Stratus OCT at the same sitting. Each scan was evaluated for errors in Retinal segmentation (i.e., correct Retinal boundaries [CRB]). Automated values were recorded while central Retinal Thickness measurements were determined manually for both patterns. The presence or absence of epiRetinal phenomenon, cystoid spaces, pigment epithelial detachment, and subRetinal fluid was also noted. Main Outcome Measures Errors in Retinal segmentation at and outside the fovea (i.e., CRB) and percentage of automated values within a clinically acceptable margin (±25 μm) of the manual central Retinal Thickness. Results A total of 147 eyes of 147 patients (95 eyes with exudative AMD, 41 eyes with DME, and 11 eyes with macular edema caused by RVO) were included. For wet AMD, the total number of CRB at the fovea and outside the fovea was 363 (63.7%) and 360 (63.2%), respectively, in FMTM and 428 (75.1%) and 426 (74.7%), respectively, in RLS ( P P = 0.11, P = 0.15, respectively). Some 40% and 56% of automated foveal center point Thicknesses on FMTM and RLS, respectively, were within ±25 μm of the manual central Retinal Thickness for AMD ( P = 0.042), versus 94% and 81% for DME and RVO, respectively ( P = 0.07). Conclusions For exudative AMD, the RLS protocol provides fewer segmentation errors than the FMTM protocol, and its automated Retinal Thickness values (e.g., foveal center point, central subfield) correlate better with manual Retinal Thickness measurement than FMTM. In DME and RVO, however, both protocols provide similar and low segmentation errors, and their automated results are close to manual measurements. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
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optical coherence tomography 3 automatic delineation of the outer neural Retinal boundary and its influence on Retinal Thickness measurements
Investigative Ophthalmology & Visual Science, 2004Co-Authors: R A Costa, Daniela Calucci, M Skaf, Jose A Cardillo, J C Castro, L A S Melo, Maria Cristina Martins, Peter K KaiserAbstract:PURPOSE. To investigate the automatic delineation of the outer limits of the macular neural retina, by using the optical coherence tomography (OCT)-3 built-in software, and to determine its intluence in assessing Retinal Thickness in the normal macula. METHODS. Retrospective analysis of the OCT3 data at a tertiary-care referral center was performed to study the automatic delineation of the outer neural retina boundary generated by the OCT built-in software. In parallel, a cross-sectional study was designed to compare Retinal Thickness measurements obtained at specific macular regions of nine normal eyes by the automatic measurement tool with those obtained using a manual-caliper-assisted technique. RESULTS. OCT data from 121 eyes were evaluated. Two parallel, linear highly reflective layers (HRL) were visible at the level of the outer Retinal boundary in normal macular regions. Disappearance of the inner and maintenance of the outer HRL was noted in the presence of eye conditions affecting the external Retinal layers. The automated software delineation for the outer Retinal border was primarily guided by the presence of the inner HRL, whereas the correlation of the OCT findings with the expected clinical and angiographic features on eyes presenting specific macular conditions pointed toward a deeper Retinal pigment epithelium-retina interface occurring at the level of the outer HRL. There was a statistically significant difference between the Retinal Thickness in specific normal macular regions obtained by the automatic measurement tool and the caliper-assisted technique in which the outer Retinal border delineation was based on the outer HRL (P = 0.008, Wilcoxon signed rank test). CONCLUSIONS. Incorrect delineation of the Outer neural retina boundary is occurring with the automated Retinal Thickness measurement tool of the OCT3 software. At specific regions of the normal macula, Retinal Thicknesses were significantly underestimated due to such misalignment.
Ursula Schmidterfurth - One of the best experts on this subject based on the ideXlab platform.
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reproducibility of Retinal Thickness measurements across spectral domain optical coherence tomography devices using iowa reference algorithm
arXiv: Medical Physics, 2016Co-Authors: Adnan Rashid, Sebastian M Waldstein, Bianca S Gerendas, Hrvoje Bogunovic, Andreas Wahle, Kyungmoo Lee, Kai Wang, Christian Simader, Michael D Abramoff, Ursula SchmidterfurthAbstract:PURPOSE: Establishing and obtaining consistent quantitative indices of Retinal Thickness from a variety of clinically used Spectral-Domain Optical Coherence Tomography scanners. DESIGN: Retinal images from five Spectral-Domain Optical Coherence Tomography scanners were used to determine total Retinal Thickness with scanner-specific correction factors establishing consistency of Thickness measurement across devices. PARTICIPANTS: 55 Fovea-centered Spectral-Domain Optical Coherence Tomography volumes from eleven subjects were analyzed, obtained from Cirrus HD-OCT, RS-3000, Heidelberg Spectralis, RTVue and Topcon2000, seven subjects with Retinal diseases and four normal controls. METHOD: The Iowa Reference Algorithm measured total Retinal Thickness. Nonlinear model of total Retinal Thickness measurement comparisons was derived and used for device-specific comparisons. Bland-Altman plots and pairwise predictive equations yielded pairwise scanner-specific differences. Mendel test determined whether measurement biases were constant for each scanner pair. RESULTS: Mendel test revealed that all pairwise scanner differences of total Retinal Thickness were constant across the cohort (p=0.992). Individual measurements can thus be bias-corrected and the Iowa Reference Algorithm serve as a scanner-agnostic independent standard of total Retinal Thickness across the five tested SD-OCT scanners. CONCLUSIONS: Combination of the Iowa Reference Algorithm with scanner-specific bias correction yields cross-scanner consistency of total Retinal Thickness measurements, facilitating scanning-device independent quantitative assessment of total Retinal Thickness, longitudinal follow-up quantification without requiring patients to be imaged on the same scanner model, and allowing for multi-center studies with heterogeneous device utilization when using the Iowa Reference Algorithm.
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Retinal Thickness and volume measurements in diabetic macular edema a comparison of four optical coherence tomography systems
Retina-the Journal of Retinal and Vitreous Diseases, 2011Co-Authors: Jan Lammer, Ursula Schmidterfurth, Christoph Scholda, Christian Prunte, Thomas Benesch, Matthias BolzAbstract:Purpose:To compare different spectral domain optical coherence tomography devices regarding Retinal Thickness values in patients with diabetic macular edema and to correlate the results with conventional time domain Stratus OCT data.Methods:Thirty eyes of 30 consecutive patients with diabetic macula
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comparing Retinal Thickness measurements from cirrus spectral domain and stratus time domain optical coherence tomography
Retina-the Journal of Retinal and Vitreous Diseases, 2010Co-Authors: W Geitzenauer, Christopher Kiss, Mary K Durbin, Maria Teresa A Abunto, Thomas Callan, Paul F Stetson, M Wieland, Neil M Bressler, Giovanni Gregori, Ursula SchmidterfurthAbstract:Purpose: The purpose of this study was to compare Retinal measurements obtained using spectral domain-optical coherence tomography with measurements obtained using time domain-optical coherence tomography. Methods: Three hundred and seventy subjects were recruited at three university-based and one community-based retina practice for a cross-sectional observational study. For each subject, one eye was enrolled as the study eye. A Stratus Fast Macular scan was performed, and a Cirrus 200 × 200 Macular Cube scan was performed. Both instruments segment the acquired images to generate Retinal Thickness values and report averages measured in nine subfields defined by the Early Treatment Diabetic Retinopathy Study. These average values were compared with each other quantitatively using linear regression and Bland-Altman plots. Results: Of the recruited subjects, 283 had acceptable images taken on the same day with both the Cirrus and Stratus devices. Mean differences between the instruments were noted in all subfields for all disease categories and ranged from 29 μm (outer superior subfield) to 54 μm (central subfield). Conclusion: Differences between time domain and spectral domain measurements of Retinal Thickness depend on pathology and location. Comparisons across instruments should be made with caution.