The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Philip J. Rosenfeld - One of the best experts on this subject based on the ideXlab platform.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective swept-source optical coherence tomography (SS-OCT) imaging study. Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the 2 visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the 2 visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P values >.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Abstract Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective SS-OCT imaging study (PLEX® Elite 9000, Carl Zeiss Meditec). Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the two visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 mm3 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the two visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P-values > 0.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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Drusen Secondary to Age-Related Macular Degeneration
Spectral Domain Optical Coherence Tomography in Macular Diseases, 2016Co-Authors: Karen B Schaal, Philip J. RosenfeldAbstract:Drusen are one of the earliest signs of age-related macular degeneration (AMD) and are important for assessing disease progression and for the staging of disease severity. SD-OCT imaging is currently the most reliable strategy for following Drusen morphology and progression over time, and SD-OCT imaging has replaced color fundus imaging for following Drusen in clinical trials. The SD-OCT algorithm used to measure Drusen defines Drusen as elevations of the overlying RPE and provides both area and volume measurements. Drusen volume was found to be a more sensitive indicator of Drusen growth compared with area measurements and offers an opportunity to study therapies at an earlier stage of AMD. By intervening earlier, there’s the potential to preserve better vision over a lifetime. An ideal baseline Drusen volume to study in clinical trials was found to be a Drusen volume of at least 0.03 mm3 (cube root volume 0.31 mm), which is easily measured by SD-OCT imaging and includes the large Drusen (125 μm) that are easily seen on color fundus imaging. To determine if Drusen actually grow or decrease in size, we recommend the use of the difference in cube-root of the volume measurements to evaluate the change in Drusen over time.
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natural history of Drusen morphology in age related macular degeneration using spectral domain optical coherence tomography
Ophthalmology, 2011Co-Authors: Zohar Yehoshua, Philip J. Rosenfeld, William J Feuer, Fenghua Wang, Fernando M Penha, Giovanni GregoriAbstract:Purpose To characterize the natural history of Drusen using spectral-domain optical coherence tomography (SD-OCT) imaging of eyes from patients with nonexudative age-related macular degeneration (AMD). Design Prospective, longitudinal, natural history study. Participants We included 143 eyes of 100 patients with at least 6 months of follow-up. Methods Patients with Drusen secondary to nonexudative AMD were scanned using the Cirrus SD-OCT instrument. Eyes were imaged using the 200×200 A-scan raster pattern contained within a 6×6 mm area. Custom software was used to quantify volumetric changes in Drusen over a period of ≥6 months and for as long as 24 months. Drusen volume and Drusen area were measured within circular regions centered at the fovea having diameters of 3 and 5 mm. The measurements were analyzed using a suitable scale transformation. For Drusen volume, a cube root transformation strategy was used. Main Outcome Measures Change in Drusen volume and area over time. Results We analyzed 143 eyes of 100 patients with 69 eyes followed for 6 months, 106 eyes followed for 12 months, 48 eyes followed for 18 months, and 48 eyes followed for 24 months. The 3 mm circle baseline Drusen volume ranged from 0.0009 to 0.7479 mm 3 or 0.10 to 0.91 mm using the cube root scale. On average, Drusen volume and Drusen area increased over time with the magnitude of the increase dependent on the length of follow-up ( P = 0.001, 3 mm circle). In the eyes with a decrease in Drusen volume, the magnitude of this decrease was dependent on the baseline Drusen volume ( P = 0.001, 3 mm circle) and independent of the follow-up interval. After 12 months, Drusen volume increased in 48% of eyes, remained stable in 40%, and decreased in 12%. Conclusions Imaging with SD-OCT revealed a dynamic, undulating growth pattern for Drusen with a tendency for Drusen to increase in volume and area over time. An appreciation of the quantitative changes in Drusen volume over time using SD-OCT imaging provides a novel strategy for following normal disease progression and for identifying novel clinical trial end points to be used when investigating therapies for the treatment of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
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spectral domain optical coherence tomography imaging of Drusen in nonexudative age related macular degeneration
Ophthalmology, 2011Co-Authors: Giovanni Gregori, Philip J. Rosenfeld, Zohar Yehoshua, Fenghua Wang, Ninel Z Gregori, Brandon J Lujan, Carmen A Puliafito, William J FeuerAbstract:Purpose To measure Drusen area and volume in eyes with nonexudative age-related macular degeneration (AMD) using spectral domain optical coherence tomography imaging (SD-OCT). Design Evaluation of diagnostic technology. Participants One hundred three eyes from 74 patients with Drusen. Methods Patients with Drusen secondary to nonexudative AMD were enrolled in this study. Five separate SD-OCT scans, each consisting of 40 000 uniformly spaced A-scans organized as 200 A-scans in each B-scan and 200 horizontal B-scans, were performed on each eye. Each scan covered a retinal area of 6×6 mm centered on the fovea. A novel algorithm was used to quantitatively assess Drusen area and volume. Measurements from the entire scans, as well as in regions contained within 3- and 5-mm circles centered on the fovea, were analyzed. Test–retest standard deviations of Drusen area and volume measurements were calculated for each eye. Main Outcome Measures Drusen area and volume. Results The algorithm created Drusen maps that permitted both qualitative and quantitative assessment of Drusen area and volume. Both the qualitative appearance and the quantitative measurements of Drusen area and volume were highly reproducible over the 5 different datasets. The intraclass correlation coefficient was >0.99 for both area and volume measurements on the entire dataset as well as the 3- and 5-mm circles. The correlation between lesion size and the test–retest standard deviations can be eliminated by performing a square root transformation of the area measurements and a cube root transformation of the volume measurements. These transformed data allowed for the inclusion of all Drusen sizes in the calculation of an estimated single pooled test–retest standard deviation, which will be useful for longitudinal studies of Drusen natural history. Conclusions A novel algorithm for the qualitative and quantitative assessment of Drusen imaged using SD-OCT was shown to be highly reproducible. The ability to assess Drusen volume reliably represents a new quantitative parameter to measure in AMD and may be useful when assessing disease progression, particularly in trials for treatments of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
Cynthia A Toth - One of the best experts on this subject based on the ideXlab platform.
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Quantitative comparison of Drusen segmented on SD-OCT versus Drusen delineated on color fundus photographs.
Investigative ophthalmology & visual science, 2010Co-Authors: Nieraj Jain, Sina Farsiu, Joseph A Izatt, Aziz A Khanifar, Srilaxmi Bearelly, R. Theodore Smith, Cynthia A TothAbstract:PURPOSE. Spectral domain– optical coherence tomography (SD-OCT) may be useful for efficient measurement of Drusen in patients with age-related macular degeneration (AMD). Areas identified as Drusen from semiautomated segmentation of Drusen on SD-OCT were compared to those identified from review of digital color fundus photographs (CFPs). METHODS. Twelve eyes with nonneovascular AMD were prospectively imaged with digital CFP and SD-OCT. For each eye, areas on CFP in which at least two of three retina specialists agreed on Drusen presence produced the composite CFP Drusen map. Automated image analysis produced another CFP map. Areas identified as Drusen by segmentation on SD-OCT B-scans were plotted as the SD-OCT Drusen map. The CFP and SD-OCT maps were compared and agreement was quantified. Disagreement was characterized into distinct types, and the frequency of each type was quantified. RESULTS. There was general agreement between CFP and SD-OCT in identifying presence and absence of Drusen, with mean agreement in 82% 9% of total image pixels. Most disagreement (80% 15%) occurred at Drusen margins. There was a trend toward greater detection of Drusen with SD-OCT in eyes with larger Drusen and with hyperpigmentation. There was a trend toward greater detection of smaller Drusen by CFP. CONCLUSIONS. Good agreement was demonstrated in Drusen detection between CFP and SD-OCT. Areas of disagreement underscore limitations of CFP-based measurement of Drusen, particularly in the sizing of large, soft Drusen. SD-OCT shows great promise as an adjunctive tool for assessing Drusen burden in AMD. (ClinicalTrials.gov number, NCT00734487.) (Invest Ophthalmol Vis Sci. 2010;51:4875– 4883) DOI:10.1167/ iovs.09-4962
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photoreceptor layer thinning over Drusen in eyes with age related macular degeneration imaged in vivo with spectral domain optical coherence tomography
Ophthalmology, 2009Co-Authors: Stefanie G Schuman, Sina Farsiu, Anjum F Koreishi, Sinho Jung, Joseph A Izatt, Cynthia A TothAbstract:Purpose Detect changes in the neurosensory retina using spectral-domain optical coherence tomography (SD OCT) imaging over Drusen in age-related macular degeneration (AMD). Quantitative imaging biomarkers may aid in defining risk of disease progression. Design Cross-sectional, case-control study evaluating SD OCT testing in AMD. Participants and Controls Seventeen eyes of 12 subjects with nonneovascular AMD and Drusen and 17 eyes of 10 age-matched control subjects. Methods Spectral-domain OCT imaging across the fovea in the study eye with multiple 10- to 12-mm scans of 1000 A scans each. Main Outcome Measures In summed SD OCT scans, the height of individual retinal layers either over Drusen or at corresponding locations in the control eye and qualitative changes in retinal layers over Drusen. Secondary measures included photoreceptor layer (PRL) area, inner retinal area, and retinal pigment epithelium (RPE)/Drusen area. Results The PRL was thinned over 97% of Drusen, average PRL thickness was reduced by 27.5% over Drusen compared with over a similar location in controls, and the finding of a difference was valid and significant ( P = 0.004). Photoreceptor outer segments were absent over at least 1 druse in 47% of eyes. Despite thinning of the PRL, inner retinal thickness remained unchanged. We observed 2 types of hyperreflective abnormalities in the neurosensory retina over Drusen. Distinct hyperreflective speckled patterns occurred over Drusen in 41% of AMD eyes and never in control eyes. A prominent hyperreflective haze was present in the photoreceptor nuclear layer over Drusen in 67% of AMD eyes and more subtly in the photoreceptor nuclear layer in 18% of control eyes (no Drusen). Conclusions With SD OCT as used in this study, we can easily detect and measure changes in PRL over Drusen. Decreased PRL thickness over Drusen suggests a degenerative process, with cell loss leading to decreased visual function. The hyperreflective foci overlying Drusen are likely to represent progression of disease RPE cell migration into the retina and possible photoreceptor degeneration or glial scar formation. A longitudinal study using SD OCT to examine and measure the neurosensory retina over Drusen will resolve the timeline of degenerative changes relative to druse formation. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
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Drusen ultrastructure imaging with spectral domain optical coherence tomography in age related macular degeneration
Ophthalmology, 2008Co-Authors: Aziz A Khanifar, Anjum F Koreishi, Joseph A Izatt, Cynthia A TothAbstract:Purpose To categorize Drusen ultrastructure in age-related macular degeneration (AMD) using spectral domain optical coherence tomography (SDOCT) and correlate the tomographic and photographic Drusen appearances. Design Prospective case series. Participants Thirty-one eyes of 31 patients with non-neovascular AMD. Methods Subjects with Drusen and a clinical diagnosis of AMD were enrolled in an SDOCT imaging study from August of 2005 to May of 2007. Foveal linear scans were acquired, and the image data were processed for analysis. Drusen were scored by 4 morphologic categories: shape, predominant internal reflectivity, homogeneity, and presence of overlying hyper-reflective foci. The prevalences of each morphologic pattern and combinations of morphologic patterns observed were calculated. The photographic appearance of each druse was compared with the tomographic classification. Interobserver and intraobserver agreement analysis was performed. Main Outcome Measures Prevalence of morphologic parameters using SDOCT. Results Twenty-one eyes of 21 patients had SDOCT B-scans of adequate quality for analysis. On the basis of the above morphologic categories, 17 different Drusen patterns were found in 120 total Drusen. The most common was convex, homogeneous, with medium internal reflectivity, and without overlying hyper-reflective foci, present in 17 of 21 eyes (81%). Of the 16 eyes (76%) with nonhomogeneous Drusen, 5 had a distinct hyper-reflective core. Hyper-reflective foci overlying Drusen were in 7 eyes (33%). Although half of the photographically soft-indistinct Drusen were convex with medium internal reflectivity and homogeneous without overlying hyper-reflective foci, the other half had significant variability in their tomographic appearance. Both interobserver and intraobserver agreement in Drusen grading were high. Readers agreed the most when grading Drusen shape and reflectivity, whereas the least agreement was for Drusen homogeneity. Conclusions Drusen ultrastructure can be imaged with SDOCT and characterized with a simple grading system. Photographic appearance may predict some but not all tomographic appearances. Trained observers have a high level of agreement with this grading system. These in vivo morphologic characteristics imaged with SDOCT may be distinct subclasses of Drusen types, may relate closely to ultrastructural Drusen elements identified in cadaveric eyes, and may be useful imaging biomarkers for disease severity or risk of progression. This will require validation from further studies. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
Giovanni Gregori - One of the best experts on this subject based on the ideXlab platform.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective swept-source optical coherence tomography (SS-OCT) imaging study. Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the 2 visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the 2 visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P values >.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Abstract Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective SS-OCT imaging study (PLEX® Elite 9000, Carl Zeiss Meditec). Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the two visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 mm3 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the two visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P-values > 0.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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natural history of Drusen morphology in age related macular degeneration using spectral domain optical coherence tomography
Ophthalmology, 2011Co-Authors: Zohar Yehoshua, Philip J. Rosenfeld, William J Feuer, Fenghua Wang, Fernando M Penha, Giovanni GregoriAbstract:Purpose To characterize the natural history of Drusen using spectral-domain optical coherence tomography (SD-OCT) imaging of eyes from patients with nonexudative age-related macular degeneration (AMD). Design Prospective, longitudinal, natural history study. Participants We included 143 eyes of 100 patients with at least 6 months of follow-up. Methods Patients with Drusen secondary to nonexudative AMD were scanned using the Cirrus SD-OCT instrument. Eyes were imaged using the 200×200 A-scan raster pattern contained within a 6×6 mm area. Custom software was used to quantify volumetric changes in Drusen over a period of ≥6 months and for as long as 24 months. Drusen volume and Drusen area were measured within circular regions centered at the fovea having diameters of 3 and 5 mm. The measurements were analyzed using a suitable scale transformation. For Drusen volume, a cube root transformation strategy was used. Main Outcome Measures Change in Drusen volume and area over time. Results We analyzed 143 eyes of 100 patients with 69 eyes followed for 6 months, 106 eyes followed for 12 months, 48 eyes followed for 18 months, and 48 eyes followed for 24 months. The 3 mm circle baseline Drusen volume ranged from 0.0009 to 0.7479 mm 3 or 0.10 to 0.91 mm using the cube root scale. On average, Drusen volume and Drusen area increased over time with the magnitude of the increase dependent on the length of follow-up ( P = 0.001, 3 mm circle). In the eyes with a decrease in Drusen volume, the magnitude of this decrease was dependent on the baseline Drusen volume ( P = 0.001, 3 mm circle) and independent of the follow-up interval. After 12 months, Drusen volume increased in 48% of eyes, remained stable in 40%, and decreased in 12%. Conclusions Imaging with SD-OCT revealed a dynamic, undulating growth pattern for Drusen with a tendency for Drusen to increase in volume and area over time. An appreciation of the quantitative changes in Drusen volume over time using SD-OCT imaging provides a novel strategy for following normal disease progression and for identifying novel clinical trial end points to be used when investigating therapies for the treatment of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
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spectral domain optical coherence tomography imaging of Drusen in nonexudative age related macular degeneration
Ophthalmology, 2011Co-Authors: Giovanni Gregori, Philip J. Rosenfeld, Zohar Yehoshua, Fenghua Wang, Ninel Z Gregori, Brandon J Lujan, Carmen A Puliafito, William J FeuerAbstract:Purpose To measure Drusen area and volume in eyes with nonexudative age-related macular degeneration (AMD) using spectral domain optical coherence tomography imaging (SD-OCT). Design Evaluation of diagnostic technology. Participants One hundred three eyes from 74 patients with Drusen. Methods Patients with Drusen secondary to nonexudative AMD were enrolled in this study. Five separate SD-OCT scans, each consisting of 40 000 uniformly spaced A-scans organized as 200 A-scans in each B-scan and 200 horizontal B-scans, were performed on each eye. Each scan covered a retinal area of 6×6 mm centered on the fovea. A novel algorithm was used to quantitatively assess Drusen area and volume. Measurements from the entire scans, as well as in regions contained within 3- and 5-mm circles centered on the fovea, were analyzed. Test–retest standard deviations of Drusen area and volume measurements were calculated for each eye. Main Outcome Measures Drusen area and volume. Results The algorithm created Drusen maps that permitted both qualitative and quantitative assessment of Drusen area and volume. Both the qualitative appearance and the quantitative measurements of Drusen area and volume were highly reproducible over the 5 different datasets. The intraclass correlation coefficient was >0.99 for both area and volume measurements on the entire dataset as well as the 3- and 5-mm circles. The correlation between lesion size and the test–retest standard deviations can be eliminated by performing a square root transformation of the area measurements and a cube root transformation of the volume measurements. These transformed data allowed for the inclusion of all Drusen sizes in the calculation of an estimated single pooled test–retest standard deviation, which will be useful for longitudinal studies of Drusen natural history. Conclusions A novel algorithm for the qualitative and quantitative assessment of Drusen imaged using SD-OCT was shown to be highly reproducible. The ability to assess Drusen volume reliably represents a new quantitative parameter to measure in AMD and may be useful when assessing disease progression, particularly in trials for treatments of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
William J Feuer - One of the best experts on this subject based on the ideXlab platform.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective swept-source optical coherence tomography (SS-OCT) imaging study. Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the 2 visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the 2 visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P values >.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Abstract Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective SS-OCT imaging study (PLEX® Elite 9000, Carl Zeiss Meditec). Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the two visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 mm3 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the two visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P-values > 0.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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natural history of Drusen morphology in age related macular degeneration using spectral domain optical coherence tomography
Ophthalmology, 2011Co-Authors: Zohar Yehoshua, Philip J. Rosenfeld, William J Feuer, Fenghua Wang, Fernando M Penha, Giovanni GregoriAbstract:Purpose To characterize the natural history of Drusen using spectral-domain optical coherence tomography (SD-OCT) imaging of eyes from patients with nonexudative age-related macular degeneration (AMD). Design Prospective, longitudinal, natural history study. Participants We included 143 eyes of 100 patients with at least 6 months of follow-up. Methods Patients with Drusen secondary to nonexudative AMD were scanned using the Cirrus SD-OCT instrument. Eyes were imaged using the 200×200 A-scan raster pattern contained within a 6×6 mm area. Custom software was used to quantify volumetric changes in Drusen over a period of ≥6 months and for as long as 24 months. Drusen volume and Drusen area were measured within circular regions centered at the fovea having diameters of 3 and 5 mm. The measurements were analyzed using a suitable scale transformation. For Drusen volume, a cube root transformation strategy was used. Main Outcome Measures Change in Drusen volume and area over time. Results We analyzed 143 eyes of 100 patients with 69 eyes followed for 6 months, 106 eyes followed for 12 months, 48 eyes followed for 18 months, and 48 eyes followed for 24 months. The 3 mm circle baseline Drusen volume ranged from 0.0009 to 0.7479 mm 3 or 0.10 to 0.91 mm using the cube root scale. On average, Drusen volume and Drusen area increased over time with the magnitude of the increase dependent on the length of follow-up ( P = 0.001, 3 mm circle). In the eyes with a decrease in Drusen volume, the magnitude of this decrease was dependent on the baseline Drusen volume ( P = 0.001, 3 mm circle) and independent of the follow-up interval. After 12 months, Drusen volume increased in 48% of eyes, remained stable in 40%, and decreased in 12%. Conclusions Imaging with SD-OCT revealed a dynamic, undulating growth pattern for Drusen with a tendency for Drusen to increase in volume and area over time. An appreciation of the quantitative changes in Drusen volume over time using SD-OCT imaging provides a novel strategy for following normal disease progression and for identifying novel clinical trial end points to be used when investigating therapies for the treatment of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
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spectral domain optical coherence tomography imaging of Drusen in nonexudative age related macular degeneration
Ophthalmology, 2011Co-Authors: Giovanni Gregori, Philip J. Rosenfeld, Zohar Yehoshua, Fenghua Wang, Ninel Z Gregori, Brandon J Lujan, Carmen A Puliafito, William J FeuerAbstract:Purpose To measure Drusen area and volume in eyes with nonexudative age-related macular degeneration (AMD) using spectral domain optical coherence tomography imaging (SD-OCT). Design Evaluation of diagnostic technology. Participants One hundred three eyes from 74 patients with Drusen. Methods Patients with Drusen secondary to nonexudative AMD were enrolled in this study. Five separate SD-OCT scans, each consisting of 40 000 uniformly spaced A-scans organized as 200 A-scans in each B-scan and 200 horizontal B-scans, were performed on each eye. Each scan covered a retinal area of 6×6 mm centered on the fovea. A novel algorithm was used to quantitatively assess Drusen area and volume. Measurements from the entire scans, as well as in regions contained within 3- and 5-mm circles centered on the fovea, were analyzed. Test–retest standard deviations of Drusen area and volume measurements were calculated for each eye. Main Outcome Measures Drusen area and volume. Results The algorithm created Drusen maps that permitted both qualitative and quantitative assessment of Drusen area and volume. Both the qualitative appearance and the quantitative measurements of Drusen area and volume were highly reproducible over the 5 different datasets. The intraclass correlation coefficient was >0.99 for both area and volume measurements on the entire dataset as well as the 3- and 5-mm circles. The correlation between lesion size and the test–retest standard deviations can be eliminated by performing a square root transformation of the area measurements and a cube root transformation of the volume measurements. These transformed data allowed for the inclusion of all Drusen sizes in the calculation of an estimated single pooled test–retest standard deviation, which will be useful for longitudinal studies of Drusen natural history. Conclusions A novel algorithm for the qualitative and quantitative assessment of Drusen imaged using SD-OCT was shown to be highly reproducible. The ability to assess Drusen volume reliably represents a new quantitative parameter to measure in AMD and may be useful when assessing disease progression, particularly in trials for treatments of nonexudative AMD. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
Luis De Sisternes - One of the best experts on this subject based on the ideXlab platform.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective swept-source optical coherence tomography (SS-OCT) imaging study. Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the 2 visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the 2 visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P values >.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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validation of a compensation strategy used to detect choriocapillaris flow deficits under Drusen with swept source oct angiography
American Journal of Ophthalmology, 2020Co-Authors: Yingying Shi, Zhongdi Chu, Liang Wang, Qinqin Zhang, William J Feuer, Luis De Sisternes, Mary K Durbin, Giovanni Gregori, Ruikang K Wang, Philip J. RosenfeldAbstract:Abstract Purpose A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under Drusen was tested in eyes with large Drusen from age-related macular degeneration (AMD) before and after the Drusen spontaneously resolved without evidence of disease progression. Design Prospective, observational consecutive case series. Methods Patients with AMD were enrolled in a prospective SS-OCT imaging study (PLEX® Elite 9000, Carl Zeiss Meditec). Consecutive eyes with large Drusen were followed, and eyes that underwent spontaneous collapse of Drusen without evidence of disease progression were identified retrospectively. The Drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying Drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after Drusen resolution. Results Resolution of Drusen was identified in 8 eyes from 8 patients. The average interval between the two visits was 7.8 months. The average Drusen volumes measured between visits were 0.23 mm3 and 0.04 mm3, respectively. After the Drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the two visits were compared, there were no statistically significant differences in any of the CC parameters within the Drusen resolved regions once the compensation strategy was applied (all P-values > 0.22). Conclusions In this naturally occurring experiment in which Drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the Drusen resolved.
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individual Drusen segmentation and repeatability and reproducibility of their automated quantification in optical coherence tomography images
Translational Vision Science & Technology, 2017Co-Authors: Luis De Sisternes, Gowtham Jonna, Margaret A Greven, Qiang Chen, Theodore Leng, Daniel L RubinAbstract:Purpose To introduce a novel method to segment individual Drusen in spectral-domain optical coherence tomography (SD-OCT), and evaluate its accuracy, and repeatability/reproducibility of Drusen quantifications extracted from the segmentation results. Methods Our method uses a smooth interpolation of the retinal pigment epithelium (RPE) outer boundary, fitted to candidate locations in proximity to Bruch's Membrane, to identify regions of substantial lifting in the inner-RPE or inner-segment boundaries, and then separates and evaluates individual druse independently. The study included 192 eyes from 129 patients. Accuracy of Drusen segmentations was evaluated measuring the overlap ratio (OR) with manual markings, also comparing the results to a previously proposed method. Repeatability and reproducibility across scanning protocols of automated Drusen quantifications were investigated in repeated SD-OCT volume pairs and compared with those measured by a commercial tool (Cirrus HD-OCT). Results Our segmentation method produced higher accuracy than a previously proposed method, showing similar differences to manual markings (0.72 ± 0.09 OR) as the measured intra- and interreader variability (0.78 ± 0.09 and 0.77 ± 0.09, respectively). The automated quantifications displayed high repeatability and reproducibility, showing a more stable behavior across scanning protocols in Drusen area and volume measurements than the commercial software. Measurements of Drusen slope and mean intensity showed significant differences across protocols. Conclusion Automated Drusen outlines produced by our method show promising accurate results that seem relatively stable in repeated scans using the same or different scanning protocols. Translational relevance The proposed method represents a viable tool to measure and track Drusen measurements in early or intermediate age-related macular degeneration patients.
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Automated Drusen segmentation and quantification in SD-OCT images
Medical image analysis, 2013Co-Authors: Qiang Chen, Luis De Sisternes, Theodore Leng, Luoluo Zheng, Lauren Kutzscher, Daniel L RubinAbstract:Spectral domain optical coherence tomography (SD-OCT) is a useful tool for the visualization of Drusen, a retinal abnormality seen in patients with age-related macular degeneration (AMD); however, objective assessment of Drusen is thwarted by the lack of a method to robustly quantify these lesions on serial OCT images. Here, we describe an automatic Drusen segmentation method for SD-OCT retinal images, which leverages a priori knowledge of normal retinal morphology and anatomical features. The highly reflective and locally connected pixels located below the retinal nerve fiber layer (RNFL) are used to generate a segmentation of the retinal pigment epithelium (RPE) layer. The observed and expected contours of the RPE layer are obtained by interpolating and fitting the shape of the segmented RPE layer, respectively. The areas located between the interpolated and fitted RPE shapes (which have nonzero area when Drusen occurs) are marked as Drusen. To enhance Drusen quantification, we also developed a novel method of retinal projection to generate an en face retinal image based on the RPE extraction, which improves the quality of Drusen visualization over the current approach to producing retinal projections from SD-OCT images based on a summed-voxel projection (SVP), and it provides a means of obtaining quantitative features of Drusen in the en face projection. Visualization of the segmented Drusen is refined through several post-processing steps, Drusen detection to eliminate false positive detections on consecutive slices, Drusen refinement on a projection view of Drusen, and Drusen smoothing. Experimental evaluation results demonstrate that our method is effective for Drusen segmentation. In a preliminary analysis of the potential clinical utility of our methods, quantitative Drusen measurements, such as area and volume, can be correlated with the Drusen progression in non-exudative AMD, suggesting that our approach may produce useful quantitative imaging biomarkers to follow this disease and predict patient outcome.
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Quantitative Evaluation of Drusen on Photographs
Ophthalmology, 2013Co-Authors: Daniel L Rubin, Luis De Sisternes, Qiang Chen, Theodore Leng, Lauren Kutzscher, Luoluo ZhengAbstract:Visualizing and tracking Drusen is important in managing age-related macular degeneration (AMD). Color fundus photography (CFP) is common in clinical practice, and but quantitative evaluation of Drusen in CFPs is difficult because of the varying background of macula, retinal pigment epithelium (RPE), and choroid.1 Spectral-domain optical coherence tomography (SD-OCT) provides high-resolution visualization of Drusen, and 2D projections resembling CFPs can be produced from SD-OCT using summed-voxel projection (SVP).2 Though SVP is a useful method for visualizing the fundus, most Drusen are not visible this way.2 Anything that produces high reflections along axial lines will produce bright areas in the SVP image and obscure Drusen (Figures 1A and 1B, yellow circles) (available at http://aaojournal.org). Thus, Drusen that are visible on B-scans may not be visible on the SVP image (Figure 1B and 1C, red circles) (available at http://aaojournal.org). Furthermore, Drusen produce distortions in the RPE layer, but do not substantially change the intensity sums in the image columns traversing the Drusen and remain invisible on SVP. Figure 1 Limitations in Drusen visualization in summed-voxel projection (SVP) fundus images. SVP fundus image (B) was derived from a 3D optical coherence tomography (OCT) dataset from a patient with non-exudative age-related macular degeneration. Two spectral-domain ... The “slab SVP” in a commercial SD-OCT system (Carl Zeiss Meditch, Inc., unpublished) and a similar methods3, 4 have improved the SVP; however, user interaction is required to localize the RPE, and the slab SVP provides no information about Drusen thickness, which could be useful for characterizing Drusen. We have developed a novel, fully automated approach, the restricted summed-voxel projection (RSVP), to generate improved visualizations of the retinal surface that incorporates image processing to enhance Drusen visualization. The RSVP has two steps: (1) restrict the projection to the sub-volume of OCT data in close proximity to the RPE, and (2) supplement the projection with image processing methods that enhance the brightness of Drusen. In the first step, the method detects and interpolates two contours in the RPE: (1) the abnormal contour of the upper boundary of the RPE which is distorted by Drusen, and (2) the expected normal (undistorted) lower contour that would be expected if Drusen were absent. The posterior boundary of the normal RPE layer is taken as the baseline of the projection region used for RSVP generation, while the top boundary of the projection region is determined by displacing the normal RPE layer anteriorly the same distance as the largest Drusen peak in the cube. All other structures in the retina that could interfere with visualization of Drusen are excluded (Figure 2) (available at http://aaojournal.org). Figure 2 Restricting the optical coherence tomography image data to the vicinity of the retinal pigment epithelium (RPE) layer for generating the restricted summed-voxel projection (RSVP). The bottom red curve is the baseline of the normal RPE layer. The top red ... In the second step, the method replaces the values of the pixels underneath distorted RPE with the maximum intensity value in each image column of the B-scan. (Figure 3) (available at http://aaojournal.org). Since the projection is based on the sum of the pixel values in each image column, the larger the height of the Drusen, the brighter the Drusen in the projection; thus, in addition to enhancing Drusen visualization, the method provides a visual indication of the thickness of Drusen. Figure 3 Filling of the projection region. Projection region (A) and filled projection region (B). Using 46 OCT datasets from eight patients, we found that the RSVP method was more effective than conventional SVP in displaying Drusen and retinal vessels (Figure 4) (available at http://aaojournal.org), and was more accurate in detecting Drusen in qualitative and quantitative evaluations. Qualitative evaluation was conducted by visual inspection of SVP and RSVP images, and comparing them with CFPs. Quantitative evaluation consisted of a comparison of Drusen detected by manual segmentation of the SVP and RSVP images in four eyes from three patients. Gold standards were obtained by manual segmentation of each of the b-scans in the cubes. They were performed twice by two separate readers. The results showed that while, on average, only 2.1% of Drusen could be detected from SVP images, 89.3% of Drusen were detected in RSVP images. Figure 4 Comparison of summed-voxel projection (SVP) (top) and restricted summed-voxel projection (RSVP) (bottom) in the right and left right eyes of a patient. Drusen poorly visualized or not apparent on the SVP are clearly shown in the RSVP, and the degree of ... Our method differs from prior approaches in that it is fully automated and it includes a highly restricted volume of the OCT in proximity to the RPE where Drusen reside; thus, Drusen visualization with a RSVP will be degraded less than current slab-like SVP methods. Furthermore, our method incorporates image processing to enhance Drusen. To date, the RSVP method is substantially more effective than current SVP methods for visualizing Drusen, and it may be useful to ophthalmologists in rapidly and quantitatively assessing Drusen in AMD patients.
