All Articles from Sina Farsiu -Optical Coherence Tomography News

Articles from Sina Farsiu

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1. Choroid Development and Feasibility of Choroidal Imaging in the Preterm and Term Infants Utilizing SD-OCT
  
  Explore iovs.org Jun 18 2013 Ophthalmology
  
  Purpose. To determine whether choroidal imaging is feasible in preterm and term infants using an 840-nm portable spectral domain optical coherence tomography (SD-OCT) system without the use of enhanced-depth imaging techniques and to assess choroidal development by comparing choroidal thickness of preterm infants, term infants, and adults. Methods. SD-OCT images were obtained from 86 preterm infants, 59 term infants, and nine adults using a portable SD-OCT system plus nine adults using a tabletop system. An unprocessed image across the macula from one randomly selected eye of each participant was selected for determination of whether the choroidal-scleral junction (CSJ) could be ...
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  Mentions: Duke University Sharon F. Freedman Cynthia A. Toth
2. Automated non-rigid registration and mosaicing for robust imaging of distinct retinal capillary beds using speckle variance optical coherence tomography
  
  Explore opticsinfobase.org May 11 2013 Ophthalmology
  
  Variance processing methods in Fourier domain optical coherence tomography (FD-OCT) have enabled depth-resolved visualization of the capillary beds in the retina due to the development of imaging systems capable of acquiring A-scan data in the 100 kHz regime. However, acquisition of volumetric variance data sets still requires several seconds of acquisition time, even with high speed systems. Movement of the subject during this time span is sufficient to corrupt visualization of the vasculature. We demonstrate a method to eliminate motion artifacts in speckle variance FD-OCT images of the retinal vasculature by creating a composite image from multiple volumes of data ...
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  Mentions: Joseph A. Izatt Duke University Sina Farsiu
3. Correction of Ocular Shape in Retinal Optical Coherence Tomography and Effect on Current Clinical Measures
  
  Explore American Journal of Ophthalmology May 11 2013 Ophthalmology
  
  Purpose To address the misrepresentation of the eye in retinal optical coherence tomography (OCT) images and to examine the effect of this misrepresentation on retinal thickness measurements. Design Prospective case series. Methods Five subjects with recent orbital magnetic resonance imaging (MRI) scans and normal eye examinations were consented from the clinics of the Duke Eye Center. Each subject had both eyes imaged using a retinal spectral-domain OCT system and ocular biometry measured. Two types of individualized optical models of the subject eyes—numerical and analytical—were used to determine the spatial paths of the OCT A-scans. These paths were used ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
4. Choroid Development and Feasibility of Choroidal Imaging in the Preterm and Term Infants Utilizing SDOCT
  
  Explore iovs.org May 9 2013 Ophthalmology
  
  Purpose: To determine whether choroidal imaging is feasible in preterm and term infants using an 840-nm portable spectral domain optical coherence tomography (SDOCT) system without the use of enhanced- depth imaging techniques and to assess choroidal development by comparing choroidal thickness of preterm infants, term infants, and adults. Methods: SDOCT images were obtained from 86 preterm infants, 59 term infants and 9 adults using a portable SDOCT (Bioptigen, Inc., NC, USA) system plus 9 adults using a tabletop system. An unprocessed image across the macula from one randomly selected eye of each participant was selected for determination of whether the ...
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  Mentions: Duke University Sharon F. Freedman Cynthia A. Toth
5. Photoreceptor and Choroid Development Assessed with Handheld SD-OCT
  
  Explore Journal of Vision Dec 27 2012 Ophthalmology
  
  Objective: Optical coherence tomography (OCT) allows examination of the human retina. While conventional OCT devices are limited mainly to adults, the availability of a handheld system has expanded the use of this technique to pediatric populations, with the primary clinical applications being shaken baby syndrome and retinopathy of prematurity. We sought to apply OCT imaging to neonatal population to assess retinal development. Methods: Subjects imaged at the Duke Neonatal Intensive Care Unit (NICU) and Duke Birthing Center. Subjects were imaged with a Bioptigen Hand Held Probe SD-OCT (HHP-SDOCT) (Bioptigen, Research Triangle Park, NC, USA). For this study, only "normal" subjects ...
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  Mentions: Duke University Cynthia A. Toth Bioptigen
6. Visualization of Real-Time Intraoperative Maneuvers with a Microscope-Mounted Spectral Domain Optical Coherence Tomography System
  
  Explore LWW Online Nov 30 2012 Ophthalmology
  
  The advent of optical coherence tomography (OCT) has revolutionized our diagnostic and therapeutic capabilities in ophthalmology and vitroretinal disease. In the clinic setting, OCT has touch nearly every aspect of vitreoretinal disease. More recently, OCT has been introduced into the operating room theater. Intraoperative OCT (iOCT) has been uses successfully...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
7. Post-Doc Job Offer in Clinical Applications of Image Processing at Duke University
  
  Explore Optical Coherence Tomography News Oct 8 2012 Jobs & Studentships
  
  There is an immediate opening in the Vision and Image Processing (VIP) Laboratory at Duke University ( http://www.duke.edu/~sf59 ) for a Postdoctoral Research Associate interested in interdisciplinary applications of image processing with emphasis on Optical Coherence Tomography (OCT) and adaptive optics. Post-doc will be supervised by Prof. Sina Farsiu in collaboration with Prof. Joseph A. Izatt and other senior professors from Duke University Electrical and Computer Engineering Department, Biomedical Engineering Department and Duke University School of Medicine. Requirement: PhD in EE, BME, or CS. No previous experience in ophthalmic sciences or optical coherence tomography is necessary. The candidate ...
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  Mentions: Joseph A. Izatt National Institutes of Health Duke University
8. Maturation of the Human Fovea: Correlation of Spectral-Domain Optical Coherence Tomography Findings With Histology
  
  Explore American Journal of Ophthalmology Aug 18 2012 Ophthalmology
  
  Purpose To correlate human foveal development visualized by spectral-domain optical coherence tomography (SDOCT) with histologic specimens. Design Retrospective, observational case series. Methods Morphology and layer thickness of retinal SDOCT images from 1 eye each of 22 premature infants, 30 term infants, 16 children, and 1 adult without macular disease were compared to light microscopic histology from comparable ages. Results SDOCT images correlate with major histologic findings at all time points. With both methods, preterm infants demonstrate a shallow foveal pit indenting inner retinal layers (IRL) and short, undeveloped foveal photoreceptors. At term, further IRL displacement forms the pit and peripheral ...
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  Mentions: Duke University Cynthia A. Toth University of Washington
9. Distributed scanning volumetric SDOCT for motion corrected corneal biometry
  
  Explore opticsinfobase.org Aug 10 2012 Ophthalmology
  
  We present a method, termed distributed scanning OCT (DSOCT), which reduces the effects of patient motion on corneal biometry utilizing current-generation clinically available spectral domain optical coherence tomography (SDOCT) systems. We first performed a pilot study of the power spectrum of normal patient axial eye motion based on repeated (M-mode) SDOCT. Using DSOCT to reduce the effects of patient motion, we conducted a preliminary patient study comparing the measured anterior and posterior corneal curvatures and the calculated corneal power to both corneal topography and Scheimpflug photography in normal subjects. The repeatability for the measured radius of curvature of both anterior ...
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  Mentions: Joseph A. Izatt Duke University Sina Farsiu
10. Imaging And Visualization Systems, Instruments, And Methods Using Optical Coherence Tomography
  
  Explore patentscope.wipo.int Jul 26 2012 Patents
  
  Imaging and visualization systems, instruments, and methods using optical coherence tomography (OCT) are disclosed. A method for OCT image capture includes determining a location of a feature of interest within an operative field. The method also includes determining a relative positioning between the feature of interest and an OCT scan location. Further, the method includes controlling capture of an OCT image at a set position relative to the feature of interest based on the relative positioning.
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
11. Feature Of The Week 6/24/12: Duke University Researchers Develop Techniques for Denoising OCT Images And Publically Share Their Software
  
  Explore Optical Coherence Tomography News Jun 24 2012
  
  Duke University researchers have a long history of major advances to the field of Optical Coherence Tomography dating back to some of the first OCT work in the very early 1990s by Dr. Joseph Izatt. Since the OCT News website started in 2007 Duke has published over 217 papers that appear on OCT News (Link). One recent example of their work was on “Sparsity Based Denoising of Spectral Domain Optical Coherence Tomography Images”. Below is a summary of this interesting work and along with a link to software they have developed and made publically available. -Eric SwansonIn this work, we ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
12. Spatial correlation between hyperpigmentary changes on color fundus photography and hyperreflective foci on SDOCT in intermediate AMD
  
  Explore iovs.org May 16 2012 Ophthalmology
  
  Purpose: Macular hyperpigmentation is associated with progression from intermediate to advanced age-related macular degeneration (AMD). The purpose of this study was to accurately correlate hyperpigmentary changes with spectral domain optical coherence tomography (SDOCT) hyperreflective foci in eyes with non-advanced AMD. Methods: A prospective cross-sectional analysis of 314 eyes (314 subjects) with intermediate AMD was performed in the multicenter AREDS2 Ancillary SDOCT Study to correlate hyperpigmentary changes on color fundus photographs (CFP) with abnormal morphology on SDOCT. Spatial coregistration was performed with an automated algorithm in 2 non-overlapping subsets of 20 study eyes with double-masked CFP and SDOCT grading by certified ...
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  Mentions: National Institutes of Health Duke University Cleveland Clinic
13. Corneal biometry from volumetric SDOCT and comparison with existing clinical modalities
  
  Explore opticsinfobase.org May 8 2012 Ophthalmology
  
  We present a comparison of corneal biometric values from dense volumetric spectral domain optical coherence tomography (SDOCT) scans to reference values in both phantoms and clinical subjects. We also present a new optically based “keratometric equivalent power” formula for SDOCT that eliminates previously described discrepancies between corneal power form SDOCT and existing clinical modalities. Phantom objects of varying radii of curvature and corneas of normal subjects were imaged with a clinical SDOCT system. The optically corrected three-dimensional surfaces were used to recover radii of curvature and power as appropriate. These were then compared to the manufacturer’s reference values in ...
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  Mentions: Joseph A. Izatt Duke University Sina Farsiu
14. Automatic segmentation of closed-contour features in ophthalmic images using graph theory and dynamic programming
  
  Explore opticsinfobase.org Apr 26 2012 Ophthalmology
  
  This paper presents a generalized framework for segmenting closed-contour anatomical and pathological features using graph theory and dynamic programming (GTDP). More specifically, the GTDP method previously developed for quantifying retinal and corneal layer thicknesses is extended to segment objects such as cells and cysts. The presented technique relies on a transform that maps closed-contour features in the Cartesian domain into lines in the quasi-polar domain. The features of interest are then segmented as layers via GTDP. Application of this method to segment closed-contour features in several ophthalmic image types is shown. Quantitative validation experiments for retinal pigmented epithelium cell segmentation ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
15. Sparsity based denoising of spectral domain optical coherence tomography images
  
  Explore opticsinfobase.org Apr 12 2012
  
  In this paper, we make contact with the field of compressive sensing and present a development and generalization of tools and results for reconstructing irregularly sampled tomographic data. In particular, we focus on denoising Spectral-Domain Optical Coherence Tomography (SDOCT) volumetric data. We take advantage of customized scanning patterns, in which, a selected number of B-scans are imaged at higher signal-to-noise ratio (SNR). We learn a sparse representation dictionary for each of these high-SNR images, and utilize such dictionaries to denoise the low-SNR B-scans. We name this method multiscale sparsity based tomographic denoising (MSBTD). We show the qualitative and quantitative superiority ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
16. Image inversion spectral-domain optical coherence tomography optimizes choroidal thickness and detail through improved contrast
  
  Explore iovs.org Mar 13 2012 Ophthalmology
  
  Purpose: To determine whether there were significant differences in choroidal thickness, contrast, outer choroidal vessel (OCV) and choroidal-scleral junction (CSJ) visualization in inverted versus upright spectral-domain optical coherence tomography (SD-OCT). Methods: Images were captured on Bioptigen SD-OCT (Bioptigen Inc., Research Triangle Park, North Carolina), Zeiss Cirrus HD-OCT (Carl Zeiss Meditec Inc, Dublin, CA), and Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) in 42 eyes of 21 healthy subjects. Average choroidal thickness across a fovea-centered 4 mm segment was determined with MATLAB. Quantitative measures of choroidal contrast were measured and CSJ assessed by applying a 0-3 score. OCV was determined by counting ...
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  Mentions: Heidelberg Engineering Duke University Cynthia A. Toth
17. Subfoveal fluid in healthy full-term newborns observed by handheld spectral domain optical coherence tomography
  
  Explore Elsevier Health Sciences Periodicals Jan 31 2012 Ophthalmology
  
  Handheld spectral domain optical coherence tomography (SD-OCT) is well tolerated by awake children and infants, and is more sensitive than clinical examination in detecting macular pathology. A recent
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  Mentions: Duke University Sharon F. Freedman Cynthia A. Toth
18. Spectral-Domain Optical Coherence Tomographic Assessment of Severity of Cystoid Macular Edema in Retinopathy of Prematurity
  
  Explore Archives of Ophthalmology Jan 9 2012 Ophthalmology
  
  Objective To investigate whether the severity of cystoid macular edema (CME) in neonates who were 31 to 36 weeks' postmenstrual age, as viewed by spectral-domain optical coherence tomography (SD-OCT) imaging, predicts the severity of retinopathy of prematurity (ROP) or is related to systemic health. Design Of 62 prematurely born neonates in a prospective institutional review board–approved study, 42 met the following inclusion criteria: at least 1 SD-OCT imaging session prior to 37 weeks' postmenstrual age and prior to ROP laser treatment, if a laser treatment was performed, and an ophthalmic ROP examination at or after 41 weeks' postmenstrual age ...
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  Mentions: Duke University Sharon F. Freedman Cynthia A. Toth
19. Validated Automatic Segmentation of AMD Pathology Including Drusen and Geographic Atrophy in SD-OCT Images
  
  Explore iovs.org Jan 8 2012 Ophthalmology
  
  Purpose. To automatically segment retinal spectral domain optical coherence tomography (SD-OCT) images of eyes with age-related macular degeneration (AMD) and various levels of image quality to advance the study of retinal pigment epithelium (RPE)+drusen complex (RPEDC) volume changes indicative of AMD progression. Methods. A general segmentation framework based on graph theory and dynamic programming was used to segment three retinal boundaries in SD-OCT images of eyes with drusen and geographic atrophy (GA). A validation study for eyes with nonneovascular AMD was conducted, forming subgroups based on scan quality and presence of GA. To test for accuracy, the layer thickness ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
20. Analysis of Pars Plana Vitrectomy for Optic Pit-Related Maculopathy With Intraoperative Optical Coherence Tomography: A Possible Connection With the Vitreous Cavity: A Possible Connection With the Vitreous Cavity
  
  Explore Archives of Ophthalmology Nov 14 2011 Ophthalmology
  
  Optimal management of optic pit–related maculopathy remains to be determined. The fluid source for the maculopathy also remains controversial. In this article, we present a unique surgical technique for internal drainage of the intraretinal fluid and describe the intraoperative use of spectral-domain optical coherence tomography to assist in the surgical management of this condition. Pars plana vitrectomy was performed with elevation of the posterior hyaloid. Following an air-fluid exchange, aspiration over the optic nerve pit was performed. Following aspiration, intraoperative spectral-domain optical coherence tomography demonstrated collapse of the retinoschisis, strongly suggesting a connection between the vitreous cavity and the ...
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  Mentions: Duke University Cynthia A. Toth Sina Farsiu
21. Validated Automatic Segmentation of AMD Pathology including Drusen and Geographic Atrophy in SDOCT Images
  
  Explore iovs.org Oct 30 2011 Ophthalmology
  
  Purpose. To automatically segment retinal spectral domain optical coherence tomography (SDOCT) images of eyes with age-related macular degeneration (AMD) pathology and varying image quality to advance the study of retinal pigment epithelium (RPE) + drusen complex (RPEDC) volume changes indicative of AMD progression. Methods. We utilized our general segmentation framework based on graph theory and dynamic programming to segment three retinal boundaries in SDOCT images of eyes with drusen and geographic atrophy (GA). We conducted a validation study for eyes with non-neovascular AMD, forming subgroups based on scan quality and presence of GA. To test for accuracy, the layer thickness results ...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
22. Dynamics of Human Foveal Development after Premature Birth
  
  Explore OphSource Sep 20 2011 Ophthalmology
  
  Purpose: To determine the dynamic morphologic development of the human fovea in vivo using portable spectral domain-optical coherence tomography (SD-OCT).Design: Prospective, observational case series.Paticipants: Thirty-one prematurely born neonates, 9 children, and 9 adults.Methods: Sixty-two neonates were enrolled in this study. After examination for retinopathy of prematurity (ROP), SD-OCT imaging was performed at the bedside in nonsedated infants aged 31 to 41 weeks postmenstrual age (PMA) (= gestational age in weeks + chronologic age) and at outpatient follow-up ophthalmic examinations. Thirty-one neonates met eligibility criteria. Nine children and nine adults without ocular pathology served as control groups. Semiautomatic retinal layer ...
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  Mentions: Joseph A. Izatt Duke University Sharon F. Freedman
23. Subfoveal Fluid in Healthy Full-term Newborns Observed by Handheld Spectral-Domain Optical Coherence Tomography
  
  Explore American Journal of Ophthalmology Sep 18 2011 Ophthalmology
  
  Purpose: To report retinal findings for healthy newborn infants imaged with handheld spectral-domain optical coherence tomography (SD OCT). Design: Prospective, observational case series. Methods: Thirty-nine full-term newborn infants underwent dilated retinal examinations by indirect ophthalmoscopy and retinal imaging by handheld SD OCT, without sedation, at the Duke Birthing Center. Results: Of the 39 infants imaged, 44% (17/39) were male. Race and ethnicity composition was 56% white, 38% black, 3% Asian, and 3% Hispanic. Median gestational age was 39 weeks (range, 36 to 41 weeks). Six (15%) of the 39 infants had bilateral subfoveal fluid on SD OCT not seen ...
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  Mentions: Duke University Sharon F. Freedman Cynthia A. Toth
24. Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming
  
  Explore opticsinfobase.org May 12 2011 Ophthalmology
  
  Segmentation of anatomical structures in corneal images is crucial for the diagnosis and study of anterior segment diseases. However, manual segmentation is a time-consuming and subjective process. This paper presents an automatic approach for segmenting corneal layer boundaries in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Our approach is robust to the low-SNR and different artifact types that can appear in clinical corneal images. We show that our method segments three corneal layer boundaries in normal adult eyes more accurately compared to an expert grader than a second grader—even in the presence of significant ...
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  Mentions: Joseph A. Izatt Duke University Sina Farsiu
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