1. All Articles

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    1. Correlation between depth and area of retinal nerve fiber layer defect as measured by spectral domain optical coherence tomography

      Correlation between depth and area of retinal nerve fiber layer defect as measured by spectral domain optical coherence tomography

      Background To evaluate the correlation between the depth and area of retinal nerve fiber layer (RNFL) defect, as measured on an RNFL map of spectral-domain optical coherence tomography (SD-OCT). Methods The RNFL of 472 glaucoma subjects and of 217 healthy subjects was imaged by an SD-OCT. RNFL defect depth and area on the RNFL map were expressed as an RNFL defect depth percentage index (RDPI) and an RNFL defect area index (RDAI), respectively, according to the following two formulas: 100×[1–{summation of thicknesses of RNFL defects/summation of thicknesses of upper 95th percentile range of age-matched healthy subjects in ...

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    2. Anterior and Posterior Ocular Biometry in Healthy Chinese Subjects: Data Based on AS-OCT and SS-OCT

      Anterior and Posterior Ocular Biometry in Healthy Chinese Subjects: Data Based on AS-OCT and SS-OCT

      Background To measure the anterior and posterior ocular biometric characteristics concurrently and to determine the relationship between the iris and choroid in healthy Chinese subjects. Methods A total of 148 subjects (270 eyes) were enrolled in this cross-section study. The anterior and posterior ocular biometric characteristics were measured simultaneously by anterior segment optical coherence tomography (AS-OCT) and swept-source optical coherence tomography (SS-OCT). Results Compared with male eyes, female eyes had narrower anterior biometric parameters that presented with smaller anterior segment parameters [including anterior chamber depth (ACD), width (ACW), area (ACA), and volume (ACV); (all p<0.001)], narrower anterior chamber ...

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    3. Optical Coherence Tomography Opens a New Era in the Afferent Visual System Evaluation

      Optical Coherence Tomography Opens a New Era in the Afferent Visual System Evaluation

      For decades, thinning of the retinal nerve fiber layer in optic neuropathy could only be observed ophthalmoscopically or using red-free fundus photography. These days are over. Subsequently, different techniques to image the optic nerve and the retina have been developed. Optical coherence tomography (OCT) has gained the most attention and has opened a new area of revolutionary diagnostic possibilities. OCT is a noncontact diagnostic imaging technique that provides detailed, cross-sectional images of the retina and the optic disc in vivo. It was first used in 1991 to visualize the eye.[ 1 ] Image capture is noninvasive, painless, and fast. The technology ...

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    4. Ultrahigh-speed optical coherence tomography utilizing all-optical 40 MHz swept-source

      Ultrahigh-speed optical coherence tomography utilizing all-optical 40 MHz swept-source

      We present an ultrahigh-speed optical coherence tomography (OCT) based on an all-optical swept-source with an A-scan rate of 40 MHz. The inertia-free swept-source, which has its output power of 41.2 mW and tuning range of 40 nm and high scan linearity in wavenumber with Pearson’s correlation coefficients r of 0.9996, consists of a supercontinuum laser, an optical band-pass filter, a linearly chirped fiber Bragg grating, an erbium-doped fiber amplifier, and two buffer stages. With sensitivity of 87 dB, high-speed OCT imaging of biological tissue in vivo is also demonstrated.

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    5. Applications of Optical Coherence Tomography in Pediatric Clinical Neuroscience

      Applications of Optical Coherence Tomography in Pediatric Clinical Neuroscience

      For nearly two centuries, the ophthalmoscope has permitted examination of the retina and optic nerve—the only axons directly visualized by the physician. The retinal ganglion cells project their axons, which travel along the innermost retina to form the optic nerve, marking the beginning of the anterior visual pathway. Both the structure and function of the visual pathway are essential components of the neurologic examination as it can be involved in numerous acquired, congenital and genetic central nervous system conditions. The development of optical coherence tomography now permits the pediatric neuroscientist to visualize and quantify the optic nerve and retinal ...

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    6. Measuring the optical characteristics of medulloblastoma with optical coherence tomography

      Measuring the optical characteristics of medulloblastoma with optical coherence tomography

      Medulloblastoma is the most common malignant pediatric brain tumor. Standard treatment consists of surgical resection, followed by radiation and high-dose chemotherapy. Despite these efforts, recurrence is common, leading to reduced patient survival. Even with successful treatment, there are often severe long-term neurologic impacts on the developing nervous system. We present two quantitative techniques that use a high-resolution optical imaging modality: optical coherence tomography (OCT) to measure refractive index, and the optical attenuation coefficient. To the best of our knowledge, this study is the first to demonstrate OCT analysis of medulloblastoma. Refractive index and optical attenuation coefficient were able to differentiate ...

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    7. “How Does Breast Cancer Develop?” Pilot Grants Awarded to Multidisciplinary Teams Using the Intraductal Approach to Advance Breast Cancer Prevention

      “How Does Breast Cancer Develop?” Pilot Grants Awarded to Multidisciplinary Teams Using the Intraductal Approach to Advance Breast Cancer Prevention

      Dr. Sheldon Feldman and Dr. Fatih Balci study intraductal approaches to breast cancer. They are currently investigating the effectiveness of optical coherence tomography (OCT), which is used in cardiology to look at blood vessels from the inside using light instead of sound (as an ultrasound does) to create three-dimensional images. OCT may be able to identify early changes in the breast duct before ductal carcinoma in situ (DCIS) or cancer forms. This consortium received $17,000 to study whether it is feasible to use OCT to distinguish different types of breast cells and tissues and whether OCT can show features ...

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    8. Differential diagnosis of human bladder mucosa pathologies in vivo with cross-polarization optical coherence tomography

      Differential diagnosis of human bladder mucosa pathologies in vivo with cross-polarization optical coherence tomography

      Quantitative image analysis and parameter extraction using a specific implementation of polarization-sensitive optical coherence tomography (OCT) provides differential diagnosis of mucosal pathologies in in-vivo human bladders. We introduce a cross-polarization (CP) OCT image metric called Integral Depolarization Factor (IDF) to enable automatic diagnosis of bladder conditions (assessment the functional state of collagen fibers). IDF-based diagnostic accuracy of identification of the severe fibrosis of normal bladder mucosa is 79%; recurrence of carcinoma on the post-operative scar is 97%; and differentiation between neoplasia and acute inflammation is 75%. The promising potential of CP OCT combined with image analysis in human urology is ...

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    9. Quantitative microvascular hemoglobin mapping using visible light spectroscopic Optical Coherence Tomography

      Quantitative microvascular hemoglobin mapping using visible light spectroscopic Optical Coherence Tomography

      Quantification of chromophore concentrations in reflectance mode remains a major challenge for biomedical optics. Spectroscopic Optical Coherence Tomography (SOCT) provides depth-resolved spectroscopic information necessary for quantitative analysis of chromophores, like hemoglobin, but conventional SOCT analysis methods are applicable only to well-defined specular reflections, which may be absent in highly scattering biological tissue. Here, by fitting of the dynamic scattering signal spectrum in the OCT angiogram using a forward model of light propagation, we quantitatively determine hemoglobin concentrations directly. Importantly, this methodology enables mapping of both oxygen saturation and total hemoglobin concentration, or alternatively, oxyhemoglobin and deoxyhemoglobin concentration, simultaneously. Quantification was ...

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    10. In vivo molecular contrast OCT imaging of methylene blue

      In vivo molecular contrast OCT imaging of methylene blue

      An 830-nm spectral-domain optical coherence tomography (OCT) system with an integrated 663-nm diode pump laser has been developed to enable molecular contrast OCT imaging of methylene blue (MB), a common vital dye used clinically. The introduction of the 663-nm diode laser, which acts as the pump in this implementation of pump-probe OCT (PPOCT), represents a minor modification to an otherwise typical OCT system. A newly developed background subtraction technique completely removes all background from intensity noise at the pump modulation frequency, simplifying the interpretation of PPOCT images. These developments have enabled the first in vivo imaging of MB with PPOCT ...

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    11. Ex vivo investigations on the potential of optical coherence tomography (OCT) as a diagnostic tool for reproductive medicine in a bovine model

      Ex vivo investigations on the potential of optical coherence tomography (OCT) as a diagnostic tool for reproductive medicine in a bovine model

      Comparative visualization of ex vivo bovine testicular tissue by the Telesto TM microscopic optical coherence tomography system (left) and corresponding H&E staining (right). Routine infertility investigations in the male and female include imaging techniques such as ultrasonography and endoscopy (fertiloscopy). However, these techniques lack the resolution to localize vital sperm or to reveal detailed morphological analysis of the oviduct which is often the cause of infertility in females. Therefore we set out to evaluate the efficiency of optical coherence tomography (OCT) as a diagnostic imaging tool for micron-scale visualization of the male and female genital tract. Using the bovine ...

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    12. Spectral-Domain Optical Coherence Tomography Angiography of Choroidal Neovascularization

      Spectral-Domain Optical Coherence Tomography Angiography of Choroidal Neovascularization

      Purpose To describe the characteristics as well as the sensitivity and specificity of detection of choroidal neovascularization (CNV) on optical coherence tomography angiography (OCTA) using spectral-domain optical coherence tomography. Design Observational, retrospective study. Participants Seventy-two eyes of 61 subjects (48 eyes of 43 subjects with CNV, 24 eyes of 18 subjects without CNV). Methods Patients imaged using the prototype AngioVue OCTA system (Optovue, Inc, Fremont, CA) between August 2014 and October 2014 at New England Eye Center were assessed. Patients in whom CNV was identified on OCTA were evaluated to define characteristics of CNV on OCTA: size using greatest linear ...

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    13. Imaging of retinal vasculature using adaptive optics SLO/OCT

      Imaging of retinal vasculature using adaptive optics SLO/OCT

      We use our previously developed adaptive optics (AO) scanning laser ophthalmoscope (SLO)/ optical coherence tomography (OCT) instrument to investigate its capability for imaging retinal vasculature. The system records SLO and OCT images simultaneously with a pixel to pixel correspondence which allows a direct comparison between those imaging modalities. Different field of views ranging from 0.8°x0.8° up to 4°x4° are supported by the instrument. In addition a dynamic focus scheme was developed for the AO-SLO/OCT system in order to maintain the high transverse resolution throughout imaging depth. The active axial eye tracking that is implemented in ...

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    14. Macular Thickness Profiles of Intra-retinal Layers in Myopia Evaluated by Ultra-High Resolution Optical Coherence Tomography

      Macular Thickness Profiles of Intra-retinal Layers in Myopia Evaluated by Ultra-High Resolution Optical Coherence Tomography

      Purpose To investigate the thickness and variation profiles of eight intra-retinal layers in myopia. Design Prospective cross-sectional study. Methods Young subjects with spherical equivalents ranging from +0.50 to -10.25 diopters and good corrected vision were divided into emmetropic (n=20), low myopic (n=50), and high myopic (n=30) groups. Retinal images centered on the fovea along the horizontal and vertical meridians were obtained by ultra-high resolution optical coherence tomography (OCT). Macular images were segmented into eight intra-retinal layers by an automatic segmentation algorithm to yield thickness profiles within a 6-mm diameter circle divided into central, pericentral, and ...

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    15. Fujimoto receives the OSA Frederic Ives Medal

      Fujimoto receives the OSA Frederic Ives Medal

      The Optical Society (OSA) announced on March 1 the selection of Professor James G. Fujimoto as the recipient of the Frederic Ives Medal / Quinn Prize. He is recognized for pioneering the field of optical coherence tomography (OCT) and for his research group’s and collaborator’s contributions leading to its widespread medical application and major commercial impact. The Frederic Ives Medal is the highest award of the OSA and recognizes overall distinction in optics.

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    16. Choroidal involvement in Rosai-Dorfman syndrome may be depicted and followed using enhanced depth imaging optical coherence tomography (EDI-OCT)

      Choroidal involvement in Rosai-Dorfman syndrome may be depicted and followed using enhanced depth imaging optical coherence tomography (EDI-OCT)

      Dear Editor, We read with interest the recently published case report by Vermeulen et al. [ 1 ] regarding “Rosai–Dorfman disease presenting as choroidal melanoma”. We previously published a similar presentation of a patient that underwent systemic work-up for bilateral choroidal masses [ 2 ]. Our patient initially presented with minimal visual complaints and best-corrected visual acuity of 20/20 OU. Sub-papillomacular bundle, amelanotic choroidal masses OU were discovered on dilated fundus exam. Initial work-up demonstrated focal pigment epithelial detachment OD but overall intact outer retinal layers OU on spectral domain optical coherence tomography (SD-OCT). Unlike the case report by Vermeulen et al ...

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    17. Speckle reduction in optical coherence tomography by two-step image registration

      Speckle reduction in optical coherence tomography by two-step image registration

      The image quality of optical coherence tomography can be severely influenced by speckle noise (i.e., signal-degrading speckle). Averaging multiple B-scans can effectively suppress speckle noise. Because of sample motion, images subject to averaging must be aligned exactly. We propose a two-step image registration scheme that combines global and local registrations for speckle reduction by the averaging of multiple B-scans. The method begins with a global registration to compensate for overall motion, which is estimated based on the rigid transformation model involving translation and rotation. Then each A-scan is aligned by cross-correlation using a graph-based algorithm, followed by a pixel ...

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    18. The butler did it! A very late stent thrombosis of TAXUS evaluated with Optical Coherence Tomography

      The butler did it! A very late stent thrombosis of TAXUS evaluated with Optical Coherence Tomography

      A 64 years old male smoker, obese, diabetic non-insulin dependent, dyslipidaemia, presented to our Emergency Department for new onset typical chest pain and EKG signs of an acute anterior ST elevation myocardial infarction. He had an history of a percutaneous coronary interventions to his three vessels with stents TAXUS in 2006 when he presented with stable angina. He performed dual antiplatelet therapy (DAT) for six months, then he assumed aspirin alone.

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    19. Progress on developing wavefront sensorless adaptive optics optical coherence tomography for in vivo retinal imaging in mice

      Progress on developing wavefront sensorless adaptive optics optical coherence tomography for in vivo retinal imaging in mice

      We present a new design for a wavefront sensorless adaptive optics (WS-AO) Fourier domain optical coherence tomography (FD-OCT) system for small animal retinal imaging in vivo. Without the optical complications necessary for inclusion of a wavefront sensor in the optical system, this version of WS-AO FD-OCT system has a simplified optical design, including elimination of long focal length scanning optics and optical conjugation of vertical and horizontal scanners. This modification provides a modular large Field of View for retinal screening (25 degree visual angle), while also allowing a “zoom” capability for allocating all the scanning resources to a smaller region ...

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    20. Experimental Demonstration of Spectral Intensity Optical Coherence Tomography

      Experimental Demonstration of Spectral Intensity Optical Coherence Tomography

      We demonstrate experimentally quantum-inspired, spectral-domain intensity optical coherence tomography. We show that the technique allows for both axial resolution improvement and dispersion cancellation compared to conventional optical coherence tomography. The method does not involve scanning and it works with classical light sources and standard photodetectors. The measurements are in excellent agreement with the theoretical predictions. We also propose an approach that enables the elimination of potential artifacts arising from multiple interfaces

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    21. Optores Introduces OGOP – the Optores GPU OCT Processing Library

      Optores Introduces OGOP – the Optores GPU OCT Processing Library

      Optores proudly introduces OGOP – the Optores GPU OCT Processing library, an ultra-fast and highly reliable processing library for optical coherence tomography (OCT) data. Based on graphic-processing unit (GPU) optimized code, OGOP enables real-time OCT processing with sustained throughput of several gigabytes per second. The library can be licensed in editions with increasing feature sets and processing capabilities. It covers the whole OCT processing pipeline from raw data to image, and features future-proof cross-platform code. OGOP can been seen in action at Optores's new youtube channel . The video shows sustained and real-time volumetric OCT imaging with 20 entire volumes per ...

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    22. Time-resolved Biofilm Deformation Measurements using Optical Coherence Tomography

      Time-resolved Biofilm Deformation Measurements using Optical Coherence Tomography

      The interaction of shear stress with the biofilm leads to a dynamic deformation, which is related to the structural and material characteristics of biofilms. We show how optical coherence tomography can be used as an imaging technique to investigate the time-resolved deformation on the biofilm mesoscale as well as to estimate mechanical properties of the biofilm. For the first time time-resolved deformation from cross-sectional views of the inner biofilm structure could be shown. Changes in the biofilm structure and rheological properties were calculated from cross sections in real time and time-lapsed measurements. Heterotrophic biofilms were grown in a flow cell ...

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