1. Christoph K. Hitzenberger

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    1. Mentioned In 89 Articles

    2. Three-beam Doppler optical coherence tomography using a facet prism telescope and MEMS mirror for improved transversal resolution

      Three-beam Doppler optical coherence tomography using a facet prism telescope and MEMS mirror for improved transversal resolution

      An improved three-beam Doppler optical coherence tomography system was developed. It utilizes a custom-made three-facet prism telescope to improve the transversal resolution at the sample. Furthermore, a two-axis gimbal-less MEMS mirror is used to minimize off-pivot beam movement at the pupil of the eye, enabling circular scanning for in vivo retinal measurements. We demonstrate the system’s abilities for in vitro circular scanning to measure absolute flow and to reconstruct the full velocity vector on a bifurcation flow phantom. Moreover, in vivo retinal measurements using circular scanning around vessel bifurcations of healthy human volunteers were performed. Measurements of the absolute ...

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    3. Peripapillary rat sclera investigated in vivo with polarization sensitive optical coherence tomography

      Peripapillary rat sclera investigated in vivo with polarization sensitive optical coherence tomography

      Purpose: To demonstrate polarization sensitive (PS) optical coherence tomography (OCT) for non-invasive, volumetric, and quantitative imaging of the birefringent properties of the peripapillary rat sclera. To compare the findings in PS-OCT images to state-of-the-art histomorphometric analysis of the same tissues. Methods: A high-speed PS-OCT prototype operating at 840 nm was modified for imaging the rat eye. Densely sampled PS-OCT raster scans covering an area of ~1.5 mm × 1.5 mm centered at the papilla were acquired in the eyes of anesthetized, male Sprague Dawley rats. Cross-sectional PS-OCT images were computed and fundus maps displaying the birefringent properties of the ...

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    4. Single input state polarization sensitive swept source optical coherence tomography based on an all single mode fiber interferometer

      Single input state polarization sensitive swept source optical coherence tomography based on an all single mode fiber interferometer
      ...olfgang Trasischker,^* Stefan Zotter, Teresa Torzicky, Bernhard Baumann, Richard Haindl, Michael Pircher, and Christoph K. Hitzenberger ^Center for Medical Physics and Biomedical Engineering, Medical University of Vien...
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    5. RETINAL PIGMENT EPITHELIUM FINDINGS IN PATIENTS WITH ALBINISM USING WIDE-FIELD POLARIZATION-SENSITIVE OPTICAL COHERENCE TOMOGRAPHY

      RETINAL PIGMENT EPITHELIUM FINDINGS IN PATIENTS WITH ALBINISM USING WIDE-FIELD POLARIZATION-SENSITIVE OPTICAL COHERENCE TOMOGRAPHY

      Purpose: To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Methods: Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 x 40[degrees] on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation ...

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    6. Detection and Analysis of Hard Exudates by Polarization-Sensitive Optical Coherence Tomography in Patients with Diabetic Maculopathy

      Detection and Analysis of Hard Exudates by Polarization-Sensitive Optical Coherence Tomography in Patients with Diabetic Maculopathy

      Purpose: To image and analyze hard exudates (HE) and their precursors in patients with diabetic macular edema (DME) using polarization sensitive optical coherence tomography (PS-OCT). Methods: Twenty-two eyes of 16 patients with DME were imaged using color fundus photography (CF) and PS-OCT. In PS-OCT, HE were automatically detected based on their distinct polarization-scrambling qualities. CF images were manually graded for the presence of HE by two masked graders and correlated with the corresponding PS-OCT HE maps: corresponding images were overlaid and an identical grid of 128x128 fields was used for correlation of detected HE. Results: In all eyes, HE were ...

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    7. In vitro and in vivo three-dimensional velocity vector measurement by three-beam spectral-domain Doppler optical coherence tomography

      In vitro and in vivo three-dimensional velocity vector measurement by three-beam spectral-domain Doppler optical coherence tomography

      We developed a three-beam Doppler optical coherence tomography (OCT) system that enables measurement of the velocity vector of moving particles in three-dimensions (3-D). The spatial orientation as well as the magnitude of motion can be determined without prior knowledge of the geometry of motion. The system combines three spectral-domain OCT interferometers whose sample beams are focused at the sample by a common focusing lens at three different angles. This provides three spatially independent velocity components simultaneously from which the velocity vector can be reconstructed. We demonstrate the system in a simple test object (rotating disc), a flow phantom, and for ...

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    8. Characterization of Stargardt disease using polarisation-sensitive optical coherence tomography and fundus autofluorescence imaging

      Characterization of Stargardt disease using polarisation-sensitive optical coherence tomography and fundus autofluorescence imaging

      Purpose: To identify disease-specific changes in Stargardt disease (STGD) based on imaging with polarisation-sensitive spectral-domain optical coherence tomography (PS-OCT) and to compare structural changes to those visible on blue light fundus autofluorescence (FAF)imaging. Methods: 28 eyes of 14 patients diagnosed with STGD were imaged using a novel high-speed, large-field PS-OCT system and FAF (Heidelberg Retina Angiograph/Spectralis, Heidelberg Engineering, Germany; excitation 488nm, emission >500nm). The ophthalmoscopic phenotype was classified into 3 groups as suggested by Fishman et al. ABCA4 mutation testing detected 15 STGD alleles, 6 of which harbour novel mutations. Results: STGD phenotype 1 (12 eyes) showed sharply ...

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    9. Imaging Retinal Pigment Epithelial Proliferation Secondary to PASCAL Photocoagulation In Vivo by Polarization-sensitive Optical Coherence Tomography

      Imaging Retinal Pigment Epithelial Proliferation Secondary to PASCAL Photocoagulation In Vivo by Polarization-sensitive Optical Coherence Tomography
      ...eorgios Mylonas Affiliations + Department of Ophthalmology, Medical University of Vienna, Vienna, Austria , * Christoph K. Hitzenberger Affiliations + Center for Medical Physics and Biomedical Engineering, Medical Univer...
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    10. Retinal polarization-sensitive optical coherence tomography at 1060 nm with 350 kHz A-scan rate using an Fourier domain mode locked laser

      Retinal polarization-sensitive optical coherence tomography at 1060 nm with 350 kHz A-scan rate using an Fourier domain mode locked laser

      We present a novel, high-speed, polarization-sensitive, optical coherence tomography set-up for retinal imaging operating at a central wavelength of 1060 nm which was tested for in vivo imaging in healthy human volunteers. We use the system in combination with a Fourier domain mode locked laser with active spectral shaping which enables the use of forward and backward sweep in order to double the imaging speed without a buffering stage. With this approach and with a custom designed data acquisition system, we show polarization-sensitive imaging with an A-scan rate of 350 kHz. The acquired three-dimensional data sets of healthy human volunteers ...

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    11. Measuring Retinal Nerve Fiber Layer Birefringence, Retardation, and Thickness Using Wide-Field, High-Speed Polarization Sensitive Spectral Domain OCT

      Measuring Retinal Nerve Fiber Layer Birefringence, Retardation, and Thickness Using Wide-Field, High-Speed Polarization Sensitive Spectral Domain OCT
      ... Hirose^2, 7. Stephan Holzer^3, 8. Julia Kroisamer^3, 9. Clemens Vass^3, 10. Ursula Schmidt-Erfurth^3 and 11. Christoph K. Hitzenberger^1 1. From the ^1Center for Medical Physics and Biomedical Engineering, Medical Unive...
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    12. Lesion Size Detection in Geographic Atrophy by Polarization-sensitive Optical Coherence Tomography and Correlation to Conventional Imaging Techniques

      Lesion Size Detection in Geographic Atrophy by Polarization-sensitive Optical Coherence Tomography and Correlation to Conventional Imaging Techniques

      Purpose: To investigate the reproducibility of automated lesion size detection in patients with geographic atrophy (GA) using polarization-sensitive spectral domain-OCT (PS-OCT) and to compare findings with scanning laser ophthalmoscopy (SLO), fundus autofluorescence (FAF), and intensity based SD-OCT. Methods: 29 eyes of 22 patients with GA were examined by PS-OCT, selectively identifying the retinal pigment epithelium (RPE). A novel segmentation algorithm was applied, automatically detecting and quantifying areas of RPE atrophy. The reproducibility of the algorithm was assessed and lesion sizes were correlated with manually delineated SLO, FAF and intensity based SD-OCT images to validate the clinical applicability of PS-OCT in ...

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    13. High-speed polarization sensitive optical coherence tomography scan engine based on Fourier domain mode locked laser

      High-speed polarization sensitive optical coherence tomography scan engine based on Fourier domain mode locked laser

      We report on a new swept source polarization sensitive optical coherence tomography scan engine that is based on polarization maintaining (PM) fiber technology. The light source is a Fourier domain mode locked laser with a PM cavity that operates in the 1300 nm wavelength regime. It is equipped with a PM buffer stage that doubles the fundamental sweep frequency of 54.5 kHz. The fiberization allows coupling of the scan engine to different delivery probes. In a first demonstration, we use the system for imaging human skin at an A-scan rate of 109 kHz. The system illuminates the sample with ...

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    14. 1-15 of 89 1 2 3 4 5 6 »
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  2. About Christoph K. Hitzenberger

    Christoph K. Hitzenberger

    Christoph K. Hitzenberger is Professor of Medical Physics and faculty member at the Center for Medical Physics and Biomedical Engineering, Medical University of Vienna. He is one of the pioneers of OCT, working in this field since 1987. Among his major contributions to OCT and related techniques are ocular biometry by low coherence interferometry (since 1989), the first in vivo retinal OCT tomogram (1993), spectral domain OCT (since 1995), and polarization sensitive OCT in the human eye (since 2004).