1. Robert J. Zawadzki

    0 Comments Leave a Comment

    1-15 of 98 1 2 3 4 5 6 7 »

    1. Mentioned In 98 Articles

    2. Functional retinal imaging using adaptive optics swept-source OCT at 1.6MHz

      Explore bioRxiv.org Ophthalmology
      Functional retinal imaging using adaptive optics swept-source OCT at 1.6MHz
      bjective optical assessment of photoreceptor function may permit earlier diagnosis of retinal disease than current methods such as perimetry, electrophysiology, and clinical imaging. In this work, we describe an adaptive optics (AO) optical coherence tomography (OCT) system designed to measure functional responses of single cones to visible stimuli. The OCT subsystem consisted of a raster-scanning Fourier-domain mode-locked laser that acquires A-scans at 1.64MHz with a center wavelength of 1063nm ...
      Read Full Article
      Mentions: John S. Werner Robert J. Zawadzki UCSD

    3. Investigation of the effect of directional (off-axis) illumination on the reflectivity of retina layers in mice using swept-source optical coherence tomography

      Explore SPIE Digital Library Ophthalmology
      Investigation of the effect of directional (off-axis) illumination on the reflectivity of retina layers in mice using swept-source optical coherence tomography
      Changes in visibility of the Henle fiber layer and photoreceptor bands of the human retina with illumination directionality have been reported in OCT clinical imaging. These are a direct consequence of the changes in back scattering due to fibrous tissue orientation and to waveguiding properties of the photoreceptors respectively. Here we report the preliminary results of a study on the effects of retinal images acquired with OCT of illumination directionality ...
      Read Full Article
      Mentions: UC Davis Robert J. Zawadzki Marinko V. Sarunic

    4. Adaptive optics with combined optical coherence tomography and scanning laser ophthalmoscopy for in vivo mouse retina imaging

      Explore SPIE Digital Library Ophthalmology
      Adaptive optics with combined optical coherence tomography and scanning laser ophthalmoscopy for in vivo mouse retina imaging
      Optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) are two state-of-the-art imaging technologies commonly used to study retina. Adaptive Optics (AO) methodologies enable high-fidelity correction of ocular aberrations, resulting in improved resolution and sensitivity for both SLO and OCT systems. Here we present work integrating OCT into a previously described mouse retinal AO-SLO system, allowing simultaneous reflectance and fluorescence imaging. The new system allows simultaneous data acquisition of AO-SLO ...
      Read Full Article
      Mentions: UC Davis Robert J. Zawadzki Marinko V. Sarunic

    5. Volumetric imaging of rod and cone photoreceptor structure with a combined adaptive optics-optical coherence tomography-scanning laser ophthalmoscope

      Explore SPIE Digital Library Ophthalmology
      Volumetric imaging of rod and cone photoreceptor structure with a combined adaptive optics-optical coherence tomography-scanning laser ophthalmoscope
      We have designed and implemented a dual-mode adaptive optics (AO) imaging system that combines spectral domain optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) for in vivo imaging of the human retina. The system simultaneously acquires SLO frames and OCT B-scans at 60 Hz with an OCT volume acquisition time of 4.2 s. Transverse eye motion measured from the SLO is used to register the OCT B-scans to ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    6. The Properties of Outer Retinal Band Three Investigated With Adaptive-Optics Optical Coherence Tomography

      Explore IOVS Journal Ophthalmology
      The Properties of Outer Retinal Band Three Investigated With Adaptive-Optics Optical Coherence Tomography
      Purpose : Optical coherence tomography's (OCT) third outer retinal band has been attributed to the zone of interdigitation between RPE cells and cone outer segments. The purpose of this paper is to investigate the structure of this band with adaptive optics (AO)-OCT. Methods : Using AO-OCT, images were obtained from two subjects. Axial structure was characterized by measuring band 3 thickness and separation between bands 2 and 3 in segmented ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    7. In vivo optophysiology reveals that G-protein activation triggers osmotic swelling and increased light scattering of rod photoreceptors

      Explore pnas.org Ophthalmology
      In vivo optophysiology reveals that G-protein activation triggers osmotic swelling and increased light scattering of rod photoreceptors
      The light responses of rod and cone photoreceptors have been studied electrophysiologically for decades, largely with ex vivo approaches that disrupt the photoreceptors subretinal microenvironment. Here we report the use of optical coherence tomography (OCT) to measure light-driven signals of rod photoreceptors in vivo. Visible light stimulation over a 200-fold intensity range caused correlated rod outer segment (OS) elongation and increased light scattering in wild-type mice, but not in mice ...
      Read Full Article
      Mentions: University of Rochester UC Davis Robert J. Zawadzki

    8. Imaging of the human choroid with a 1.7 MHz A-scan rate FDML swept source OCT system

      Explore Conference Proceedings
      Imaging of the human choroid with a 1.7 MHz A-scan rate FDML swept source OCT system
      We demonstrate OCT angiography (OCTA) and Doppler OCT imaging of the choroid in the eyes of two healthy volunteers and in a geographic atrophy case. We show that visualization of specific choroidal layers requires selection of appropriate OCTA methods. We investigate how imaging speed, B-scan averaging and scanning density influence visualization of various choroidal vessels. We introduce spatial power spectrum analysis of OCT en face angiographic projections as a method ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    10. A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future

      Explore IOVS Journal Ophthalmology
      A Review of Adaptive Optics Optical Coherence Tomography: Technical Advances, Scientific Applications, and the Future
      Purpose : Optical coherence tomography (OCT) has enabled virtual biopsy of the living human retina, revolutionizing both basic retina research and clinical practice over the past 25 years. For most of those years, in parallel, adaptive optics (AO) has been used to improve the transverse resolution of ophthalmoscopes to foster in vivo study of the retina at the microscopic level. Here, we review work done over the last 15 years to ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    11. Lens-based wavefront sensorless adaptive optics swept source OCT

      Explore Nature Publishing Group
      Lens-based wavefront sensorless adaptive optics swept source OCT
      Optical coherence tomography (OCT) has revolutionized modern ophthalmology, providing depth resolved images of the retinal layers in a system that is suited to a clinical environment. Although the axial resolution of OCT system, which is a function of the light source bandwidth, is sufficient to resolve retinal features at a micrometer scale, the lateral resolution is dependent on the delivery optics and is limited by ocular aberrations. Through the combination ...
      Read Full Article
      Mentions: UC Davis Robert J. Zawadzki Marinko V. Sarunic

    12. Phase-Variance Optical Coherence Tomographic Angiography Imaging of Choroidal Perfusion Changes Associated With Acute Posterior Multifocal Placoid Pigment Epitheliopathy

      Explore JAMA Network Ophthalmology
      Phase-Variance Optical Coherence Tomographic Angiography Imaging of Choroidal Perfusion Changes Associated With Acute Posterior Multifocal Placoid Pigment Epitheliopathy
      This case report uses phase-variance optical coherence tomographic angiography to demonstrate transient inner choroidal flow changes associated with acute posterior multifocal placoid pigment epitheliopathy. Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is characterized by bilateral multiple placoid white-gray lesions of the posterior pole at the level of the retinal pigment epithelium (RPE) and/or choriocapillaris, which self-resolve with recovery of vision. 1 , 2 The etiology is unknown, but APMPPE has ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    13. Post-Doc Position for Biomedical Engineer / Vision Scientist in the UC Davis EyePod - Small Animal Retinal Imaging Laboratory at University of California, Davis

      Explore Optical Coherence Tomography News Jobs & Studentships
      Post-Doc Position for Biomedical Engineer / Vision Scientist in the UC Davis EyePod - Small Animal Retinal Imaging Laboratory at University of California, Davis
      ...te on existing projects while pursuing a path toward an independent career. Postdoc will be supervised by Dr. Robert J. Zawadzki in collaboration with Prof. Edward N. Pugh Jr. The laboratory has close affiliations with t...
      Read Full Article
      Mentions: UC Davis Robert J. Zawadzki

    14. Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid

      Explore OSA | OSA Publishing Ophthalmology
      Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid
      We compared the performance of three OCT angiography (OCTA) methods: speckle variance, amplitude decorrelation and phase variance for imaging of the human retina and choroid. Two averaging methods, split spectrum and volume averaging, were compared to assess the quality of the OCTA vascular images. All data were acquired using a swept-source OCT system at 1040 nm central wavelength, operating at 100,000 A-scans/s. We performed a quantitative comparison using ...
      Read Full Article
      Mentions: John S. Werner UC Davis Robert J. Zawadzki

    16. In vivo wide-field multispectral scanning laser ophthalmoscopy–optical coherence tomography mouse retinal imager: longitudinal imaging of ganglion cells, microglia, and Müller glia, and mapping of the mouse retinal and choroidal vasculature

      Explore SPIE | Journal Ophthalmology
      In vivo wide-field multispectral scanning laser ophthalmoscopy–optical coherence tomography mouse retinal imager: longitudinal imaging of ganglion cells, microglia, and Müller glia, and mapping of the mouse retinal and choroidal vasculature
      Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) provide complementary views of the retina, with the former collecting fluorescence data with good lateral but relatively low-axial resolution, and the latter collecting label-free backscattering data with comparable lateral but much higher axial resolution. To take maximal advantage of the information of both modalities in mouse retinal imaging, we have constructed a compact, four-channel, wide-field ( 50 deg ) system that simultaneously acquires ...
      Read Full Article
      Mentions: UC Davis Robert J. Zawadzki Marinko V. Sarunic
    17. 1-15 of 98 1 2 3 4 5 6 7 »
  1. Search:

  2. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology

    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents

    3. Technology:

      Broadband Sources, Probes, Tunable Sources

    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks

  4. About Robert J. Zawadzki

    Robert J. Zawadzki

    Robert J. Zawadzki (b.1975) received his MSc in Medical Physics from Nicholas Copernicus University (NCU), Torun, Poland under Prof. Andrzej Kowalczyk  supervision. He received his PhD in natural sciences from Technical University of Vienna, Vienna, Austria based on his work in the field of OCT at Medical Physics Institute, University of Vienna under Prof. Adolf F. Fercher supervision.

    Presently he has a faculty position of assistant professional research in Dept. of Ophthalmology and Vision Science at University of California Davis, Sacramento, CA USA and works together with Prof. John S. Werner in his Vision Science and Advanced Retinal Imaging Laboratory. His research interest includes development and application of novel instrumentation for high resolution in-vivo retinal imaging. This includes Adaptive Optics (AO), Optical Coherence Tomography (OCT), Scanning Laser Ophthalmoscopy (SLO) and its combination.

  5. Related Topics

    1. Simultaneous imaging of human cone mosaic with adaptive optics enhanced scanning laser ophthalmoscopy and high-speed transversal scanning optical coherence tomography
      89 articles also mentioned UC Davis
    2. Evaluation of complex conjugate artifact removal methods used in spectrometer-based Fourier-domain optical coherence tomography systems - a comparative study
      22 articles also mentioned Dae Yu Kim
    3. Performance of a MEMS-based AO-OCT system
      17 articles also mentioned Lawrence Livermore National Laboratory
    4. High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair.
      14 articles also mentioned Susanna S. Park