1. UC Davis

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    1. Mentioned In 100 Articles

    2. Maximum Likelihood Doppler Frequency Estimation under Decorrelation Noise for Quantifying Flow in Optical Coherence Tomography

      Maximum Likelihood Doppler Frequency Estimation under Decorrelation Noise for Quantifying Flow in Optical Coherence Tomography

      Recent hardware advances in optical coherence tomography (OCT) have led to ever higher A-scan rates. However, the estimation of blood flow axial velocities is limited by the presence and type of noise. Higher acquisition rates alone do not necessarily enable precise quantification of Doppler velocities, particularly if the estimator is sub-optimal. In previous work, we have shown that the Kasai autocorrelation estimator is statistically sub-optimal under conditions of additive white Gaussian noise. In addition, for practical OCT measurements of flow, decorrelation noise affects Doppler frequency estimation by broadening the signal spectrum. Here we derive a general maximum likelihood estimator (MLE ...

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    3. Improved in vivo imaging of human blood circulation in the chorioretinal complex using phase variance method with new phase stabilized 1 μm swept-source optical coherence tomography (pv-SSOCT)

      Improved in vivo imaging of human blood circulation in the chorioretinal complex using phase variance method with new phase stabilized 1 μm swept-source optical coherence tomography (pv-SSOCT)

      We demonstrate the feasibility of our newly developed phase stabilized high-speed (100 kHz A-scans/s) 1 μm sweptsource optical coherence tomography (SSOCT) system with the phase-variance based motion contrast method for visualization of human chorioretinal complex microcirculation. Compared to our previously reported spectral domain (spectrometer based) phase-variance (pv)-SDOCT system it has advantages of higher sensitivity, reduced fringe washout for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization method ...

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    4. The Dose-Dependent Macular Thickness Changes Assessed By FD-OCT in Patients With Retinitis Pigmentosa Treated With Ciliary Neurotrophic Factor

      The Dose-Dependent Macular Thickness Changes Assessed By FD-OCT in Patients With Retinitis Pigmentosa Treated With Ciliary Neurotrophic Factor

      Purpose: To evaluate the effect of intravitreal ciliary neurotrophic factor (CNTF) implant on mean macular thickness (MMT) in eyes with retinitis pigmentosa using high-resolution Fourier domain optical coherence tomography imaging. Methods: A cohort of 8 patients (CNTF-3: n = 5; CNTF-4: n = 3) enrolled in Neurotech sponsored Phase 2 clinical trial underwent Fourier domain optical coherence tomography imaging. A >=3% change in MMT from baseline or fellow eye was considered as a measurable change. Results: Two patients enrolled in the CNTF-3 study received low-dose implant. At 18 months, a change in MMT from -4.47 [mu]m to 6 [mu]m ...

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    5. Progress on Developing Adaptive Optics–Optical Coherence Tomography for In Vivo Retinal Imaging: Monitoring and Correction of Eye Motion Artifacts

      Progress on Developing Adaptive Optics–Optical Coherence Tomography for In Vivo Retinal Imaging: Monitoring and Correction of Eye Motion Artifacts

      Recent progress in retinal image acquisition techniques, including optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO), combined with improved performance of adaptive optics (AO) instrumentation, has resulted in improvement in the quality of in vivo images of cellular structures in the human retina. Here, we present a short review of progress on developing AO-OCT instruments. Despite significant progress in imaging speed and resolution, eye movements present during acquisition of a retinal image with OCT introduce motion artifacts into the image, complicating analysis and registration. This effect is especially pronounced in high-resolution datasets acquired with AO-OCT instruments. Several retinal tracking ...

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    6. Research Scientist Positions in the Vision Science and Advanced Retinal Imaging Laboratory at the University of California, Davis

      Research Scientist Positions in the Vision Science and Advanced Retinal Imaging Laboratory at the University of California, Davis

      Two research scientist positions are available in the Vision Science and Advanced Retinal Imaging Laboratory at the University of California, Davis. One position will be filled by someone with background in vision science while the other will be for a person with experience in a high-resolution imaging modality such as OCT, adaptive optics or scanning laser ophthalmoscope. Strong skills in programming or image processing would be an asset. The positions will be open until filled. Salary will be based on experience and salary scales of the UC. The University of California is committed to diversity. Minorities, women, veterans and persons ...

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    7. Feature Of The Week 10/20/13: Multiparametric, Longitudinal Optical Coherence Tomography Imaging Reveals Acute Injury and Chronic Recovery in Experimental Ischemic Stroke

      Feature Of The Week 10/20/13: Multiparametric, Longitudinal Optical Coherence Tomography Imaging Reveals Acute Injury and Chronic Recovery in Experimental Ischemic Stroke
      ...ion see recent Article. Courtesy of Vivek J. Srinivasan from University of California at Davis, USA. For more information see recent Article. Courtesy of Vivek Srinivasan from University of California at Davis....
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    8. Macular edema in the era of spectral-domain optical coherence tomography

      Macular edema in the era of spectral-domain optical coherence tomography

      The development of spectral-domain optical coherence tomography (OCT) allows for the highest commercially available resolution of in vivo retinal anatomic details to date. The ability to see the macula with ever increasing detail is dramatically improving our understanding of the pathogenesis of retinal disease. However, the only prospective study that partially evaluated spectral-domain OCT versus time-domain OCT failed to show any clinical benefit of increased OCT resolution. Clinical outcomes, eg, best-corrected visual acuity, central macular thickness and number of injections, with “newer” OCT technologies remain an unproven advantage.

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      Mentions: UC Davis
    9. Baseline Retinal Nerve Fiber Layer Thickness and Macular Volume Quantified by OCT in the North American Phase 3 Fingolimod Trial for Relapsing-Remitting Multiple Sclerosis

      Baseline Retinal Nerve Fiber Layer Thickness and Macular Volume Quantified by OCT in the North American Phase 3 Fingolimod Trial for Relapsing-Remitting Multiple Sclerosis

      Background: Patients with multiple sclerosis (MS) demonstrate thinning of peripapillary retinal nerve fiber layer (RNFL) and decreased macular volume as measured by optical coherence tomography (OCT). To our knowledge, there are no previous reports from a large MS OCT database with strict quality control measures that quantitate RNFL and macula in patients with relapsing-remitting multiple sclerosis. Methods: The University of California Davis OCT Reading Center gathered OCT data at baseline as part of the North American phase 3 trial of fingolimod (Gilenya). Average RNFL thickness (RNFLT) and macular volume (TMV) were measured using time domain OCT (TD-OCT). RNFL quadrants, clock ...

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    10. Volumetric imaging and quantification of cytoarchitecture and myeloarchitecture with intrinsic scattering contrast

      Volumetric imaging and quantification of cytoarchitecture and myeloarchitecture with intrinsic scattering contrast

      We present volumetric imaging and computational techniques to quantify neuronal and myelin architecture with intrinsic scattering contrast. Using spectral / Fourier domain Optical Coherence Microscopy (OCM) and software focus-tracking we validate imaging of neuronal cytoarchitecture and demonstrate quantification in the rodent cortex in vivo . Additionally, by ex vivo imaging in conjunction with optical clearing techniques, we demonstrate that intrinsic scattering contrast is preserved in the brain, even after sacrifice and fixation. We volumetrically image cytoarchitecture and myeloarchitecture ex vivo across the entire depth of the rodent cortex. Cellular-level imaging up to the working distance of our objective (~3 mm) is demonstrated ...

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  2. About UC Davis

    UC Davis

    University of California at Davis  is a public university located in the city of Davis, California and is one of the ten campuses of the University of California. Vision Science and Advanced Retinal Imaging Laboratory is at the University of California, Davis and is concerned with understanding the functional and structural basis of early stage mechanisms of human vision. Center for Biophotonics, Science and Technology at The University of California at Davis.  The Center for Biophotonics, Science and Technology (CBST) was conceived in response to the NRC recommendations. UC Davis Medical Center is a major research hospital located in Sacramento, California and is the primary teaching hospital of UC Davis School of Medicine. Researchers and specialists at the 577 licensed bed medical center work in over 150 areas of specialty. The UC Davis hospital has been ranked among the top 50 hospitals in the nation in the 2004 survey of US News and World Report. Particularly respected are its programs in heart surgery and ear, nose, and throat treatment. It is also a Level I trauma center for both adults and pediatrics.