Dr. Kazuhiro Kurokawa Profile

Dr. Kazuhiro Kurokawa

Assistant Scientist at Legacy Health

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Author

Publications (23)

Proceedings Article | 5 January 2024 Open Access

Photopigment density variation of individual cone photoreceptors revealed by phase-sensitive AO-OCT (Erratum)

Marcel Bernucci, Yan Liu, James Crowell, Kazuhiro Kurokawa, Qiuzhi Ji, Donald Miller

Proceedings Volume 12360, 1236010 (2024) https://doi.org/10.1117/12.3025262

KEYWORDS: Adaptive optics optical coherence tomography, Cones, Retina

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Proceedings Article | 15 March 2023 Presentation + Paper

Photopigment density variation of individual cone photoreceptors revealed by phase-sensitive AO-OCT

Marcel Bernucci, Yan Liu, James Crowell, Kazuhiro Kurokawa, Qiuzhi Ji, Donald Miller

Proceedings Volume 12360, 1236006 (2023) https://doi.org/10.1117/12.2649489

KEYWORDS: Cones, Adaptive optics optical coherence tomography, Spectral density, Spectral response, Histograms, Visible radiation, Retina, Retinal diseases, Resolution enhancement technologies, In vivo imaging

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Numerous retinal pathologies affect cone photoreceptor photopigment density, making it a potentially attractive functional biomarker for detecting and tracking disease progression. Conventional methods to measure photopigment density include psychophysical color matching, microspectrophotometry, and retinal densitometry, but these are either subjective, measure the aggregate response/change of thousands of cones, or are performed ex vivo. Recently, we have developed a method to measure spectral sensitivities of individual human cone photoreceptors objectively, non-invasively, and in vivo with adaptive optics optical coherence tomography (AO-OCT). In preliminary results we have observed variability in the spectral sensitivities of individual cones of the same type (S, M or L) that we hypothesize attributes to inter-cone variations in photopigment density. If correct, this may be of significant clinical interest. Here, we test this hypothesis by (1) deriving an expression for the relative photopigment densities of individual cone photoreceptors based on a theoretical model of the cone absorption process and (2) using this expression to estimate photopigment density from our AO-OCT measurements of spectral sensitivity. Our mean spectral sensitivity measurements align well to Stockman & Sharpe’s well-recognized cone fundamentals with a total least-squared error of 0.12 and confidence intervals (CI) <0.36, <0.025 and <0.017 for S, M, and L cones, respectively. The substantive variability in individual cone spectral sensitivities once related to photopigment density exhibits a distribution of standard deviation=0.177 for a group of 703 cones. This indicates a two-fold difference in light sensitivity between the least sensitive cone (least amount of photopigment) and the most sensitive cone (largest amount of photopigment) for 95% of the cones measured. Furthermore, we found relative photopigment density decreased with increasing retinal eccentricity from nasal to temporal retina at 3.8° eccentricity with a slope of -0.24/° (p < .001). Both density distribution and eccentricity dependence are consistent with the literature.

Proceedings Article | 15 March 2023 Presentation + Paper

Low-latency, photon-efficient wavefront sensing for ultrafast adaptive optics imaging of the human retina

Yan Liu, James Crowell, Kazuhiro Kurokawa, Marcel Bernucci, Qiuzhi Ji, Ayoub Lassoued, Hae Won Jung, Donald Miller

Proceedings Volume 12360, 123600A (2023) https://doi.org/10.1117/12.2650674

KEYWORDS: Adaptive optics, Wavefront sensors, Wavefront errors, Photons, Eye, Wavefront aberrations, Cameras, Adaptive optics optical coherence tomography, Optical coherence tomography

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Proceedings Article | 5 March 2021 Presentation

Ultrafast adaptive optics for imaging the living human retina

Yan Liu, James Crowell, Kazuhiro Kurokawa, Ayoub Lassoued, Hae Won Jung, Marcel Bernucci, Donald Miller

Proceedings Volume 11623, 1162307 (2021) https://doi.org/10.1117/12.2578701

KEYWORDS: Adaptive optics

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Proceedings Article | 5 March 2021 Presentation

Multiple-reference global registration in adaptive optics OCT retina images

Kazuhiro Kurokawa, James Crowell, Nhan Do, John Lee, Donald Miller

Proceedings Volume 11623, 116230A (2021) https://doi.org/10.1117/12.2578886

KEYWORDS: Image registration, Eye, Retina, Optical coherence tomography, Adaptive optics optical coherence tomography, Adaptive optics, Cones, Signal to noise ratio, Video, Tissues

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Proceedings Article | 5 March 2021 Presentation

Noninvasive method to objectively measure the spectral sensitivity of individual cone photoreceptors using AO-OCT

Marcel Bernucci, Kazuhiro Kurokawa, Furu Zhang, Yan Liu, James Crowell, Donald Miller

Proceedings Volume 11623, 1162312 (2021) https://doi.org/10.1117/12.2578429

KEYWORDS: Cones, Adaptive optics optical coherence tomography, Visible radiation, Spectral resolution, Retina, In vivo imaging, Eye, Color vision

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SPIE Journal Paper | 25 January 2021 Open Access

Multi-reference global registration of individual A-lines in adaptive optics optical coherence tomography retinal images (Publisher’s Note)

Kazuhiro Kurokawa, James Crowell, Nhan Do, John Lee, Donald Miller

JBO, Vol. 26, Issue 01, 019803, (January 2021) https://doi.org/10.1117/12.10.1117/1.JBO.26.1.019803

KEYWORDS: Image registration, Adaptive optics optical coherence tomography

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SPIE Journal Paper | 6 January 2021 Open Access

Multi-reference global registration of individual A-lines in adaptive optics optical coherence tomography retinal images

Kazuhiro Kurokawa, James Crowell, Nhan Do, John Lee, Donald Miller

JBO, Vol. 26, Issue 01, 016001, (January 2021) https://doi.org/10.1117/12.10.1117/1.JBO.26.1.016001

KEYWORDS: Image registration, Eye, Adaptive optics optical coherence tomography, 3D acquisition, Cones, Detection and tracking algorithms, Video, 3D image processing, Image quality, Distortion

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Significance: Adaptive optics optical coherence tomography (AO-OCT) technology enables non-invasive, high-resolution three-dimensional (3D) imaging of the retina and promises earlier detection of ocular disease. However, AO-OCT data are corrupted by eye-movement artifacts that must be removed in post-processing, a process rendered time-consuming by the immense quantity of data. Aim: To efficiently remove eye-movement artifacts at the level of individual A-lines, including those present in any individual reference volume. Approach: We developed a registration method that cascades (1) a 3D B-scan registration algorithm with (2) a global A-line registration algorithm for correcting torsional eye movements and image scaling and generating global motion-free coordinates. The first algorithm corrects 3D translational eye movements to a single reference volume, accelerated using parallel computing. The second algorithm combines outputs of multiple runs of the first algorithm using different reference volumes followed by an affine transformation, permitting registration of all images to a global coordinate system at the level of individual A-lines. Results: The 3D B-scan algorithm estimates and corrects 3D translational motions with high registration accuracy and robustness, even for volumes containing microsaccades. Averaging registered volumes improves our image quality metrics up to 22 dB. Implementation in CUDA™ on a graphics processing unit registers a 512 × 512 × 512 volume in only 10.6 s, 150 times faster than MATLAB™ on a central processing unit. The global A-line algorithm minimizes image distortion, improves regularity of the cone photoreceptor mosaic, and supports enhanced visualization of low-contrast retinal cellular features. Averaging registered volumes improves our image quality up to 9.4 dB. It also permits extending the imaging field of view (∼2.1 × ) and depth of focus (∼5.6 × ) beyond what is attainable with single-reference registration. Conclusions: We can efficiently correct eye motion in all 3D at the level of individual A-lines using a global coordinate system.

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SPIE Journal Paper | 14 March 2020 Open Access

Suite of methods for assessing inner retinal temporal dynamics across spatial and temporal scales in the living human eye

Kazuhiro Kurokawa, James Crowell, Furu Zhang, Donald Miller

NPh, Vol. 7, Issue 01, 015013, (March 2020) https://doi.org/10.1117/12.10.1117/1.NPh.7.1.015013

KEYWORDS: Adaptive optics optical coherence tomography, Eye, Tissues, Speckle, Video, Retina, Neurophotonics, Reflectivity, Tissue optics, Optical coherence tomography

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Proceedings Article | 19 February 2020 Paper

Fully automatic quantification of individual ganglion cells from AO-OCT volumes via weakly supervised learning

Somayyeh Soltanian-Zadeh, Kazuhiro Kurokawa, Zhuolin Liu, Daniel Hammer, Donald Miller, Sina Farsiu

Proceedings Volume 11218, 112180Q (2020) https://doi.org/10.1117/12.2543964

KEYWORDS: Adaptive optics optical coherence tomography, Image segmentation, Optical coherence tomography, Retina, Machine learning, Adaptive optics, In vivo imaging

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Proceedings Article | 19 February 2020 Paper

Measuring dysfunction of cone photoreceptors in retinitis pigmentosa with phase-sensitive AO-OCT

Ayoub Lassoued, Furu Zhang, Kazuhiro Kurokawa, Yan Liu, James Crowell, Donald Miller

Proceedings Volume 11218, 1121815 (2020) https://doi.org/10.1117/12.2550216

KEYWORDS: Cones, Adaptive optics optical coherence tomography, Control systems, Optical coherence tomography, Image segmentation, Eye, Light emitting diodes, Retina, Video, Adaptive optics

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Proceedings Article | 28 February 2019 Paper

Classifying cone photoreceptors in the living human eye using their unique phase response to light

Furu Zhang, Kazuhiro Kurokawa, Ayoub Lassoued, James Crowell, Donald Miller

Proceedings Volume 10858, 108580K (2019) https://doi.org/10.1117/12.2508901

KEYWORDS: Cones, Adaptive optics, Color vision, Adaptive optics optical coherence tomography, Eye, Densitometry, In vivo imaging, Retina

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Proceedings Article | 28 February 2019 Paper

Method to track and measure loss of inner retinal neurons in the living human eye

Kazuhiro Kurokawa, Furu Zhang, James Crowell, Ayoub Lassoued, Donald Miller

Proceedings Volume 10858, 108580L (2019) https://doi.org/10.1117/12.2508909

KEYWORDS: Adaptive optics optical coherence tomography, Eye, Visualization, Neurons, Retina, Imaging systems, Optical inspection, Reflectivity, Optic nerve, Cell death

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Proceedings Article | 19 February 2018 Paper

Method to investigate temporal dynamics of ganglion and other retinal cells in the living human eye

Kazuhiro Kurokawa, Zhuolin Liu, James Crowell, Furu Zhang, Donald Miller

Proceedings Volume 10474, 104740W (2018) https://doi.org/10.1117/12.2292413

KEYWORDS: Adaptive optics optical coherence tomography, Retina, Speckle, Neurons, Dynamic light scattering, Glia

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Proceedings Article | 28 February 2017 Paper

Tracking dynamics of photoreceptor disc shedding with adaptive optics-optical coherence tomography

Furu Zhang, Zhuolin Liu, Kazuhiro Kurokawa, Donald Miller

Proceedings Volume 10045, 1004517 (2017) https://doi.org/10.1117/12.2256146

KEYWORDS: Cones, Retina, Adaptive optics, Adaptive optics optical coherence tomography, Animal model studies, Optical coherence tomography, Eye, Video, Tomography

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Proceedings Article | 8 February 2017 Paper

Characterizing motility dynamics in human RPE cells

Zhuolin Liu, Kazuhiro Kurokawa, Furu Zhang, Donald Miller

Proceedings Volume 10045, 1004515 (2017) https://doi.org/10.1117/12.2256144

KEYWORDS: Adaptive optics, Retina, Adaptive optics optical coherence tomography, Speckle, Optical coherence tomography, Correlation function, In vivo imaging, Eye, Tomography, Physiology, Axons, Video, Image segmentation, Imaging systems

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Proceedings Article | 8 March 2016 Presentation + Paper

Quantitative optical coherence tomography by maximum a-posteriori estimation of signal intensity

Aaron Chan, Kazuhiro Kurokawa, Shuichi Makita, Young-Joo Hong, Arata Miyazawa, Masahiro Miura, Yoshiaki Yasuno

Proceedings Volume 9697, 96971W (2016) https://doi.org/10.1117/12.2212329

KEYWORDS: Optical coherence tomography, Signal attenuation, Tissues, Statistical analysis, Light scattering, Retinal scanning, Birefringence, Scattering, Optical properties, Retina, Signal to noise ratio, Reliability, Polarization, Composites, Vitreous, Optic nerve

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Proceedings Article | 8 March 2016 Presentation + Paper

Noise-immune complex correlation for vasculature imaging based on standard and Jones-matrix optical coherence tomography

Shuichi Makita, Kazuhiro Kurokawa, Young-Joo Hong, En Li, Masahiro Miura, Yoshiaki Yasuno

Proceedings Volume 9697, 96970J (2016) https://doi.org/10.1117/12.2214683

KEYWORDS: Optical coherence tomography, Polarization, Angiography, In vivo imaging, Coherence (optics), Computing systems, Eye, Tissues, Doppler tomography, Signal to noise ratio, Signal detection

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Proceedings Article | 4 March 2014 Paper

Quantitative two-dimensional micro-displacement measurement by optical coherence tomography

Kazuhiro Kurokawa, Shuichi Makita, Young-Joo Hong, Yoshiaki Yasuno

Proceedings Volume 8934, 89340V (2014) https://doi.org/10.1117/12.2038643

KEYWORDS: Optical coherence tomography, Laser irradiation, Doppler tomography, Optical testing, Doppler effect, Tissues, Laser tissue interaction, Laser applications, Visualization, Mirrors

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Proceedings Article | 14 February 2011 Paper

Wide field of view retinal imaging using one-micrometer adaptive optics scanning laser ophthalmoscope

Kazuhiro Sasaki, Kazuhiro Kurokawa, Shuichi Makita, Daiki Tamada, Yiheng Lim, Barry Cense, Yoshiaki Yasuno

Proceedings Volume 7931, 793106 (2011) https://doi.org/10.1117/12.874473

KEYWORDS: Adaptive optics, Scanners, Retina, Retinal scanning, Scanning laser ophthalmoscopes, Image resolution, Eye, Rhodium, Signal processing, Light sources

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Proceedings Article | 20 February 2010 Paper

Adaptive optics spectral domain optical coherence tomography with one-micrometer light source

Kazuhiro Kurokawa, Kazuhiro Sasaki, Shuichi Makita, Yoshiaki Yasuno

Proceedings Volume 7554, 75540E (2010) https://doi.org/10.1117/12.841666

KEYWORDS: Adaptive optics, Optical coherence tomography, Light sources, Eye, Interfaces, Indium gallium arsenide, Image resolution, Wavefront sensors, Nerve, Coherence (optics)

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Proceedings Article | 1 July 2009 Paper

Investigation of retinal microstructure by adaptive optics scanning laser ophthalmoscope with 1-micrometer wavelength probe

Y, Yasuno, K. Kurokawa, S. Makita, M. Miura, K. Kawana, F. Okamoto, T. Oshika

Proceedings Volume 7367, 736704 (2009) https://doi.org/10.1117/12.831490

KEYWORDS: Adaptive optics, Scanning laser ophthalmoscopes, Microscopy, Biomedical optics, Current controlled current source, Wavefronts, Eye, Cones, Visualization

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Proceedings Article | 18 February 2009 Paper

1 &mgr;m wavelength adaptive optics scanning laser ophthalmoscope

Kazuhiro Kurokawa, Shuichi Makita, Yoshiaki Yasuno

Proceedings Volume 7163, 71630I (2009) https://doi.org/10.1117/12.808753

KEYWORDS: Adaptive optics, Visualization, Scanners, Retina, Wavefronts, Wavefront sensors, Retinal scanning, Image resolution, Light sources, Eye

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Showing 5 of 23 publications

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