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Zhao Y, Sun B, Fu X, Zuo Z, Qin H, Yao K. YAP in development and disease: Navigating the regulatory landscape from retina to brain. Biomed Pharmacother 2024; 175:116703. [PMID: 38713948 DOI: 10.1016/j.biopha.2024.116703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/30/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024] Open
Abstract
The distinctive role of Yes-associated protein (YAP) in the nervous system has attracted widespread attention. This comprehensive review strategically uses the retina as a vantage point, embarking on an extensive exploration of YAP's multifaceted impact from the retina to the brain in development and pathology. Initially, we explore the crucial roles of YAP in embryonic and cerebral development. Our focus then shifts to retinal development, examining in detail YAP's regulatory influence on the development of retinal pigment epithelium (RPE) and retinal progenitor cells (RPCs), and its significant effects on the hierarchical structure and functionality of the retina. We also investigate the essential contributions of YAP in maintaining retinal homeostasis, highlighting its precise regulation of retinal cell proliferation and survival. In terms of retinal-related diseases, we explore the epigenetic connections and pathophysiological regulation of YAP in diabetic retinopathy (DR), glaucoma, and proliferative vitreoretinopathy (PVR). Lastly, we broaden our exploration from the retina to the brain, emphasizing the research paradigm of "retina: a window to the brain." Special focus is given to the emerging studies on YAP in brain disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD), underlining its potential therapeutic value in neurodegenerative disorders and neuroinflammation.
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Affiliation(s)
- Yaqin Zhao
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Bin Sun
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xuefei Fu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Zhuan Zuo
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Huan Qin
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China.
| | - Kai Yao
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan 430065, China; College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China.
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2
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Grannonico M, Miller DA, Liu M, Krause MA, Savier E, Erisir A, Netland PA, Cang J, Zhang HF, Liu X. Comparative In Vivo Imaging of Retinal Structures in Tree Shrews, Humans, and Mice. eNeuro 2024; 11:ENEURO.0373-23.2024. [PMID: 38538082 PMCID: PMC10972737 DOI: 10.1523/eneuro.0373-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 02/29/2024] [Accepted: 03/07/2024] [Indexed: 04/01/2024] Open
Abstract
Rodent models, such as mice and rats, are commonly used to examine retinal ganglion cell damage in eye diseases. However, as nocturnal animals, rodent retinal structures differ from primates, imposing significant limitations in studying retinal pathology. Tree shrews (Tupaia belangeri) are small, diurnal paraprimates that exhibit superior visual acuity and color vision compared with mice. Like humans, tree shrews have a dense retinal nerve fiber layer (RNFL) and a thick ganglion cell layer (GCL), making them a valuable model for investigating optic neuropathies. In this study, we applied high-resolution visible-light optical coherence tomography to characterize the tree shrew retinal structure in vivo and compare it with that of humans and mice. We quantitatively characterize the tree shrew's retinal layer structure in vivo, specifically examining the sublayer structures within the inner plexiform layer (IPL) for the first time. Next, we conducted a comparative analysis of retinal layer structures among tree shrews, mice, and humans. We then validated our in vivo findings in the tree shrew inner retina using ex vivo confocal microscopy. The in vivo and ex vivo analyses of the shrew retina build the foundation for future work to accurately track and quantify the retinal structural changes in the IPL, GCL, and RNFL during the development and progression of human optic diseases.
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Affiliation(s)
- Marta Grannonico
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - David A Miller
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208
| | - Mingna Liu
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Michael A Krause
- Departments of Ophthalmology, University of Virginia, Charlottesville, Virginia 22904
| | - Elise Savier
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Alev Erisir
- Psychology, University of Virginia, Charlottesville, Virginia 22904
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia 22904
| | - Peter A Netland
- Departments of Ophthalmology, University of Virginia, Charlottesville, Virginia 22904
| | - Jianhua Cang
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
- Psychology, University of Virginia, Charlottesville, Virginia 22904
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia 22904
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208
| | - Xiaorong Liu
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
- Psychology, University of Virginia, Charlottesville, Virginia 22904
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia 22904
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Malone JD, Hussain I, Bowden AK. SmartOCT: smartphone-integrated optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2023; 14:3138-3151. [PMID: 37497502 PMCID: PMC10368059 DOI: 10.1364/boe.492439] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 07/28/2023]
Abstract
Smartphone devices have seen unprecedented technical innovation in computational power and optical imaging capabilities, making them potentially invaluable tools in scientific imaging applications. The smartphone's compact form-factor and broad accessibility has motivated researchers to develop smartphone-integrated imaging systems for a wide array of applications. Optical coherence tomography (OCT) is one such technique that could benefit from smartphone-integration. Here, we demonstrate smartOCT, a smartphone-integrated OCT system that leverages built-in components of a smartphone for detection, processing and display of OCT data. SmartOCT uses a broadband visible-light source and line-field OCT design that enables snapshot 2D cross-sectional imaging. Furthermore, we describe methods for processing smartphone data acquired in a RAW data format for scientific applications that improves the quality of OCT images. The results presented here demonstrate the potential of smartphone-integrated OCT systems for low-resource environments.
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Affiliation(s)
- Joseph D. Malone
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN
37235, USA
- Vanderbilt University, Vanderbilt Biophotonics Center, Nashville, TN
37235, USA
| | - Iftak Hussain
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN
37235, USA
- Vanderbilt University, Vanderbilt Biophotonics Center, Nashville, TN
37235, USA
| | - Audrey K. Bowden
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN
37235, USA
- Vanderbilt University, Vanderbilt Biophotonics Center, Nashville, TN
37235, USA
- Vanderbilt University, Dept. of Electrical and Computer Engineering,
Nashville, TN 37235, USA
- Vanderbilt University, Vanderbilt Institute of Global Health, Nashville,
TN 37235, USA
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4
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Rubinoff I, Kuranov RV, Fang R, Ghassabi Z, Wang Y, Beckmann L, Miller DA, Wollstein G, Ishikawa H, Schuman JS, Zhang HF. Adaptive spectroscopic visible-light optical coherence tomography for clinical retinal oximetry. COMMUNICATIONS MEDICINE 2023; 3:57. [PMID: 37095177 PMCID: PMC10126115 DOI: 10.1038/s43856-023-00288-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 04/13/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND Retinal oxygen saturation (sO2) provides essential information about the eye's response to pathological changes that can result in vision loss. Visible-light optical coherence tomography (vis-OCT) is a noninvasive tool that has the potential to measure retinal sO2 in a clinical setting. However, its reliability is currently limited by unwanted signals referred to as spectral contaminants (SCs), and a comprehensive strategy to isolate true oxygen-dependent signals from SCs in vis-OCT is lacking. METHODS We develop an adaptive spectroscopic vis-OCT (ADS-vis-OCT) technique that can adaptively remove SCs and accurately measure sO2 under the unique conditions of each vessel. We also validate the accuracy of ADS-vis-OCT using ex vivo blood phantoms and assess its repeatability in the retina of healthy volunteers. RESULTS In ex vivo blood phantoms, ADS-vis-OCT agrees with a blood gas machine with only a 1% bias in samples with sO2 ranging from 0% to 100%. In the human retina, the root mean squared error between sO2 values in major arteries measured by ADS-vis-OCT and a pulse oximeter is 2.1% across 18 research participants. Additionally, the standard deviations of repeated ADS-vis-OCT measurements of sO2 values in smaller arteries and veins are 2.5% and 2.3%, respectively. Non-adaptive methods do not achieve comparable repeatabilities from healthy volunteers. CONCLUSIONS ADS-vis-OCT effectively removes SCs from human images, yielding accurate and repeatable sO2 measurements in retinal arteries and veins with varying diameters. This work could have important implications for the clinical use of vis-OCT to manage eye diseases.
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Affiliation(s)
- Ian Rubinoff
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Roman V Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Opticent Inc., Evanston, IL, 60201, USA
| | - Raymond Fang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Zeinab Ghassabi
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Yuanbo Wang
- Currently with Department of Ophthalmology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - David A Miller
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Gadi Wollstein
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
- Currently with Department of Ophthalmology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Joel S Schuman
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
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Chen S, Abu-Qamar O, Kar D, Messinger JD, Hwang Y, Moult EM, Lin J, Baumal CR, Witkin A, Liang MC, Waheed NK, Curcio CA, Fujimoto JG. Ultrahigh resolution optical coherence tomography markers of normal aging and early age-related macular degeneration. OPHTHALMOLOGY SCIENCE 2023; 3:100277. [PMID: 36970115 PMCID: PMC10034509 DOI: 10.1016/j.xops.2023.100277] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/04/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023]
Abstract
Purpose Ultrahigh resolution spectral domain-OCT (UHR SD-OCT) enables in vivo visualization of micrometric structural markers which differentially associate with normal aging versus age-related macular degeneration (AMD). This study explores the hypothesis that UHR SD-OCT can detect and quantify sub-retinal pigment epithelium (RPE) deposits in early AMD, separating AMD pathology from normal aging. Design Prospective cross-sectional study. Participants A total of 53 nonexudative (dry) AMD eyes from 39 patients, and 63 normal eyes from 39 subjects. Methods Clinical UHR SD-OCT scans were performed using a high-density protocol. Exemplary high-resolution histology and transmission electron microscopy images were obtained from archive donor eyes. Three trained readers evaluated and labeled outer retina morphological features, including the appearance of a hyporeflective split within the RPE-RPE basal lamina (RPE-BL)-Bruch's membrane (BrM) complex on UHR brightness (B)-scans. A semi-automatic segmentation algorithm measured the thickness of the RPE-BL-BrM split/hyporeflective band. Main Outcome Measures Qualitative description of outer retinal morphological changes on UHR SD-OCT B-scans; the proportion of the RPE-BL-BrM complex with visible split (%) and the thickness of the resulting hyporeflective band (μm). Results In young normal eyes, UHR SD-OCT consistently revealed an RPE-BL-BrM split/hyporeflective band. Its visibility and thickness were less in eyes of advanced age. However, the split/hyporeflective band was again visible in early AMD eyes. Both qualitative reading and quantitative thickness measurements showed significantly elevated visibility and thickness of the RPE-BL-BrM split/hyporeflective in early AMD eyes compared to age-matched controls. Conclusions Our imaging results strongly support the hypothesis that appearance of the RPE-BL-BrM split/hyporeflective band in older subjects is dominated by the BL deposit, an indicator of early AMD well known from histology. Ultrahigh resolution SD-OCT can be used to investigate physiological aging as well as early AMD pathology in clinical imaging studies. Developing quantifiable markers associated with disease pathogenesis and progression can facilitate drug discovery, as well as reduce clinical trial times. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Song W, Zhang S, Kim YM, Sadlak N, Fiorello MG, Desai M, Yi J. Visible Light Optical Coherence Tomography of Peripapillary Retinal Nerve Fiber Layer Reflectivity in Glaucoma. Transl Vis Sci Technol 2022; 11:28. [PMID: 36166221 PMCID: PMC9526364 DOI: 10.1167/tvst.11.9.28] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/19/2022] [Indexed: 01/01/2023] Open
Abstract
Purpose To evaluate the clinical utility of visible light optical coherence tomography (VIS-OCT) and to test whether VIS-OCT reflectivity and spectroscopy of peripapillary retinal nerve fiber layer (pRNFL) are correlated with severity of glaucoma, compared with standard-of-care OCT thickness measurements. Methods In total 54 eyes (20 normal, 17 suspect/preperimetric glaucoma [GS/PPG], 17 perimetric glaucoma [PG]) were successfully imaged with complete datasets. All the eyes were scanned by a custom-designed dual-channel device that simultaneously acquired VIS-OCT and near-infrared OCT (NIR-OCT) images. A 5 × 5 mm2 scan was taken of the pRNFL. The pRNFL reflectivity was calculated for both channels and the spectroscopic marker was quantified by pVN, defined as the ratio of VIS-OCT to NIR-OCT pRNFL reflectivity. The results were compared with ophthalmic examinations and Zeiss Cirrus OCT. Results VIS-OCT pRNFL reflectivity significantly, sequentially decreased from normal to GS/PPG to PG, as did NIR-OCT pRNFL reflectivity. The pVN had the same decreasing trend among three groups. Normal and GS/PPG eyes were significantly different in VIS-OCT pRNFL reflectivity (P = 0.002) and pVN (P < 0.001), but were not in NIR-OCT pRNFL reflectivity (P = 0.14), circumpapillary RNFL thickness (P = 0.17), or macular ganglion cell layer and inner plexiform layer thickness (P = 0.07) in a mixed linear regression model. Conclusions VIS-OCT pRNFL reflectivity and pVN better distinguished GS/PPG from normal eyes than Cirrus OCT thickness measurements. Translational Relevance VIS-OCT pRNFL reflectivity and pVN could be useful metrics in the early detection of glaucoma upon further longitudinal validation.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
| | - Sui Zhang
- Department of Epidemiology, School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Yumi Mun Kim
- Department of Philosophy & Neuroscience, Boston University, Boston, USA
| | - Natalie Sadlak
- Department of Ophthalmology, Boston Medical Center, Boston, MA, USA
| | | | - Manishi Desai
- Department of Ophthalmology, Boston Medical Center, Boston, MA, USA
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
- Department of Ophthalmology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA
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7
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Srinivasan VJ, Kho AM, Chauhan P. Visible Light Optical Coherence Tomography Reveals the Relationship of the Myoid and Ellipsoid to Band 2 in Humans. Transl Vis Sci Technol 2022; 11:3. [PMID: 36053140 PMCID: PMC9440607 DOI: 10.1167/tvst.11.9.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose We employ visible light optical coherence tomography (OCT) to investigate the relationship between the myoid, ellipsoid, and band 2 in the living human retina. Rather than refute existing theories, we aim to reveal new bands and better delineate the structures at hand. Methods An upgraded spectral/Fourier domain visible light OCT prototype, with 1.0-µm axial resolution, imaged 13 eyes of 13 young adult human subjects (23–40 years old) without a history of ocular pathology. The external limiting membrane (band 1) and band 2 edges were segmented. Reflectivity was examined along the inner segment (IS), defined as extending from band 1 to the band 2 center, and within band 2 itself. Results Images highlight a nearly continuously resolved extrafoveal internal limiting membrane, the peripheral single-cell thick ganglion cell layer, and the peripheral photoreceptor axonal fiber layer, a peripheral division of band 2 into bands 2a and 2b, and a reflectivity-based division of the IS into “m” and “e” zones. Discussion Topography and transverse intensity variations of the outermost band 2b suggest an association with rods. The “m” and “e” zone border is consistent with the myoid–ellipsoid boundary, even recapitulating the well-documented distribution of mitochondria throughout the IS at the foveal center. Theories of outer retinal reflectivity in OCT must adequately explain these observations. Translational Relevance Findings support that band 2 does partially overlap with the ellipsoid in transversally averaged OCT images due to photoreceptor IS length dispersion but argue that the inner ellipsoid must be inner to band 2, as suggested by prior quantitative measurements.
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Affiliation(s)
- Vivek J Srinivasan
- Department of Ophthalmology, NYU Langone Health, New York, NY, USA.,Department of Radiology, NYU Langone Health, New York, NY, USA.,Tech4Health Institute, NYU Langone Health, New York, NY, USA.,Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Aaron M Kho
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Pooja Chauhan
- Department of Radiology, NYU Langone Health, New York, NY, USA.,Tech4Health Institute, NYU Langone Health, New York, NY, USA
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Chauhan P, Kho AM, FitzGerald P, Shibata B, Srinivasan VJ. Subcellular Comparison of Visible-Light Optical Coherence Tomography and Electron Microscopy in the Mouse Outer Retina. Invest Ophthalmol Vis Sci 2022; 63:10. [PMID: 35943734 PMCID: PMC9379865 DOI: 10.1167/iovs.63.9.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/30/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose We employed in vivo, 1.0-µm axial resolution visible-light optical coherence tomography (OCT) and ex vivo electron microscopy (EM) to investigate three subcellular features in the mouse outer retina: reflectivity oscillations inner to band 1 (study 1); hyperreflective band 2, attributed to the ellipsoid zone or inner segment/outer segment (IS/OS) junction (study 2); and the hyperreflective retinal pigment epithelium (RPE) within band 4 (study 3). Methods Pigmented (C57BL/6J, n = 10) and albino (BALB/cJ, n = 3) mice were imaged in vivo. Enucleated eyes were processed for light and electron microscopy. Using well-accepted reference surfaces, we compared micrometer-scale axial reflectivity of visible-light OCT with subcellular organization, as revealed by 9449 annotated EM organelles and features across four pigmented eyes. Results In study 1, outer nuclear layer reflectivity peaks coincided with valleys in heterochromatin clump density (-0.34 ± 2.27 µm limits of agreement [LoA]). In study 2, band 2 depth on OCT and IS/OS junction depth on EM agreed (-0.57 ± 0.76 µm LoA), with both having similar distributions. In study 3, RPE electron dense organelle distribution did not agree with reflectivity in C57BL/6J mice, with OCT measures of RPE thickness exceeding those of EM (2.09 ± 0.89 µm LoA). Finally, RPE thickness increased with age in pigmented mice (slope = 0.056 µm/mo; P = 6.8 × 10-7). Conclusions Visible-light OCT bands arise from subcellular organization, enabling new measurements in mice. Quantitative OCT-EM comparisons may be confounded by hydration level, particularly in the OS and RPE. Caution is warranted in generalizing results to other species.
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Affiliation(s)
- Pooja Chauhan
- Department of Radiology, NYU Langone Health, New York, New York, United States
| | - Aaron M. Kho
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States
| | - Paul FitzGerald
- Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States
| | - Bradley Shibata
- Biological Electron Microscopy Facility, University of California Davis, Davis, California, United States
| | - Vivek J. Srinivasan
- Department of Radiology, NYU Langone Health, New York, New York, United States
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States
- Department of Ophthalmology, NYU Langone Health, New York, New York, United States
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9
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Alexopoulos P, Madu C, Wollstein G, Schuman JS. The Development and Clinical Application of Innovative Optical Ophthalmic Imaging Techniques. Front Med (Lausanne) 2022; 9:891369. [PMID: 35847772 PMCID: PMC9279625 DOI: 10.3389/fmed.2022.891369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/22/2022] Open
Abstract
The field of ophthalmic imaging has grown substantially over the last years. Massive improvements in image processing and computer hardware have allowed the emergence of multiple imaging techniques of the eye that can transform patient care. The purpose of this review is to describe the most recent advances in eye imaging and explain how new technologies and imaging methods can be utilized in a clinical setting. The introduction of optical coherence tomography (OCT) was a revolution in eye imaging and has since become the standard of care for a plethora of conditions. Its most recent iterations, OCT angiography, and visible light OCT, as well as imaging modalities, such as fluorescent lifetime imaging ophthalmoscopy, would allow a more thorough evaluation of patients and provide additional information on disease processes. Toward that goal, the application of adaptive optics (AO) and full-field scanning to a variety of eye imaging techniques has further allowed the histologic study of single cells in the retina and anterior segment. Toward the goal of remote eye care and more accessible eye imaging, methods such as handheld OCT devices and imaging through smartphones, have emerged. Finally, incorporating artificial intelligence (AI) in eye images has the potential to become a new milestone for eye imaging while also contributing in social aspects of eye care.
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Affiliation(s)
- Palaiologos Alexopoulos
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Chisom Madu
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
- Center for Neural Science, College of Arts & Science, New York University, New York, NY, United States
| | - Joel S. Schuman
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
- Center for Neural Science, College of Arts & Science, New York University, New York, NY, United States
- Department of Electrical and Computer Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
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10
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Wang J, Song W, Sadlak N, Fiorello MG, Desai M, Yi J. A Baseline Study of Oxygen Saturation in Parafoveal Vessels Using Visible Light Optical Coherence Tomography. Front Med (Lausanne) 2022; 9:886576. [PMID: 35646980 PMCID: PMC9133487 DOI: 10.3389/fmed.2022.886576] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/20/2022] [Indexed: 01/02/2023] Open
Abstract
The retinal macula is at the center of our visual field, and thus pathological damage in the macula significantly impacts an individual's quality of life. The parafoveal vessels form the inner retina provide oxygen perfusion, and the measurement of parafoveal oxygen saturation (sO2) can evaluate macular metabolism and provide pathophysiological insight. In this paper, for the first time, we present a baseline study of microvascular oxygen saturation (sO2) in perifoveal macular region using visible light optical coherence tomography (VIS-OCT) on normal eyes. The arterial and venous sO2 from all eyes was 92.1 ± 7.1 (vol %) and 48.4 ± 5.0 (vol %) (mean ± SD), respectively. Arteriovenous sO2 difference was 43.8 ± 9.5 (vol %). Marginal correlation was found between venous sO2 and intraocular pressure (IOP) among eyes. No significant correlation was found between sO2 and vessel topological features, including length, diameter, and distance to fovea. This baseline study could serve as a benchmark for the future sO2 investigation of retinal macular pathologies.
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Affiliation(s)
- Jingyu Wang
- Department of Ophthalmology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Weiye Song
- School of Mechanical Engineering, Shandong University, Jinan, China,Department of Ophthalmology, Boston Medical Center, Boston, MA, United States
| | - Natalie Sadlak
- Department of Ophthalmology, Boston Medical Center, Boston, MA, United States
| | - Marissa G. Fiorello
- Department of Ophthalmology, Boston Medical Center, Boston, MA, United States
| | - Manishi Desai
- Department of Ophthalmology, Boston Medical Center, Boston, MA, United States
| | - Ji Yi
- Department of Ophthalmology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States,*Correspondence: Ji Yi
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11
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Lichtenegger A, Mukherjee P, Zhu L, Morishita R, Tomita K, Oida D, Leskovar K, Abd El-Sadek I, Makita S, Kirchberger S, Distel M, Baumann B, Yasuno Y. Non-destructive characterization of adult zebrafish models using Jones matrix optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:2202-2223. [PMID: 35519284 PMCID: PMC9045912 DOI: 10.1364/boe.455876] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
The zebrafish is a valuable vertebrate animal model in pre-clinical cancer research. A Jones matrix optical coherence tomography (JM-OCT) prototype operating at 1310 nm and an intensity-based spectral-domain OCT setup at 840 nm were utilized to investigate adult wildtype and a tumor-developing zebrafish model. Various anatomical features were characterized based on their inherent scattering and polarization signature. A motorized translation stage in combination with the JM-OCT prototype enabled large field-of-view imaging to investigate adult zebrafish in a non-destructive way. The diseased animals exhibited tumor-related abnormalities in the brain and near the eye region. The scatter intensity, the attenuation coefficients and local polarization parameters such as the birefringence and the degree of polarization uniformity were analyzed to quantify differences in tumor versus control regions. The proof-of-concept study in a limited number of animals revealed a significant decrease in birefringence in tumors found in the brain and near the eye compared to control regions. The presented work showed the potential of OCT and JM-OCT as non-destructive, high-resolution, and real-time imaging modalities for pre-clinical research based on zebrafish.
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Affiliation(s)
- Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Pradipta Mukherjee
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Lida Zhu
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Rion Morishita
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Kiriko Tomita
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Daisuke Oida
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | - Konrad Leskovar
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Ibrahim Abd El-Sadek
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
- Department of Physics, Faculty of Science, Damietta University, Egypt
| | - Shuichi Makita
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
| | | | - Martin Distel
- St. Anna Children’s Cancer Research Institute (CCRI), Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Yoshiaki Yasuno
- Computational Optics Group, Institute of Applied Physics, University of Tsukuba, Japan
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12
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Wang J, Baker A, Subramanian ML, Siegel NH, Chen X, Ness S, Yi J. Simultaneous visible light optical coherence tomography and near infrared OCT angiography in retinal pathologies: A case study. Exp Biol Med (Maywood) 2022; 247:377-384. [PMID: 34904454 PMCID: PMC8919322 DOI: 10.1177/15353702211063839] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A dual-channel optical coherence tomography system with wavelengths in the visible and near-infrared light ranges can provide both structural and functional information for retinal microvasculature simultaneously. We applied this integrated system in an ongoing clinical study of patients with various retinal pathologies. Here, we present case study results of patients with diabetic retinopathy, central retinal vein occlusion, and sickle cell retinopathy compared to a healthy subject. For the first time, this comparison validates the system's ability to detect structural anomalies in both en face and B-scan images with simultaneous retinal optical coherence tomography angiography and measurement of sO2 in parafoveal vessels that are around 20-30 µm in diameter. This integrated system represents a powerful instrument with potentially far-reaching clinical implications for the early detection and diagnosis of retinal vascular diseases.
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Affiliation(s)
- Jingyu Wang
- Department of Ophthalmology, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Andrew Baker
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Manju L Subramanian
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Nicole H Siegel
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Xuejing Chen
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Steven Ness
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Ji Yi
- Department of Ophthalmology, Johns Hopkins University, Baltimore, MD 21231, USA,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA,Ji Yi.
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13
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Abstract
Similar to other organs, the retina relies on tightly regulated perfusion and oxygenation. Previous studies have demonstrated that retinal blood flow is affected in a variety of eye and systemic diseases, including diabetic retinopathy, age-related macular degeneration, and glaucoma. Although measurement of peripheral oxygen saturation has become a standard clinical measurement through the development of pulse oximetry, developing a noninvasive technique to measure retinal oxygen saturation has proven challenging, and retinal oximetry technology currently remains inadequate for reliable clinical use. Here, we review current strategies and approaches, as well as several newer technologies in development, and discuss the future of retinal oximetry.
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Affiliation(s)
- Anupam K Garg
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA.,School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Darren Knight
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Leonardo Lando
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Daniel L Chao
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA.,School of Medicine, University of California San Diego, La Jolla, CA, USA.,Janssen Research and Development, Raritan, NJ, USA
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14
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Ringel MJ, Tang EM, Tao YK. Advances in multimodal imaging in ophthalmology. Ther Adv Ophthalmol 2021; 13:25158414211002400. [PMID: 35187398 PMCID: PMC8855415 DOI: 10.1177/25158414211002400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 02/23/2021] [Indexed: 12/12/2022] Open
Abstract
Multimodality ophthalmic imaging systems aim to enhance the contrast, resolution, and functionality of existing technologies to improve disease diagnostics and therapeutic guidance. These systems include advanced acquisition and post-processing methods using optical coherence tomography (OCT), combined scanning laser ophthalmoscopy and OCT systems, adaptive optics, surgical guidance, and photoacoustic technologies. Here, we provide an overview of these ophthalmic imaging systems and their clinical and basic science applications.
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Affiliation(s)
- Morgan J. Ringel
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Eric M. Tang
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Yuankai K. Tao
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
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15
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Zhang T, Kho AM, Yiu G, Srinivasan VJ. Visible Light Optical Coherence Tomography (OCT) Quantifies Subcellular Contributions to Outer Retinal Band 4. Transl Vis Sci Technol 2021; 10:30. [PMID: 34003965 PMCID: PMC7998011 DOI: 10.1167/tvst.10.3.30] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/17/2021] [Indexed: 01/07/2023] Open
Abstract
Purpose To use visible light optical coherence tomography (OCT) to investigate subcellular reflectivity contributions to the outermost (4th) of the retinal hyperreflective bands visualized by current clinical near-infrared (NIR) OCT. Methods Visible light OCT, with 1.0 µm axial resolution, was performed in 28 eyes of 19 human subjects (21-57 years old) without history of ocular pathology. Two foveal and three extrafoveal hyperreflective zones were consistently depicted within band 4 in all eyes. The two outermost hyperreflective bands, occasionally visualized by NIR OCT, were presumed to be the retinal pigment epithelium (RPE) and Bruch's membrane (BM). RPE thickness, BM thickness, and RPE interior reflectivity were quantified topographically across the macula. Results A method for correcting RPE multiple scattering tails was found to both improve the Gaussian goodness-of-fit for the BM intensity profile and reduce the coefficient of variation of BM thickness in vivo. No major topographical differences in macular BM thickness were noted. RPE thickness decreased with increasing eccentricity. Visible light OCT signal intensity in the RPE was weighted to the apical side and attenuated more across the RPE in the fovea than peripherally. Conclusions Morphometry of the presumed RPE and BM bands is consistent with known anatomy. Weighting of RPE reflectivity toward the apical side suggests that melanosomes are the predominant contributors to RPE backscattering and signal attenuation in young eyes. Translational Relevance By enabling morphometric analysis of the RPE and BM, visible light OCT deciphers the main reflectivity contributions to outer retinal band 4, commonly visualized by commercial OCT systems.
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Affiliation(s)
- Tingwei Zhang
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Aaron M. Kho
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Glenn Yiu
- Department of Ophthalmology and Vision Science, University of California Davis, Davis School of Medicine, Sacramento, California, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
- Department of Ophthalmology and Vision Science, University of California Davis, Davis School of Medicine, Sacramento, California, USA
- Department of Ophthalmology, New York University Langone Health, New York, New York, USA
- Department of Radiology, New York University Langone Health, New York, New York, USA
- Tech4Health Institute, New York University Langone Health, New York, New York, USA
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16
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Beykin G, Norcia AM, Srinivasan VJ, Dubra A, Goldberg JL. Discovery and clinical translation of novel glaucoma biomarkers. Prog Retin Eye Res 2020; 80:100875. [PMID: 32659431 DOI: 10.1016/j.preteyeres.2020.100875] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 06/01/2020] [Accepted: 06/04/2020] [Indexed: 12/16/2022]
Abstract
Glaucoma and other optic neuropathies are characterized by progressive dysfunction and loss of retinal ganglion cells and their axons. Given the high prevalence of glaucoma-related blindness and the availability of treatment options, improving the diagnosis and precise monitoring of progression in these conditions is paramount. Here we review recent progress in the development of novel biomarkers for glaucoma in the context of disease pathophysiology and we propose future steps for the field, including integration of exploratory biomarker outcomes into prospective therapeutic trials. We anticipate that, when validated, some of the novel glaucoma biomarkers discussed here will prove useful for clinical diagnosis and prediction of progression, as well as monitoring of clinical responses to standard and investigational therapies.
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Affiliation(s)
- Gala Beykin
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
| | - Anthony M Norcia
- Department of Psychology, Stanford University, 290 Jane Stanford Way, Stanford, CA, 94305, USA.
| | - Vivek J Srinivasan
- Department of Biomedical Engineering, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA; Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, 4610 X St, Sacramento, CA, 96817, USA.
| | - Alfredo Dubra
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
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17
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Song W, Shao W, Yi W, Liu R, Desai M, Ness S, Yi J. Visible light optical coherence tomography angiography (vis-OCTA) facilitates local microvascular oximetry in the human retina. BIOMEDICAL OPTICS EXPRESS 2020; 11:4037-4051. [PMID: 33014584 PMCID: PMC7510897 DOI: 10.1364/boe.395843] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 05/06/2023]
Abstract
We report herein the first visible light optical coherence tomography angiography (vis-OCTA) for human retinal imaging. Compared to the existing vis-OCT systems, we devised a spectrometer with a narrower bandwidth to increase the spectral power density for OCTA imaging, while retaining the major spectral contrast in the blood. We achieved a 100 kHz A-line rate, the fastest acquisition speed reported so far for human retinal vis-OCT. We rigorously optimized the imaging protocol such that a single acquisition took < 6 seconds with a field of view (FOV) of 3×7.8 mm2. The angiography enables accurate localization of microvasculature down to the capillary level and thus enables oximetry at vessels < 100 µm in diameter. We demonstrated microvascular hemoglobin oxygen saturation (sO2) at the feeding and draining vessels at the perifoveal region. The longitudinal repeatability was assessed by < 5% coefficient of variation (CV). The unique capabilities of our vis-OCTA system may allow studies on the role of microvascular oxygen in various retinal pathologies.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
| | - Wenjun Shao
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
| | - Wei Yi
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
| | - Rongrong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Manishi Desai
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
| | - Steven Ness
- Department of Ophthalmology, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston 02118, USA
- Department of Biomedical Engineering, Boston University, Boston 02118, USA
- Department of Electronic and Computer Engineering, Boston University, Boston 02118, USA
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18
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Lee B, Chen S, Moult EM, Yu Y, Alibhai AY, Mehta N, Baumal CR, Waheed NK, Fujimoto JG. High-Speed, Ultrahigh-Resolution Spectral-Domain OCT with Extended Imaging Range Using Reference Arm Length Matching. Transl Vis Sci Technol 2020; 9:12. [PMID: 32832219 PMCID: PMC7414734 DOI: 10.1167/tvst.9.7.12] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/02/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To develop high-speed, extended-range, ultrahigh-resolution spectral-domain optical coherence tomography (UHR SD-OCT) and demonstrate scan protocols for clinical retinal imaging. Methods A UHR SD-OCT operating at 840-nm with 150-nm bandwidths was developed. The axial imaging range was extended by dynamically matching reference arm length to the retinal contour during acquisition. Two scan protocols were demonstrated for imaging healthy participants and patients with dry age-related macular degeneration. A high-definition raster protocol with intra–B-scan reference arm length matching (ReALM) was used for high-quality cross-sectional imaging. A cube volume scan using horizontal and vertical rasters with inter–B-scan ReALM and software motion correction was used for en face and cross-sectional imaging. Linear OCT signal display enhanced visualization of outer retinal features. Results UHR SD-OCT was demonstrated at 128- and 250-kHz A-scan rates with 2.7 µm axial resolution and a 1.2-mm, 6-dB imaging range in the eye. Dynamic ReALM was used to maintain the retina within the 6-dB imaging range over wider fields of view. Outer retinal features, including the rod and cone interdigitation zones, retinal pigment epithelium, and Bruch's membrane were visualized and alterations observed in age-related macular degeneration eyes. Conclusions Technological advances and dynamic ReALM improve the imaging performance and clinical usability of UHR SD-OCT. Translational Relevance These advances should simplify clinical imaging workflow, reduce imaging session times, and improve yield of high quality images. Improved visualization of photoreceptors, retinal pigment epithelium, and Bruch's membrane may facilitate diagnosis and monitoring of age-related macular degeneration and other retinal diseases.
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Affiliation(s)
- ByungKun Lee
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Siyu Chen
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric M Moult
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yue Yu
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - A Yasin Alibhai
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Nihaal Mehta
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Caroline R Baumal
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Nadia K Waheed
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
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19
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Pi S, Hormel TT, Wei X, Cepurna W, Morrison JC, Jia Y. Imaging retinal structures at cellular-level resolution by visible-light optical coherence tomography. OPTICS LETTERS 2020; 45:2107-2110. [PMID: 32236080 PMCID: PMC8575555 DOI: 10.1364/ol.386454] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/05/2020] [Indexed: 05/10/2023]
Abstract
In vivo high-resolution images are the most direct way to understand retinal function and diseases. Here we report the use of visible-light optical coherence tomography with volumetric registration and averaging to achieve cellular-level retinal structural imaging in a rat eye, covering the entire depth of the retina. Vitreous fibers, nerve fiber bundles, and vasculature were clearly revealed, as well as at least three laminar sublayers in the inner plexiform layer. We also successfully visualized ganglion cell somas in the ganglion cell layer, cells in the inner nuclear layer, and photoreceptors in the outer nuclear layer and ellipsoid zone. This technique provides, to the best of our knowledge, a new means to visualize the retina in vivo at a cellular resolution and may enable detection or discovery of cellular neuronal biomarkers to help better diagnose ocular disease.
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Affiliation(s)
- Shaohua Pi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Tristan T. Hormel
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Xiang Wei
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - William Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - John C. Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
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20
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Augustin M, Harper DJ, Merkle CW, Glösmann M, Hitzenberger CK, Baumann B. Optical Coherence Tomography Findings in the Retinas of SOD1 Knockout Mice. Transl Vis Sci Technol 2020; 9:15. [PMID: 32818102 PMCID: PMC7396182 DOI: 10.1167/tvst.9.4.15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 12/16/2019] [Indexed: 01/22/2023] Open
Abstract
Purpose The retinal phenotype of popular mouse models mimicking ophthalmic diseases, such as the superoxide dismutase 1 (SOD1) knockout (KO) mouse model, has mainly been assessed by ex vivo histology and in vivo fundus photography. We used multifunctional optical coherence tomography (OCT) to characterize the retinas of SOD1 KO mice in vivo. Methods The custom-made ophthalmoscope featured a combination of conventional OCT, polarization-sensitive OCT, and OCT angiography. Seven SOD1 KO mice and nine age-matched controls were imaged between 6 and 17 months of age. A postprocessing framework was used to analyze total and outer retinal thickness changes. Drusenlike lesions were segmented, and their sizes and the number of lesions were assessed quantitatively. Their appearance in the conventional reflectivity images, as well as in the corresponding polarization-sensitive images, was characterized qualitatively. Results Drusenlike lesions increased in size and number with age for SOD1 KO mice. Exploiting the multiple contrast channels, the appearance of the lesions was found to resemble pseudodrusen observed in eyes of patients suffering from dry age-related macular degeneration. The total and outer retinal thicknesses were lower on average after 11 months and 7 months in SOD1 KO mice compared with age-matched controls. Neovascularizations were found in one out of seven KO animals. Conclusions OCT imaging proved beneficial for a detailed in vivo characterization of the pathological changes in SOD1 KO mice. Translational Relevance Phenotyping of animal models using modern imaging concepts can be conducted with more precision and might also ease the translation of conclusions between clinical and preclinical research.
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Affiliation(s)
- Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Danielle J Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Conrad W Merkle
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Martin Glösmann
- VetCore Facility for Research, Imaging Unit, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Christoph K Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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21
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22
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Liu R, Cheng S, Tian L, Yi J. Deep spectral learning for label-free optical imaging oximetry with uncertainty quantification. LIGHT, SCIENCE & APPLICATIONS 2019; 8:102. [PMID: 31754429 PMCID: PMC6864044 DOI: 10.1038/s41377-019-0216-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/17/2019] [Accepted: 11/01/2019] [Indexed: 05/06/2023]
Abstract
Measurement of blood oxygen saturation (sO2) by optical imaging oximetry provides invaluable insight into local tissue functions and metabolism. Despite different embodiments and modalities, all label-free optical-imaging oximetry techniques utilize the same principle of sO2-dependent spectral contrast from haemoglobin. Traditional approaches for quantifying sO2 often rely on analytical models that are fitted by the spectral measurements. These approaches in practice suffer from uncertainties due to biological variability, tissue geometry, light scattering, systemic spectral bias, and variations in the experimental conditions. Here, we propose a new data-driven approach, termed deep spectral learning (DSL), to achieve oximetry that is highly robust to experimental variations and, more importantly, able to provide uncertainty quantification for each sO2 prediction. To demonstrate the robustness and generalizability of DSL, we analyse data from two visible light optical coherence tomography (vis-OCT) setups across two separate in vivo experiments on rat retinas. Predictions made by DSL are highly adaptive to experimental variabilities as well as the depth-dependent backscattering spectra. Two neural-network-based models are tested and compared with the traditional least-squares fitting (LSF) method. The DSL-predicted sO2 shows significantly lower mean-square errors than those of the LSF. For the first time, we have demonstrated en face maps of retinal oximetry along with a pixel-wise confidence assessment. Our DSL overcomes several limitations of traditional approaches and provides a more flexible, robust, and reliable deep learning approach for in vivo non-invasive label-free optical oximetry.
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Affiliation(s)
- Rongrong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Shiyi Cheng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
| | - Ji Yi
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02215 USA
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118 USA
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23
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Pi S, Hormel TT, Wei X, Cepurna W, Camino A, Guo Y, Huang D, Morrison J, Jia Y. Monitoring retinal responses to acute intraocular pressure elevation in rats with visible light optical coherence tomography. NEUROPHOTONICS 2019; 6:041104. [PMID: 31312671 PMCID: PMC6624745 DOI: 10.1117/1.nph.6.4.041104] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/21/2019] [Indexed: 05/08/2023]
Abstract
Elevated intraocular pressure (IOP) is an important risk factor for glaucoma. However, the role of IOP in glaucoma progression, as well as retinal physiology in general, remains incompletely understood. We demonstrate the use of visible light optical coherence tomography to measure retinal responses to acute IOP elevation in Brown Norway rats. We monitored retinal responses in reflectivity, angiography, blood flow, oxygen saturation ( sO 2 ), and oxygen metabolism over a range of IOP from 10 to 100 mmHg. As IOP was elevated, nerve fiber layer reflectivity was found to decrease. Vascular perfusion in the three retinal capillary plexuses remained steady until IOP exceeded 70 mmHg and arterial flow was noted to reverse periodically at high IOPs. However, a significant drop in total retinal blood flow was observed first at 40 mmHg. As IOP increased, the venous sO 2 demonstrated a gradual decrease despite steady arterial sO 2 , which is consistent with increased arterial-venous oxygen extraction across the retinal capillary beds. Calculated total retinal oxygen metabolism was steady, reflecting balanced responses of blood flow and oxygen extraction, until IOP exceeded 40 mmHg, and fell to 0 at 70 and 80 mmHg. Above this, measurements were unattainable. All measurements reverted to baseline when the IOP was returned to 10 mmHg, indicating good recovery following acute pressure challenge. These results demonstrate the ability of this system to monitor retinal oxygen metabolism noninvasively and how it can help us understand retinal responses to elevated IOP.
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Affiliation(s)
- Shaohua Pi
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Tristan T. Hormel
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Xiang Wei
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - William Cepurna
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Acner Camino
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Yukun Guo
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - David Huang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - John Morrison
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Yali Jia
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
- Address all correspondence to Yali Jia, E-mail:
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Beckmann L, Zhang X, Nadkarni NA, Cai Z, Batra A, Sullivan DP, Muller WA, Sun C, Kuranov R, Zhang HF. Longitudinal deep-brain imaging in mouse using visible-light optical coherence tomography through chronic microprism cranial window. BIOMEDICAL OPTICS EXPRESS 2019; 10:5235-5250. [PMID: 31646044 PMCID: PMC6788609 DOI: 10.1364/boe.10.005235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 05/02/2023]
Abstract
We longitudinally imaged both the superficial and deep cortical microvascular networks in brains of healthy mice and in a mouse model of stroke in vivo using visible-light optical coherence tomography (vis-OCT). We surgically implanted a microprism in mouse brains sealed by a chronic cranial window. The microprism enabled vis-OCT to image the entire depth of the mouse cortex. Following microprism implantation, we imaged the mice for 28 days and found that that it took around 15 days for both the superficial and deep cortical microvessels to recover from the implantation surgery. After the brains recovered, we introduced ischemic strokes by transient middle cerebral artery occlusion (tMCAO). We monitored the strokes for up to 60 days and observed different microvascular responses to tMCAO at different cortical depths in both the acute and chronic phases of the stroke. This work demonstrates that the combined microprism and cranial window is well-suited for longitudinal investigation of cortical microvascular disorders using vis-OCT.
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Affiliation(s)
- Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- These authors contributed equally to this work
| | - Xian Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
- These authors contributed equally to this work
| | - Neil A. Nadkarni
- Department of Neurology, Northwestern University, Chicago IL 60611, USA
| | - Zhen Cai
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Ayush Batra
- Department of Neurology, Northwestern University, Chicago IL 60611, USA
| | - David P. Sullivan
- Department of Pathology, Northwestern University, Chicago IL 60611, USA
| | - William A. Muller
- Department of Pathology, Northwestern University, Chicago IL 60611, USA
| | - Cheng Sun
- Department of Mechanical Engineering, Northwestern University, Evanston IL 60208, USA
| | - Roman Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Opticent Health, Evanston IL, Evanston IL 60201, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
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25
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Rubinoff I, Beckmann L, Wang Y, Fawzi AA, Liu X, Tauber J, Jones K, Ishikawa H, Schuman JS, Kuranov R, Zhang HF. Speckle reduction in visible-light optical coherence tomography using scan modulation. NEUROPHOTONICS 2019; 6:041107. [PMID: 31482105 PMCID: PMC6718816 DOI: 10.1117/1.nph.6.4.041107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/08/2019] [Indexed: 05/25/2023]
Abstract
We present a technique to reduce speckle in visible-light optical coherence tomography (vis-OCT) that preserves fine structural details and is robust against sample motion. Specifically, we locally modulate B-scans orthogonally to their axis of acquisition. Such modulation enables acquisition of uncorrelated speckle patterns from similar anatomical locations, which can be averaged to reduce speckle. To verify the effectiveness of speckle reduction, we performed in-vivo retinal imaging using modulated raster and circular scans in both mice and humans. We compared speckle-reduced vis-OCT images with the images acquired with unmodulated B-scans from the same anatomical locations. We compared contrast-to-noise ratio (CNR) and equivalent number of looks (ENL) to quantify the image quality enhancement. Speckle-reduced images showed up to a 2.35-dB improvement in CNR and up to a 3.1-fold improvement in ENL with more discernable anatomical features using eight modulated A-line averages at a 25-kHz A-line rate.
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Affiliation(s)
- Ian Rubinoff
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Lisa Beckmann
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Yuanbo Wang
- Opticent Health, Evanston, Illinois, United States
| | - Amani A. Fawzi
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
| | - Xiaorong Liu
- University of Virginia, Department of Biology and Psychology, Charlottesville, Virginia, United States
| | - Jenna Tauber
- New York University, Department of Ophthalmology, New York, United States
| | - Katie Jones
- New York University, Department of Ophthalmology, New York, United States
| | - Hiroshi Ishikawa
- New York University, Department of Ophthalmology, New York, United States
| | - Joel S. Schuman
- New York University, Department of Ophthalmology, New York, United States
| | - Roman Kuranov
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Opticent Health, Evanston, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
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26
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Song W, Fu S, Song S, Zhang S, Zhang L, Ness S, Desai M, Yi J. Longitudinal detection of retinal alterations by visible and near-infrared optical coherence tomography in a dexamethasone-induced ocular hypertension mouse model. NEUROPHOTONICS 2019; 6:041103. [PMID: 31312670 PMCID: PMC6614697 DOI: 10.1117/1.nph.6.4.041103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 06/12/2019] [Indexed: 05/23/2023]
Abstract
The retina, as part of the central nervous system, has distinct anatomical and structural properties for its visual function. Light scattering spectroscopy, while widely used for tissue structural characterization and disease diagnosis, has been relatively unexplored in the living retina. Recently, we have developed a fiber-based visible and near-infrared optical coherence tomography system (vnOCT) for in vivo retinal imaging, to uniquely measure a spectroscopic marker (VN ratio) sensitive to nanoscale pathological changes. In the present study, we applied vnOCT in an animal model of glaucoma (dexamethasone-induced ocular hypertension mouse) and tested the capabilities of four optical markers, VN ratio, peripapillary retinal nerve fiber layer (RNFL) thickness, total retinal blood flow, and hemoglobin oxygen saturation ( sO 2 ), for the detection of retinal ganglion cell (RGC) damage in association with ocular hypertension. We found that RNFL-RGC VN ratio and arteriovenous (A-V) sO 2 are capable of detecting early retinal alteration in ocular hypertensive eyes, preceding measurable change of RNFL thickness. This study suggests a potential clinical application of vnOCT in early detection of glaucoma.
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Affiliation(s)
- Weiye Song
- Boston University School of Medicine, Boston Medical Center, Department of Medicine, Boston, Massachusetts, United States
| | - Sipei Fu
- Boston University, Department of Biology, Boston, Massachusetts, United States
| | - Shangshang Song
- Boston University Sargent School of Rehabilitation, Department of Health Science, Boston, Massachusetts, United States
| | - Sui Zhang
- Dana-Farber Cancer Institute, Boston, Massachusetts, United States
| | - Lei Zhang
- Boston University School of Medicine, Boston Medical Center, Department of Medicine, Boston, Massachusetts, United States
| | - Steven Ness
- Boston Medical Center, Department of Ophthalmology, Boston, Massachusetts, United States
| | - Manishi Desai
- Boston Medical Center, Department of Ophthalmology, Boston, Massachusetts, United States
| | - Ji Yi
- Boston University School of Medicine, Boston Medical Center, Department of Medicine, Boston, Massachusetts, United States
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
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27
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Zhang T, Kho AM, Srinivasan VJ. Improving visible light OCT of the human retina with rapid spectral shaping and axial tracking. BIOMEDICAL OPTICS EXPRESS 2019; 10:2918-2931. [PMID: 31259062 PMCID: PMC6583340 DOI: 10.1364/boe.10.002918] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 05/23/2023]
Abstract
Visible light optical coherence tomography (OCT) theoretically provides finer axial resolution than near-infrared OCT for a given wavelength bandwidth. To realize this potential in the human retina in vivo, the unique technical challenges of visible light OCT must be addressed. We introduce three advances to further the performance of visible light OCT in the human retina. First, we incorporate a grating light valve spatial light modulator (GLV-SLM) spectral shaping stage to modify the source spectrum. This enables comfortable subject alignment with a red light spectrum, and image acquisition with a broad "white light" spectrum, shaped to minimize sidelobes. Second, we develop a novel, Fourier transform-free, software axial motion tracking algorithm with fast, magnetically actuated stage to maintain near-optimal axial resolution and sensitivity in the presence of eye motion. Third, we implement spatially dependent numerical dispersion compensation for the first time in the human eye in vivo. In vivo human retinal OCT images clearly show that the inner plexiform layer consists of 3 hyper-reflective bands and 2 hypo-reflective bands, corresponding with the standard anatomical division of the IPL. Wavelength-dependent images of the outer retina suggest that, beyond merely improving the axial resolution, shorter wavelength visible light may also provide unique advantages for visualizing Bruch's membrane.
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Affiliation(s)
- Tingwei Zhang
- Biomedical Engineering Department, University of California Davis, Davis, California, 95616, USA
| | - Aaron M. Kho
- Biomedical Engineering Department, University of California Davis, Davis, California, 95616, USA
| | - Vivek J. Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, California, 95616, USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, California, 95817, USA
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28
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Shu X, Beckmann L, Wang Y, Rubinoff I, Lucy K, Ishikawa H, Wollstein G, Fawzi AA, Schuman JS, Kuranov RV, Zhang HF. Designing visible-light optical coherence tomography towards clinics. Quant Imaging Med Surg 2019; 9:769-781. [PMID: 31281773 PMCID: PMC6571199 DOI: 10.21037/qims.2019.05.01] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/04/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND The capabilities of visible-light optical coherence tomography (vis-OCT) in noninvasive anatomical and functional retinal imaging have been demonstrated by multiple groups in both rodents and healthy human subjects. Translating laboratory prototypes to an integrated clinical-environment-friendly system is required to explore the full potential of vis-OCT in disease management. METHODS We developed and optimized a portable vis-OCT system for human retinal imaging in clinical settings. We acquired raster- and circular-scan images from both healthy and diseased human eyes. RESULTS The new vis-OCT provided high-quality retinal images of both subjects without any known eye diseases and patients with various retinal diseases, including retinal occlusive disease and diabetic retinopathy (DR) over a broad range of ages. CONCLUSIONS A newly designed vis-OCT system is sufficiently optimized to be suited for routine patients' examinations in clinics. Vis-OCT has the potential to add new anatomical and functional imaging capabilities to ophthalmic clinical care.
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Affiliation(s)
- Xiao Shu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | | | - Ian Rubinoff
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Katie Lucy
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Hiroshi Ishikawa
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Gadi Wollstein
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
| | - Joel S. Schuman
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Roman V. Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Opticent Health, Evanston, IL, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
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29
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Song W, Zhou L, Yi J. Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy (oSLO) and Optical Coherence Tomography (OCT). J Vis Exp 2018. [PMID: 30124648 DOI: 10.3791/57814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
While fluorescence imaging is widely used in ophthalmology, a large field of view (FOV) three-dimensional (3D) fluorescence retinal image is still a big challenge with the state-of-the-art retinal imaging modalities because they would require z-stacking to compile a volumetric dataset. Newer optical coherence tomography (OCT) and OCT angiography (OCTA) systems overcome these restrictions to provide three-dimensional (3D) anatomical and vascular images, but the dye-free nature of OCT cannot visualize leakage indicative of vascular dysfunction. This protocol describes a novel oblique scanning laser ophthalmoscopy (oSLO) technique that provides 3D volumetric fluorescence retinal imaging. The setup of the imaging system generates the oblique scanning by a dove tail slider and aligns the final imaging system at an angle to detect fluorescent cross-sectional images. The system uses the laser scanning method, and therefore, allows an easy incorporation of OCT as a complementary volumetric structural imaging modality. In vivo imaging on rat retina is demonstrated here. Fluorescein solution is intravenously injected to produce volumetric fluorescein angiography (vFA).
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine
| | - Libo Zhou
- Department of Medicine, Boston University School of Medicine
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine; Department of Biomedical Engineering, Boston University;
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30
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Soetikno BT, Beckmann L, Zhang X, Fawzi AA, Zhang HF. Visible-light optical coherence tomography oximetry based on circumpapillary scan and graph-search segmentation. BIOMEDICAL OPTICS EXPRESS 2018; 9:3640-3652. [PMID: 30338145 PMCID: PMC6191632 DOI: 10.1364/boe.9.003640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/25/2018] [Accepted: 06/25/2018] [Indexed: 05/18/2023]
Abstract
Visible-light optical coherence tomography (vis-OCT) enables retinal oximetry by measuring the oxygen saturation of hemoglobin (sO2) from within individual retinal blood vessels. The sO2 calculation requires reliable estimation of the true spectrum of backscattered light from the posterior vessel wall. Unfortunately, subject motion and image noise make averaging from multiple A-lines at the same depth position challenging, and lead to inaccurate sO2 estimation. In this study, we developed an algorithm to reliably extract the backscattered light's spectrum. We used circumpapillary scanning to sample the vessels repeatedly at the same location. A combination of cross-correlation and graph-search based segmentation extracted the posterior wall locations. Using measurements from 100 B-scans as a gold standard, we demonstrated that our method achieved highly accurate measures of sO2 with minimal bias. In addition, we also investigated how the number of repeated measurements affects the accuracy of sO2 measurement. Our method sets the stage for large-scale studies of retinal oxygenation in animals and humans.
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Affiliation(s)
- Brian T. Soetikno
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
- Medical Scientist Training Program, Northwestern University, Chicago, IL, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Xian Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
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31
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Song W, Zhou L, Zhang S, Ness S, Desai M, Yi J. Fiber-based visible and near infrared optical coherence tomography (vnOCT) enables quantitative elastic light scattering spectroscopy in human retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:3464-3480. [PMID: 29984110 PMCID: PMC6033571 DOI: 10.1364/boe.9.003464] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/09/2018] [Accepted: 06/21/2018] [Indexed: 05/18/2023]
Abstract
Elastic light scattering spectroscopy (ELSS) has been proven a powerful method in measuring tissue structures with exquisite nanoscale sensitivity. However, ELSS contrast in the living human retina has been relatively underexplored, primarily due to the lack of imaging tools with a large spectral bandwidth. Here, we report a simple all fiber-based setup to implement dual-channel visible and near infrared (NIR) optical coherence tomography (vnOCT) for human retinal imaging, bridging over a 300nm spectral gap. Remarkably, the fiber components in our vnOCT system support single-mode propagation for both visible and NIR light, both of which maintain excellent interference efficiencies with fringe visibility of 97% and 90%, respectively. The longitudinal chromatic aberration from the eye is corrected by a custom-designed achromatizing lens. The elegant fiber-based design enables simultaneous imaging for both channels and allows comprehensive ELSS analysis on several important anatomical layers, including nerve fiber layer, outer segment of the photoreceptors and retinal pigment epithelium. This vnOCT platform and method of ELSS analysis open new opportunities in understanding structure-function relationship in the human retina and in exploring new biomarkers for retinal diseases.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Libo Zhou
- College of Electronic Science and Engineering, Jilin University, Changchun, Jilin, 130012, China
| | - Sui Zhang
- Danna-Farber Cancer Institute, Boston, MA 02215, USA
| | - Steven Ness
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Manishi Desai
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02118, USA
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32
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Harper DJ, Augustin M, Lichtenegger A, Eugui P, Reyes C, Glösmann M, Hitzenberger CK, Baumann B. White light polarization sensitive optical coherence tomography for sub-micron axial resolution and spectroscopic contrast in the murine retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:2115-2129. [PMID: 29760974 PMCID: PMC5946775 DOI: 10.1364/boe.9.002115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 05/03/2023]
Abstract
A white light polarization sensitive optical coherence tomography system has been developed, using a supercontinuum laser as the light source. By detecting backscattered light from 400 - 700 nm, an axial resolution of 1.0 µm in air was achieved. The system consists of a free-space interferometer and two homemade spectrometers that detect orthogonal polarization states. Following system specifications, images of a healthy murine retina as acquired by this non-contact system are presented, showing high resolution reflectivity images as well as spectroscopic and polarization sensitive contrast. Additional images of the very-low-density-lipoprotein-receptor (VLDLR) knockout mouse model were acquired. The high resolution allows the detection of small lesions in the retina.
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Affiliation(s)
- Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Carlos Reyes
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Martin Glösmann
- University of Veterinary Medicine Vienna, Core Facility for Research and Technology, Veterinaerplatz 1, 1210 Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
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33
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Chong SP, Zhang T, Kho A, Bernucci MT, Dubra A, Srinivasan VJ. Ultrahigh resolution retinal imaging by visible light OCT with longitudinal achromatization. BIOMEDICAL OPTICS EXPRESS 2018; 9:1477-1491. [PMID: 29675296 PMCID: PMC5905900 DOI: 10.1364/boe.9.001477] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 01/30/2018] [Accepted: 02/03/2018] [Indexed: 05/18/2023]
Abstract
Chromatic aberrations are an important design consideration in high resolution, high bandwidth, refractive imaging systems that use visible light. Here, we present a fiber-based spectral/Fourier domain, visible light OCT ophthalmoscope corrected for the average longitudinal chromatic aberration (LCA) of the human eye. Analysis of complex speckles from in vivo retinal images showed that achromatization resulted in a speckle autocorrelation function that was ~20% narrower in the axial direction, but unchanged in the transverse direction. In images from the improved, achromatized system, the separation between Bruch's membrane (BM), the retinal pigment epithelium (RPE), and the outer segment tips clearly emerged across the entire 6.5 mm field-of-view, enabling segmentation and morphometry of BM and the RPE in a human subject. Finally, cross-sectional images depicted distinct inner retinal layers with high resolution. Thus, with chromatic aberration compensation, visible light OCT can achieve volume resolutions and retinal image quality that matches or exceeds ultrahigh resolution near-infrared OCT systems with no monochromatic aberration compensation.
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Affiliation(s)
- Shau Poh Chong
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
- Equal contributions
| | - Tingwei Zhang
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
- Equal contributions
| | - Aaron Kho
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
| | - Marcel T. Bernucci
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
| | - Alfredo Dubra
- Byers Eye Institute, Stanford University, Palo Alto, CA 94303, USA
| | - Vivek J. Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817, USA
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34
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Marchand PJ, Szlag D, Bouwens A, Lasser T. In vivo high-resolution cortical imaging with extended-focus optical coherence microscopy in the visible-NIR wavelength range. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-7. [PMID: 29575831 DOI: 10.1117/1.jbo.23.3.036012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/07/2018] [Indexed: 05/10/2023]
Abstract
Visible light optical coherence tomography has shown great interest in recent years for spectroscopic and high-resolution retinal and cerebral imaging. Here, we present an extended-focus optical coherence microscopy system operating from the visible to the near-infrared wavelength range for high axial and lateral resolution imaging of cortical structures in vivo. The system exploits an ultrabroad illumination spectrum centered in the visible wavelength range (λc = 650 nm, Δλ ∼ 250 nm) offering a submicron axial resolution (∼0.85 μm in water) and an extended-focus configuration providing a high lateral resolution of ∼1.4 μm maintained over ∼150 μm in depth in water. The system's axial and lateral resolution are first characterized using phantoms, and its imaging performance is then demonstrated by imaging the vasculature, myelinated axons, and neuronal cells in the first layers of the somatosensory cortex of mice in vivo.
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Affiliation(s)
- Paul J Marchand
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Daniel Szlag
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Arno Bouwens
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Theo Lasser
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
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35
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Shu X, Beckmann L, Zhang HF. Visible-light optical coherence tomography: a review. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-14. [PMID: 29218923 PMCID: PMC5745673 DOI: 10.1117/1.jbo.22.12.121707] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 11/13/2017] [Indexed: 05/03/2023]
Abstract
Visible-light optical coherence tomography (vis-OCT) is an emerging imaging modality, providing new capabilities in both anatomical and functional imaging of biological tissue. It relies on visible light illumination, whereas most commercial and investigational OCTs use near-infrared light. As a result, vis-OCT requires different considerations in engineering design and implementation but brings unique potential benefits to both fundamental research and clinical care of several diseases. Here, we intend to provide a summary of the development of vis-OCT and its demonstrated applications. We also provide perspectives on future technology improvement and applications.
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Affiliation(s)
- Xiao Shu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Lisa Beckmann
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
- Address all correspondence to: Hao F. Zhang, E-mail:
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36
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Pi S, Camino A, Zhang M, Cepurna W, Liu G, Huang D, Morrison J, Jia Y. Angiographic and structural imaging using high axial resolution fiber-based visible-light OCT. BIOMEDICAL OPTICS EXPRESS 2017; 8:4595-4608. [PMID: 29082087 PMCID: PMC5654802 DOI: 10.1364/boe.8.004595] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/14/2017] [Accepted: 09/17/2017] [Indexed: 05/20/2023]
Abstract
Optical coherence tomography using visible-light sources can increase the axial resolution without the need for broader spectral bandwidth. Here, a high-resolution, fiber-based, visible-light optical coherence tomography system is built and used to image normal retina in rats and blood vessels in chicken embryo. In the rat retina, accurate segmentation of retinal layer boundaries and quantification of layer thicknesses are accomplished. Furthermore, three distinct capillary plexuses in the retina and the choriocapillaris are identified and the characteristic pattern of the nerve fiber layer thickness in rats is revealed. In the chicken embryo model, the microvascular network and a venous bifurcation are examined and the ability to identify and segment large vessel walls is demonstrated.
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Affiliation(s)
- Shaohua Pi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
- These authors contributed equally to this work
| | - Acner Camino
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
- These authors contributed equally to this work
| | - Miao Zhang
- Optovue Inc. 2800 Bayview Dr., Fremont, CA 94538, USA
| | - William Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Gangjun Liu
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - John Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
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Nesper PL, Soetikno BT, Zhang HF, Fawzi AA. OCT angiography and visible-light OCT in diabetic retinopathy. Vision Res 2017; 139:191-203. [PMID: 28601429 PMCID: PMC5723235 DOI: 10.1016/j.visres.2017.05.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 12/31/2022]
Abstract
In recent years, advances in optical coherence tomography (OCT) techniques have increased our understanding of diabetic retinopathy, an important microvascular complication of diabetes. OCT angiography is a non-invasive method that visualizes the retinal vasculature by detecting motion contrast from flowing blood. Visible-light OCT shows promise as a novel technique for quantifying retinal hypoxia by measuring the retinal oxygen delivery and metabolic rates. In this article, we discuss recent insights provided by these techniques into the vascular pathophysiology of diabetic retinopathy. The next milestones for these modalities are large multicenter studies to establish consensus on the most reliable and consistent outcome parameters to study diabetic retinopathy.
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Affiliation(s)
- Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA.
| | - Brian T Soetikno
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA; Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA; Medical Scientist Training Program, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA.
| | - Hao F Zhang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA; Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA.
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Shu X, Liu W, Duan L, Zhang HF. Spectroscopic Doppler analysis for visible-light optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-8. [PMID: 29043714 PMCID: PMC5644441 DOI: 10.1117/1.jbo.22.12.121702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/18/2017] [Indexed: 05/20/2023]
Abstract
Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.
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Affiliation(s)
- Xiao Shu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Wenzhong Liu
- Opticent Health, Evanston, Illinois, United States
| | - Lian Duan
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
- Address all correspondence to: Hao F. Zhang, E-mail:
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39
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Song W, Zhang L, Ness S, Yi J. Wavelength-dependent optical properties of melanosomes in retinal pigmented epithelium and their changes with melanin bleaching: a numerical study. BIOMEDICAL OPTICS EXPRESS 2017; 8:3966-3980. [PMID: 29026682 PMCID: PMC5611916 DOI: 10.1364/boe.8.003966] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 05/21/2023]
Abstract
In this paper, we present the first numerical study on full metrics of wavelength-dependent optical properties of melanosomes in retinal pigmented epithelial (RPE) cells. T-matrix method was used to simulate the spheroidal shapes of mature melanosomes, and the complex refractive index was calculated by a subtractive Kramers-Kronig relation for melanin. The validity of the method was first confirmed by Mie theory, and corroborated by a comparison between visible light and near infrared (NIR) optical coherence tomography (OCT) on human retinal imaging. We also studied the changes of melanosome optical properties due to melanin bleaching by numerically reducing the absorption of melanin. This study implies a unique approach to detect melanin changes specifically in RPE by a spectroscopic contrast of optical coherence tomography.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Lei Zhang
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Steve Ness
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Center of Regenerative Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Boston University Photonics Center, Boston, MA 02215, USA
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40
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Lichtenegger A, Harper DJ, Augustin M, Eugui P, Muck M, Gesperger J, Hitzenberger CK, Woehrer A, Baumann B. Spectroscopic imaging with spectral domain visible light optical coherence microscopy in Alzheimer's disease brain samples. BIOMEDICAL OPTICS EXPRESS 2017; 8:4007-4025. [PMID: 28966843 PMCID: PMC5611919 DOI: 10.1364/boe.8.004007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/02/2017] [Accepted: 08/02/2017] [Indexed: 05/18/2023]
Abstract
A visible light spectral domain optical coherence microscopy system was developed. A high axial resolution of 0.88 μm in tissue was achieved using a broad visible light spectrum (425 - 685 nm). Healthy human brain tissue was imaged to quantify the difference between white (WM) and grey matter (GM) in intensity and attenuation. The high axial resolution enables the investigation of amyloid-beta plaques of various sizes in human brain tissue and animal models of Alzheimer's disease (AD). By performing a spectroscopic analysis of the OCM data, differences in the characteristics for WM, GM, and neuritic amyloid-beta plaques were found. To gain additional contrast, Congo red stained AD brain tissue was investigated. A first effort was made to investigate optically cleared mouse brain tissue to increase the penetration depth and visualize hyperscattering structures in deeper cortical regions.
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Affiliation(s)
- Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Martina Muck
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Johanna Gesperger
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Adelheid Woehrer
- Institute of Neurology, General Hospital and Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna,
Austria
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Liu W, Wang S, Soetikno B, Yi J, Zhang K, Chen S, Linsenmeier RA, Sorenson CM, Sheibani N, Zhang HF. Increased Retinal Oxygen Metabolism Precedes Microvascular Alterations in Type 1 Diabetic Mice. Invest Ophthalmol Vis Sci 2017; 58:981-989. [PMID: 28535269 PMCID: PMC5308771 DOI: 10.1167/iovs.16-20600] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose To investigate inner retinal oxygen metabolic rate (IRMRO2) during early stages of type 1 diabetes in a transgenic mouse model. Methods In current study, we involved seven diabetic mice (Akita/+, TSP1−/−) and seven control mice (TSP1−/−), and applied visible-light optical coherence tomography (vis-OCT) to image functional parameters including retinal blood flow rate, oxygen saturation (sO2) and the IRMRO2 value longitudinally from 5 weeks of age to 13 weeks of age. After imaging at 13 weeks of age, we analyzed the imaging results, and examined histology of mouse retina. Results Between diabetic mice and the control group, we observed significant differences in venous sO2 from 9 weeks of age (P = 0.006), and significant increment in IRMRO2 from 11 weeks of age (P = 0.001) in diabetic mice compared with control group. We did not find significant differences in retinal blood flow rate as well as arterial sO2 during imaging between diabetic and control mice. Histologic examination of diabetic and control mice at 13 weeks of age also revealed no anatomical retinal alternations. Conclusions In diabetic retinopathy, complications in retinal oxygen metabolism may occur before changes of retinal anatomical structure.
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Affiliation(s)
- Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Shoujian Wang
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Brian Soetikno
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Ji Yi
- Department of Medicine, Boston University, Boston, Massachusetts, United States
| | - Kevin Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Robert A Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States 5Department of Neurobiology, Northwestern University, Evanston, Illinois, United States
| | - Christine M Sorenson
- Department of Pediatrics, University Wisconsin, Madison, Wisconsin, United States
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States
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42
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Shah RS, Soetikno BT, Yi J, Liu W, Skondra D, Zhang HF, Fawzi AA. Visible-Light Optical Coherence Tomography Angiography for Monitoring Laser-Induced Choroidal Neovascularization in Mice. Invest Ophthalmol Vis Sci 2017; 57:OCT86-95. [PMID: 27409510 PMCID: PMC4968775 DOI: 10.1167/iovs.15-18891] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This study sought to determine the earliest time-point at which evidence of choroidal neovascularization (CNV) could be detected with visible-light optical coherence tomography angiography (vis-OCTA) in a mouse model of laser-induced CNV. Methods Visible light-OCTA was used to study laser-induced CNV at different time-points after laser injury to monitor CNV development and measure CNV lesion size. Measurements obtained from vis-OCTA angiograms were compared with histopathologic measurements from isolectin-stained choroidal flatmounts. Results Choroidal neovascularization area measurements between the vis-OCTA system and isolectin-stained choroidal flatmounts were significantly different in area for days 2 to 4 postlaser injury, and were not significantly different in area for days 5, 7, and 14. Choroidal neovascularization area measurements taken from the stained flatmounts were larger than their vis-OCTA counterparts for all time-points. Both modalities showed a similar trend of CNV size increasing from the day of laser injury until a peak of day 7 postlaser injury and subsequently decreasing by day 14. Conclusions The earliest vis-OCTA can detect the presence of aberrant vessels in a mouse laser-induced CNV model is 5 days after laser injury. Visible light-OCTA was able to visualize the maximum of the CNV network 7 days postlaser injury, in accordance with choroidal flatmount immunostaining. Visible light-OCTA is a reliable tool in both detecting the presence of CNV development, as well as accurately determining the size of the lesion in a mouse laser-induced CNV model.
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Affiliation(s)
- Ronil S Shah
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Brian T Soetikno
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States 3Med
| | - Ji Yi
- Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Wenzhong Liu
- Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Dimitra Skondra
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Hao F Zhang
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Amani A Fawzi
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
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43
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Duan L, McRaven MD, Liu W, Shu X, Hu J, Sun C, Veazey RS, Hope TJ, Zhang HF. Colposcopic imaging using visible-light optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:56003. [PMID: 28492851 PMCID: PMC5421648 DOI: 10.1117/1.jbo.22.5.056003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/17/2017] [Indexed: 05/12/2023]
Abstract
High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6 × 4.6 - mm 2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.
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Affiliation(s)
- Lian Duan
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Michael D. McRaven
- Northwestern University, Department of Cell and Molecular Biology, Chicago, Illinois, United States
| | - Wenzhong Liu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Xiao Shu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Jianmin Hu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Wuhan University of Technology, School of Information Engineering, Wuhan, Hubei, China
| | - Cheng Sun
- Northwestern University, Department of Mechanical Engineering, Evanston, Illinois, United States
| | - Ronald S. Veazey
- Tulane University, School of Medicine, Tulane National Primate Research Center, Covington, Louisiana, United States
| | - Thomas J. Hope
- Northwestern University, Department of Cell and Molecular Biology, Chicago, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
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44
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Chen S, Shu X, Nesper PL, Liu W, Fawzi AA, Zhang HF. Retinal oximetry in humans using visible-light optical coherence tomography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1415-1429. [PMID: 28663838 PMCID: PMC5480553 DOI: 10.1364/boe.8.001415] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/01/2017] [Accepted: 02/01/2017] [Indexed: 05/18/2023]
Abstract
We measured hemoglobin oxygen saturation (sO2) in the retinal circulation in healthy humans using visible-light optical coherence tomography (vis-OCT). The measurements showed clear oxygenation differences between central retinal arteries and veins close to the optic nerve head. Spatial variations at different vascular branching levels were also revealed. In addition, we presented theoretical and experimental results to establish that noises in OCT intensity followed Rice distribution. We used this knowledge to retrieve unbiased estimation of true OCT intensity to improve the accuracy of vis-OCT oximetry, which had inherently lower signal-to-nose ratio from human eyes due to safety and comfort limitations. We demonstrated that the new statistical-fitting sampling strategy could reduce the estimation error in sO2 by three percentage points (pp). The presented work aims to provide a foundation for using vis-OCT to achieve accurate retinal oximetry in clinical settings.
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Affiliation(s)
- Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Xiao Shu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Peter L. Nesper
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
| | - Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Currently with Opticent Health, Evanston, IL 60208, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
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45
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Bai DY, Wang X, Zhao JY, Li L, Gao J, Wang NL. Comparison of Color Fundus Photography, Infrared Fundus Photography, and Optical Coherence Tomography in Detecting Retinal Hamartoma in Patients with Tuberous Sclerosis Complex. Chin Med J (Engl) 2017; 129:1229-35. [PMID: 27174333 PMCID: PMC4878170 DOI: 10.4103/0366-6999.181976] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND A sensitive method is required to detect retinal hamartomas in patients with tuberous sclerosis complex (TSC). The aim of the present study was to compare the color fundus photography, infrared imaging (IFG), and optical coherence tomography (OCT) in the detection rate of retinal hamartoma in patients with TSC. METHODS This study included 11 patients (22 eyes) with TSC, who underwent color fundus photography, IFG, and spectral-domain OCT to detect retinal hamartomas. TSC1 and TSC2RESULTS: The mean age of the 11 patients was 8.0 ± 2.1 years. The mean spherical equivalent was -0.55 ± 1.42 D by autorefraction with cycloplegia. In 11 patients (22 eyes), OCT, infrared fundus photography, and color fundus photography revealed 26, 18, and 9 hamartomas, respectively. The predominant hamartoma was type I (55.6%). All the hamartomas that detected by color fundus photography or IFG can be detected by OCT. CONCLUSION Among the methods of color fundus photography, IFG, and OCT, the OCT has higher detection rate for retinal hamartoma in TSC patients; therefore, OCT might be promising for the clinical diagnosis of TSC.
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Affiliation(s)
- Da-Yong Bai
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing 100045; Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing 100730, China
| | - Xu Wang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Jun-Yang Zhao
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Li Li
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Jun Gao
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Ning-Li Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing 100730, China
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46
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Linsenmeier RA, Zhang HF. Retinal oxygen: from animals to humans. Prog Retin Eye Res 2017; 58:115-151. [PMID: 28109737 DOI: 10.1016/j.preteyeres.2017.01.003] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/13/2017] [Accepted: 01/17/2017] [Indexed: 10/20/2022]
Abstract
This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O2 in the retina: measurements of PO2 with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O2 concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO2 in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.
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Affiliation(s)
- Robert A Linsenmeier
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Neurobiology Department, Northwestern University, 2205 Tech Drive, Evanston 60208-3520, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
| | - Hao F Zhang
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
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47
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Chong SP, Bernucci M, Radhakrishnan H, Srinivasan VJ. Structural and functional human retinal imaging with a fiber-based visible light OCT ophthalmoscope. BIOMEDICAL OPTICS EXPRESS 2017; 8:323-337. [PMID: 28101421 PMCID: PMC5231302 DOI: 10.1364/boe.8.000323] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 05/18/2023]
Abstract
The design of a multi-functional fiber-based Optical Coherence Tomography (OCT) system for human retinal imaging with < 2 micron axial resolution in tissue is described. A detailed noise characterization of two supercontinuum light sources with different pulse repetition rates is presented. The higher repetition rate and lower noise source is found to enable a sensitivity of 96 dB with 0.15 mW light power at the cornea and a 98 microsecond exposure time. Using a broadband (560 ± 50 nm), 90/10, fused single-mode fiber coupler designed for visible wavelengths, the sample arm is integrated into an ophthalmoscope platform, similar to current clinical OCT systems. To demonstrate the instrument's range of operation, in vivo structural retinal imaging is also shown at 0.15 mW exposure with 10,000 and 70,000 axial scans per second (the latter comparable to commercial OCT systems), and at 0.03 mW exposure and 10,000 axial scans per second (below maximum permissible continuous exposure levels). Lastly, in vivo spectroscopic imaging of anatomy, saturation, and hemoglobin content in the human retina is also demonstrated.
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Affiliation(s)
- Shau Poh Chong
- Biomedical Engineering Department, University of California Davis, Davis, California 95616,
USA
| | - Marcel Bernucci
- Biomedical Engineering Department, University of California Davis, Davis, California 95616,
USA
| | - Harsha Radhakrishnan
- Biomedical Engineering Department, University of California Davis, Davis, California 95616,
USA
| | - Vivek J. Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, California 95616,
USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, California 95817,
USA
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48
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Scarinci F, Nesper PL, Fawzi AA. Deep Retinal Capillary Nonperfusion Is Associated With Photoreceptor Disruption in Diabetic Macular Ischemia. Am J Ophthalmol 2016; 168:129-138. [PMID: 27173374 PMCID: PMC4969199 DOI: 10.1016/j.ajo.2016.05.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/29/2016] [Accepted: 05/02/2016] [Indexed: 11/23/2022]
Abstract
PURPOSE To report outer retinal structural changes associated with macular capillary nonperfusion at the level of deep capillary plexus (DCP) in diabetic patients. DESIGN Prospective observational cross-sectional study. METHODS The study included 14 eyes of 10 patients who were diagnosed as having diabetic retinopathy. To study the outer retina and localize areas of capillary nonperfusion at the superficial (SCP) or DCP, we used the spectral-domain optical coherence tomography (SDOCT) device (RTVue-XR Avanti; Optovue Inc, Fremont, California, USA) with split-spectrum amplitude-decorrelation angiography (SSADA) software for optical coherence tomography angiography (OCTA). Two independent masked graders (F.S. and A.A.F.) qualitatively evaluated SDOCT scans as either normal or having outer retina disruption. The angiographic images were examined to define the presence and location of capillary nonperfusion. RESULTS Eight eyes showed outer retinal disruption on SDOCT that co-localized to areas of enlarged foveal avascular zone, areas of no flow between capillaries, and capillary nonperfusion of the DCP. Six eyes without outer retinal changes on SDOCT showed robust perfusion of the DCP. CONCLUSIONS Using OCTA, this study shows that macular photoreceptor disruption on SDOCT in patients with diabetic retinopathy corresponds to areas of capillary nonperfusion at the level of the DCP. This is important in highlighting the contribution of the DCP to the oxygen requirements of the photoreceptors as well as the outer retina in diabetic macular ischemia.
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Affiliation(s)
- Fabio Scarinci
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; G.B. Bietti Eye Foundation-IRCCS, Rome, Italy
| | - Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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Shu X, Bondu M, Dong B, Podoleanu A, Leick L, Zhang HF. Single all-fiber-based nanosecond-pulsed supercontinuum source for multispectral photoacoustic microscopy and optical coherence tomography. OPTICS LETTERS 2016; 41:2743-6. [PMID: 27304278 DOI: 10.1364/ol.41.002743] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report the usefulness of a single all-fiber-based supercontinuum (SC) source for combined photoacoustic microscopy (PAM) and optical coherence tomography (OCT). The SC light is generated by a tapered photonic crystal fiber pumped by a nanosecond pulsed master oscillator power amplifier at 1064 nm. The spectrum is split into a shorter wavelength band (500-800 nm) for single/multi-spectral PAM and a longer wavelength band (800-900 nm) band for OCT. In vivo mouse ear imaging was achieved with an integrated dual-modality system. We further demonstrated its potential for spectroscopic photoacoustic imaging by doing multispectral measurements on retinal pigment epithelium and blood samples with 15-nm linewidth.
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50
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Chen S, Shu X, Yi J, Fawzi A, Zhang HF. Dual-band optical coherence tomography using a single supercontinuum laser source. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:66013. [PMID: 27304421 PMCID: PMC4908275 DOI: 10.1117/1.jbo.21.6.066013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/20/2016] [Indexed: 05/03/2023]
Abstract
We developed a simultaneous visible-light (Vis) and near-infrared (NIR) dual-band optical coherence tomography (OCT) system using a single supercontinuum laser source. The goal was to benchmark our newly developed Vis-OCT against the well-developed NIR-OCT. The Vis-OCT subsystem operated at 91 nm full-width-at-half-maximum (FWHM) bandwidth centered at 566 nm; the NIR-OCT subsystem operated at 93 nm FWHM bandwidth centered at 841 nm. The axial resolutions were 1.8 and 4.4 μm in air for the Vis- and NIR-OCT subsystems, respectively. We compared the respective performances, including anatomical imaging, angiography, absolute retinal blood flow measurements, and spectroscopic analysis for retinal blood oxygen saturation (sO2), between the two subsystems in rodents in vivo. While demonstrating minor discrepancies related to operation wavelengths, both subsystems showed comparable performances in the first three tests. However, we were only able to retrieve sO2 using the Vis-OCT subsystem.
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Affiliation(s)
- Siyu Chen
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Xiao Shu
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Ji Yi
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Boston University, Department of Medicine, 650 Albany Street, Boston, Massachusetts 02118, United States
| | - Amani Fawzi
- Northwestern University, Department of Ophthalmology, 300 East Superior Street, Chicago, Illinois 60611, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Northwestern University, Department of Ophthalmology, 300 East Superior Street, Chicago, Illinois 60611, United States
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