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Shang X, Wang X, Zhou K, Pan X, Huang Q, Chu X, Hu C, Xu X, Liang Y. Faster Macular Vessel Density Loss in More Advanced Primary Open Angle Glaucoma Eyes. Ophthalmic Res 2022; 66:345-353. [PMID: 36380622 DOI: 10.1159/000526850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/14/2022] [Indexed: 12/23/2023]
Abstract
PURPOSE The aim of the study was to characterize and compare the longitudinal changes of macular vessel density (VD) in primary open angle glaucoma (POAG) eyes across different disease stages. METHODS This is a sub-analysis of a prospective cohort study. A total of 103 eyes (53 eyes in the mild stage, 50 eyes in the moderate-to-advanced stage) of 75 POAG patients followed for more than 1 year with at least 2 qualified optical coherence tomography (OCT) angiography (OCTA) images were included. The rates of macular VD change were determined by linear regression and compared using the generalized linear mixed models between groups. Mixed effect models were used to evaluate the demographic and ocular parameters associated with the VD loss rate. RESULTS With a mean follow-up time of 2.36 years, the rates of macular VD change were significantly different from zero in both groups. The rates of macular VD loss were significantly faster in moderate-to-advanced-stage group than in mild-stage group in whole image (-2.46%/year vs. -1.47%/year, p = 0.002);, superior hemifield (-2.42%/year vs. -1.30%/year, p = 0.001); parafovea (-2.35%/year vs. -1.26, p = 0.001); superior (-2.20%/year vs. -1.01%/year, p = 0.002), nasal (-2.41%/year vs. -1.04%/year, p = 0.001), inferior (-2.46%/year vs. -1.43%/year, p = 0.018), and temporal sectors (-2.32%/year vs. -1.58%/year, p = 0.012). Baseline mean deviation and OCT parameters were associated with the rates of macular VD loss. CONCLUSIONS OCTA measurements could detect vascular deterioration over time in POAG eyes at different stages. The rates of macular VD loss were significantly faster in more advanced POAG eyes.
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Affiliation(s)
- Xiao Shang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China,
- Glaucoma Research Institute of Wenzhou Medical University, Wenzhou, China,
- National Clinical Research Center for Ocular Diseases, Wenzhou, China,
| | - Xiaoyan Wang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Kun Zhou
- Department of Ophthalmology, Xi'an First Hospital, Xi'an, China
| | - Xiafei Pan
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qiangjie Huang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Xizhong Chu
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Chengju Hu
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Xiang Xu
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Yuanbo Liang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- Glaucoma Research Institute of Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Wenzhou, China
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Shi Y, Lu J, Le N, Wang RK. Integrating a pressure sensor with an OCT handheld probe to facilitate imaging of microvascular information in skin tissue beds. BIOMEDICAL OPTICS EXPRESS 2022; 13:6153-6166. [PMID: 36733756 PMCID: PMC9872897 DOI: 10.1364/boe.473013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 05/05/2023]
Abstract
Optical coherence tomography (OCT) and OCT angiography (OCTA) have been increasingly applied in skin imaging applications in dermatology, where the imaging is often performed with the OCT probe in contact with the skin surface. However, this contact mode imaging can introduce uncontrollable mechanical stress applied to the skin, inevitably complicating the interpretation of OCT/OCTA imaging results. There remains a need for a strategy for assessing local pressure applied on the skin during imaging acquisition. This study reports a handheld scanning probe integrated with built-in pressure sensors, allowing the operator to control the mechanical stress applied to the skin in real-time. With real time feedback information, the operator can easily determine whether the pressure applied to the skin would affect the imaging quality so as to obtain repeatable and reliable OCTA images for a more accurate investigation of skin conditions. Using this probe, imaging of palm skin was used in this study to demonstrate how the OCTA imaging would have been affected by different mechanical pressures ranging from 0 to 69 kPa. The results showed that OCTA imaging is relatively stable when the pressure is less than 11 kPa, and within this range, the change of vascular area density calculated from the OCTA imaging is below 0.13%. In addition, the probe was used to augment the OCT monitoring of blood flow changes during a reactive hyperemia experiment, in which the operator could properly control the amount of pressure applied to the skin surface and achieve full release after compression stimulation.
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Affiliation(s)
- Yaping Shi
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
- These authors contributed equally to this study
| | - Jie Lu
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
- These authors contributed equally to this study
| | - Nhan Le
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
- Department of Ophthalmology, University of Washington, Seattle, WA 98105, USA
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Courtie E, Gilani A, Veenith T, Blanch RJ. Optical coherence tomography angiography as a surrogate marker for end-organ resuscitation in sepsis: A review. Front Med (Lausanne) 2022; 9:1023062. [PMID: 36341253 PMCID: PMC9630739 DOI: 10.3389/fmed.2022.1023062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/03/2022] [Indexed: 11/25/2022] Open
Abstract
Sepsis is a severe illness which results in alterations in the end organ microvascular haemodynamics and is associated with a high risk of mortality. There is currently no real-time method of monitoring microcirculatory perfusion during sepsis. Retinal microcirculation is closely linked to cerebral perfusion and may reflect systemic vascular alterations. Retinal perfusion can be assessed using the non-invasive imaging technique of optical coherence tomography angiography (OCTA). This narrative review aims to discuss the utility of using retinal imaging and OCTA in systemic illness and sepsis. OCTA can be used as a functional, non-invasive and real-time biomarker along with other haemodynamic parameters for assessing and managing patients with sepsis.
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Affiliation(s)
- Ella Courtie
- Neuroscience and Ophthalmology Research Group, University of Birmingham, Birmingham, United Kingdom
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Surgical Reconstruction and Microbiology Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Ahmed Gilani
- Critical Care Unit, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Tonny Veenith
- Critical Care Unit, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Department of Trauma Sciences, University of Birmingham, Birmingham, United Kingdom
- Tonny Veenith,
| | - Richard J. Blanch
- Neuroscience and Ophthalmology Research Group, University of Birmingham, Birmingham, United Kingdom
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Surgical Reconstruction and Microbiology Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- *Correspondence: Richard J. Blanch,
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Bapir M, Untracht GR, Cooke D, McVey JH, Skene SS, Campagnolo P, Whyte MB, Dikaios N, Rodriguez-Mateos A, Sampson DD, Sampson DM, Heiss C. Cocoa flavanol consumption improves lower extremity endothelial function in healthy individuals and people with type 2 diabetes. Food Funct 2022; 13:10439-10448. [PMID: 36164983 DOI: 10.1039/d2fo02017c] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Background: diabetes and age are major risk factors for the development of lower extremity peripheral artery disease (PAD). Cocoa flavanol (CF) consumption is associated with lower risk for PAD and improves brachial artery (BA) endothelial function. Objectives: to assess if femoral artery (FA) endothelial function and dermal microcirculation are impaired in individuals with type 2 diabetes mellitus (T2DM) and evaluate the acute effect of CF consumption on FA endothelial function. Methods: in a randomised, controlled, double-blind, cross-over study, 22 individuals (n = 11 healthy, n = 11 T2DM) without cardiovascular disease were recruited. Participants received either 1350 mg CF or placebo capsules on 2 separate days in random order. Endothelial function was measured as flow-mediated dilation (FMD) using ultrasound of the common FA and the BA before and 2 hours after interventions. The cutaneous microvasculature was assessed using optical coherence tomography angiography. Results: baseline FA-FMD and BA-FMD were significantly lower in T2DM (FA: 3.2 ± 1.1% [SD], BA: 4.8 ± 0.8%) compared to healthy (FA: 5.5 ± 0.7%, BA: 6.0 ± 0.8%); each p < 0.001. Whereas in healthy individuals FA-FMD did not significantly differ from BA-FMD (p = 0.144), FA-FMD was significantly lower than BA-FMD in T2DM (p = 0.003) indicating pronounced and additional endothelial dysfunction of lower limb arteries (FA-FMD/BA-FMD: 94 ± 14% [healthy] vs. 68 ± 22% [T2DM], p = 0.007). The baseline FA blood flow rate (0.42 ± 0.23 vs. 0.73 ± 0.35 l min-1, p = 0.037) and microvascular dilation in response to occlusion in hands and feet were significantly lower in T2DM subjects than in healthy ones. CF increased both FA- and BA-FMD at 2 hours, compared to placebo, in both healthy and T2DM subgroups (FA-FMD effect: 2.9 ± 1.4%, BA-FMD effect 3.0 ± 3.5%, each pintervention< 0.001). In parallel, baseline FA blood flow and microvascular diameter significantly increased in feet (3.5 ± 3.5 μm, pintervention< 0.001) but not hands. Systolic blood pressure and pulse wave velocity significantly decreased after CF in both subgroups (-7.2 ± 9.6 mmHg, pintervention = 0.004; -1.3 ± 1.3 m s-1, pintervention = 0.002). Conclusions: individuals with T2DM exhibit decreased endothelial function that is more pronounced in the femoral than in the brachial artery. CFs increase endothelial function not only in the BA but also the FA both in healthy individuals and in those with T2DM who are at increased risk of developing lower extremity PAD and foot ulcers.
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Affiliation(s)
- Mariam Bapir
- Department of Clinical and Experimental Medicine, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom.
| | - Gavrielle R Untracht
- Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, Australia.,Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Debbie Cooke
- School of Health Sciences, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - John H McVey
- Department of Biochemical Sciences, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom
| | - Simon S Skene
- Department of Clinical and Experimental Medicine, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom.
| | - Paola Campagnolo
- Department of Biochemical Sciences, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom
| | - Martin B Whyte
- Department of Clinical and Experimental Medicine, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom.
| | | | - Ana Rodriguez-Mateos
- Department of Nutritional Sciences, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, London, United Kingdom
| | - David D Sampson
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Danuta M Sampson
- Department of Clinical and Experimental Medicine, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom. .,Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, United Kingdom.,University College London, Institute of Ophthalmology, London, United Kingdom
| | - Christian Heiss
- Department of Clinical and Experimental Medicine, School of Bioscience & Medicine, University of Surrey, Guildford, United Kingdom. .,Surrey and Sussex NHS Healthcare Trust, Redhill, United Kingdom
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Zhang Y, Li J, Liu C, Zheng K, Zhang B, Zhou Y, Dai C, Fan S, Yao Y, Zhuang R, Guo D, Huang Z, Mao J, Liang J, Yang H, Wang L, Liu G, Chen X, Zhao Q. Development of a multi-scene universal multiple wavelet-FFT algorithm (MW-FFTA) for denoising motion artifacts in OCT-angiography in vivo imaging. OPTICS EXPRESS 2022; 30:35854-35870. [PMID: 36258527 DOI: 10.1364/oe.465255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Optical coherence tomography angiography (OCTA) images suffer from inevitable micromotion (breathing, heartbeat, and blinking) noise. These image artifacts can severely disturb the visibility of results and reduce accuracy of vessel morphological and functional metrics quantization. Herein, we propose a multiple wavelet-FFT algorithm (MW-FFTA) comprising multiple integrated processes combined with wavelet-FFT and minimum reconstruction that can be used to effectively attenuate motion artifacts and significantly improve the precision of quantitative information. We verified the fidelity of image information and reliability of MW-FFTA by the image quality evaluation. The efficiency and robustness of MW-FFTA was validated by the vessel parameters on multi-scene in vivo OCTA imaging. Compared with previous algorithms, our method provides better visual and quantitative results. Therefore, the MW-FFTA possesses the potential capacity to improve the diagnosis of clinical diseases with OCTA.
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Chen G, Wang W, Li Y. Comparative study of OCTA algorithms with a high-sensitivity multi-contrast Jones matrix OCT system for human skin imaging. BIOMEDICAL OPTICS EXPRESS 2022; 13:4718-4736. [PMID: 36187265 PMCID: PMC9484425 DOI: 10.1364/boe.462941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/21/2022] [Accepted: 07/28/2022] [Indexed: 06/16/2023]
Abstract
The multi-contrast Jones matrix OCT (JMT) system can not only improve the tissue-specific contrast but also enhance the sensitivity of detecting flow, which is gaining increasing attention. However, for the JMT system, there is currently a lack of studies evaluating and guiding the selection of suitable angiography algorithms to map the most appealing quality of angiograms for clinical use. In this paper, by a homemade high-sensitivity multi-contrast JMT system based 200 kHz swept source, the performance of two complex-signal-based OCTA methods that are insensitive to phase instability and one amplitude-signal-based OCTA method are compared for in-vivo imaging of human skin qualitatively and quantitatively. Six metrics, including vascular connectivity, image contrast-to-noise ratio, image signal-to-noise ratio, vessel diameter index, blood vessel density, and processing time, are assessed. The results show that the vascular networks processed by all OCTA methods and the texture of skin could be visualized simultaneously and markedly. Additionally, the complex-signal-based OCTA methods successfully suppress phase instabilities and even outperform the amplitude-signal-based OCTA algorithm in some indicators. This paper has a certain guiding significance for selecting an appropriate angiography algorithm and expanding the application field with this system.
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Affiliation(s)
- Guoqiang Chen
- Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China, School of Optics and Photonics, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
| | - Wen’ai Wang
- Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China, School of Optics and Photonics, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
- Institute of Engineering Medicine, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
| | - Yanqiu Li
- Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China, School of Optics and Photonics, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
- Institute of Engineering Medicine, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, China
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Tan Y, Zhu W, Zou Y, Zhang B, Yu Y, Li W, Jin G, Liu Z. Hotspots and trends in ophthalmology in recent 5 years: Bibliometric analysis in 2017–2021. Front Med (Lausanne) 2022; 9:988133. [PMID: 36091704 PMCID: PMC9462464 DOI: 10.3389/fmed.2022.988133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose The purpose of this study was to investigate the hotspots and research trends of ophthalmology research. Method Ophthalmology research literature published between 2017 and 2021 was obtained in the Web of Science Core Collection database. The bibliometric analysis and network visualization were performed with the VOSviewer and CiteSpace. Publication-related information, including publication volume, citation counts, countries, journals, keywords, subject categories, and publication time, was analyzed. Results A total of 10,469 included ophthalmology publications had been cited a total of 7,995 times during the past 5 years. The top countries and journals for the number of publications were the United States and the Ophthalmology. The top 25 global high-impact documents had been identified using the citation ranking. Keyword co-occurrence analysis showed that the hotspots in ophthalmology research were epidemiological characteristics and treatment modalities of ocular diseases, artificial intelligence and fundus imaging technology, COVID-19-related telemedicine, and screening and prevention of ocular diseases. Keyword burst analysis revealed that “neural network,” “pharmacokinetics,” “geographic atrophy,” “implementation,” “variability,” “adverse events,” “automated detection,” and “retinal images” were the research trends of research in the field of ophthalmology through 2021. The analysis of the subject categories demonstrated the close cooperation relationships that existed between different subject categories, and collaborations with non-ophthalmology-related subject categories were increasing over time in the field of ophthalmology research. Conclusions The hotspots in ophthalmology research were epidemiology, prevention, screening, and treatment of ocular diseases, as well as artificial intelligence and fundus imaging technology and telemedicine. Research trends in ophthalmology research were artificial intelligence, drug development, and fundus diseases. Knowledge from non-ophthalmology fields is likely to be more involved in ophthalmology research.
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Affiliation(s)
- Yuan Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Weining Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Zhongshan Medical School, Sun Yat-sen University, Guangzhou, China
| | - Yingshi Zou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Bowen Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Zhongshan Medical School, Sun Yat-sen University, Guangzhou, China
| | - Yinglin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Wei Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Zhongshan Medical School, Sun Yat-sen University, Guangzhou, China
| | - Guangming Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
- *Correspondence: Guangming Jin
| | - Zhenzhen Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
- Zhenzhen Liu
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Wang L, Chen Z, Zhu Z, Yu X, Mo J. Compressive-sensing swept-source optical coherence tomography angiography with reduced noise. JOURNAL OF BIOPHOTONICS 2022; 15:e202200087. [PMID: 35488181 DOI: 10.1002/jbio.202200087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/25/2022] [Accepted: 04/28/2022] [Indexed: 06/14/2023]
Abstract
Optical coherence tomography angiography (OCTA), as a functional extension of optical coherence tomography (OCT), has exhibited a great potential to aid in clinical diagnostics. Currently, OCTA still suffers from motion artifact and noise. Therefore, in this article, we propose to implement compressive sensing (CS) on B-scans to reduce motion artifact by increasing B-scan rate. Meanwhile, a noise reduction filter is specially designed by combining CS, Gaussian filter and median filter. Specially, CS filtering is realized by averaging multiple CS repetitions on en-face OCTA images with varied sampling functions. The method is evaluated on in vivo OCTA images of human skin. The results show that vasculature structures can be reconstructed well through CS on B-scans with a sampling rate of 70%. Moreover, the noise can be significantly eliminated by the developed filter. This implies that our method has a good potential to expedite OCTA imaging and improve the image quality.
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Affiliation(s)
- Lingyun Wang
- School of Electronics and Information Engineering, Soochow University, Suzhou, China
| | - Ziye Chen
- School of Electronics and Information Engineering, Soochow University, Suzhou, China
| | - Zhanyu Zhu
- School of Electronics and Information Engineering, Soochow University, Suzhou, China
| | - Xiaojun Yu
- School of Automation, Northwestern Polytechnical University, Xi'an, China
| | - Jianhua Mo
- School of Electronics and Information Engineering, Soochow University, Suzhou, China
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Pandurangan K, Sachidanandam R, Sen P. Structural and functional changes among diabetics with no diabetic retinopathy and mild non-proliferative diabetic retinopathy using swept-source optical coherence tomography angiography and photopic negative response. Doc Ophthalmol 2022; 145:113-125. [PMID: 35902440 DOI: 10.1007/s10633-022-09891-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 07/08/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE To assess the structural and functional changes among diabetics with no diabetic retinopathy (NDR) and mild non-proliferative diabetic retinopathy (NPDR) using swept-source optical coherence tomography angiography (SSOCTA) and photopic negative response (PhNR) and to find the earliest changes. METHODS This was a prospective, cross-sectional, case-control study. Participants with minimum 5 years of diabetes mellitus (DM) were recruited and classified as NDR and mild NPDR based on fundus findings. Age-matched normals with nil ocular pathology were considered as controls. SSOCTA scan acquisition (6*6 mm angiography), followed by full field photopic electroretinography (FFERG) and red on blue PhNR (R/B PhNR) were done with complete pupillary dilatation. RESULTS A total of 88 participants were included with 35 controls, 39 NDR and 14 mild NPDR subjects. Vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of mild NPDR were significantly reduced compared to the controls (17.12 ± 2.65 mm-1 vs. 18.75 ± 0.90 mm-1, p = 0.025 and 7.96 ± 3.92 mm-1 vs. 11.83 ± 3.05 mm-1, p = 0.001 respectively). None of the parameters of controls had significant difference compared to NDR group (p > 0.05). The amplitudes of white on white (W/W) a-wave, W/W b-wave, red on blue (R/B) PhNR baseline to trough (BT) and R/B PhNR peak to trough in controls were significantly high compared to NDR and mild NPDR. Amplitude of R/B PhNR BT had the maximum area under the curve of 75.9% with a sensitivity and specificity of 94.3and 77.4%, respectively. CONCLUSION A significant decrease in functional changes as measured by ERG especially PhNR, is seen even among the NDR group compared to controls unlike SSOCTA parameters that measures very early vascular structural changes. PhNR is a sensitive test to identify early preclinical changes in DR when microvascular structural changes as determined by SSOCTA are normal.
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Affiliation(s)
| | - Ramya Sachidanandam
- Elite School of Optometry, Unit of Medical Research Foundation, Chennai, India
| | - Parveen Sen
- Department of Vitreo-Retinal Services, Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Medical Research Foundation, 18 College Road, Nungambakkam, Chennai, 600 006, India.
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Liu X, Yang B, Tian Y, Ma S, Zhong J. Quantitative assessment of retinal vessel density and thickness changes in internal carotid artery stenosis patients using optical coherence tomography angiography. Photodiagnosis Photodyn Ther 2022; 39:103006. [PMID: 35835327 DOI: 10.1016/j.pdpdt.2022.103006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/12/2022] [Accepted: 07/06/2022] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To quantitatively assess the retinal features of patients with different degrees of internal carotid artery stenosis (ICAS), particularly mild ICAS patients, utilizing optical coherence tomography angiography (OCTA). METHODS Thirty-two mild ICAS patients (mild ICAS group), 34 moderate to severe ICAS patients (nonmild ICAS group), and 40 controls were enrolled in this study. Retinal vessel density was quantitatively measured by OCTA, including radial peripapillary capillary vessel density (RPC-VD), superficial and deep capillary plexus vessel density (SCP/DCP-VD). Structural parameters were collected from optical coherence tomography (OCT), including retinal thickness and subfoveal choroidal thickness (SFCT). Furthermore, LASSO-penalized logistic regression was used to construct the diagnostic model based on retinal parameters. ROC curves and nomogram plots were used to assess the diagnostic ability of this model for ICAS. RESULTS The macular SCP-VD of mild ICAS patients was significantly lower than that of controls and lower than that of nonmild ICAS patients (all p < 0.05). However, there was no difference among the three groups in terms of DCP-VD (p > 0.05). RPC-VD could effectively discriminate between the mild ICAS group and the nonmild ICAS group (p = 0.005). For structural OCT, only the SFCT decreased as the ICAS degree increased (p < 0.05). Diagnostic scores based on retinal parameters showed a strong diagnostic capability for mild ICAS (AUC = 0.8656). CONCLUSION Mild ICAS patients exhibited distinct retinal features compared to nonmild ICAS patients and control subjects. OCTA potentially represents a promising method for the early detection of ICAS patients and the noninvasive surveillance of haemodynamic changes in those patients.
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Affiliation(s)
- Xiao Liu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Bing Yang
- Department of Neurology and Stroke Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Yuan Tian
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Shisi Ma
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Jingxiang Zhong
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China; Department of Ophthalmology, The Sixth Affiliated Hospital of Jinan University, Dongguan, Guangdong 523573, China.
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Ming Y, Hao S, Wang F, Lewis-Israeli YR, Volmert BD, Xu Z, Goestenkors A, Aguirre A, Zhou C. Longitudinal morphological and functional characterization of human heart organoids using optical coherence tomography. Biosens Bioelectron 2022; 207:114136. [PMID: 35325716 PMCID: PMC9713770 DOI: 10.1016/j.bios.2022.114136] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 12/17/2022]
Abstract
Organoids play an increasingly important role as in vitro models for studying organ development, disease mechanisms, and drug discovery. Organoids are self-organizing, organ-like three-dimensional (3D) cell cultures developing organ-specific cell types and functions. Recently, three groups independently developed self-assembling human heart organoids (hHOs) from human pluripotent stem cells (hPSCs). In this study, we utilized a customized spectral-domain optical coherence tomography (SD-OCT) system to characterize the growth of hHOs. Development of chamber structures and beating patterns of the hHOs were observed via OCT and calcium imaging. We demonstrated the capability of OCT to produce 3D images in a fast, label-free, and non-destructive manner. The hHOs formed cavities of various sizes, and complex interconnections were observed as early as on day 4 of differentiation. The hHOs models and the OCT imaging system showed promising insights as an in vitro platform for investigating heart development and disease mechanisms.
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Affiliation(s)
- Yixuan Ming
- Department of Biomedical Engineering, Washington University in Saint Louis, USA
| | - Senyue Hao
- Department of Electrical & Systems Engineering, Washington University in Saint Louis, USA
| | - Fei Wang
- Department of Biomedical Engineering, Washington University in Saint Louis, USA
| | - Yonatan R Lewis-Israeli
- Institute for Quantitative Health Science and Engineering, Division of Developmental and Stem Cell Biology, Michigan State University, USA; Department of Biomedical Engineering, College of Engineering, Michigan State University, USA
| | - Brett D Volmert
- Institute for Quantitative Health Science and Engineering, Division of Developmental and Stem Cell Biology, Michigan State University, USA; Department of Biomedical Engineering, College of Engineering, Michigan State University, USA
| | - Zhiyao Xu
- Department of Biomedical Engineering, Washington University in Saint Louis, USA
| | - Anna Goestenkors
- Department of Biomedical Engineering, Washington University in Saint Louis, USA
| | - Aitor Aguirre
- Institute for Quantitative Health Science and Engineering, Division of Developmental and Stem Cell Biology, Michigan State University, USA; Department of Biomedical Engineering, College of Engineering, Michigan State University, USA
| | - Chao Zhou
- Department of Biomedical Engineering, Washington University in Saint Louis, USA.
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62
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Repeatability and Reproducibility of 4.5 by 4.5 mm Peripapillary Optical Coherence Tomography Angiography Scans in Glaucoma and Nonglaucoma Eyes. J Glaucoma 2022; 31:773-782. [PMID: 35726955 DOI: 10.1097/ijg.0000000000002054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 05/10/2022] [Indexed: 11/26/2022]
Abstract
PRCIS Peripapillary vessel parameters from optical coherence tomography angiography (OCTA) 4.5×4.5 mm scans in nonglaucomatous and glaucomatous eyes showed high repeatability and reproducibility, with higher reliability for commercially developed OCTA parameters compared with custom OCTA parameters. PURPOSE The purpose of this study was to assess intrasession repeatability versus intersession reproducibility of peripapillary vessel parameters from 4.5×4.5 mm OCTA scans in nonglaucomatous eyes and glaucomatous eyes. MATERIALS AND METHODS In a longitudinal study, peripapillary OCTA scans were quantified using research-oriented custom quantification software that calculated vessel area density (VAD) and flux and clinic-oriented commercially developed software (Cirrus 11.0) that calculated perfusion density (PD) and flux index (FI). Intrasession repeatability and intersession reproducibility were evaluated using within-eye coefficient of variation (CVW) and intraclass correlation coefficient (ICC). RESULTS With 127 nonglaucomatous eyes, intrasession CVW for VAD, PD, flux, and FI were 1.900%, 1.174%, 2.787%, and 1.425%, respectively. The intersession CVW were 2.039%, 1.606%, 4.053%, and 2.798%, respectively. Intrasession ICC ranged from 0.903 to 0.956, and intersession ICC ranged from 0.850 to 0.896. Among 144 glaucomatous eyes, intrasession CVW for VAD, PD, flux, and FI were: 3.841%, 1.493%, 5.009%, and 2.432%, respectively. The intersession CVW were 4.991%, 2.155%, 6.360%, and 3.458%, respectively. Intrasession ICC ranged from 0.956 to 0.969, and intersession ICC ranged from 0.918 to 0.964. CONCLUSIONS Among nonglaucomatous and glaucomatous eyes, the majority of peripapillary OCTA vessel parameters from 4.5×4.5 mm scans had greater intrasession repeatability than intersession reproducibility. There was a greater agreement for the commercially developed quantification parameters than for their custom quantification counterparts.
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63
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Deng X, Liu K, Zhu T, Guo D, Yin X, Yao L, Ding Z, Ye J, Li P. Dynamic inverse SNR-decorrelation OCT angiography with GPU acceleration. BIOMEDICAL OPTICS EXPRESS 2022; 13:3615-3628. [PMID: 35781971 PMCID: PMC9208597 DOI: 10.1364/boe.459632] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/12/2022] [Accepted: 05/22/2022] [Indexed: 05/02/2023]
Abstract
Dynamic OCT angiography (OCTA) is an attractive approach for monitoring stimulus-evoked hemodynamics; however, a 4D (3D space and time) dataset requires a long acquisition time and has a large data size, thereby posing a great challenge to data processing. This study proposed a GPU-based real-time data processing pipeline for dynamic inverse SNR-decorrelation OCTA (ID-OCTA), offering a measured line-process rate of 133 kHz for displaying OCT and OCTA cross-sections in real time. Real-time processing enabled automatic optimization of angiogram quality, which improved the vessel SNR, contrast-to-noise ratio, and connectivity by 14.37, 14.08, and 9.76%, respectively. Furthermore, motion-contrast 4D angiographic imaging of stimulus-evoked hemodynamics was achieved within a single trail in the mouse retina. Consequently, a flicker light stimulus evoked an apparent dilation of the retinal arterioles and venules and an elevation of the decorrelation value in the retinal plexuses. Therefore, GPU ID-OCTA enables real-time and high-quality angiographic imaging and is particularly suitable for hemodynamic studies.
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Affiliation(s)
- Xiaofeng Deng
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
- These authors contributed equally to this
work
| | - Kaiyuan Liu
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
- These authors contributed equally to this
work
| | - Tiepei Zhu
- Eye center of the Second Affiliated
Hospital, College of Medicine, Zhejiang
University, Hangzhou, Zhejiang 310003, China
| | - Dayou Guo
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
| | - Xiaoting Yin
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
| | - Lin Yao
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
| | - Zhihua Ding
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
| | - Juan Ye
- Eye center of the Second Affiliated
Hospital, College of Medicine, Zhejiang
University, Hangzhou, Zhejiang 310003, China
| | - Peng Li
- State Key Laboratory of Modern Optical
Instrumentation, College of Optical Science and
Engineering, Zhejiang University, Hangzhou 310027,
China
- Jiaxing Key Laboratory of
Photonic Sensing & Intelligent Imaging, Jiaxing
314000, China
- Intelligent Optics &
Photonics Research Center, Jiaxing Research Institute, Zhejiang
University, Jiaxing 314000, China
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64
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Lu Y, Zhou H, Zhou X, Chen Y, Wang RK. Correlation Between Laser Speckle Flowgraphy and OCT-Derived Retinal and Choroidal Metrics in Healthy Human Eye. Transl Vis Sci Technol 2022; 11:15. [PMID: 35704328 PMCID: PMC9206497 DOI: 10.1167/tvst.11.6.15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/17/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose To investigate the correlation between laser speckle flowgraphy (LSFG) signals and the quantitative metrics derived from optical coherence tomography (OCT) in normal eyes. Methods LSFG, OCT, and OCT angiography (OCTA) imaging were performed on normal participants using a custom-designed LSFG system and a commercial swept-source OCT system. Mean (PWM) and amplitude (PWA) of the LSFG pulse waveform were selected to quantify the LSFG signals. Retinal and choroidal maps were obtained using the standard 6 × 6 mm OCT and OCTA scans. Structural and vascular metrics maps, including thickness, vessel area density, vessel skeleton density, and vessel diameter index of the retina, and choroidal thickness (CT), choroidal vessel volume (CVV) and choroidal vessel index (CVI), were employed to quantify the retinal and choroidal properties. Correlation analysis was then performed between the LSFG, retinal, and choroidal metrics maps. Results Twelve healthy participants aged 23 to 36 years were enrolled in this study. The spatial distribution of the PWM and PWA values was highly correlated with that of the CT and CVV metrics. On average, Spearman correlation coefficients (ρ) were 0.80 and 0.78 (all P < 0.001) for the correlations between PWM and CT and CVV, respectively, and were 0.61 and 0.63 (all P < 0.05) for the correlations between PWA and CT and CVV, respectively. In comparison, both PWM and PWA were generally weak or not correlated with all the retinal metrics and CVI. Conclusions LSFG signals were positively correlated with the choroidal thickness and vessel volume, suggesting choroidal blood flows dominate the LSFG signals at the area absent of large retinal vessels. Translational Relevance This study illustrates the dominant source of the LSFG signals in the eye.
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Affiliation(s)
- Yiming Lu
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Hao Zhou
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Xiao Zhou
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Yuxuan Chen
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Karalis Johnson Retina Center, Department of Ophthalmology, University of Washington, Seattle, WA, USA
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65
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Choi WJ, Li Y, Wang RK, Kim JK. Automated counting of cerebral penetrating vessels using optical coherence tomography images of a mouse brain in vivo. Med Phys 2022; 49:5225-5235. [PMID: 35616390 DOI: 10.1002/mp.15775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
RATIONALE AND OBJECTIVES Penetrating blood vessels emanating from cortical surface vasculature and lying deep in the cortex are essential vascular conduits for the shuttling of blood from superficial pial vessels to the capillary beds in parenchyma for the nourishment of neuronal brain tissues. Locating and counting the penetrating vessels is beneficial for the quantification of a course of ischemia in blood occlusive events such as stroke. This paper seeks to demonstrate and validate a method for automated penetrating vessel counting that uses optical coherence tomography (OCT). MATERIALS AND METHODS This paper proposes an OCT method that effectively identifies and grades the cortical penetrating vessels in perfusion. The key to the proposed method is the harnessing of vascular features found in the penetrating vessels, which are distinctive from those of other vessels. In particular, with an increase in the light attenuation and flow turbulence, the contrast in the mean projection of the OCT datacube decreases, whereas that in the maximum projection of the Doppler frequency variance datacube increases. By multiplying the inversion of the former with the latter, its binary thresholding is sufficient to highlight the penetrating vessels and allows for their counting over the projection image. RESULTS A computational method that leverages the decrease in mean OCT projection intensity and the increase in Doppler frequency variance at the penetrating vessel is developed. It successfully identifies and counts penetrating vessels with a high accuracy of over 87%. The penetrating vessel density is observed to be significantly reduced in the mouse model of focal ischemic stroke. CONCLUSION The OCT analysis is effective for counting penetrating blood vessels in mice brains and may be applied to the rapid diagnosis and treatment of stroke in stroke models of small animals. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Woo June Choi
- School of Electrical and Electronics Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06974, Korea
| | - Yuandong Li
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Jun Ki Kim
- Department of Convergence Medicine, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Korea.,Asan Institute for Life Science, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Korea
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66
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Fu YS, Chen PR, Yeh CC, Pan JY, Kuo WC, Tseng KW. Human Umbilical Mesenchymal Stem Cell Xenografts Repair UV-Induced Photokeratitis in a Rat Model. Biomedicines 2022; 10:biomedicines10051125. [PMID: 35625862 PMCID: PMC9138504 DOI: 10.3390/biomedicines10051125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 01/04/2023] Open
Abstract
Most patients with a corneal injury are administered anti-inflammatory medications and antibiotics, but no other treatments are currently available. Thus, the corneal injury healing is unsatisfactory, affects the vision, and has a risk of blindness in severe cases. Human umbilical mesenchymal stem cells exhibit pluripotent and anti-inflammatory properties and do not cause immunological rejection in the host. Rats were irradiated with type B ultraviolet (UVB) light to generate a stable animal model of photokeratitis. After irradiation-induced photokeratitis, human umbilical mesenchymal stem cells were implanted into the subconjunctival space of the lateral sclera, and the changes in the corneal pathology were evaluated. Three weeks after implantation, many mesenchymal stem cells were visible in the subconjunctival space. These mesenchymal stem cells effectively reduced the extent of injury to the adjacent corneal tissue. They accelerated the epithelial layer repair, reduced the inflammatory response and neovascularization, and improved the disorganization of collagen and fibronectin in the corneal stroma caused by the injury. In conclusion, xenografted human umbilical mesenchymal stem cells can survive in rat eye tissues for a long time, effectively support the structural integrity of injured corneal tissues, restore corneal permeability, and reduce abnormal neovascularization. This study provides a new approach to the treatment of photokeratitis.
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Affiliation(s)
- Yu-Show Fu
- Department of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan;
| | - Po-Ru Chen
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan;
| | - Chang-Ching Yeh
- Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei 112, Taiwan;
- Department of Obstetrics and Gynecology, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
- Department of Nurse-Midwifery and Women Health, National Taipei University of Nursing and Health Sciences, Taipei 112, Taiwan
| | - Jian-Yu Pan
- Institute of Biophotonics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan;
| | - Wen-Chuan Kuo
- Institute of Biophotonics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan;
- Correspondence: (W.-C.K.); (K.-W.T.); Tel.: +886-2-2826-7000 (ext. 7950) (W.-C.K.); +886-2-2636-0303 (ext. 1227) (K.-W.T.)
| | - Kuang-Wen Tseng
- Department of Medicine, Mackay Medical College, New Taipei 252, Taiwan
- Correspondence: (W.-C.K.); (K.-W.T.); Tel.: +886-2-2826-7000 (ext. 7950) (W.-C.K.); +886-2-2636-0303 (ext. 1227) (K.-W.T.)
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67
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Chen Z, Xiong Y, Wei H, Zhao R, Duan X, Shen H. Dual-consistency semi-supervision combined with self-supervision for vessel segmentation in retinal OCTA images. BIOMEDICAL OPTICS EXPRESS 2022; 13:2824-2834. [PMID: 35774329 PMCID: PMC9203111 DOI: 10.1364/boe.458004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/04/2022] [Accepted: 04/12/2022] [Indexed: 06/15/2023]
Abstract
Optical coherence tomography angiography(OCTA) is an advanced noninvasive vascular imaging technique that has important implications in many vision-related diseases. The automatic segmentation of retinal vessels in OCTA is understudied, and the existing segmentation methods require large-scale pixel-level annotated images. However, manually annotating labels is time-consuming and labor-intensive. Therefore, we propose a dual-consistency semi-supervised segmentation network incorporating multi-scale self-supervised puzzle subtasks(DCSS-Net) to tackle the challenge of limited annotations. First, we adopt a novel self-supervised task in assisting semi-supervised networks in training to learn better feature representations. Second, we propose a dual-consistency regularization strategy that imposed data-based and feature-based perturbation to effectively utilize a large number of unlabeled data, alleviate the overfitting of the model, and generate more accurate segmentation predictions. Experimental results on two OCTA retina datasets validate the effectiveness of our DCSS-Net. With very little labeled data, the performance of our method is comparable with fully supervised methods trained on the entire labeled dataset.
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Affiliation(s)
- Zailiang Chen
- School of Information Science and Engineering, Central South University, Changsha 410083, China
| | - Yuchen Xiong
- School of Information Science and Engineering, Central South University, Changsha 410083, China
| | - Hao Wei
- School of Information Science and Engineering, Central South University, Changsha 410083, China
| | - Rongchang Zhao
- School of Information Science and Engineering, Central South University, Changsha 410083, China
| | - Xuanchu Duan
- Changsha Aier Eye Hospital, Changsha 410015, China
| | - Hailan Shen
- School of Information Science and Engineering, Central South University, Changsha 410083, China
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68
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Kim TH, Ma G, Son T, Yao X. Functional Optical Coherence Tomography for Intrinsic Signal Optoretinography: Recent Developments and Deployment Challenges. Front Med (Lausanne) 2022; 9:864824. [PMID: 35445037 PMCID: PMC9013890 DOI: 10.3389/fmed.2022.864824] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Intrinsic optical signal (IOS) imaging of the retina, also termed as optoretinogram or optoretinography (ORG), promises a non-invasive method for the objective assessment of retinal function. By providing the unparalleled capability to differentiate individual retinal layers, functional optical coherence tomography (OCT) has been actively investigated for intrinsic signal ORG measurements. However, clinical deployment of functional OCT for quantitative ORG is still challenging due to the lack of a standardized imaging protocol and the complication of IOS sources and mechanisms. This article aims to summarize recent developments of functional OCT for ORG measurement, OCT intensity- and phase-based IOS processing. Technical challenges and perspectives of quantitative IOS analysis and ORG interpretations are discussed.
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Affiliation(s)
- Tae-Hoon Kim
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Guangying Ma
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Taeyoon Son
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Xincheng Yao
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
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69
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Luisi JD, Lin JL, Ameredes BT, Motamedi M. Spatial-Temporal Speckle Variance in the En-Face View as a Contrast for Optical Coherence Tomography Angiography (OCTA). SENSORS (BASEL, SWITZERLAND) 2022; 22:s22072447. [PMID: 35408061 PMCID: PMC9003003 DOI: 10.3390/s22072447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/19/2022] [Accepted: 03/20/2022] [Indexed: 05/09/2023]
Abstract
Optical Coherence Tomography (OCT) is an adaptable depth-resolved imaging modality capable of creating a non-invasive 'digital biopsy' of the eye. One of the latest advances in OCT is optical coherence tomography angiography (OCTA), which uses the speckle variance or phase change in the signal to differentiate static tissue from blood flow. Unlike fluorescein angiography (FA), OCTA is contrast free and depth resolved. By combining high-density scan patterns and image processing algorithms, both morphometric and functional data can be extracted into a depth-resolved vascular map of the retina. The algorithm that we explored takes advantage of the temporal-spatial relationship of the speckle variance to improve the contrast of the vessels in the en-face OCT with a single frame. It also does not require the computationally inefficient decorrelation of multiple A-scans to detect vasculature, as used in conventional OCTA analysis. Furthermore, the spatial temporal OCTA (ST-OCTA) methodology tested offers the potential for post hoc analysis to improve the depth-resolved contrast of specific ocular structures, such as blood vessels, with the capability of using only a single frame for efficient screening of large sample volumes, and additional enhancement by processing with choice of frame averaging methods. Applications of this method in pre-clinical studies suggest that the OCTA algorithm and spatial temporal methodology reported here can be employed to investigate microvascularization and blood flow in the retina, and possibly other compartments of the eye.
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Affiliation(s)
- Jonathan D. Luisi
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA; (J.D.L.); (B.T.A.)
| | - Jonathan L. Lin
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA;
| | - Bill T. Ameredes
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA; (J.D.L.); (B.T.A.)
- Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA
| | - Massoud Motamedi
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA;
- Correspondence:
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70
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In-vivo functional and structural retinal imaging using multiwavelength photoacoustic remote sensing microscopy. Sci Rep 2022; 12:4562. [PMID: 35296738 PMCID: PMC8927130 DOI: 10.1038/s41598-022-08508-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 03/08/2022] [Indexed: 11/16/2022] Open
Abstract
Many important eye diseases as well as systemic disorders manifest themselves in the retina. Retinal imaging technologies are rapidly growing and can provide ever-increasing amounts of information about the structure, function, and molecular composition of retinal tissue in-vivo. Photoacoustic remote sensing (PARS) is a novel imaging modality based on all-optical detection of photoacoustic signals, which makes it suitable for a wide range of medical applications. In this study, PARS is applied for in-vivo imaging of the retina and estimating oxygen saturation in the retinal vasculature. To our knowledge, this is the first time that a non-contact photoacoustic imaging technique is applied for in-vivo imaging of the retina. Here, optical coherence tomography is also used as a well-established retinal imaging technique to navigate the PARS imaging beams and demonstrate the capabilities of the optical imaging setup. The system is applied for in-vivo imaging of both microanatomy and the microvasculature of the retina. The developed system has the potential to advance the understanding of the ocular environment and to help in monitoring of ophthalmic diseases.
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71
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Changes of the retinal and choroidal vasculature in cerebral small vessel disease. Sci Rep 2022; 12:3660. [PMID: 35256658 PMCID: PMC8901619 DOI: 10.1038/s41598-022-07638-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 02/21/2022] [Indexed: 12/21/2022] Open
Abstract
Cerebral small vessel disease (CSVD) is associated with changes in the retinal vasculature which can be assessed non-invasively with much higher resolution than the cerebral vasculature. To detect changes at a microvascular level, we used optical coherence tomography angiography which resolves retinal and choroidal vasculature. Participants with CSVD and controls were included. White matter lesions were determined on magnetic resonance imaging (MRI). The retinal and choroidal vasculature were quantified using swept-source optical coherence tomography angiography. Data were analysed using linear regression. We included 30 participants (18 females; patients, n = 20; controls, n = 10) with a mean age of 61 ± 10 years. Patients had a higher mean white matter lesion index and number of lesions than controls (p ≤ 0.002). The intraindividual deviation of choriocapillaris reflectivity differed significantly between age-matched patients (0.234 ± 0.012) and controls (0.247 ± 0.011; p = 0.029). Skeleton density of the deep retinal capillaries was significantly associated with the number of lesions on MRI (β = − 5.3 × 108, 95%-confidence interval [− 10.3 × 108; − 0.2 × 108]) when controlling for age. The choroidal microvasculature and the deep retinal vascular plexus, as quantified by optical coherence tomography angiography, are significantly altered in CSVD. The value of these findings in diagnosing or monitoring CSVD need to be assessed in future studies.
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72
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Jafari CZ, Mihelic SA, Engelmann S, Dunn AK. High-resolution three-dimensional blood flow tomography in the subdiffuse regime using laser speckle contrast imaging. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210364SSR. [PMID: 35362273 PMCID: PMC8968074 DOI: 10.1117/1.jbo.27.8.083011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
SIGNIFICANCE Visualizing high-resolution hemodynamics in cerebral tissue over a large field of view (FOV), provides important information in studying disease states affecting the brain. Current state-of-the-art optical blood flow imaging techniques either lack spatial resolution or are too slow to provide high temporal resolution reconstruction of flow map over a large FOV. AIM We present a high spatial resolution computational optical imaging technique based on principles of laser speckle contrast imaging (LSCI) for reconstructing the blood flow maps in complex tissue over a large FOV provided that the three-dimensional (3D) vascular structure is known or assumed. APPROACH Our proposed method uses a perturbation Monte Carlo simulation of the high-resolution 3D geometry for both accurately deriving the speckle contrast forward model and calculating the Jacobian matrix used in our reconstruction algorithm to achieve high resolution. Given the convex nature of our highly nonlinear problem, we implemented a mini-batch gradient descent with an adaptive learning rate optimization method to iteratively reconstruct the blood flow map. Specifically, we implemented advanced optimization techniques combined with efficient parallelization and vectorization of the forward and derivative calculations to make reconstruction of the blood flow map feasible with reconstruction times on the order of tens of minutes. RESULTS We tested our reconstruction algorithm through simulation of both a flow phantom model as well as an anatomically correct murine cerebral tissue and vasculature captured via two-photon microscopy. Additionally, we performed a noise study, examining the robustness of our inverse model in presence of 0.1% and 1% additive noise. In all cases, the blood flow reconstruction error was <2 % for most of the vasculature, except for the peripheral vasculature which suffered from insufficient photon sampling. Descending vasculature and deeper structures showed slightly higher sensitivity to noise compared with vasculature with a horizontal orientation at the more superficial layers. Our results show high-resolution reconstruction of the blood flow map in tissue down to 500 μm and beyond. CONCLUSIONS We have demonstrated a high-resolution computational imaging technique for visualizing blood flow map in complex tissue over a large FOV. Once a high-resolution structural image is captured, our reconstruction algorithm only requires a few LSCI images captured through a camera to reconstruct the blood flow map computationally at a high resolution. We note that the combination of high temporal and spatial resolution of our reconstruction algorithm makes the solution well-suited for applications involving fast monitoring of flow dynamics over a large FOV, such as in functional neural imaging.
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Affiliation(s)
- Chakameh Z. Jafari
- The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas, United States
| | - Samuel A. Mihelic
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Shaun Engelmann
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Andrew K. Dunn
- The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas, United States
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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73
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Huang Y, Qiao Z, Chen J, Zhang D, Hao Q. Full-range optical coherence refraction tomography. OPTICS LETTERS 2022; 47:894-897. [PMID: 35167552 DOI: 10.1364/ol.445716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
In full-range optical coherence tomography (FROCT), the axial resolution is often superior to the lateral resolution, which is degraded by its signal processing and presents nonuniformity at different imaging depths due to the defocus effect. Optical coherence refraction tomography (OCRT) uses images from multiple angles to computationally reconstruct an image with isotropic resolution, solving the problem of image resolution anisotropy in the sub-millimeter imaging depth range. In this work, we report full-range OCRT (FROCRT), which uses full-range complex conjugate-free optical coherence tomography (OCT) images from multiple angles to reconstruct an isotropic spatial resolution image with extended imaging range. We build a system that can automatically acquire images from 360° for reconstruction. We further apply FROCRT to tape phantom, optical-cleared mouse leg bone and spinal cord samples, and aloe sample, achieving extended imaging depth and isotropic resolution. We propose FROCRT, as an extension to OCRT, will enable broader applications.
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74
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Occelli LM, Pirie CG, Petersen‐Jones SM. Non‐invasive optical coherence tomography angiography: A comparison with fluorescein and indocyanine green angiography in normal adult dogs and cats. Vet Ophthalmol 2022; 25 Suppl 1:164-178. [DOI: 10.1111/vop.12973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 01/08/2023]
Affiliation(s)
- Laurence M. Occelli
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
| | - Chris G. Pirie
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
| | - Simon M. Petersen‐Jones
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
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75
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Zuhayri H, Nikolaev VV, Lepekhina TB, Sandykova EA, Krivova NA, Kistenev YV. The In Vivo Quantitative Assessment of the Effectiveness of Low-Dose Photodynamic Therapy on Wound Healing Using Optical Coherence Tomography. Pharmaceutics 2022; 14:399. [PMID: 35214134 PMCID: PMC8877015 DOI: 10.3390/pharmaceutics14020399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/30/2022] [Accepted: 02/09/2022] [Indexed: 12/10/2022] Open
Abstract
The effect of low-dose photodynamic therapy on in vivo wound healing was investigated using optical coherence tomography. This work aims to develop an approach to quantitative assessment of the wound's state during wound healing including the effect of low-dose photodynamic therapy using topical application of two different photosensitizers, 5-aminolevulinic acid and methylene blue, and two laser doses of 1 J/cm2 and 4 J/cm2. It was concluded that the laser dose of 4 J/cm2 was better compared to 1 J/cm2 and allowed the wound healing process to accelerate.
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Affiliation(s)
| | | | | | | | | | - Yury V. Kistenev
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (H.Z.); (V.V.N.); (T.B.L.); (E.A.S.); (N.A.K.)
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76
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INFLUENCE OF HIGH MYOPIA ON CHORIOCAPILLARIS PERFUSION AND CHOROIDAL THICKNESS IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY. Retina 2022; 42:1077-1084. [PMID: 35174807 DOI: 10.1097/iae.0000000000003427] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate the impact of high myopia on choriocapillaris (CC) perfusion and choroidal thickness (CT) in diabetic patients without diabetic retinopathy. METHODS Healthy subjects and patients with diabetes mellitus were recruited from communities in Guangzhou. They were divided into four groups according to the presence of diabetes and high myopia: healthy control (n = 77), diabetes (n = 77), high myopia (n = 77), and diabetes with high myopia (n = 77). Swept-source optical coherence tomography angiography (SS-OCTA) measured CC perfusion and CT. CC perfusion was quantified using the choriocapillaris perfusion index (CPI). RESULTS A total of 308 subjects (308 eyes) were included in the study. The average CPI was 91.11 ± 0.84, 90.16 ± 1.46, 89.80 ± 1.42, and 89.36 ± 1.19% in the control, diabetes, high myopia, and diabetes with high myopia groups, respectively (p < 0.001); the average CT was 227.55 ± 43.13, 205.70 ± 59.66, 158.38 ± 45.24, and 144.22 ± 45.12μm, respectively (p < 0.001). After adjusting for age and sex, the average CPI decreased 0.95 ± 0.20% (p < 0.001) in the diabetes group, 1.33 ± 0.20% (p < 0.001) in the high myopia group, and 1.76 ± 0.20% (p < 0.001) in the diabetes with high myopia group relative to the control group; the average CT decreased 23.53 ± 8.12 (p = 0.004), 70.73 ± 9.41 (p < 0.001), and 85.90 ± 8.12 μm (p < 0.001), respectively. Further adjustment for other risk factors yielded a similar result. CONCLUSION Diabetes and high myopia significantly impact CPI and CT, and the presence of both conditions is more damaging to CPI and CT than diabetes or high myopia alone.
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77
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Baumann B, Merkle CW, Augustin M, Glösmann M, Garhöfer G. Pulsatile tissue deformation dynamics of the murine retina and choroid mapped by 4D optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:647-661. [PMID: 35284183 PMCID: PMC8884196 DOI: 10.1364/boe.445093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/20/2021] [Accepted: 12/28/2021] [Indexed: 05/11/2023]
Abstract
Irregular ocular pulsatility and altered mechanical tissue properties are associated with some of the most sight-threatening eye diseases. Here we present 4D optical coherence tomography (OCT) for the quantitative assessment and depth-resolved mapping of pulsatile dynamics in the murine retina and choroid. Through a pixel-wise analysis of phase changes of the complex OCT signal, we reveal spatiotemporal displacement characteristics across repeated frame acquisitions. We demonstrate in vivo fundus elastography (FUEL) imaging in wildtype mouse retinas and in a mouse model of retinal neovascularization and uncover subtle structural deformations related to ocular pulsation. Our data in mouse eyes hold promise for a powerful retinal elastography technique that may enable a new paradigm of OCT-based measurements and image contrast.
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Affiliation(s)
- Bernhard Baumann
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Conrad W. Merkle
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Martin Glösmann
- Core Facility for Research and Technology,
University of Veterinary Medicine Vienna,
Veterinärplatz 1, 1210 Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology,
Medical University of Vienna, Währinger
Gürtel 18-20, 1090 Vienna, Austria
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78
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Kushner-Lenhoff S, Li Y, Zhang Q, Wang RK, Jiang X, Kashani AH. OCTA Derived Vessel Skeleton Density Versus Flux and Their Associations With Systemic Determinants of Health. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35142788 PMCID: PMC8842473 DOI: 10.1167/iovs.63.2.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose To examine the associations of optical coherence tomography angiography (OCTA)-derived retinal capillary flux with systemic determinants of health. Methods This is a cross-sectional study of subjects recruited from the African American Eye Disease Study. A commercially available swept-source (SS)-OCTA device was used to image the central 3 × 3 mm macular region. Retinal capillary perfusion was assessed using vessel skeleton density (VSD) and flux. Flux approximates the number of red blood cells moving through vessel segments and is a novel metric, whereas VSD is a previously validated measure commonly used to quantify capillary density. The associations of OCTA derived measures with systemic determinants of health were evaluated using multivariate generalized linear mixed-effects models. Results A total of 154 eyes from 83 participants were enrolled. Mean VSD and flux were 0.148 ± 0.009 and 0.156 ± 0.016, respectively. In a model containing age, systolic blood pressure, diabetes status, hematocrit, and presence of retinopathy as covariates, there was a negative correlation between VSD and age (P < 0.001) and retinopathy (P = 0.02), but not with hematocrit (P = 0.85) or other factors. There was a positive correlation between flux and hematocrit (P = 0.02), as well as a negative correlation for flux with age (P < 0.001), systolic blood pressure (P = 0.04), and diabetes status (P = 0.02). A 1% decrease in hematocrit was associated with the same magnitude change in flux as ∼1.24 years of aging. Signal strength was associated with flux (P < 0.001), but not VSD (P = 0.51). Conclusions SS-OCTA derived flux provides additional information about retinal perfusion distinct from that obtained with skeleton density-based measures. Flux is appropriate for detecting subclinical changes in perfusion in the absence of clinical retinopathy.
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Affiliation(s)
- Sam Kushner-Lenhoff
- Department of Ophthalmology, UW Medicine Eye Institute, University of Washington, Seattle, Washington, United States
| | - Yuandong Li
- Department of Biomedical Therapeutics, University of Washington, Seattle, Washington, United States
| | - Qinqin Zhang
- Department of Biomedical Therapeutics, University of Washington, Seattle, Washington, United States
| | - Ruikang K Wang
- Department of Biomedical Therapeutics, University of Washington, Seattle, Washington, United States
| | - Xuejuan Jiang
- Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Amir H Kashani
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States
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79
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Lu J, Zhou H, Shi Y, Choe J, Shen M, Wang L, Chen K, Zhang Q, Feuer WJ, Gregori G, Rosenfeld PJ, Wang RK. Interocular asymmetry of choroidal thickness and vascularity index measurements in normal eyes assessed by swept-source optical coherence tomography. Quant Imaging Med Surg 2022; 12:781-795. [PMID: 34993118 DOI: 10.21037/qims-21-813] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 08/25/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND To investigate the symmetry of interocular choroidal thickness and vascularity index measurements in normal eyes using swept-source optical coherence tomography (SS-OCT). Cross-sectional and observational study. This study included 244 eyes of 122 normal adults with ages uniformly distributed from 19 to 89 years. METHODS SS-OCT imaging was performed using a scanning pattern of 12×12 mm. Mean choroidal thickness (MCT) and choroidal vascularity index (CVI) measurements in the entire scanning region were obtained using a validated and published automatic method. The correlation and differences (including signed and absolute differences) between bilateral MCT and CVI measurements were analyzed at the following 6 regions: 3 concentric circles centered on the fovea with diameters of 2.5, 5, and 11 mm; the inner rim from 2.5 to 5 mm circle; the outer rim from 5 to 11 mm circle; and the entire 12×12-mm scan region, respectively. Comparison of interocular MCT and CVI measurements. RESULTS MCT measurements in right and left eyes were strongly correlated in all regions [all intraclass correlation (ICC) >0.73], but MCT measurements in right eyes were significantly thicker than in left eyes. CVI measurements in right and left eyes were moderately correlated in all regions (all ICC >0.46), but CVI measurements in right eyes were significantly smaller than that in left eyes in the macular subregions (2.5 mm circle, 5 mm circle, and the inner rim). Neither signed nor absolute interocular differences in MCT were correlated with corresponding CVI interocular differences. CONCLUSIONS Choroidal differences exist between normal fellow eyes in adults in the absence of obvious pathology. This study is useful in assisting clinicians and researchers in distinguishing asymmetric changes that are to be expected in normal eyes versus changes that could be associated with diseases.
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Affiliation(s)
- Jie Lu
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Hao Zhou
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Yingying Shi
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - James Choe
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Mengxi Shen
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Liang Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kelly Chen
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - William J Feuer
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Giovanni Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Philip J Rosenfeld
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA.,Department of Ophthalmology, University of Washington, Seattle, WA, USA
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80
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Untracht GR, Matos RS, Dikaios N, Bapir M, Durrani AK, Butsabong T, Campagnolo P, Sampson DD, Heiss C, Sampson DM. OCTAVA: An open-source toolbox for quantitative analysis of optical coherence tomography angiography images. PLoS One 2021; 16:e0261052. [PMID: 34882760 PMCID: PMC8659314 DOI: 10.1371/journal.pone.0261052] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022] Open
Abstract
Optical coherence tomography angiography (OCTA) performs non-invasive visualization and characterization of microvasculature in research and clinical applications mainly in ophthalmology and dermatology. A wide variety of instruments, imaging protocols, processing methods and metrics have been used to describe the microvasculature, such that comparing different study outcomes is currently not feasible. With the goal of contributing to standardization of OCTA data analysis, we report a user-friendly, open-source toolbox, OCTAVA (OCTA Vascular Analyzer), to automate the pre-processing, segmentation, and quantitative analysis of en face OCTA maximum intensity projection images in a standardized workflow. We present each analysis step, including optimization of filtering and choice of segmentation algorithm, and definition of metrics. We perform quantitative analysis of OCTA images from different commercial and non-commercial instruments and samples and show OCTAVA can accurately and reproducibly determine metrics for characterization of microvasculature. Wide adoption could enable studies and aggregation of data on a scale sufficient to develop reliable microvascular biomarkers for early detection, and to guide treatment, of microvascular disease.
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Affiliation(s)
- Gavrielle R. Untracht
- Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, Western Australia, Australia
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
- * E-mail:
| | - Rolando S. Matos
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | | | - Mariam Bapir
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - Abdullah K. Durrani
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - Teemapron Butsabong
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - Paola Campagnolo
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - David D. Sampson
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - Christian Heiss
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
- Surrey and Sussex Healthcare NHS Trust, East Surrey Hospital, Redhill, Surrey, United Kingdom
| | - Danuta M. Sampson
- Department of Biochemical Sciences and Department of Clinical and Experimental Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
- Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, United Kingdom
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81
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Federated Learning for Microvasculature Segmentation and Diabetic Retinopathy Classification of OCT Data. OPHTHALMOLOGY SCIENCE 2021; 1:100069. [PMID: 36246944 PMCID: PMC9559956 DOI: 10.1016/j.xops.2021.100069] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/01/2021] [Accepted: 09/28/2021] [Indexed: 12/26/2022]
Abstract
Purpose To evaluate the performance of a federated learning framework for deep neural network-based retinal microvasculature segmentation and referable diabetic retinopathy (RDR) classification using OCT and OCT angiography (OCTA). Design Retrospective analysis of clinical OCT and OCTA scans of control participants and patients with diabetes. Participants The 153 OCTA en face images used for microvasculature segmentation were acquired from 4 OCT instruments with fields of view ranging from 2 × 2-mm to 6 × 6-mm. The 700 eyes used for RDR classification consisted of OCTA en face images and structural OCT projections acquired from 2 commercial OCT systems. Methods OCT angiography images used for microvasculature segmentation were delineated manually and verified by retina experts. Diabetic retinopathy (DR) severity was evaluated by retinal specialists and was condensed into 2 classes: non-RDR and RDR. The federated learning configuration was demonstrated via simulation using 4 clients for microvasculature segmentation and was compared with other collaborative training methods. Subsequently, federated learning was applied over multiple institutions for RDR classification and was compared with models trained and tested on data from the same institution (internal models) and different institutions (external models). Main Outcome Measures For microvasculature segmentation, we measured the accuracy and Dice similarity coefficient (DSC). For severity classification, we measured accuracy, area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve, balanced accuracy, F1 score, sensitivity, and specificity. Results For both applications, federated learning achieved similar performance as internal models. Specifically, for microvasculature segmentation, the federated learning model achieved similar performance (mean DSC across all test sets, 0.793) as models trained on a fully centralized dataset (mean DSC, 0.807). For RDR classification, federated learning achieved a mean AUROC of 0.954 and 0.960; the internal models attained a mean AUROC of 0.956 and 0.973. Similar results are reflected in the other calculated evaluation metrics. Conclusions Federated learning showed similar results to traditional deep learning in both applications of segmentation and classification, while maintaining data privacy. Evaluation metrics highlight the potential of collaborative learning for increasing domain diversity and the generalizability of models used for the classification of OCT data.
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82
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Le N, Cheng H, Subhash H, Kilpatrick-Liverman L, Wang RK. Gingivitis resolution followed by optical coherence tomography and fluorescence imaging: A case study. JOURNAL OF BIOPHOTONICS 2021; 14:e202100191. [PMID: 34453488 DOI: 10.1002/jbio.202100191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/27/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Gingivitis is highly prevalent in adults, and if left untreated, can progress to periodontitis. In this article, we present an interesting case study where the resolution of gingivitis was followed over a period of 10 days using optical coherence tomography (OCT) and light-induced autofluorescence (LIAF). We demonstrate that OCT and its functional angiography can distinctively capture the changes during the resolution of gingivitis; while LIAF can detect red-fluorescent signals associated with mature plaque present at the inflamed site. The acute inflammatory region showed evidence of angiogenesis based on the quantification of vessel density and number; while no angiogenesis was detected within the less inflamed region. Gingival thickness showed a reduction of 140 ± 26 μm on average, measured between the peak gingivitis event and the period wherein the inflammation was resolved. Vessels in the angiogenesis site was found to reduce exponentially. The mildly inflamed site showed a decreasing trend in the vessel size, which however was within the error of the measurement.
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Affiliation(s)
- Nhan Le
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Harrison Cheng
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Hrebesh Subhash
- Clinical Method Development-Oral Care, Colgate-Palmolive Company, Piscataway, New Jersey, USA
| | | | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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Møller Israelsen N, Mogensen M, Jensen M, Haedersdal M, Bang O. Delineating papillary dermis around basal cell carcinomas by high and ultrahigh resolution optical coherence tomography-A pilot study. JOURNAL OF BIOPHOTONICS 2021; 14:e202100083. [PMID: 34245133 DOI: 10.1002/jbio.202100083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/18/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Bedside diagnosis of skin cancer remains a challenging task. The real-time noninvasive technology of optical coherence tomography (OCT) masters a high diagnostic accuracy in basal cell carcinoma (BCC) but a lower specificity in recognizing imitators and other carcinomas. We investigate the delicate signal of papillary dermis using an in-house developed ultrahigh resolution OCT (UHR-OCT) system with shadow compensation and a commercial multi-focus high resolution OCT (HR-OCT) system for clinical BCC imaging. We find that the HR-OCT system struggled to resolve the dark band signal of papillary dermis where the UHR-OCT located this in all cases and detected changes in signal width. UHR-OCT is able to monitor extension and position of papillary dermis suggesting a novel feature for delineating superficial BCCs in pursuit of a fast accurate diagnosis. Comprehensive studies involving more patients are imperative in order to corroborate results.
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Affiliation(s)
- Niels Møller Israelsen
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Mette Mogensen
- Department of Dermatology, Bisbebjerg Hospital, University Hospitals of Copenhagen, Copenhagen, NV, Denmark
| | - Mikkel Jensen
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Merete Haedersdal
- Department of Dermatology, Bisbebjerg Hospital, University Hospitals of Copenhagen, Copenhagen, NV, Denmark
| | - Ole Bang
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
- NKT Photonics A/S, Birkerød, Denmark
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Desissaire S, Schwarzhans F, Steiner S, Vass C, Fischer G, Pircher M, Hitzenberger CK. Temporal phase evolution OCT for measurement of tissue deformation in the human retina in-vivo. BIOMEDICAL OPTICS EXPRESS 2021; 12:7092-7112. [PMID: 34858702 PMCID: PMC8606136 DOI: 10.1364/boe.440893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/13/2021] [Accepted: 10/13/2021] [Indexed: 05/08/2023]
Abstract
We demonstrate the use of temporal phase evolution (TPE-) OCT methods to evaluate retinal tissue deformation in-vivo over time periods of several seconds. A custom built spectral domain (SD)-OCT system with an integrated retinal tracker, ensuring stable imaging with sub-speckle precision, was used for imaging. TPE-OCT measures and images phase differences between an initial reference B-scan and each of the subsequent B-scans of the evaluated temporal sequence. In order to demonstrate the precision and repeatability of the measurements, retinal nerve fiber (RNF) tissue deformations induced by retinal vessels pulsating with the heartbeat were analyzed in several healthy subjects. We show TPE maps (M-scans of phase evolution as a function of position along B-scan trace vs. time) of wrapped phase data and corresponding deformation maps in selected regions of the RNF layer (RNFL) over the course of several cardiac cycles. A reproducible phase pattern is seen at each heartbeat cycle for all imaged volunteers. RNF tissue deformations near arteries and veins up to ∼ 1.6 µm were obtained with an average precision for a single pixel of about 30 nm. Differences of motion induced by arteries and veins are also investigated.
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Affiliation(s)
- Sylvia Desissaire
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Vienna, 1090, Austria
| | - Florian Schwarzhans
- Center for Medical Statistics, Informatics
and Intelligent Systems, Medical University of
Vienna, Vienna, 1090, Austria
| | - Stefan Steiner
- Department of Ophthalmology and Optometry,
Medical University of Vienna, Vienna, 1090,
Austria
| | - Clemens Vass
- Department of Ophthalmology and Optometry,
Medical University of Vienna, Vienna, 1090,
Austria
| | - Georg Fischer
- Center for Medical Statistics, Informatics
and Intelligent Systems, Medical University of
Vienna, Vienna, 1090, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Vienna, 1090, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna,
Vienna, 1090, Austria
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85
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Liu Y, Chen D, Xu J, Tan Y, Wang Y, Zhao H, Li H, Liu H, Gu Y, Qiu H. Quantitative assessment of vascular features in port wine stains through optical coherence tomography angiography. Photodiagnosis Photodyn Ther 2021; 36:102607. [PMID: 34706276 DOI: 10.1016/j.pdpdt.2021.102607] [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: 02/09/2021] [Revised: 10/16/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Vascular lesions such as port wine stains (PWS) lead to facial and psychological problems, which require careful and precise treatments. The key point of treating PWS is to selectively destroy the abnormal blood vessels. Hence, the in vivo monitoring of targeted vessels is crucial. Optical coherence tomography angiography (OCTA), an emerging label-free imaging tool, facilitates the evaluation of skin structure and vasculature at a high resolution. In this study, we utilised OCTA to capture the structural and vascular morphology in patients with PWS. Moreover, we quantitatively characterised the morphological features of different types of PWS. METHODS This observational clinical study was conducted on 3 patients with flat PWS and 3 patients with thickened PWS. The age range was 4-27 years, and all of them had not received any treatment before this study. The OCTA images of the PWS lesions and contralateral skin were compared. Vascular morphology was characterized, and ectatic vessel depth was quantified according to the OCTA images. RESULTS The blood vessels of the PWS lesions tend to had larger diameters and higher densities than those in the contralateral normal skin. The vessel diameters of PWS lesions were 73 ± 14 μm, with high heterogeneity ranging from 10 to >150 μm, however, the vessel diameters of normal skin were 28 ± 2 μm, ranging from 10 μm to 60 μm. In terms of different PWS lesions, the thickened type showed a trend of larger vessel diameter and higher density than those of the purplish red type. The ectatic vessels were located at the depth of 216 ± 13 μm in the PWS skin. CONCLUSIONS OCTA can facilitate the in vivo three-dimensional visualization of structure and vasculature for PWS lesions. Various quantitative analysis parameters, such as vessel diameter, density, and depth, are typically measured using OCTA. This fact demonstrates the superior capability of OCTA for the precise and comprehensive assessment of PWS lesions.
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Affiliation(s)
- Yidi Liu
- Medical School of Chinese PLA, Beijing 100853, China; Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Defu Chen
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
| | - Jingjiang Xu
- School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | - Yizhou Tan
- Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Ying Wang
- Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Hongyou Zhao
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
| | - Hui Li
- Medical School of Chinese PLA, Beijing 100853, China; Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Haolin Liu
- Medical School of Chinese PLA, Beijing 100853, China; Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Ying Gu
- Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China; Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China; Precision laser medical diagnosis and treatment Innovation unit, Chinese Academy of Medical Sciences, Beijing 100000, China.
| | - Haixia Qiu
- Department of Laser Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China.
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86
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Tang P, Wang RK. 1700 nm broadband laser source enables deep brain optical biopsy. LIGHT, SCIENCE & APPLICATIONS 2021; 10:205. [PMID: 34608128 PMCID: PMC8490362 DOI: 10.1038/s41377-021-00652-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An OCM system that employs a 1700 nm broadband laser source enables cellular level deep brain imaging, providing cytoarchitectural and myeloarchitectural information across cortical depth, without requiring tissue slicing. CC – corpus callosum. [Image: see text]
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Affiliation(s)
- Peijun Tang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98195, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA, 98195, USA.
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87
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Nakamichi Y, Chiu KS, Sun CW. Signal properties of split-spectrum amplitude decorrelation angiography for quantitative optical coherence tomography-based velocimetry. BIOMEDICAL OPTICS EXPRESS 2021; 12:5955-5968. [PMID: 34745715 PMCID: PMC8548019 DOI: 10.1364/boe.432297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 05/17/2023]
Abstract
Split-spectrum amplitude-decorrelation angiography (SSADA) is a noninvasive and three-dimensional angiographic technique with a microscale spatial resolution based on optical coherence tomography. The SSADA signal is known to be correlated with the blood flow velocity and the quantitative velocimetry with SSADA has been expected; however, the signal properties of SSADA are not completely understood due to lack of comprehensive investigations of parameters related to SSADA signals. In this study, phantom experiments were performed to comprehensively investigate the relation of SSADA signals with flow velocities, time separations, particle concentrations, signal-to-noise ratios, beam spot sizes, and viscosities, and revealed that SSADA signals reflect the spatial commonality within a coherence volume between adjacent A-scans.
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Affiliation(s)
- Yu Nakamichi
- Department of Mechanical Engineering, Faculty of Engineering, Sanyo-Onoda City University, 1-1-1, Daigaku-dori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan
| | - Kai-shih Chiu
- Biomedical Optical Imaging Lab, Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, No. 1001, Daxue Rd., East Dist., Hsinchu, 30010, Taiwan
| | - Chia-Wei Sun
- Biomedical Optical Imaging Lab, Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, No. 1001, Daxue Rd., East Dist., Hsinchu, 30010, Taiwan
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88
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Jiao S, Jia Y, Yao X. Emerging imaging developments in experimental vision sciences and ophthalmology. Exp Biol Med (Maywood) 2021; 246:2137-2139. [PMID: 34404253 PMCID: PMC8718248 DOI: 10.1177/15353702211038891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Shuliang Jiao
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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89
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Abstract
Early detection and monitoring are critical to the diagnosis and management of glaucoma, a progressive optic neuropathy that causes irreversible blindness. Optical coherence tomography (OCT) has become a commonly utilized imaging modality that aids in the detection and monitoring of structural glaucomatous damage. Since its inception in 1991, OCT has progressed through multiple iterations, from time-domain OCT, to spectral-domain OCT, to swept-source OCT, all of which have progressively improved the resolution and speed of scans. Even newer technological advancements and OCT applications, such as adaptive optics, visible-light OCT, and OCT-angiography, have enriched the use of OCT in the evaluation of glaucoma. This article reviews current commercial and state-of-the-art OCT technologies and analytic techniques in the context of their utility for glaucoma diagnosis and management, as well as promising future directions.
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Affiliation(s)
- Alexi Geevarghese
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA
- Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA
| | - Joel S Schuman
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA
- Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA
- Department of Physiology and Neuroscience, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA
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90
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Alexandrov S, Arangath A, Zhou Y, Murphy M, Duffy N, Neuhaus K, Shaw G, McAuley R, Leahy M. Accessing depth-resolved high spatial frequency content from the optical coherence tomography signal. Sci Rep 2021; 11:17123. [PMID: 34429483 PMCID: PMC8385072 DOI: 10.1038/s41598-021-96619-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/28/2021] [Indexed: 11/17/2022] Open
Abstract
Optical coherence tomography (OCT) is a rapidly evolving technology with a broad range of applications, including biomedical imaging and diagnosis. Conventional intensity-based OCT provides depth-resolved imaging with a typical resolution and sensitivity to structural alterations of about 5–10 microns. It would be desirable for functional biological imaging to detect smaller features in tissues due to the nature of pathological processes. In this article, we perform the analysis of the spatial frequency content of the OCT signal based on scattering theory. We demonstrate that the OCT signal, even at limited spectral bandwidth, contains information about high spatial frequencies present in the object which relates to the small, sub-wavelength size structures. Experimental single frame imaging of phantoms with well-known sub-micron internal structures confirms the theory. Examples of visualization of the nanoscale structural changes within mesenchymal stem cells (MSC), which are invisible using conventional OCT, are also shown. Presented results provide a theoretical and experimental basis for the extraction of high spatial frequency information to substantially improve the sensitivity of OCT to structural alterations at clinically relevant depths.
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Affiliation(s)
- Sergey Alexandrov
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland.
| | - Anand Arangath
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Yi Zhou
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Mary Murphy
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Niamh Duffy
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Kai Neuhaus
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Georgina Shaw
- Regenerative Medicine Institute, School of Medicine, National University of Ireland, Galway, Ireland
| | - Ryan McAuley
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland
| | - Martin Leahy
- National University of Ireland, National Biophotonics and Imaging Platform, School of Physics, Tissue Optics and Microcirculation Imaging Group, Galway, H91 TK33, Ireland.,Institute of Photonic Sciences (ICFO), Barcelona, Spain
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91
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Zhang W, Davis CM, Zeppenfeld DM, Golgotiu K, Wang MX, Haveliwala M, Hong D, Li Y, Wang RK, Iliff JJ, Alkayed NJ. Role of endothelium-pericyte signaling in capillary blood flow response to neuronal activity. J Cereb Blood Flow Metab 2021; 41:1873-1885. [PMID: 33853406 PMCID: PMC8327110 DOI: 10.1177/0271678x211007957] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Local blood flow in the brain is tightly coupled to metabolic demands, a phenomenon termed functional hyperemia. Both capillaries and arterioles contribute to the hyperemic response to neuronal activity via different mechanisms and timescales. The nature and specific signaling involved in the hyperemic response of capillaries versus arterioles, and their temporal relationship are not fully defined. We determined the time-dependent changes in capillary flux and diameter versus arteriolar velocity and flow following whisker stimulation using optical microangiography (OMAG) and two-photon microscopy. We further characterized depth-resolved responses of individual capillaries versus capillary networks. We hypothesized that capillaries respond first to neuronal activation, and that they exhibit a coordinated response mediated via endothelial-derived epoxyeicosatrienoates (EETs) acting on pericytes. To visualize peri-capillary pericytes, we used Tie2-GFP/NG2-DsRed mice, and to determine the role of endothelial-derived EETs, we compared cerebrovascular responses to whisker stimulation between wild-type mice and mice with lower endothelial EETs (Tie2-hsEH). We found that capillaries respond immediately to neuronal activation in an orchestrated network-level manner, a response attenuated in Tie2-hsEH and inhibited by blocking EETs action on pericytes. These results demonstrate that capillaries are first responders during functional hyperemia, and that they exhibit a network-level response mediated via endothelial-derived EETs' action on peri-capillary pericytes.
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Affiliation(s)
- Wenri Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Douglas M Zeppenfeld
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Kirsti Golgotiu
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Marie X Wang
- Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Mariya Haveliwala
- Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Daniel Hong
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Yuandong Li
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Jeffrey J Iliff
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA.,Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
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92
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Huang Y, Li X, Liu J, Qiao Z, Chen J, Hao Q. Robotic-arm-assisted flexible large field-of-view optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:4596-4609. [PMID: 34457434 PMCID: PMC8367223 DOI: 10.1364/boe.431318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Optical coherence tomography (OCT) is a three-dimensional non-invasive high-resolution imaging modality that has been widely used for applications ranging from medical diagnosis to industrial inspection. Common OCT systems are equipped with limited field-of-view (FOV) in both the axial depth direction (a few millimeters) and lateral direction (a few centimeters), prohibiting their applications for samples with large and irregular surface profiles. Image stitching techniques exist but are often limited to at most 3 degrees-of-freedom (DOF) scanning. In this work, we propose a robotic-arm-assisted OCT system with 7 DOF for flexible large FOV 3D imaging. The system consists of a depth camera, a robotic arm and a miniature OCT probe with an integrated RGB camera. The depth camera is used to get the spatial information of targeted sample at large scale while the RGB camera is used to obtain the exact position of target to align the image probe. Eventually, the real-time 3D OCT imaging is used to resolve the relative pose of the probe to the sample and as a feedback for imaging pose optimization when necessary. Flexible probe pose manipulation is enabled by the 7 DOF robotic arm. We demonstrate a prototype system and present experimental results with flexible tens of times enlarged FOV for plastic tube, phantom human finger, and letter stamps. It is expected that robotic-arm-assisted flexible large FOV OCT imaging will benefit a wide range of biomedical, industrial and other scientific applications.
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Affiliation(s)
- Yong Huang
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
- Equal contributors
| | - Xiaochen Li
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
- Equal contributors
| | - Junyu Liu
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
| | - Zhengyu Qiao
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
| | - Jingsi Chen
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
| | - Qun Hao
- School of Optics and Photonics, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Haidian, Beijing 100081, China
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93
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Abdurashitov AS, Prikhozhdenko ES, Mayorova OA, Plastun VO, Gusliakova OI, Shushunova NA, Kulikov OA, Tuchin VV, Sukhorukov GB, Sindeeva OA. Optical coherence microangiography of the mouse kidney for diagnosis of circulatory disorders. BIOMEDICAL OPTICS EXPRESS 2021; 12:4467-4477. [PMID: 34457426 PMCID: PMC8367229 DOI: 10.1364/boe.430393] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/17/2021] [Accepted: 06/20/2021] [Indexed: 05/02/2023]
Abstract
Optical coherence tomography (OCT) has become widespread in clinical applications in which precise three-dimensional functional imaging of living organs is required. Nevertheless, the kidney is inaccessible for the high resolution OCT imaging due to a high light attenuation coefficient of skin and soft tissues that significantly limits the penetration depth of the probing laser beam. Here, we introduce a surgical protocol and fixation scheme that enables functional visualization of kidney's peritubular capillaries via OCT microangiography. The model of reversible/irreversible glomerulus embolization using drug microcarriers confirms the ability of OCT to detect circulatory disorders. This approach can be used for choosing optimal carriers, their dosages and diagnosis of other blood flow pathologies.
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Affiliation(s)
- Arkady S Abdurashitov
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, 3 Nobel str., Moscow 143005, Russia
| | | | - Oksana A Mayorova
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
| | - Valentina O Plastun
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
| | - Olga I Gusliakova
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
| | - Natalia A Shushunova
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
| | - Oleg A Kulikov
- Ogarev Mordovia State University, 68 Bolshevistskaya str., Saransk 430005, Russia
| | - Valery V Tuchin
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
- Interdisciplinary Laboratory of Biophotonics, National Research Tomsk State University, 36 Lenina Avenue, Tomsk 634050, Russia
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control of the Russian Academy of Science, 24 Rabochaya Str., Saratov 410028, Russia
| | - Gleb B Sukhorukov
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, 3 Nobel str., Moscow 143005, Russia
- School of Engineering and Materials Science, Queen Mary University of London, Mile End, Eng, 215, London E1 4NS, United Kingdom
| | - Olga A Sindeeva
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, 3 Nobel str., Moscow 143005, Russia
- Science Medical Center, Saratov State University, 83 Astrakhanskaya str., Saratov 410012, Russia
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94
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Tan B, Sim YC, Chua J, Yusufi D, Wong D, Yow AP, Chin C, Tan ACS, Sng CCA, Agrawal R, Gopal L, Sim R, Tan G, Lamoureux E, Schmetterer L. Developing a normative database for retinal perfusion using optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2021; 12:4032-4045. [PMID: 34457397 PMCID: PMC8367249 DOI: 10.1364/boe.423469] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 05/25/2023]
Abstract
Visualizing and characterizing microvascular abnormalities with optical coherence tomography angiography (OCTA) has deepened our understanding of ocular diseases, such as glaucoma, diabetic retinopathy, and age-related macular degeneration. Two types of microvascular defects can be detected by OCTA: focal decrease because of localized absence and collapse of retinal capillaries, which is referred to as the non-perfusion area in OCTA, and diffuse perfusion decrease usually detected by comparing with healthy case-control groups. Wider OCTA allows for insights into peripheral retinal vascularity, but the heterogeneous perfusion distribution from the macula, parapapillary area to periphery hurdles the quantitative assessment. A normative database for OCTA could estimate how much individual's data deviate from the normal range, and where the deviations locate. Here, we acquired OCTA images using a swept-source OCT system and a 12×12 mm protocol in healthy subjects. We automatically segmented the large blood vessels with U-Net, corrected for anatomical factors such as the relative position of fovea and disc, and segmented the capillaries by a moving window scheme. A total of 195 eyes were included and divided into 4 age groups: < 30 (n=24) years old, 30-49 (n=28) years old, 50-69 (n=109) years old and >69 (n=34) years old. This provides an age-dependent normative database for characterizing retinal perfusion abnormalities in 12×12 mm OCTA images. The usefulness of the normative database was tested on two pathological groups: one with diabetic retinopathy; the other with glaucoma.
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Affiliation(s)
- Bingyao Tan
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- NTU Institute for Health Technologies, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Yin Ci Sim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Jacqueline Chua
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
| | - Dheo Yusufi
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Damon Wong
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- NTU Institute for Health Technologies, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Ai Ping Yow
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- NTU Institute for Health Technologies, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Calvin Chin
- Duke-NUS Medical School, Singapore
- National Heart Centre Singapore, Singapore
| | - Anna C. S. Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
- Changi General Hospital, Singapore
| | - Chelvin C. A. Sng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Department of Ophthalmology, National University Hospital, Singapore
| | - Rupesh Agrawal
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | | | - Ralene Sim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Gavin Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
| | - Ecosse Lamoureux
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
| | - Leopold Schmetterer
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- NTU Institute for Health Technologies, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
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95
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Dadkhah A, Paudel D, Jiao S. Comparative study of optical coherence tomography angiography algorithms for rodent retinal imaging. Exp Biol Med (Maywood) 2021; 246:2207-2213. [PMID: 34120494 DOI: 10.1177/15353702211024572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Optical coherence tomography angiography (OCTA) is a functional extension of optical coherence tomography for non-invasive in vivo three-dimensional imaging of the microvasculature of biological tissues. Several algorithms have been developed to construct OCTA images from the measured optical coherence tomography signals. In this study, we compared the performance of three OCTA algorithms that are based on the variance of phase, amplitude, and the complex representations of the optical coherence tomography signals for rodent retinal imaging, namely the phase variance, improved speckle contrast, and optical microangiography. The performance of the different algorithms was evaluated by comparing the quality of the OCTA images regarding how well the vasculature network can be resolved. Quantities that are widely used in ophthalmic studies including blood vessel density, vessel diameter index, vessel perimeter index, vessel complexity index were also compared. Results showed that both the improved speckle contrast and optical microangiography algorithms are more robust than phase variance, and they can reveal similar vasculature features while there are statistical differences in the calculated quantities.
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Affiliation(s)
- Arash Dadkhah
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
| | - Dhruba Paudel
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
| | - Shuliang Jiao
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
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96
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Pakdaman Zangabad R, Iskander-Rizk S, van der Meulen P, Meijlink B, Kooiman K, Wang T, van der Steen AFW, van Soest G. Photoacoustic flow velocity imaging based on complex field decorrelation. PHOTOACOUSTICS 2021; 22:100256. [PMID: 33868919 PMCID: PMC8040274 DOI: 10.1016/j.pacs.2021.100256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/16/2021] [Accepted: 02/21/2021] [Indexed: 05/18/2023]
Abstract
Photoacoustic (PA) imaging can be used to monitor flowing blood inside the microvascular and capillary bed. Ultrasound speckle decorrelation based velocimetry imaging was previously shown to accurately estimate blood flow velocity in mouse brain (micro-)vasculature. Translating this method to photoacoustic imaging will allow simultaneous imaging of flow velocity and extracting functional parameters like blood oxygenation. In this study, we use a pulsed laser diode and a quantitative method based on normalized first order field autocorrelation function of PA field fluctuations to estimate flow velocities in an ink tube phantom and in the microvasculature of the chorioallantoic membrane of a chicken embryo. We demonstrate how the decorrelation time of signals acquired over frames are related to the flow speed and show that the PA flow analysis based on this approach is an angle independent flow velocity imaging method.
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Affiliation(s)
- Reza Pakdaman Zangabad
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sophinese Iskander-Rizk
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Pim van der Meulen
- Department of Microelectronics, Delft University of Technology, Delft, The Netherlands
| | - Bram Meijlink
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Klazina Kooiman
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tianshi Wang
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Antonius F W van der Steen
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Imaging Science and Physics, Delft University of Technology, Delft, The Netherlands
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Gijs van Soest
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
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97
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Hekimsoy V, Kılınç Hekimsoy H, Şekeroğlu MA, Kaya EB, Tokgözoğlu L. The relationship between retinal microcirculation and right heart catheterization and echocardiography findings in patients with idiopathic pulmonary arterial hypertension. Microcirculation 2021; 28:e12704. [PMID: 33971060 DOI: 10.1111/micc.12704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 03/20/2021] [Accepted: 05/02/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the possible alterations of retinal microcirculation associated with right-sided intracardiac pressures in patients with IPAH. METHODS Twenty patients with IPAH and 20 age- and sex-matched healthy controls were included in the study. Hemodynamic data were obtained from the most recent right heart catheterization. Echocardiographic examination was performed within 24 h of ophthalmological examination. For the right eyes of all participants, high-resolution scans of chorioretinal microvascular networks at different depths of the retina were captured via OCT angiography. RESULTS The perfusion of the superficial and deep capillary plexus (SCP and DCP), and choriocapillaris (CCP) flow area were significantly lower than those in healthy control subjects (p < .05 for all). In IPAH group, PVR and mPAP were correlated significantly with the perfusion measurements at SCP and DCP (r = .461, r = .626 and r = .625, r =0.730, respectively, p < .05). sPAP and TRV were positively correlated with the perfusion measurements at SCP and DCP (r = .600, r = .662 and r = .670, r = .655 p < .05). CONCLUSIONS The positive correlation of retinal perfusion at SCP and DCP with right-sided echocardiographic and hemodynamic measurements unveiled that retinal microcirculation is affected by the pressure alterations in the pulmonary circulation of IPAH patients.
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Affiliation(s)
- Vedat Hekimsoy
- Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Hilal Kılınç Hekimsoy
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Mehmet Ali Şekeroğlu
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Ergün Barış Kaya
- Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Lale Tokgözoğlu
- Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
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98
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Abstract
PURPOSE Intravitreal injections acutely and temporarily increase intraocular pressure (IOP), and this may have cumulative long-term effects including an increased risk for glaucoma surgery. This study was designed to measure retinal perfusion density changes on optical coherence tomography (OCT) angiography and OCT thickness alterations associated with acutely increased IOP after intravitreal injections. METHODS Retrospective observational clinical study of 40 eyes (39 patients) with various retinopathies from October 2016 to June 2017 at a tertiary care retina clinic in NYC. Patients were older than 18 years, with vision >20/100, able to fixate and without media opacities precluding OCT angiography, receiving intravitreal bevacizumab or aflibercept for diabetic retinopathy, retinal vein occlusion, macular degeneration, retinal neovascularization, or radiation retinopathy. The 3-mm × 3-mm macular and 4.5-mm × 4.5-mm peripapillary OCT angiography perfusion density, macular OCT thickness, and IOP were measured before and immediately after intravitreal injections. Paired t-test was used to compare preinjection and postinjection values for perfusion density and OCT thickness. Regression analysis was performed for potential effects of baseline IOP, IOP change, and age. RESULTS Statistically significant decreases in angiographic perfusion density (P < 0.05) were found in most areas of the superficial and deep layer macular OCT angiography, and the overall optic nerve head and the radial peripapillary capillary layer, preferentially temporal. Macular OCT thickness was significantly decreased in the temporal region and increased in the nasal region. Regression analysis showed relationships between age and decreased superficial macular perfusion. Preinjection IOP was only related to OCT thickness in the fovea. Intraocular pressure change was related only to decreased superficial macular perfusion density. CONCLUSION Intravitreal injections produce acute IOP changes that are associated with reduced macular and peripapillary perfusion density. Therefore, it is possible that patients receiving regular intravitreal injections may be sustaining perfusion-related injury to ocular structures that may produce glaucomatous damage to the macula and optic nerve.
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99
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McKay GN, Niemeier RC, Castro-González C, Durr NJ. Scattering oblique plane microscopy for in-vivo blood cell imaging. BIOMEDICAL OPTICS EXPRESS 2021; 12:2575-2585. [PMID: 34123489 PMCID: PMC8176791 DOI: 10.1364/boe.422993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/18/2021] [Accepted: 03/30/2021] [Indexed: 05/10/2023]
Abstract
Oblique plane microscopy (OPM) enables high speed, volumetric fluorescence imaging through a single-objective geometry. While these advantages have positioned OPM as a valuable tool to probe biological questions in animal models, its potential for in vivo human imaging is largely unexplored due to its typical use with exogenous fluorescent dyes. Here we introduce a scattering-contrast oblique plane microscope (sOPM) and demonstrate label-free imaging of blood cells flowing through human capillaries in vivo. The sOPM illuminates a capillary bed in the ventral tongue with an oblique light sheet, and images side- and back- scattered signal from blood cells. By synchronizing the sOPM with a conventional capillaroscope, we acquire paired widefield and axial images of blood cells flowing through a capillary loop. The widefield capillaroscope image provides absorption contrast and confirms the presence of red blood cells (RBCs), while the sOPM image may aid in determining whether optical absorption gaps (OAGs) between RBCs have cellular or acellular composition. Further, we demonstrate consequential differences between fluorescence and scattering versions of OPM by imaging the same polystyrene beads sequentially with each technique. Lastly, we substantiate in vivo observations by imaging isolated red blood cells, white blood cells, and platelets in vitro using 3D agar phantoms. These results demonstrate a promising new avenue towards in vivo blood analysis.
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Affiliation(s)
- Gregory N. McKay
- Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ryan C. Niemeier
- Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Nicholas J. Durr
- Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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100
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He Q, Sun Z, Li Y, Wang W, Wang RK. Spatiotemporal monitoring of changes in oxy/deoxy-hemoglobin concentration and blood pulsation on human skin using smartphone-enabled remote multispectral photoplethysmography. BIOMEDICAL OPTICS EXPRESS 2021; 12:2919-2937. [PMID: 34168907 PMCID: PMC8194624 DOI: 10.1364/boe.423160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 06/13/2023]
Abstract
We propose a smartphone-enabled remote multispectral photoplethysmography (SP-rmPPG) system and method to realize spatiotemporal monitoring of perfusion changes and pulsations of the oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) information of the effective blood volume within light interrogated skin tissue beds. The system is implemented on an unmodified smartphone utilizing its built-in camera and flashlight to acquire videos of the skin reflectance. The SP-rmPPG method converts the RGB video into multispectral cubes, upon which to decouple the dynamic changes in HbO2 and Hb information using a modified Beer-Lambert law and the selective wavelength bands of 500 nm and 650 nm. Blood pulsation amplitudes are then obtained by applying a window-based lock-in amplification on the derived spatiotemporal changes in HbO2 or Hb signals. To demonstrate the feasibility of proposed method, we conduct two experiments on the skin tissue beds that are conditioned by occlusive maneuver of supplying arteries: one using the popular blood cuff pressure maneuver on the upper arm, and another artificially inducing a transient ischemic condition on the facial skin tissue beds by finger pressing on the supplying external carotid artery. The cuff experiment shows that the measured dynamic information of HbO2 and Hb in the downstream agrees well with the parallel measurements of oxygenation saturation given by the standard pulse oximeter. We also observe the expected imbalance of spatiotemporal changes in the HbO2 and Hb between the right and left cheeks when the transient ischemic condition is induced in the one side of facial skin tissue beds. The results from the two experiments sufficiently demonstrate the feasibility of the proposed method to monitor the spatiotemporal changes in the skin hemodynamics, including blood oxygenation and pulsation amplitudes. Considering the ever-growing accessibility and affordability of the smartphone to the general public, the proposed strategy promises the early screening of vascular diseases and improving general public health particularly in rural areas with low resource settings.
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Affiliation(s)
- Qinghua He
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Zhiyuan Sun
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Yuandong Li
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Wendy Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
- Department of Ophthalmology, University of Washington, Seattle, WA98105, USA
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