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Son T, Ma G, Yao X. Functional OCT reveals anisotropic changes of retinal flicker-evoked vasodilation. OPTICS LETTERS 2024; 49:2121-2124. [PMID: 38621091 DOI: 10.1364/ol.520840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/18/2024] [Indexed: 04/17/2024]
Abstract
The purpose of this study is to verify the effect of anisotropic property of retinal biomechanics on vasodilation measurement. A custom-built optical coherence tomography (OCT) was used for time-lapse imaging of flicker stimulation-evoked vessel lumen changes in mouse retinas. A comparative analysis revealed significantly larger (18.21%) lumen dilation in the axial direction compared to the lateral (10.77%) direction. The axial lumen dilation predominantly resulted from the top vessel wall movement toward the vitreous direction, whereas the bottom vessel wall remained stable. This observation indicates that the traditional vasodilation measurement in the lateral direction may result in an underestimated value.
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Ma G, Kim TH, Son T, Ding J, Ahmed S, Adejumo T, Yao X. Intrinsic signal optoretinography revealing AD-induced retinal photoreceptor hyperexcitability before a detectable morphological abnormality. OPTICS LETTERS 2023; 48:5129-5132. [PMID: 37773402 PMCID: PMC10963897 DOI: 10.1364/ol.501851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/08/2023] [Indexed: 10/01/2023]
Abstract
Neuronal hyperexcitability promises an early biomarker of Alzheimer's disease (AD). However, in vivo detection of neuronal hyperexcitability in the brain is technically challenging. The retina, one part of the central nervous system, presents a unique window for noninvasive monitoring of the brain function. This study aims to test the feasibility of using intrinsic signal optoretinography (ORG) for mapping retinal hyperexcitability associated with early-stage AD. Custom-designed optical coherence tomography (OCT) was employed for both morphological measurement and functional ORG of wild-type mice and 3xTg-AD mice. Comparative analysis revealed AD-induced retinal photoreceptor hyperexcitability prior to detectable structural degeneration.
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Affiliation(s)
- Guangying Ma
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Tae-Hoon Kim
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Jie Ding
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Shaiban Ahmed
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Tobiloba Adejumo
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, Illinois 60612, USA
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3
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AttaAllah HR, Abdelaziz STA, Mohamed AAM, Ibrahiem MFK. Assessment of macular microvascular changes in children following treatment of anisometropic myopic amblyopia using optical coherence tomography angiography. Graefes Arch Clin Exp Ophthalmol 2023; 261:2689-2699. [PMID: 37052667 PMCID: PMC10432315 DOI: 10.1007/s00417-023-06055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 03/23/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023] Open
Abstract
PURPOSE To evaluate macular microvascular changes in the form of foveal avascular zone (FAZ) area and vessel density in the superficial, deep capillary plexuses, and choriocapillaris using optical coherence tomography angiography (OCTA) in children with anisometropic myopic amblyopia before and after treatment. METHODS This prospective observational study included 32 patients younger than 12 years old with anisomyopic amblyopia. OCTA was done before patients' treatment with optical correction with or without patching and was repeated after successful amblyopia treatment. Outcomes included superficial, deep, and choriocapillaris vessel density (VD) and superficial and deep FAZ areas. RESULTS The study included 13 males (40.6%) and 19 females (59.4%), and the mean age was 9.52 ± 1.33 years. Fifty-three percent (53%) of patients needed only optical correction, and the remaining 47% needed additional patching therapy. After successful treatment, there was a significant improvement in amblyopic eyes in best-corrected visual acuity (p < 0.001), with higher VD values in superficial capillary plexuses (p < 0.001), deep capillary plexuses (p < 0.001), and foveal choriocapillaris (p = 0.030). In the glasses with patching subgroup, the difference between pre-treatment and post-treatment parameters revealed a significant improvement in vessel density in superficial retinal plexuses (foveal and parafoveal; p values 0.023 and < 0.001, respectively) and deep retinal plexuses (whole image, foveal, and parafoveal; p values 0.003, < 0.001, and 0.002, respectively). While amblyopic eyes treated with glasses alone had a significantly greater difference in choriocapillaris foveal VD (p value = 0.022). CONCLUSION After effective amblyopia treatment, amblyopic eyes exhibited improved best-corrected visual acuity and better macular perfusion along the superficial, deep vascular density, and choriocapillaris foveal VD. CLINICAL TRIAL REGISTRATION CinicalTrials.gov Identifier: NCT05223153.
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Affiliation(s)
- Heba Radi AttaAllah
- Ophthalmology department, Faculty of Medicine, Minia University, Minia, Egypt
| | - Sahar Torky Abdelrazik Abdelaziz
- Ophthalmology department, Faculty of Medicine, Minia University, Minia, Egypt.
- Ophthalmology department, Minia University Hospital, Minia University, Minia, 61111, Egypt.
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Nelis P, Nieweler A, Brücher V, Eter N, Ten Tusscher M, Alnawaiseh M. Light conditions influence optic nerve OCT angiography parameter in healthy subjects with neutral pupils. Sci Rep 2023; 13:9154. [PMID: 37280254 DOI: 10.1038/s41598-023-36069-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 05/29/2023] [Indexed: 06/08/2023] Open
Abstract
Optical coherence tomography angiography measurements are influenced by a range of environmental factors as blood pressure and physical fitness. The present study aimed to evaluate the effects of light and dark exposure in eyes with neutral and mydriatic pupils on vessel density in the macular and optic nerve head regions, as measured using optical coherence tomography angiography (OCTA). 55 eyes of 55 healthy volunteers (28 patients with neutral pupils; 27.18 ± 4.33 years) were examined using a high-speed and high-resolution spectral-domain OCT XR Avanti system with a split-spectrum amplitude de-correlation angiography algorithm. OCTA imaging was performed after dark adaptation and after exposure to light. The vessel density data of the superficial and deep retinal macular and optic nerve head region OCT-angiogram were analyzed for these two light conditions. Through Bonferroni correction for multiple testing, the p- value was adapted from 0.05 to 0.017. In eyes with neutral pupils, a significant increase was found in the capillary region of the optic nerve head region (p = 0.002), comparing dark- and light-adaptation. In the macular region of eyes with neutral (p = 0.718) and mydriatic pupils (p = 0.043), no significant differences were observed, as were any in the optic nerve head region of the mydriatic eyes (p = 0.797). This observation suggests that light conditions could be a possible factor influencing OCTA measurements. After dark exposure, vessel density data were significantly different between eyes with neutral and mydriatic pupils (nerve head region: p < 0.0001, superficial macula: p < 0.0001, deep macula: p = 0.0025). These data warn for the effect of mydriatic drops on vessel density measurements.
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Affiliation(s)
- Pieter Nelis
- Department of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany.
- Department of Ophthalmology, Vrije Universiteit Brussel, Brussels, Belgium.
- Department of Ophthalmology, Helios Augenklinik Berlin-Buch, Berlin-Buch, Germany.
| | - A Nieweler
- Department of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany
| | - V Brücher
- Department of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany
| | - N Eter
- Department of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany
| | - M Ten Tusscher
- Department of Ophthalmology, Vrije Universiteit Brussel, Brussels, Belgium
| | - M Alnawaiseh
- Department of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany
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Liu K, Zhu T, Gao M, Yin X, Zheng R, Yan Y, Gao L, Ding Z, Ye J, Li P. Functional OCT angiography reveals early retinal neurovascular dysfunction in diabetes with capillary resolution. BIOMEDICAL OPTICS EXPRESS 2023; 14:1670-1684. [PMID: 37078055 PMCID: PMC10110312 DOI: 10.1364/boe.485940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/18/2023] [Accepted: 03/18/2023] [Indexed: 05/03/2023]
Abstract
Altered retinal neurovascular coupling may contribute to the development and progression of diabetic retinopathy (DR) but remains highly challenging to measure due to limited resolution and field of view of the existing functional hyperemia imaging. Here, we present a novel modality of functional OCT angiography (fOCTA) that allows a 3D imaging of retinal functional hyperemia across the entire vascular tree with single-capillary resolution. In fOCTA, functional hyperemia was evoked by a flicker light stimulation, recorded by a synchronized time-lapse OCTA (i.e., 4D), and extracted precisely from each capillary segment (space) and stimulation period (time) in the OCTA time series. The high-resolution fOCTA revealed that the retinal capillaries, particularly the intermediate capillary plexus, exhibited apparent hyperemic response in normal mice, and significant functional hyperemia loss (P < 0.001) at an early stage of DR with few overt signs of retinopathy and visible restoration after aminoguanidine treatment (P < 0.05). Retinal capillary functional hyperemia has strong potential to provide sensitive biomarkers of early DR, and retinal fOCTA would provide new insights into the pathophysiology, screening and treatment of early DR.
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Affiliation(s)
- Kaiyuan Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Tiepei Zhu
- Eye Center of the Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Mengqin Gao
- 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
| | - Rong Zheng
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yan Yan
- Eye Center of the Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Lei Gao
- Jiaxing Key Laboratory of Photonic Sensing & Intelligent Imaging, Jiaxing 314000, China
- Intelligent Optics & Photonics Research Center, Jiaxing Research Institute, Zhejiang University, Jiaxing 314000, 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 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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Pfäffle C, Spahr H, Gercke K, Puyo L, Höhl S, Melenberg D, Miura Y, Hüttmann G, Hillmann D. Phase-Sensitive Measurements of Depth-Dependent Signal Transduction in the Inner Plexiform Layer. Front Med (Lausanne) 2022; 9:885187. [PMID: 35721092 PMCID: PMC9198552 DOI: 10.3389/fmed.2022.885187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/10/2022] [Indexed: 12/01/2022] Open
Abstract
Non-invasive spatially resolved functional imaging in the human retina has recently attracted considerable attention. Particularly functional imaging of bipolar and ganglion cells could aid in studying neuronal activity in humans, including an investigation of processes of the central nervous system. Recently, we imaged the activity of the inner neuronal layers by measuring nanometer-size changes of the cells within the inner plexiform layer (IPL) using phase-sensitive optical coherence tomography (OCT). In the IPL, there are connections between the neuronal cells that are dedicated to the processing of different aspects of the visual information, such as edges in the image or temporal changes. Still, so far, it was not possible to assign functional changes to single cells or cell classes in living humans, which is essential for studying the vision process. One characteristic of signal processing in the IPL is that different aspects of the visual impression are only processed in specific sub-layers (strata). Here, we present an investigation of these functional signals for three different sub-layers in the IPL with the aim to separate different properties of the visual signal processing. Whereas the inner depth-layer, closest to the ganglion cells, exhibits an increase in the optical path length, the outer depth-layer, closest to the bipolar cell layer, exhibits a decrease in the optical path length. Additionally, we found that the central depth is sensitive to temporal changes, showing a maximum response at a stimulation frequency of around 12.5 Hz. The results demonstrate that the signals from different cell types can be distinguished by phase-sensitive OCT.
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Affiliation(s)
- Clara Pfäffle
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Hendrik Spahr
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Katharina Gercke
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Léo Puyo
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Medical Laser Center Lübeck GmbH, Lübeck, Germany
| | - Svea Höhl
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - David Melenberg
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Department of Ophthalmology, University of Lübeck, Lübeck, Germany
| | - Gereon Hüttmann
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.,Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Dierck Hillmann
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Thorlabs GmbH, Lübeck, Germany.,Department of Physics, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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7
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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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8
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Zhang L, Dong R, Zawadzki RJ, Zhang P. Volumetric data analysis enabled spatially resolved optoretinogram to measure the functional signals in the living retina. JOURNAL OF BIOPHOTONICS 2022; 15:e202100252. [PMID: 34817116 PMCID: PMC8901551 DOI: 10.1002/jbio.202100252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/21/2021] [Accepted: 11/22/2021] [Indexed: 05/05/2023]
Abstract
Optoretinogram, a technique in which optical coherence tomography (OCT) is used to measure retinal functions in response to a visible light stimulus, can be a potentially useful tool to quantify retinal health alterations. Existing experimental studies on animals have focused on measuring the global retinal response by transversally averaging 3D data across the retina, which minimizes the spatial resolution of the signals, and limits the signal-to-noise ratio because only central B-scans are collected and analyzed. These problems were addressed in this study by collecting volumetric data to probe functional signals and developing an improved 3D registration approach to align such series-acquired OCT volumes. These data were then divided into small blocks and subject to a spatiotemporal analysis, whose results confirmed the spatial-dependence of functional signals. By further averaging, the overall measurement accuracies for the position and the scattering signals were estimated to be approximately 30 nm and 1.1 %, respectively. With improved accuracy, this method revealed certain novel functional signals that have not been previously reported. In conclusion, this work provides a powerful tool to monitor retinal local and global functional changes in aging, diseased, or treated rodent eyes.
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Affiliation(s)
- Lijie Zhang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, 116024, China
| | - Rongyao Dong
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, 116024, China
| | - Robert J. Zawadzki
- UC Davis Eye-Pod Small Animals Ocular Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, 95616, United States
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, California, 95817, United States
| | - Pengfei Zhang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, 116024, China
- UC Davis Eye-Pod Small Animals Ocular Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, 95616, United States
- Correspondence: Pengfei Zhang, Dalian University of Technology, 116024, China,
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Quantitative Optical Coherence Tomography for Longitudinal Monitoring of Postnatal Retinal Development in Developing Mouse Eyes. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12041860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A better study of postnatal retinal development is essential for the in-depth understanding of the nature of the vision system. To date, quantitative analysis of postnatal retinal development is primarily limited to endpoint histological examination. This study is to validate in vivo optical coherence tomography (OCT) for longitudinal monitoring of postnatal retinal development in developing mouse eyes. OCT images of C57BL/6J mice were recorded from postnatal day (P) 14 to P56. Three-dimensional (3D) frame registration and super averaging were adopted to investigate the fine structure of the retina. Quantitative OCT analysis revealed distinct outer and inner retinal layer changes, corresponding to eye development. At the outer retina, external limiting membrane (ELM) and ellipsoid zone (EZ) band intensities gradually increased with aging, and the IZ band was detectable by P28. At the inner retina, a hyporeflective layer (HRL) between the nerve fiber layer (NFL) and inner plexiform layer (IPL) was observed in developing eyes and gradually disappeared with aging. Further image analysis revealed individual RGCs within the HRL layer of the young mouse retina. However, RGCs were merged with the NFL and the IPL in the aged mouse retina. Moreover, the sub-IPL layer structure was observed to be gradually enhanced with aging. To interpret the observed retinal layer kinetics, a model based on eyeball expansion, cell apoptosis, and retinal structural modification was proposed.
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10
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OCT-Angiography Findings in Patients with Amblyopia: Comparison between Healthy Controls, Treatment-Responsive, and Treatment-Unresponsive Amblyopic Patients. Diagnostics (Basel) 2021; 11:diagnostics11101751. [PMID: 34679448 PMCID: PMC8534794 DOI: 10.3390/diagnostics11101751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022] Open
Abstract
There is no consensus on whether amblyopia affects the retinal vascular plexus and morphology. Previous studies focused on the differences between amblyopic patients and normal controls without evaluating amblyopic eyes after patching. To evaluate differences in the superficial vascular density of amblyopic eyes, normal eyes, and amblyopic eyes reaching normal BCVA after patch therapy, OCTA was used. All patients underwent a comprehensive ophthalmological examination, including visual acuity, refraction, ocular motility tests, and anterior and posterior segment examination. OCTA was performed by an expert physician using the Zeiss Cirrus 5000-HD-OCT Angioplex (Carl Zeiss, Meditec, Inc., Dublin, OH, USA). OCTA scans were performed using a 3 × 3 mm2 and 6 × 6 mm2 fovea-centered image setting. The mean outer macular vessel density in the previously amblyopic group was 19.15 ± 0.51%. This was statistically significantly higher than in both the amblyopic group (18.70 ± 1.14%) and the normal controls (18.18 ± 1.40%) (p = 0.014). The previously amblyopic group also significantly differed from both normal controls and amblyopic eyes with regards to the inner (p = 0.011), outer (p = 0.006), and full (p = 0.003) macular perfusion. Finally, linear regression analysis revealed that BCVA was linearly correlated to outer perfusion in amblyopic (p = 0.003) and ex amblyopic eyes (p < 0.001). Considering the cross-sectional nature of our study, from our results, we can only hypothesize a possible correlation between light stimulation and retinal vasculature development. However, further longitudinal studies are needed to support this hypothesis.
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Kim TH, Son T, Klatt D, Yao X. Concurrent OCT and OCT angiography of retinal neurovascular degeneration in the 5XFAD Alzheimer's disease mice. NEUROPHOTONICS 2021; 8:035002. [PMID: 34277888 PMCID: PMC8271351 DOI: 10.1117/1.nph.8.3.035002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/25/2021] [Indexed: 05/15/2023]
Abstract
Significance: As one part of the central nervous system, the retina manifests neurovascular defects in Alzheimer's disease (AD). Quantitative imaging of retinal neurovascular abnormalities may promise a new method for early diagnosis and treatment assessment of AD. Previous imaging studies of transgenic AD mouse models have been limited to the central part of the retina. Given that the pathological hallmarks of AD frequently appear in different peripheral quadrants, a comprehensive regional investigation is needed for a better understanding of the retinal degeneration associated with AD-like pathology. Aim: We aim to demonstrate concurrent optical coherence tomography (OCT) and OCT angiography (OCTA) of retinal neuronal and vascular abnormalities in the 5XFAD mouse model and to investigate region-specific retinal degeneration. Approach: A custom-built OCT system was used for retinal imaging. Retinal thickness, vessel width, and vessel density were quantitatively measured. The artery and vein (AV) were classified for differential AV analysis, and trilaminar vascular plexuses were segmented for depth-resolved density measurement. Results: It was observed that inner and outer retinal thicknesses were explicitly reduced in the dorsal and temporal quadrants, respectively, in 5XFAD mice. A significant arterial narrowing in 5XFAD mice was also observed. Moreover, overall capillary density consistently showed a decreasing trend in 5XFAD mice, but regional specificity was not identified. Conclusions: Quadrant- and layer-specific neurovascular degeneration was observed in 5XFAD mice. Concurrent OCT and OCTA promise a noninvasive method for quantitative monitoring of AD progression and treatment assessment.
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Affiliation(s)
- Tae-Hoon Kim
- University of Illinois at Chicago, Department of Bioengineering, Chicago, Illinois, United States
| | - Taeyoon Son
- University of Illinois at Chicago, Department of Bioengineering, Chicago, Illinois, United States
| | - Dieter Klatt
- University of Illinois at Chicago, Department of Bioengineering, Chicago, Illinois, United States
| | - Xincheng Yao
- University of Illinois at Chicago, Department of Bioengineering, Chicago, Illinois, United States
- University of Illinois at Chicago, Department of Ophthalmology and Visual Sciences, Chicago, Illinois, United States
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12
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Ma G, Son T, Kim TH, Yao X. In vivo optoretinography of phototransduction activation and energy metabolism in retinal photoreceptors. JOURNAL OF BIOPHOTONICS 2021; 14:e202000462. [PMID: 33547871 PMCID: PMC8240094 DOI: 10.1002/jbio.202000462] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/09/2021] [Accepted: 02/02/2021] [Indexed: 05/05/2023]
Abstract
The objective of this study is to verify the anatomic correlate of the second (2nd) outer retina band in optical coherence tomography (OCT), and to demonstrate the potential of using intrinsic optical signal (IOS) imaging for concurrent optoretinography (ORG) of phototransduction activation and energy metabolism in stimulus activated retinal photoreceptors. A custom-designed OCT was employed for depth-resolved IOS imaging in mouse retina activated by a visible light flicker stimulation. The spatiotemporal properties of the IOS changes at the photoreceptor outer segment (OS) and inner segment (IS) were quantitatively evaluated. Rapid IOS change was observed at the OS almost right away, and the IOS at the IS was relatively slow. Comparative analysis indicates that the OS-IOS reflects transient OS deformation caused by the phototransduction activation, and IS-IOS might reflect the energy metabolism caused by mitochondria activation in retinal photoreceptors. The consistency of the distribution of the IS-IOS and the 2nd OCT band supports the IS ellipsoid (ISe), which has abundant mitochondria, as the signal source of the 2nd OCT band of the outer retina.
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Affiliation(s)
- Guangying Ma
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois
- Correspondence: Xincheng Yao, Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA.
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Son T, Kim TH, Ma G, Kim H, Yao X. Functional intrinsic optical signal imaging for objective optoretinography of human photoreceptors. Exp Biol Med (Maywood) 2021; 246:639-643. [PMID: 33307802 PMCID: PMC7988726 DOI: 10.1177/1535370220978898] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/16/2020] [Indexed: 12/18/2022] Open
Abstract
Functional mapping of photoreceptor physiology is important for better disease diagnosis and treatment assessment. Fast intrinsic optical signal (IOS), which arises before light-evoked pupillary response, promises a unique biomarker of photoreceptor physiology for objective optoretinography with high resolution. This study is to test the feasibility of non-mydriatic IOS mapping of retinal photoreceptors in awake human. Depth-resolved optical coherence tomography verified outer segment (OS) as the anatomic origin of fast photoreceptor-IOS. Dynamic IOS changes are primarily confined at OS boundaries connected with inner segment and retinal pigment epithelium, supporting transient OS shrinkage due to phototransduction process as the mechanism of the fast photoreceptor-IOS response.
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Affiliation(s)
- Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Guangying Ma
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Hoonsup Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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14
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Kim TH, Le D, Son T, Yao X. Vascular morphology and blood flow signatures for differential artery-vein analysis in optical coherence tomography of the retina. BIOMEDICAL OPTICS EXPRESS 2021; 12:367-379. [PMID: 33520388 PMCID: PMC7818960 DOI: 10.1364/boe.413149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 05/09/2023]
Abstract
Differential artery-vein (AV) analysis is essential for retinal study, disease detection, and treatment assessment. This study is to characterize vascular reflectance profiles and blood flow patterns of retinal artery and vein systems in optical coherence tomography (OCT) and OCT angiography (OCTA), and establish them as robust signatures for objective AV classification. A custom designed OCT was employed for three-dimensional (3D) imaging of mouse retina, and corresponding OCTA was reconstructed. Radially resliced OCT B-scans revealed two, i.e. top and bottom, hyperreflective wall boundaries in retinal arteries, while these wall boundaries were absent in OCT of retinal veins. Additional OCTA analysis consistently displayed a layered speckle distribution in the vein, which may indicate the venous laminar flow. These OCT and OCTA differences offer unique signatures for objective AV classification in OCT and OCTA.
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Affiliation(s)
- Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - David Le
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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15
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Full-field flicker evoked changes in parafoveal retinal blood flow. Sci Rep 2020; 10:16051. [PMID: 32994535 PMCID: PMC7524838 DOI: 10.1038/s41598-020-73032-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/08/2020] [Indexed: 12/16/2022] Open
Abstract
When retinal activity is increased by exposure to dynamic visual stimuli, blood vessels dilate and the flow of blood within vessels increases to meet the oxygen and glucose demands of the neurons. This relationship is termed ‘neurovascular coupling’ and it is critical for regulating control of the human retinal vasculature. In this study, we used a recently developed technique based on a dual-beam adaptive optics scanning laser ophthalmoscope to measure changes in red blood cell velocities, vessel diameter, and flow in interconnected small parafoveal retinal vessels (< 50 µm) of nine healthy participants. A full-field flicker stimulus was presented onto the retina to induce a vascular response to neural activity. Flicker stimulation increased blood velocity, vessel diameter, and therefore flow in arterioles, capillaries, and venules in all nine subjects. ANOVA and post hoc t-test showed significant increases in velocity and flow in arterioles and venules. These measurements indicate that the mechanism of neurovascular coupling systematically affects the vascular response in small retinal vessels in order to maintain hemodynamic regulation in the retina when exposed to visual stimulation, in our case flicker. Our findings may provide insight into future investigations on the impairments of neurovascular coupling from vascular diseases such as diabetic mellitus.
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Kim TH, Wang B, Lu Y, Son T, Yao X. Functional optical coherence tomography enables in vivo optoretinography of photoreceptor dysfunction due to retinal degeneration. BIOMEDICAL OPTICS EXPRESS 2020; 11:5306-5320. [PMID: 33014616 PMCID: PMC7510876 DOI: 10.1364/boe.399334] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/20/2020] [Accepted: 08/20/2020] [Indexed: 05/16/2023]
Abstract
Stimulus-evoked intrinsic optical signal (IOS), which occurs almost immediately after the onset of retinal stimulus has been observed in retinal photoreceptors, promises to be a unique biomarker for objective optoretinography (ORG) of photoreceptor function. We report here the first-time in vivo ORG detection of photoreceptor dysfunction due to retinal degeneration. A custom-designed optical coherence tomography (OCT) was employed for longitudinal ORG monitoring of photoreceptor-IOS distortions in retinal degeneration mice. Depth-resolved OCT analysis confirmed the outer segment (OS) as the physical source of the photoreceptor-IOS. Comparative ERG measurement verified the phototransduction activation as the physiological correlator of the photoreceptor-IOS. Histological examination revealed disorganized OS discs, i.e. the pathological origin of the photoreceptor-IOS distortion.
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Affiliation(s)
- Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Benquan Wang
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Yiming Lu
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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17
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Yao X, Kim TH. Fast intrinsic optical signal correlates with activation phase of phototransduction in retinal photoreceptors. Exp Biol Med (Maywood) 2020; 245:1087-1095. [PMID: 32558598 PMCID: PMC7400727 DOI: 10.1177/1535370220935406] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
IMPACT STATEMENT As the center of phototransduction, retinal photoreceptors are responsible for capturing and converting photon energy to bioelectric signals for following visual information processing in the retina. This article summarizes experimental observation and discusses biophysical mechanism of fast photoreceptor-intrinsic optical signal (IOS) correlated with early phase of phototransduction. Quantitative imaging of fast photoreceptor-IOS may provide objective optoretinography to advance the study and diagnosis of age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy, and other eye diseases that can cause photoreceptor dysfunctions.
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Affiliation(s)
- Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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18
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Tang P, Li Y, Rakymzhan A, Xie Z, Wang RK. Measurement and visualization of stimulus-evoked tissue dynamics in mouse barrel cortex using phase-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2020; 11:699-710. [PMID: 32206393 PMCID: PMC7041479 DOI: 10.1364/boe.381332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/04/2019] [Accepted: 01/02/2020] [Indexed: 05/24/2023]
Abstract
We describe a method to measure tissue dynamics in mouse barrel cortex during functional activation via phase-sensitive optical coherence tomography (PhS-OCT). The method measures the phase changes in OCT signals, which are induced by the tissue volume change, upon which to localize the activated tissue region. Phase unwrapping, compensation and normalization are applied to increase the dynamic range of the OCT phase detection. To guide the OCT scanning, intrinsic optical signal imaging (IOSI) system equipped with a green light laser source (532 nm) is integrated with the PhS-OCT system to provide a full field time-lapsed images of the reflectance that is used to identify the transversal 2D localized tissue response in the mouse brain. The OCT results show a localized decrease in the OCT phase signal in the activated region of the mouse brain tissue. The decrease in the phase signal may be originated from the brain tissue compression caused by the vasodilatation in the activated region. The activated region revealed in the cross-sectional OCT image is consistent with that identified by the IOSI imaging, indicating the phase change in the OCT signals may associate with the changes in the corresponding hemodynamics. In vivo localized tissue dynamics in the barrel cortex at depth during whisker stimulation is observed and monitored in this study.
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Pfäffle C, Spahr H, Kutzner L, Burhan S, Hilge F, Miura Y, Hüttmann G, Hillmann D. Simultaneous functional imaging of neuronal and photoreceptor layers in living human retina. OPTICS LETTERS 2019; 44:5671-5674. [PMID: 31774751 DOI: 10.1364/ol.44.005671] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/24/2019] [Indexed: 05/18/2023]
Abstract
Functional retinal imaging, especially of neuronal activity non-invasively in humans, is of tremendous interest. Although the activation of photoreceptor cells (PRCs) could be detected in humans, imaging the function of other retinal neurons had been so far hardly possible. Here, using phase-sensitive full-field swept-source optical coherence tomography (FF-SS-OCT), we show simultaneous imaging of the activation in the photoreceptor and ganglion cell layer/inner plexiform layer (GCL/IPL). The signals from the GCL/IPL are 10-fold smaller than those from the PRC and were detectable only using algorithms for suppression of motion artifacts and pulsatile blood flow in the retinal vessels. FF-SS-OCT with improved phase evaluation algorithms, therefore, allowed us to map functional connections between PRC and GCL/IPL, confirming previous ex vivo results. The demonstrated functional imaging of retinal neuronal layers can be a valuable tool in diagnostics and basic research.
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Jendzjowsky NG, Steinback CD, Herman RJ, Tsai WH, Costello FE, Wilson RJA. Functional-Optical Coherence Tomography: A Non-invasive Approach to Assess the Sympathetic Nervous System and Intrinsic Vascular Regulation. Front Physiol 2019; 10:1146. [PMID: 31572206 PMCID: PMC6751282 DOI: 10.3389/fphys.2019.01146] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 08/22/2019] [Indexed: 11/13/2022] Open
Abstract
Sympathetic nervous system dysregulation and vascular impairment in neuronal tissue beds are hallmarks of prominent cardiorespiratory diseases. However, an accurate and convenient method of assessing SNA and local vascular regulation is lacking, hindering routine clinical and research assessments. To address this, we investigated whether spectral domain optical coherence tomography (OCT), that allows investigation of retina and choroid vascular responsiveness, reflects sympathetic activity in order to develop a quick, easy and non-invasive sympathetic index. Here, we compare choroid and retina vascular perfusion density (VPD) acquired with OCT and heart rate variability (HRV) to microneurography. We recruited 6 healthy males (26 ± 3 years) and 5 healthy females (23 ± 1 year) and instrumented them for respiratory parameters, ECG, blood pressure and muscle sympathetic nerve microneurography. Choroid VPD decreases with the cold pressor test, inhaled hypoxia and breath-hold, and increases with hyperoxia and hyperpnea suggesting that sympathetic activity dominates choroid responses. In contrast, retina VPD was unaffected by the cold pressor test, increased with hypoxia and breath hold and decreases with hyperoxia and hyperpnea, suggesting metabolic vascular regulation dominates the retina. With regards to integrated muscle sympathetic nerve activity, HRV had low predictive power whereas choroid VPD was strongly (inversely) correlated with integrated muscle sympathetic nerve activity (R = -0.76; p < 0.0001). These data suggest that Functional-OCT may provide a novel approach to assess sympathetic activity and intrinsic vascular responsiveness (i.e., autoregulation). Given that sympathetic nervous system activity is the main determinant of autonomic function, sympathetic excitation is associated with severe cardiovascular/cardiorespiratory diseases and autoregulation is critical for brain health, we suggest that the use of our new Functional-OCT technique will be of broad interest to clinicians and researchers.
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Affiliation(s)
- Nicholas G Jendzjowsky
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Craig D Steinback
- Program for Pregnancy and Postpartum Health, Physical Activity and Diabetes Laboratory, Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Robert J Herman
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Willis H Tsai
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Fiona E Costello
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Kim TH, Son T, Yao X. Functional OCT angiography reveals early physiological dysfunction of hyaloid vasculature in developing mouse eye. Exp Biol Med (Maywood) 2019; 244:819-823. [PMID: 31126209 DOI: 10.1177/1535370219850787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Hyaloid vascular system (HVS) is a transient capillary network nourishing developing eye. Better study of the HVS regression correlated with eye development is essential for in-depth understanding of the nature of vision system. In this study, we demonstrate the feasibility of longitudinal optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of the HVS in C57BL/6J mice. OCT enables morphological monitoring of the HVS regression, and OCTA allows physiological assessment of the HVS involution correlated with eye development. Functional OCTA reveals early physiological dysfunction before morphological regression of the hyaloid vasculature in developing mouse eye. We anticipate that noninvasive, simultaneous OCT/OCTA observation of morphological regression and physiological degradation in normal and diseased animal models will be valuable to unravel the complex mechanisms of the HVS regression correlated with normal eye development and abnormal persistent hyaloid conditions. Impact statement Hyaloid vascular system (HVS) is known to have an essential role in the eye development. However, established knowledge of the HVS largely relies on end-point studies with biochemically fixed tissues, lacking a full description of the natural dynamics of the HVS correlated with eye development. An imaging methodology for noninvasive, longitudinal, and high-resolution monitoring of the HVS is important not only for better understanding of the nature of the vision system and is also valuable for better study of abnormal eye conditions. Here, we report the feasibility of in vivo optical coherence tomography (OCT) and OCT angiography (OCTA) imaging of the HVS regression in developing mouse eye. OCT enables morphological imaging of the HVS structure, and OCTA allows functional assessment of the HVS physiology correlated with eye development.
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Affiliation(s)
- Tae-Hoon Kim
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA.,2 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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Kim TH, Son T, Lu Y, Alam M, Yao X. Comparative Optical Coherence Tomography Angiography of Wild-Type and rd10 Mouse Retinas. Transl Vis Sci Technol 2018; 7:42. [PMID: 30619662 PMCID: PMC6314228 DOI: 10.1167/tvst.7.6.42] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 11/02/2018] [Indexed: 12/11/2022] Open
Abstract
Purpose To conduct longitudinal optical coherence tomography angiography (OCTA) to characterize dynamic changes of trilaminar vascular plexuses in wild-type (WT) and retinal degeneration 10 (rd10) mouse retinas. Methods Longitudinal in vivo OCT/OCTA measurements of WT and rd10 mouse retinas were conducted at postnatal day 14 (P14), P17, P21, P24, and P28. OCT images were used to quantify retinal thickness changes, while OCTA images were used to investigate vascular dynamics within the trilaminar vascular plexuses, that is, superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). Blood vessel densities of all three plexus layers were quantitatively evaluated separately. The caliber of first-order blood vessel branches in the SVP layer was also measured. Results Vascular densities in all three plexuses continuously decreased with aging in both WT and rd10. However, abnormal density reduction in rd10 occurred at P17 in both ICP (P < 0.001) and DCP (P < 0.001). While the ICP of rd10 showed density recovery at P24, the DCP of rd10 showed significantly low density. Remarkable vascular narrowing in rd10 was also observed in the SVP, especially at P28. Conclusions The most severe vascular impairment happened in the DCP, while the ICP showed the transient recovery of vascular density after the onset of retinal degeneration. The SVP was most resistant to the retinal degeneration, but the first-order blood vessel branches within the SVP showed progressive narrowing. Translational Relevance Better understanding of the vascular changes correlated with retinal development, and retinal degeneration can provide insights in advanced development of treatment protocols of retinal degenerative diseases.
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Affiliation(s)
- Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Yiming Lu
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Minhaj Alam
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
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Yao X, Son T, Kim TH, Lu Y. Functional optical coherence tomography of retinal photoreceptors. Exp Biol Med (Maywood) 2018; 243:1256-1264. [PMID: 30482040 DOI: 10.1177/1535370218816517] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
IMPACT STATEMENT Retinal photoreceptors are the primary target of age-related macular degeneration (AMD) which is the leading cause of severe vision loss and legal blindness. An objective method for functional assessment of photoreceptor physiology can benefit early detection and better treatment evaluation of AMD and other eye diseases that are known to cause photoreceptor dysfunctions. This article summarizes in vitro study of IOS mechanisms and in vivo demonstration of IOS imaging of intact animals. Further development of the functional IOS imaging may provide a revolutionary solution to achieve objective assessment of human photoreceptors.
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Affiliation(s)
- Xincheng Yao
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA.,2 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Taeyoon Son
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Tae-Hoon Kim
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yiming Lu
- 1 Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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