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Jamal SZ, Dieckmann BW, McCollum GW, Penn JS, Jayagopal A, Imam Uddin MD. Imaging Hypoxia to Predict Primary Neuronal Cell Damage in Branch Retinal Artery Occlusion. Microcirculation 2024:e12883. [PMID: 39213162 DOI: 10.1111/micc.12883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 07/28/2024] [Accepted: 08/09/2024] [Indexed: 09/04/2024]
Abstract
PURPOSE To develop a reliable method to generate a mouse model of branch retinal artery occlusion (BRAO) using laser-induced thrombosis of a major artery in the mouse retina. Also, to develop a reliable method to detect retinal hypoxia as predictive biomarker for the risk of neuronal cell damage in BRAO. METHODS A reliable and reproducible model of laser-induced BRAO was developed in mouse retina using Rose Bengal. To characterize retinal hypoxia in BRAO, pimonidazole immunostaining and HYPOX-4 molecular imaging methods were used. Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) was used to characterize neuronal cell damage in the BRAO retina. Expression of mRNA in retinal tissues from BRAO and age-matched control retinas were analyzed using qRT-PCR. RESULTS Occlusion of a branch retinal artery near the optic nerve head (ONH) caused a pattern of retinal tissue hypoxia covering about 12.5% of the entire retina. TUNEL-positive cells were localized in all layers in BRAO retinal tissue cross sections. In addition, qRT-PCR data analysis suggests that BRAO is associated with both inflammation and hypoxia. CONCLUSIONS This study provides a reliable method for BRAO in mouse retina and demonstrates the utility of molecular imaging method to detect retinal hypoxia as predictive biomarker for the risk of neuronal cell damage in BRAO. In addition, our data suggest that BRAO retinas are associated with inflammation and also associated with hypoxia-related neuronal cell damage. PERSPECTIVES Imaging areas of retinal hypoxia may provide accurate diagnosis, evaluating retinal tissue injury from BRAO.
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Affiliation(s)
- Sara Z Jamal
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Blake W Dieckmann
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Gary W McCollum
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - John S Penn
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | | | - M D Imam Uddin
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
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2
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Rubinoff I, Kuranov RV, Fang R, Ghassabi Z, Wang Y, Beckmann L, Miller DA, Wollstein G, Ishikawa H, Schuman JS, Zhang HF. Adaptive spectroscopic visible-light optical coherence tomography for clinical retinal oximetry. COMMUNICATIONS MEDICINE 2023; 3:57. [PMID: 37095177 PMCID: PMC10126115 DOI: 10.1038/s43856-023-00288-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 04/13/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND Retinal oxygen saturation (sO2) provides essential information about the eye's response to pathological changes that can result in vision loss. Visible-light optical coherence tomography (vis-OCT) is a noninvasive tool that has the potential to measure retinal sO2 in a clinical setting. However, its reliability is currently limited by unwanted signals referred to as spectral contaminants (SCs), and a comprehensive strategy to isolate true oxygen-dependent signals from SCs in vis-OCT is lacking. METHODS We develop an adaptive spectroscopic vis-OCT (ADS-vis-OCT) technique that can adaptively remove SCs and accurately measure sO2 under the unique conditions of each vessel. We also validate the accuracy of ADS-vis-OCT using ex vivo blood phantoms and assess its repeatability in the retina of healthy volunteers. RESULTS In ex vivo blood phantoms, ADS-vis-OCT agrees with a blood gas machine with only a 1% bias in samples with sO2 ranging from 0% to 100%. In the human retina, the root mean squared error between sO2 values in major arteries measured by ADS-vis-OCT and a pulse oximeter is 2.1% across 18 research participants. Additionally, the standard deviations of repeated ADS-vis-OCT measurements of sO2 values in smaller arteries and veins are 2.5% and 2.3%, respectively. Non-adaptive methods do not achieve comparable repeatabilities from healthy volunteers. CONCLUSIONS ADS-vis-OCT effectively removes SCs from human images, yielding accurate and repeatable sO2 measurements in retinal arteries and veins with varying diameters. This work could have important implications for the clinical use of vis-OCT to manage eye diseases.
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Affiliation(s)
- Ian Rubinoff
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Roman V Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Opticent Inc., Evanston, IL, 60201, USA
| | - Raymond Fang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Zeinab Ghassabi
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Yuanbo Wang
- Currently with Department of Ophthalmology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - David A Miller
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Gadi Wollstein
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
- Currently with Department of Ophthalmology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Joel S Schuman
- Department of Ophthalmology, New York University, New York, NY, 10017, USA
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
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3
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Ma Q, Zhou J, Yang Z, Xue Y, Xie X, Li T, Yang Y. Mingmu Xiaoyao granules regulate the PI3K/Akt/mTOR signaling pathway to reduce anxiety and depression and reverse retinal abnormalities in rats. Front Pharmacol 2022; 13:1003614. [PMID: 36278192 PMCID: PMC9579374 DOI: 10.3389/fphar.2022.1003614] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/20/2022] [Indexed: 11/20/2022] Open
Abstract
Objective: To investigate the effects of Mingmu Xiaoyao granules (MMXY) on the morphology and function of the retina and the mechanism of PI3K/Akt/mTOR pathway-related proteins in rats with anxiety and depression induced by chronic unpredictable mild stress (CUMS). Methods: Fifty-two male Sprague Dawley rats were randomly allocated to either a control (n = 14) or a simulated CUMS group (n = 38). The CUMS model was established successfully at 4 weeks. Six rats in each group were randomly selected to be sacrificed and their retinas isolated for histological examination. At 5 weeks, rats in the CUMS group were randomly allocated to the following groups: Model (CUMS + pure water), MMXY-H (CUMS + MMXY 7.2 g/kg/d), MMXY-L (CUMS + MMXY 3.6 g/kg/d), and CBZ (CUMS + Carbamazepine 20 mg/kg/d), with eight rats in each group. All rats were given the relevant intervention once a day. At 12 weeks, sucrose preference and open field tests were performed to evaluate the anxiety and depression status of rats. In live rats, optical coherence tomography angiography was used to measure retinal thickness and blood flow, while electroretinograms (ERGs) and visual evoked potentials (VEPs) were used to evaluate retinal function. The next day, the specimens were sacrificed for serological, histological, immunofluorescence, Western blot and transmission electron microscopy examinations to explore the mechanism of MMXY in CUMS rats. Results: MMXY improved the anxiety and depression-like behavior of rats. Results of optical coherence tomography angiography showed that MMXY improved retinal inner thickness and blood flow in CUMS rats. MMXY improved the amplitude of a- and b-waves in the scotopic and photopic ERG, as well as N2 and P2 peak time and amplitude in the flash-VEP in CUMS rats. Retinal histological staining and transmission electron microscopy showed that MMXY reversed retinal morphology and ultrastructure in CUMS rats. MMXY reduced the expression of Beclin1 and LC3I/II proteins, regulated the PI3K/Akt/mTOR pathway, inhibited autophagy, and had a protective effect on the retina in CUMS rats. Conclusion: MMXY may effectively improve retinal morphology and function as well as anxiety and depression-like behaviors in CUMS rats by regulating the PI3K/Akt/mTOR signaling pathway.
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Affiliation(s)
- Qiuyan Ma
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
- Ophthalmology Department, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Jian Zhou
- Ophthalmology Department, Dongfang Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Ziyi Yang
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Yuxin Xue
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Xinran Xie
- Ophthalmology Department, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
- Beijing Institute of Traditional Chinese Medicine, Beijing, China
| | - Tiejun Li
- Ophthalmology Department, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Yingxin Yang
- Ophthalmology Department, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
- *Correspondence: Yingxin Yang,
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4
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Taylor-Williams M, Spicer G, Bale G, Bohndiek SE. Noninvasive hemoglobin sensing and imaging: optical tools for disease diagnosis. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-220074VR. [PMID: 35922891 PMCID: PMC9346606 DOI: 10.1117/1.jbo.27.8.080901] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/27/2022] [Indexed: 05/08/2023]
Abstract
SIGNIFICANCE Measurement and imaging of hemoglobin oxygenation are used extensively in the detection and diagnosis of disease; however, the applied instruments vary widely in their depth of imaging, spatiotemporal resolution, sensitivity, accuracy, complexity, physical size, and cost. The wide variation in available instrumentation can make it challenging for end users to select the appropriate tools for their application and to understand the relative limitations of different methods. AIM We aim to provide a systematic overview of the field of hemoglobin imaging and sensing. APPROACH We reviewed the sensing and imaging methods used to analyze hemoglobin oxygenation, including pulse oximetry, spectral reflectance imaging, diffuse optical imaging, spectroscopic optical coherence tomography, photoacoustic imaging, and diffuse correlation spectroscopy. RESULTS We compared and contrasted the ability of different methods to determine hemoglobin biomarkers such as oxygenation while considering factors that influence their practical application. CONCLUSIONS We highlight key limitations in the current state-of-the-art and make suggestions for routes to advance the clinical use and interpretation of hemoglobin oxygenation information.
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Affiliation(s)
- Michaela Taylor-Williams
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
| | - Graham Spicer
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
| | - Gemma Bale
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Electrical Division, Department of Engineering, Cambridge, United Kingdom, United Kingdom
| | - Sarah E Bohndiek
- University of Cambridge, Department of Physics, Cavendish Laboratory, Cambridge, United Kingdom, United Kingdom
- University of Cambridge, Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, United Kingdom
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5
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Alexopoulos P, Madu C, Wollstein G, Schuman JS. The Development and Clinical Application of Innovative Optical Ophthalmic Imaging Techniques. Front Med (Lausanne) 2022; 9:891369. [PMID: 35847772 PMCID: PMC9279625 DOI: 10.3389/fmed.2022.891369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/22/2022] Open
Abstract
The field of ophthalmic imaging has grown substantially over the last years. Massive improvements in image processing and computer hardware have allowed the emergence of multiple imaging techniques of the eye that can transform patient care. The purpose of this review is to describe the most recent advances in eye imaging and explain how new technologies and imaging methods can be utilized in a clinical setting. The introduction of optical coherence tomography (OCT) was a revolution in eye imaging and has since become the standard of care for a plethora of conditions. Its most recent iterations, OCT angiography, and visible light OCT, as well as imaging modalities, such as fluorescent lifetime imaging ophthalmoscopy, would allow a more thorough evaluation of patients and provide additional information on disease processes. Toward that goal, the application of adaptive optics (AO) and full-field scanning to a variety of eye imaging techniques has further allowed the histologic study of single cells in the retina and anterior segment. Toward the goal of remote eye care and more accessible eye imaging, methods such as handheld OCT devices and imaging through smartphones, have emerged. Finally, incorporating artificial intelligence (AI) in eye images has the potential to become a new milestone for eye imaging while also contributing in social aspects of eye care.
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Affiliation(s)
- Palaiologos Alexopoulos
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Chisom Madu
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
- Center for Neural Science, College of Arts & Science, New York University, New York, NY, United States
| | - Joel S. Schuman
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
- Center for Neural Science, College of Arts & Science, New York University, New York, NY, United States
- Department of Electrical and Computer Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
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6
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Pesce NA, Canovai A, Plastino F, Lardner E, Kvanta A, Cammalleri M, André H, Dal Monte M. An imbalance in autophagy contributes to retinal damage in a rat model of oxygen-induced retinopathy. J Cell Mol Med 2021; 25:10480-10493. [PMID: 34623024 PMCID: PMC8581343 DOI: 10.1111/jcmm.16977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 01/18/2023] Open
Abstract
In retinopathy of prematurity (ROP), the abnormal retinal neovascularization is often accompanied by retinal neuronal dysfunction. Here, a rat model of oxygen‐induced retinopathy (OIR), which mimics the ROP disease, was used to investigate changes in the expression of key mediators of autophagy and markers of cell death in the rat retina. In addition, rats were treated from birth to postnatal day 14 and 18 with 3‐methyladenine (3‐MA), an inhibitor of autophagy. Immunoblot and immunofluorescence analysis demonstrated that autophagic mechanisms are dysregulated in the retina of OIR rats and indicated a possible correlation between autophagy and necroptosis, but not apoptosis. We found that 3‐MA acts predominantly by reducing autophagic and necroptotic markers in the OIR retinas, having no effects on apoptotic markers. However, 3‐MA does not ameliorate retinal function, which results compromised in this model. Taken together, these results revealed the crucial role of autophagy in retinal cells of OIR rats. Thus, inhibiting autophagy may be viewed as a putative strategy to counteract ROP.
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Affiliation(s)
- Noemi Anna Pesce
- Department of Biology, University of Pisa, Pisa, Italy.,Department of Clinical Neuroscience, Division of Eye and Vision, St Erik Eye Hospital, Karolinska Institutet, Solna, Sweden
| | | | - Flavia Plastino
- Department of Clinical Neuroscience, Division of Eye and Vision, St Erik Eye Hospital, Karolinska Institutet, Solna, Sweden
| | - Emma Lardner
- Department of Clinical Neuroscience, Division of Eye and Vision, St Erik Eye Hospital, Karolinska Institutet, Solna, Sweden
| | - Anders Kvanta
- Department of Clinical Neuroscience, Division of Eye and Vision, St Erik Eye Hospital, Karolinska Institutet, Solna, Sweden
| | | | - Helder André
- Department of Clinical Neuroscience, Division of Eye and Vision, St Erik Eye Hospital, Karolinska Institutet, Solna, Sweden
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7
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Liu R, Cheng S, Tian L, Yi J. Deep spectral learning for label-free optical imaging oximetry with uncertainty quantification. LIGHT, SCIENCE & APPLICATIONS 2019; 8:102. [PMID: 31754429 PMCID: PMC6864044 DOI: 10.1038/s41377-019-0216-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/17/2019] [Accepted: 11/01/2019] [Indexed: 05/06/2023]
Abstract
Measurement of blood oxygen saturation (sO2) by optical imaging oximetry provides invaluable insight into local tissue functions and metabolism. Despite different embodiments and modalities, all label-free optical-imaging oximetry techniques utilize the same principle of sO2-dependent spectral contrast from haemoglobin. Traditional approaches for quantifying sO2 often rely on analytical models that are fitted by the spectral measurements. These approaches in practice suffer from uncertainties due to biological variability, tissue geometry, light scattering, systemic spectral bias, and variations in the experimental conditions. Here, we propose a new data-driven approach, termed deep spectral learning (DSL), to achieve oximetry that is highly robust to experimental variations and, more importantly, able to provide uncertainty quantification for each sO2 prediction. To demonstrate the robustness and generalizability of DSL, we analyse data from two visible light optical coherence tomography (vis-OCT) setups across two separate in vivo experiments on rat retinas. Predictions made by DSL are highly adaptive to experimental variabilities as well as the depth-dependent backscattering spectra. Two neural-network-based models are tested and compared with the traditional least-squares fitting (LSF) method. The DSL-predicted sO2 shows significantly lower mean-square errors than those of the LSF. For the first time, we have demonstrated en face maps of retinal oximetry along with a pixel-wise confidence assessment. Our DSL overcomes several limitations of traditional approaches and provides a more flexible, robust, and reliable deep learning approach for in vivo non-invasive label-free optical oximetry.
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Affiliation(s)
- Rongrong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Shiyi Cheng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
| | - Ji Yi
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02215 USA
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118 USA
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8
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Beckmann L, Zhang X, Nadkarni NA, Cai Z, Batra A, Sullivan DP, Muller WA, Sun C, Kuranov R, Zhang HF. Longitudinal deep-brain imaging in mouse using visible-light optical coherence tomography through chronic microprism cranial window. BIOMEDICAL OPTICS EXPRESS 2019; 10:5235-5250. [PMID: 31646044 PMCID: PMC6788609 DOI: 10.1364/boe.10.005235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 05/02/2023]
Abstract
We longitudinally imaged both the superficial and deep cortical microvascular networks in brains of healthy mice and in a mouse model of stroke in vivo using visible-light optical coherence tomography (vis-OCT). We surgically implanted a microprism in mouse brains sealed by a chronic cranial window. The microprism enabled vis-OCT to image the entire depth of the mouse cortex. Following microprism implantation, we imaged the mice for 28 days and found that that it took around 15 days for both the superficial and deep cortical microvessels to recover from the implantation surgery. After the brains recovered, we introduced ischemic strokes by transient middle cerebral artery occlusion (tMCAO). We monitored the strokes for up to 60 days and observed different microvascular responses to tMCAO at different cortical depths in both the acute and chronic phases of the stroke. This work demonstrates that the combined microprism and cranial window is well-suited for longitudinal investigation of cortical microvascular disorders using vis-OCT.
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Affiliation(s)
- Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- These authors contributed equally to this work
| | - Xian Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
- These authors contributed equally to this work
| | - Neil A. Nadkarni
- Department of Neurology, Northwestern University, Chicago IL 60611, USA
| | - Zhen Cai
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Ayush Batra
- Department of Neurology, Northwestern University, Chicago IL 60611, USA
| | - David P. Sullivan
- Department of Pathology, Northwestern University, Chicago IL 60611, USA
| | - William A. Muller
- Department of Pathology, Northwestern University, Chicago IL 60611, USA
| | - Cheng Sun
- Department of Mechanical Engineering, Northwestern University, Evanston IL 60208, USA
| | - Roman Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
- Opticent Health, Evanston IL, Evanston IL 60201, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208, USA
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9
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Zhou TE, Zhu T, Rivera JC, Omri S, Tahiri H, Lahaie I, Rouget R, Wirth M, Nattel S, Lodygensky G, Ferbeyre G, Nezhady M, Desjarlais M, Hamel P, Chemtob S. The Inability of the Choroid to Revascularize in Oxygen-Induced Retinopathy Results from Increased p53/miR-Let-7b Activity. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:2340-2356. [PMID: 31430465 DOI: 10.1016/j.ajpath.2019.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 07/13/2019] [Accepted: 07/26/2019] [Indexed: 12/18/2022]
Abstract
Retinopathy of prematurity (ROP) is characterized by an initial retinal avascularization, followed by pathologic neovascularization. Recently, choroidal thinning has also been detected in children formerly diagnosed with ROP; a similar sustained choroidal thinning is observed in ROP models. But the mechanism underlying the lack of choroidal revascularization remains unclear and was investigated in an oxygen-induced retinopathy (OIR) model. In OIR, evidence of senescence was detected, preceded by oxidative stress in the choroid and the retinal pigment epithelium. This was associated with a global reduction of proangiogenic factors, including insulin-like growth factor 1 receptor (Igf1R). Coincidentally, tumor suppressor p53 was highly expressed in the OIR retinae. Curtailing p53 activity resulted in reversal of senescence, normalization of Igf1r expression, and preservation of choroidal integrity. OIR-induced down-regulation of Igf1r was mediated at least partly by miR-let-7b as i) let-7b expression was augmented throughout and beyond the period of oxygen exposure, ii) let-7b directly targeted Igf1r mRNA, and iii) p53 knock-down blunted let-7b expression, restored Igf1r expression, and elicited choroidal revascularization. Finally, restoration of Igf1r expression rescued choroid thickness. Altogether, this study uncovers a significant mechanism for defective choroidal revascularization in OIR, revealing a new role for p53/let-7b/IGF-1R axis in the retina. Future investigations on this (and connected) pathway could further our understanding of other degenerative choroidopathies, such as geographic atrophy.
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Affiliation(s)
- Tianwei E Zhou
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada.
| | - Tang Zhu
- Department of Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada
| | - José C Rivera
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada; Department of Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada; Department of Ophthalmology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada
| | - Samy Omri
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada
| | - Houda Tahiri
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada
| | - Isabelle Lahaie
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada
| | - Raphaël Rouget
- Department of Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada
| | - Maëlle Wirth
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada
| | - Stanley Nattel
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Department of Medicine, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada
| | - Gregory Lodygensky
- Department of Pediatrics, Sainte-Justine University Hospital Centre, Université de Montréal, Montréal, Québec, Canada
| | - Gerardo Ferbeyre
- Department of Biochemistry, Université de Montréal, Montréal, Québec, Canada
| | - Mohammad Nezhady
- Department of Pathology and Cell Biology, University of Montréal, Montréal, Québec, Canada
| | - Michel Desjarlais
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada
| | - Patrick Hamel
- Department of Ophthalmology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada
| | - Sylvain Chemtob
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, Université de Montréal, Montréal, Québec, Canada; Department of Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada; Department of Ophthalmology, Centre Hospitalier Universitaire Sainte-Justine Hospital, Université de Montréal, Montréal, Québec, Canada; Department of Pediatrics, Sainte-Justine University Hospital Centre, Université de Montréal, Montréal, Québec, Canada.
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10
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Rountree CM, Troy JB, Saggere L. Investigation of Injection Depth for Subretinal Delivery of Exogenous Glutamate to Restore Vision via Biomimetic Chemical Neuromodulation. IEEE Trans Biomed Eng 2019; 67:464-470. [PMID: 31071013 DOI: 10.1109/tbme.2019.2915255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chemical neuromodulation of the retina using native neurotransmitters to biomimetically activate target retinal neurons through chemical synapses is a promising biomimetic alternative to electrical stimulation for restoring vision in blindness caused by photoreceptor degenerative diseases. Recent research has shown that subretinal chemical stimulation could be advantageous for treating photoreceptor degenerative diseases but many of the parameters for achieving efficacious chemical neuromodulation are yet to be explored. In this paper, we investigated how the depth at which neurotransmitter is injected subretinally affects the success rate, spike rate characteristics (i.e., amplitude, response latency, and time width), and spatial resolution of chemical stimulation in wild-type Long Evans and photoreceptor degenerated S334ter-3 transgenic rat retinas in vitro. We compared the responses to injections of glutamate at the subretinal surface and two subsurface depths near the outer and inner plexiform layers and found that while injections at all depths elicited robust retinal ganglion cell responses, they differed significantly in terms of the spike rate characteristics and spatial resolutions across injection depths. Shallow subsurface injections near the outer plexiform layer evoked the highest spike rate amplitudes and had the highest spatial resolution and success rates, while deep subsurface injections near the inner plexiform layer elicited the shortest latencies and narrowest time widths. Our results suggest that surface injections are suboptimal for subretinal chemical neuromodulation, while shallow subsurface and deep subsurface injections may optimize high spatial and high temporal resolution, respectively. These findings have great significance for the design and development of a potential neurotransmitter-based subretinal prosthesis.
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11
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Shu X, Beckmann L, Wang Y, Rubinoff I, Lucy K, Ishikawa H, Wollstein G, Fawzi AA, Schuman JS, Kuranov RV, Zhang HF. Designing visible-light optical coherence tomography towards clinics. Quant Imaging Med Surg 2019; 9:769-781. [PMID: 31281773 PMCID: PMC6571199 DOI: 10.21037/qims.2019.05.01] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/04/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND The capabilities of visible-light optical coherence tomography (vis-OCT) in noninvasive anatomical and functional retinal imaging have been demonstrated by multiple groups in both rodents and healthy human subjects. Translating laboratory prototypes to an integrated clinical-environment-friendly system is required to explore the full potential of vis-OCT in disease management. METHODS We developed and optimized a portable vis-OCT system for human retinal imaging in clinical settings. We acquired raster- and circular-scan images from both healthy and diseased human eyes. RESULTS The new vis-OCT provided high-quality retinal images of both subjects without any known eye diseases and patients with various retinal diseases, including retinal occlusive disease and diabetic retinopathy (DR) over a broad range of ages. CONCLUSIONS A newly designed vis-OCT system is sufficiently optimized to be suited for routine patients' examinations in clinics. Vis-OCT has the potential to add new anatomical and functional imaging capabilities to ophthalmic clinical care.
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Affiliation(s)
- Xiao Shu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | | | - Ian Rubinoff
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Katie Lucy
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Hiroshi Ishikawa
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Gadi Wollstein
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
| | - Joel S. Schuman
- NYU Langone Eye Center, NYU School of Medicine, New York, NY, USA
| | - Roman V. Kuranov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Opticent Health, Evanston, IL, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
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Villamor-Martinez E, Cavallaro G, Raffaeli G, Mohammed Rahim OMM, Gulden S, Ghazi AMT, Mosca F, Degraeuwe P, Villamor E. Chorioamnionitis as a risk factor for retinopathy of prematurity: An updated systematic review and meta-analysis. PLoS One 2018; 13:e0205838. [PMID: 30332485 PMCID: PMC6192636 DOI: 10.1371/journal.pone.0205838] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 10/02/2018] [Indexed: 12/23/2022] Open
Abstract
The role of chorioamnionitis (CA) in the development of retinopathy of prematurity (ROP) is difficult to establish, because CA-exposed and CA-unexposed infants frequently present different baseline characteristics. We performed an updated systematic review and meta-analysis of studies reporting on the association between CA and ROP. We searched PubMed and EMBASE for relevant articles. Studies were included if they examined preterm or very low birth weight (VLBW, <1500g) infants and reported primary data that could be used to measure the association between exposure to CA and the presence of ROP. Of 748 potentially relevant studies, 50 studies met the inclusion criteria (38,986 infants, 9,258 CA cases). Meta-analysis showed a significant positive association between CA and any stage ROP (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.11 to 1.74). CA was also associated with severe (stage ≥3) ROP (OR 1.63, 95% CI 1.41 to 1.89). Exposure to funisitis was associated with a higher risk of ROP than exposure to CA in the absence of funisitis. Additional meta-analyses showed that infants exposed to CA had lower gestational age (GA) and lower birth weight (BW). Meta-regression showed that lower GA and BW in the CA-exposed group was significantly associated with a higher risk of ROP. Meta-analyses of studies with data adjusted for confounders could not find a significant association between CA and ROP. In conclusion, our study confirms that CA is a risk factor for developing ROP. However, part of the effects of CA on the pathogenesis of ROP may be mediated by the role of CA as an etiological factor for very preterm birth.
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Affiliation(s)
- Eduardo Villamor-Martinez
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
| | - Giacomo Cavallaro
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Genny Raffaeli
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Owais M. M. Mohammed Rahim
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
| | - Silvia Gulden
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Amro M. T. Ghazi
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
| | - Fabio Mosca
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Pieter Degraeuwe
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
| | - Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
- * E-mail:
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Soetikno BT, Beckmann L, Zhang X, Fawzi AA, Zhang HF. Visible-light optical coherence tomography oximetry based on circumpapillary scan and graph-search segmentation. BIOMEDICAL OPTICS EXPRESS 2018; 9:3640-3652. [PMID: 30338145 PMCID: PMC6191632 DOI: 10.1364/boe.9.003640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/25/2018] [Accepted: 06/25/2018] [Indexed: 05/18/2023]
Abstract
Visible-light optical coherence tomography (vis-OCT) enables retinal oximetry by measuring the oxygen saturation of hemoglobin (sO2) from within individual retinal blood vessels. The sO2 calculation requires reliable estimation of the true spectrum of backscattered light from the posterior vessel wall. Unfortunately, subject motion and image noise make averaging from multiple A-lines at the same depth position challenging, and lead to inaccurate sO2 estimation. In this study, we developed an algorithm to reliably extract the backscattered light's spectrum. We used circumpapillary scanning to sample the vessels repeatedly at the same location. A combination of cross-correlation and graph-search based segmentation extracted the posterior wall locations. Using measurements from 100 B-scans as a gold standard, we demonstrated that our method achieved highly accurate measures of sO2 with minimal bias. In addition, we also investigated how the number of repeated measurements affects the accuracy of sO2 measurement. Our method sets the stage for large-scale studies of retinal oxygenation in animals and humans.
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Affiliation(s)
- Brian T. Soetikno
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
- Medical Scientist Training Program, Northwestern University, Chicago, IL, USA
| | - Lisa Beckmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Xian Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL, USA
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Shu X, Beckmann L, Zhang HF. Visible-light optical coherence tomography: a review. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-14. [PMID: 29218923 PMCID: PMC5745673 DOI: 10.1117/1.jbo.22.12.121707] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 11/13/2017] [Indexed: 05/03/2023]
Abstract
Visible-light optical coherence tomography (vis-OCT) is an emerging imaging modality, providing new capabilities in both anatomical and functional imaging of biological tissue. It relies on visible light illumination, whereas most commercial and investigational OCTs use near-infrared light. As a result, vis-OCT requires different considerations in engineering design and implementation but brings unique potential benefits to both fundamental research and clinical care of several diseases. Here, we intend to provide a summary of the development of vis-OCT and its demonstrated applications. We also provide perspectives on future technology improvement and applications.
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Affiliation(s)
- Xiao Shu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Lisa Beckmann
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
- Address all correspondence to: Hao F. Zhang, E-mail:
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Becker S, Wang H, Stoddard GJ, Hartnett ME. Effect of subretinal injection on retinal structure and function in a rat oxygen-induced retinopathy model. Mol Vis 2017; 23:832-843. [PMID: 29259390 PMCID: PMC5723151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/27/2017] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Subretinal injections are used to deliver agents in experimental studies of retinal diseases, often through viral vectors. However, few studies have investigated the effects of subretinal injections alone on the structure and function of the healthy or diseased retina, particularly in models of oxygen-induced retinopathy (OIR). We report on the effects of subretinal injections in a rat OIR model, which is used to study mechanisms of retinopathy of prematurity. METHODS Within 6 h of birth, neonatal rat pups were exposed to repeated cycles of oxygen between 50% and 10% O2 every 24 h for 14 days and subsequently moved to room air. On postnatal day 8 (P8), animals were treated in both eyes with advancement of the injection needle into the vitreous (pilot-treated) or with a subretinal PBS injection (sPBS-treated) or were left untreated (untreated). Additional control animals were exposed to microscope light after eyelid opening only (light-treated). Retinal fundus images were recorded on P26. Areas of the avascular retina and intravitreal neovascularization were determined in flat mounted retinas stained with isolectin B4 on P32. Retinal function of the respective eyes was assessed with the Ganzfeld electroretinogram (ERG) on P31 or P32 and with focal ERG in the central retina on P28 or P29. The thickness of the retinal layers was measured with spectral domain optical coherence tomography (OCT) on P30 and in opsin- and TO-PRO 3-stained retinal cryosections from pups euthanized on P32. Two sections were analyzed in each pup. For each section, three images of three different locations were analyzed accounting for 18 thickness measurements per pup. RESULTS Compared to untreated animals, the avascular area of the retina was greater in the pilot-treated (p<0.05) and sPBS-treated eyes (p<0.01), and the sPBS-treated eyes had a greater avascular retinal area compared to the pilot-treated eyes (p<0.01). The intravitreal neovascular area was larger in the sPBS-treated eyes compared to the untreated eyes (p<0.01). The outer nuclear and outer segment layers were thinner in the pilot- (p<0.01) and sPBS-treated eyes (p<0.05) compared to the untreated eyes as measured with OCT and immunohistochemical staining of the retinal cryosections. Compared to the untreated eyes, the amplitudes of the scotopic a- and b-waves in the Ganzfeld ERG were reduced in the pilot-treated eyes (p<0.001 and p<0.01, respectively), but only the a-wave was reduced in the sPBS-treated eyes (p<0.001). The a-wave amplitude in the focal ERG was reduced in the pilot- and sPBS-treated eyes, and no difference was seen in the b-wave amplitude between any of the groups. There was no difference between the light-treated and untreated eyes in the areas of the avascular retina or intravitreal neovascularization or Ganzfeld or focal ERG. CONCLUSIONS Pilot injections alone without injection into the subretinal space resulted in an increased avascular retinal area, reduced thickness of the photoreceptors, and reduced ERG function compared to the untreated animals. Although subretinal PBS injections further increased the areas of avascular retina and intravitreal neovascularization and resulted in similar retinal thinning compared to the pilot treatment, inner retinal function was improved, as evidenced by higher Ganzfeld b-wave amplitudes. Differences in the Ganzfeld and focal ERGs may indicate that the peripheral retina is more susceptible to remote beneficial effects from potential protective mechanisms induced by subretinal injection. This study stresses the importance of appropriate controls in experiments with subretinal delivery of agents.
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Affiliation(s)
- Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Haibo Wang
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT
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16
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Cavallaro G, Villamor-Martínez E, Filippi L, Mosca F, Villamor E. Probiotic supplementation in preterm infants does not affect the risk of retinopathy of prematurity: a meta-analysis of randomized controlled trials. Sci Rep 2017; 7:13014. [PMID: 29026199 PMCID: PMC5638943 DOI: 10.1038/s41598-017-13465-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 09/26/2017] [Indexed: 12/13/2022] Open
Abstract
Retinopathy of prematurity (ROP) is a vascular disorder of the developing retina in preterm infants and is a leading cause of childhood blindness. Perinatal infection plays a pathogenic role in ROP. Probiotic supplementation reduces the risk of late onset sepsis (LOS) in preterm infants but it remains to be determined whether this reduction translates into a reduction of other complications. We conducted a systematic review and meta-analysis to evaluate the possible role of probiotics in altering the risk of ROP. Eleven randomized controlled trials (4250 infants; probiotics: 2121) were included in the meta-analysis that showed a significantly decreased rate of LOS with a risk ratio (RR) of 0.807 and a 95% confidence interval (CI) of 0.705 to 0.924 (P = 0.010; fixed effects model) but could not demonstrate a significant effect of probiotics on any stage ROP (RR 1.053, 95% CI 0.903 to 1.228, P = 0.508, 4 studies), or severe ROP (RR 0.841, 95% CI 0.666 to 1.063, P = 0.148, 9 studies). Meta-regression did not show any significant association between the RR for LOS and the RR for severe ROP. In conclusion, our results suggest that infection prevention by probiotics does not affect the risk of developing ROP in preterm infants.
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Affiliation(s)
- Giacomo Cavallaro
- Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, 20122, Italy
| | - Eduardo Villamor-Martínez
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, 6202 AZ, Netherlands.
| | - Luca Filippi
- Neonatal Intensive Care Unit, Medical and Surgical Feto-Neonatal Department, "A. Meyer" University Children's Hospital, 50139, Florence, Italy
| | - Fabio Mosca
- Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, 20122, Italy
| | - Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, 6202 AZ, Netherlands
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Nesper PL, Soetikno BT, Zhang HF, Fawzi AA. OCT angiography and visible-light OCT in diabetic retinopathy. Vision Res 2017; 139:191-203. [PMID: 28601429 PMCID: PMC5723235 DOI: 10.1016/j.visres.2017.05.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 12/31/2022]
Abstract
In recent years, advances in optical coherence tomography (OCT) techniques have increased our understanding of diabetic retinopathy, an important microvascular complication of diabetes. OCT angiography is a non-invasive method that visualizes the retinal vasculature by detecting motion contrast from flowing blood. Visible-light OCT shows promise as a novel technique for quantifying retinal hypoxia by measuring the retinal oxygen delivery and metabolic rates. In this article, we discuss recent insights provided by these techniques into the vascular pathophysiology of diabetic retinopathy. The next milestones for these modalities are large multicenter studies to establish consensus on the most reliable and consistent outcome parameters to study diabetic retinopathy.
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Affiliation(s)
- Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA.
| | - Brian T Soetikno
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA; Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA; Medical Scientist Training Program, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA.
| | - Hao F Zhang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA; Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 440, Chicago, IL 60611, USA.
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18
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A Method for Combined Retinal Vascular and Tissue Oxygen Tension Imaging. Sci Rep 2017; 7:10622. [PMID: 28878307 PMCID: PMC5587610 DOI: 10.1038/s41598-017-10955-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/17/2017] [Indexed: 11/17/2022] Open
Abstract
The retina requires adequate oxygenation to maintain cellular metabolism and visual function. Inner retinal oxygen metabolism is directly related to retinal vascular oxygen tension (PO2) and inner retinal oxygen extraction fraction (OEF), whereas outer retinal oxygen consumption (QO2) relies on oxygen availability by the choroid and is contingent upon retinal tissue oxygen tension (tPO2) gradients across the retinal depth. Thus far, these oxygenation and metabolic parameters have been measured independently by different techniques in separate animals, precluding a comprehensive and correlative assessment of retinal oxygenation and metabolism dynamics. The purpose of the current study is to report an innovative optical system for dual oxyphor phosphorescence lifetime imaging to near-simultaneously measure retinal vascular PO2 and tPO2 in rats. The use of a new oxyphor with different spectral characteristics allowed differentiation of phosphorescence signals from the retinal vasculature and tissue. Concurrent measurements of retinal arterial and venous PO2, tPO2 through the retinal depth, inner retinal OEF, and outer retinal QO2 were demonstrated, permitting a correlative assessment of retinal oxygenation and metabolism. Future application of this method can be used to investigate the relations among retinal oxygen content, extraction and metabolism under pathologic conditions and thus advance knowledge of retinal hypoxia pathophysiology.
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Uddin MI, Jayagopal A, McCollum GW, Yang R, Penn JS. In Vivo Imaging of Retinal Hypoxia Using HYPOX-4-Dependent Fluorescence in a Mouse Model of Laser-Induced Retinal Vein Occlusion (RVO). Invest Ophthalmol Vis Sci 2017; 58:3818-3824. [PMID: 28750413 PMCID: PMC5531786 DOI: 10.1167/iovs.16-21187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To demonstrate the utility of a novel in vivo molecular imaging probe, HYPOX-4, to detect and image retinal hypoxia in real time, in a mouse model of retinal vein occlusion (RVO). Methods Retinal vein occlusion was achieved in adult mice by photodynamic retinal vein thrombosis (PRVT). One or two major retinal vein(s) was/were occluded in close proximity to the optic nerve head (ONH). In vivo imaging of retinal hypoxia was performed using, HYPOX-4, an imaging probe developed by our laboratory. Pimonidazole-adduct immunostaining was performed and used as a standard ex vivo method for the detection of retinal hypoxia in this mouse RVO model. The retinal vasculature was imaged using fluorescein angiography (FA) and isolectin B4 staining. Retinal thickness was assessed by spectral-domain optical coherence tomography (SD-OCT) analysis. Results By application of the standard ex vivo pimonidazole-adduct immunostaining technique, retinal hypoxia was observed within 2 hours post-PRVT. The observed hypoxic retinal areas depended on whether one or two retinal vein(s) was/were occluded. Similar areas of hypoxia were imaged in vivo using HYPOX-4. Using OCT, retinal edema was observed immediately post-PRVT induction, resolving 8 days later. Nominal preretinal neovascularization was observed at 10 to 14 days post-RVO. Conclusions HYPOX-4 is an efficient probe capable of imaging retinal hypoxia in vivo, in RVO mice. Future studies will focus on its use in correlating retinal hypoxia to the onset and progression of ischemic vasculopathies.
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Affiliation(s)
- Md Imam Uddin
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Ashwath Jayagopal
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd. Basel, Switzerland
| | - Gary W McCollum
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Rong Yang
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - John S Penn
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States 2Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd. Basel, Switzerland 3Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States 4Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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20
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Matsumoto T, Saito Y, Itokawa T, Shiba T, Oba MS, Takahashi H, Hori Y. Retinal VEGF levels correlate with ocular circulation measured by a laser speckle-micro system in an oxygen-induced retinopathy rat model. Graefes Arch Clin Exp Ophthalmol 2017; 255:1981-1990. [PMID: 28791491 DOI: 10.1007/s00417-017-3756-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 06/12/2017] [Accepted: 07/17/2017] [Indexed: 01/12/2023] Open
Abstract
PURPOSE We used a Laser speckle flowgraphy (LSFG)-micro system to examine the relationship between ocular blood flow and retinal vascular endothelial growth factor (VEGF) at retinopathy onset in oxygen-induced ischemic retinopathy (OIR) model rats. METHODS Sixteen 50/10 OIR rats were compared with 17 control rats reared in room air. In postnatal day 14 (P14) and P18 rats, we measured and analyzed the left eye's mean blur rate (MBR) by setting a rubber band on the optic nerve head center, using the LSFG-Micro. At P18, the rats were sacrificed and their left-eye retinas were fixed, flat-mounted and stained with adenosine diphosphatase (ADPase). The right-eye retinas were homogenized; the lysate was centrifuged for an enzyme-linked immunosorbent assay (ELISA). The avascular area was measured as the percentage (%AVA) of the total retinal area. Retinal VEGF was measured by an ELISA. RESULTS The examination's reproducibility was good. Our multivariate linear mixed model analysis revealed significantly high MBRs in the OIR rats (p = 0.0017). In the P18 OIR rats, significant correlations were seen between the MBR and %AVA (r = 0.80, p = 0.0002) and between the MBR and VEGF (r = 0.76, p = 0.0006). CONCLUSIONS The LSFG-Micro provided reproducible blood flow measurements in neonatal rats. Because of the vitreous blood vessels, measurement of only the retinal vessels was not possible. However, the MBR was higher in the OIR rats than in the control rats, and the MBR and %AVA were correlated, as were the MBR and retinal VEGF. The MBR may thus serve as an indicator of OIR severity.
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Affiliation(s)
- Tadashi Matsumoto
- Department of Ophthalmology, School of Medicine, Toho University, 6-11-1 Omori-Nishi, Ota-ku, Tokyo, 143-8541, Japan.
| | - Yuta Saito
- Department of Ophthalmology, School of Medicine, Showa University, Tokyo, Japan
| | - Takashi Itokawa
- Department of Ophthalmology, School of Medicine, Toho University, 6-11-1 Omori-Nishi, Ota-ku, Tokyo, 143-8541, Japan
| | - Tomoaki Shiba
- Department of Ophthalmology, School of Medicine, Toho University, 6-11-1 Omori-Nishi, Ota-ku, Tokyo, 143-8541, Japan
| | - Mari S Oba
- Department of Medical Statistics Faculty of Medicine, Toho University, Tokyo, Japan
| | - Haruo Takahashi
- Department of Ophthalmology, School of Medicine, Showa University, Tokyo, Japan
| | - Yuichi Hori
- Department of Ophthalmology, School of Medicine, Toho University, 6-11-1 Omori-Nishi, Ota-ku, Tokyo, 143-8541, Japan
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Liu W, Wang S, Soetikno B, Yi J, Zhang K, Chen S, Linsenmeier RA, Sorenson CM, Sheibani N, Zhang HF. Increased Retinal Oxygen Metabolism Precedes Microvascular Alterations in Type 1 Diabetic Mice. Invest Ophthalmol Vis Sci 2017; 58:981-989. [PMID: 28535269 PMCID: PMC5308771 DOI: 10.1167/iovs.16-20600] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose To investigate inner retinal oxygen metabolic rate (IRMRO2) during early stages of type 1 diabetes in a transgenic mouse model. Methods In current study, we involved seven diabetic mice (Akita/+, TSP1−/−) and seven control mice (TSP1−/−), and applied visible-light optical coherence tomography (vis-OCT) to image functional parameters including retinal blood flow rate, oxygen saturation (sO2) and the IRMRO2 value longitudinally from 5 weeks of age to 13 weeks of age. After imaging at 13 weeks of age, we analyzed the imaging results, and examined histology of mouse retina. Results Between diabetic mice and the control group, we observed significant differences in venous sO2 from 9 weeks of age (P = 0.006), and significant increment in IRMRO2 from 11 weeks of age (P = 0.001) in diabetic mice compared with control group. We did not find significant differences in retinal blood flow rate as well as arterial sO2 during imaging between diabetic and control mice. Histologic examination of diabetic and control mice at 13 weeks of age also revealed no anatomical retinal alternations. Conclusions In diabetic retinopathy, complications in retinal oxygen metabolism may occur before changes of retinal anatomical structure.
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Affiliation(s)
- Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Shoujian Wang
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Brian Soetikno
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Ji Yi
- Department of Medicine, Boston University, Boston, Massachusetts, United States
| | - Kevin Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Robert A Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States 5Department of Neurobiology, Northwestern University, Evanston, Illinois, United States
| | - Christine M Sorenson
- Department of Pediatrics, University Wisconsin, Madison, Wisconsin, United States
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States
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22
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Lajko M, Cardona HJ, Taylor JM, Farrow KN, Fawzi AA. Photoreceptor oxidative stress in hyperoxia-induced proliferative retinopathy accelerates rd8 degeneration. PLoS One 2017; 12:e0180384. [PMID: 28671996 PMCID: PMC5495396 DOI: 10.1371/journal.pone.0180384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/14/2017] [Indexed: 12/13/2022] Open
Abstract
To investigate the impact of photoreceptor oxidative stress on photoreceptor degeneration in mice carrying the rd8 mutation (C57BL/6N). We compared the hyperoxia-induced proliferative retinopathy (HIPR) model in two mouse strains (C57BL/6J and C57BL/6N). Pups were exposed to 75% oxygen, starting at birth and continuing for 14 days (P14). Mice were euthanized at P14, or allowed to recover in room air for one day (P15), seven days (P21), or 14 days (P28). We quantified retinal thickness and the length of residual photoreceptors not affected by rosette formation. In addition we explored differences in retinal immunostaining for NADPH oxidase 4 (NOX4), Rac1, vascular endothelium, and activated Mϋller cells. We analyzed photoreceptor oxidative stress using DCF staining in cross sections and quantified NOX4 protein levels using western blotting. C57BL/6N mice in HIPR showed increased oxidative stress, NOX4, and Rac1 in the photoreceptors at P14 and P15 compared to C57BL/6J. In addition, we observed significant progression of photoreceptor degeneration, with significantly accelerated rosette formation in C57BL/6N under HIPR, compared to their room air counterparts. Furthermore, C57BL/6N under HIPR had significantly thinner central retinas than C57BL/6J in HIPR. We did not find a difference in vascular disruption or Mϋller cell activation comparing the two strains in hyperoxia. In HIPR, the C57BL/6N strain carrying the rd8 mutation showed significantly accelerated photoreceptor degeneration, mediated via exacerbated photoreceptor oxidative stress, which we believe relates to Rac1-NOX dysregulation in the setting of Crb1 loss-of-function.
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Affiliation(s)
- Michelle Lajko
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Herminio J. Cardona
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Joann M. Taylor
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Kathryn N. Farrow
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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23
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Shah RS, Soetikno BT, Yi J, Liu W, Skondra D, Zhang HF, Fawzi AA. Visible-Light Optical Coherence Tomography Angiography for Monitoring Laser-Induced Choroidal Neovascularization in Mice. Invest Ophthalmol Vis Sci 2017; 57:OCT86-95. [PMID: 27409510 PMCID: PMC4968775 DOI: 10.1167/iovs.15-18891] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This study sought to determine the earliest time-point at which evidence of choroidal neovascularization (CNV) could be detected with visible-light optical coherence tomography angiography (vis-OCTA) in a mouse model of laser-induced CNV. Methods Visible light-OCTA was used to study laser-induced CNV at different time-points after laser injury to monitor CNV development and measure CNV lesion size. Measurements obtained from vis-OCTA angiograms were compared with histopathologic measurements from isolectin-stained choroidal flatmounts. Results Choroidal neovascularization area measurements between the vis-OCTA system and isolectin-stained choroidal flatmounts were significantly different in area for days 2 to 4 postlaser injury, and were not significantly different in area for days 5, 7, and 14. Choroidal neovascularization area measurements taken from the stained flatmounts were larger than their vis-OCTA counterparts for all time-points. Both modalities showed a similar trend of CNV size increasing from the day of laser injury until a peak of day 7 postlaser injury and subsequently decreasing by day 14. Conclusions The earliest vis-OCTA can detect the presence of aberrant vessels in a mouse laser-induced CNV model is 5 days after laser injury. Visible light-OCTA was able to visualize the maximum of the CNV network 7 days postlaser injury, in accordance with choroidal flatmount immunostaining. Visible light-OCTA is a reliable tool in both detecting the presence of CNV development, as well as accurately determining the size of the lesion in a mouse laser-induced CNV model.
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Affiliation(s)
- Ronil S Shah
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Brian T Soetikno
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States 3Med
| | - Ji Yi
- Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Wenzhong Liu
- Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Dimitra Skondra
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Hao F Zhang
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Functional Optical Imaging Laboratory, Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, United States
| | - Amani A Fawzi
- Department of Ophthalmology Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
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24
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Hartnett ME. Advances in understanding and management of retinopathy of prematurity. Surv Ophthalmol 2017; 62:257-276. [PMID: 28012875 PMCID: PMC5401801 DOI: 10.1016/j.survophthal.2016.12.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 12/11/2016] [Accepted: 12/12/2016] [Indexed: 12/16/2022]
Abstract
The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.
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Affiliation(s)
- Mary Elizabeth Hartnett
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
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25
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Chen S, Shu X, Nesper PL, Liu W, Fawzi AA, Zhang HF. Retinal oximetry in humans using visible-light optical coherence tomography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1415-1429. [PMID: 28663838 PMCID: PMC5480553 DOI: 10.1364/boe.8.001415] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/01/2017] [Accepted: 02/01/2017] [Indexed: 05/18/2023]
Abstract
We measured hemoglobin oxygen saturation (sO2) in the retinal circulation in healthy humans using visible-light optical coherence tomography (vis-OCT). The measurements showed clear oxygenation differences between central retinal arteries and veins close to the optic nerve head. Spatial variations at different vascular branching levels were also revealed. In addition, we presented theoretical and experimental results to establish that noises in OCT intensity followed Rice distribution. We used this knowledge to retrieve unbiased estimation of true OCT intensity to improve the accuracy of vis-OCT oximetry, which had inherently lower signal-to-nose ratio from human eyes due to safety and comfort limitations. We demonstrated that the new statistical-fitting sampling strategy could reduce the estimation error in sO2 by three percentage points (pp). The presented work aims to provide a foundation for using vis-OCT to achieve accurate retinal oximetry in clinical settings.
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Affiliation(s)
- Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Xiao Shu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Peter L. Nesper
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
| | - Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Currently with Opticent Health, Evanston, IL 60208, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
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26
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Linsenmeier RA, Zhang HF. Retinal oxygen: from animals to humans. Prog Retin Eye Res 2017; 58:115-151. [PMID: 28109737 DOI: 10.1016/j.preteyeres.2017.01.003] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/13/2017] [Accepted: 01/17/2017] [Indexed: 10/20/2022]
Abstract
This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O2 in the retina: measurements of PO2 with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O2 concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO2 in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.
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Affiliation(s)
- Robert A Linsenmeier
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Neurobiology Department, Northwestern University, 2205 Tech Drive, Evanston 60208-3520, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
| | - Hao F Zhang
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
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27
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Lajko M, Cardona HJ, Taylor JM, Shah RS, Farrow KN, Fawzi AA. Hyperoxia-Induced Proliferative Retinopathy: Early Interruption of Retinal Vascular Development with Severe and Irreversible Neurovascular Disruption. PLoS One 2016; 11:e0166886. [PMID: 27861592 PMCID: PMC5115836 DOI: 10.1371/journal.pone.0166886] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 11/05/2016] [Indexed: 11/26/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a major cause of neonatal morbidity in premature infants, occurring as a result of arrested lung development combined with multiple postnatal insults. Infants with BPD exposed to supplemental oxygen are at risk of retinopathy of prematurity as well. Thus, we studied the effects of hyperoxia on the retinal vasculature in a murine model of BPD. The retinal phenotype of this model, which we termed hyperoxia-induced proliferative retinopathy (HIPR), shows severe disruption of retinal vasculature and loss of vascular patterning, disorganized intra-retinal angiogenesis, inflammation and retinal detachment. Neonatal mice were subjected to 75% oxygen exposure from postnatal day (P)0 to P14 to model BPD, then allowed to recover in room air for 1 (P15), 7 (P21), or 14 days (P28). We quantified retinal thickness, protein levels of HIF-1α, NOX2, and VEGF, and examined the cellular locations of these proteins by immunohistochemistry. We examined the retinal blood vessel integrity and inflammatory markers, including macrophages (F4/80) and lymphocytes (CD45R). Compared to controls, normal retinal vascular development was severely disrupted and replaced by a disorganized sheet of intra-retinal angiogenesis in the HIPR mice. At all time-points, HIPR showed persistent hyaloidal vasculature and a significantly thinner central retina compared to controls. HIF-1α protein levels were increased at P15, while VEGF levels continued to increase until P21. Intra-retinal fibrinogen was observed at P21 followed by sub-retinal deposition in at P28. Inflammatory lymphocytes and macrophages were observed at P21 and P28, respectively. This model presents a severe phenotype of disrupted retinal vascular development, intra-retinal angiogenesis inflammation and retinal detachment.
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Affiliation(s)
- Michelle Lajko
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
| | - Herminio J. Cardona
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
| | - Joann M. Taylor
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
| | - Ronil S. Shah
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
| | - Kathryn N. Farrow
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States
- * E-mail:
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28
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Augustin M, Fialová S, Himmel T, Glösmann M, Lengheimer T, Harper DJ, Plasenzotti R, Pircher M, Hitzenberger CK, Baumann B. Multi-Functional OCT Enables Longitudinal Study of Retinal Changes in a VLDLR Knockout Mouse Model. PLoS One 2016; 11:e0164419. [PMID: 27711217 PMCID: PMC5053493 DOI: 10.1371/journal.pone.0164419] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/23/2016] [Indexed: 12/24/2022] Open
Abstract
We present a multi-functional optical coherence tomography (OCT) imaging approach to study retinal changes in the very-low-density-lipoprotein-receptor (VLDLR) knockout mouse model with a threefold contrast. In the retinas of VLDLR knockout mice spontaneous retinal-chorodoidal neovascularizations form, having an appearance similar to choroidal and retinal neovascularizations (CNV and RNV) in neovascular age-related macular degeneration (AMD) or retinal angiomatous proliferation (RAP). For this longitudinal study, the mice were imaged every 4 to 6 weeks starting with an age of 4 weeks and following up to the age of 11 months. Significant retinal changes were identified by the multi-functional imaging approach offering a threefold contrast: reflectivity, polarization sensitivity (PS) and motion contrast based OCT angiography (OCTA). By use of this intrinsic contrast, the long-term development of neovascularizations was studied and associated processes, such as the migration of melanin pigments or retinal-choroidal anastomosis, were assessed in vivo. Furthermore, the in vivo imaging results were validated with histological sections at the endpoint of the experiment. Multi-functional OCT proves as a powerful tool for longitudinal retinal studies in preclinical research of ophthalmic diseases. Intrinsic contrast offered by the functional extensions of OCT might help to describe regulative processes in genetic animal models and potentially deepen the understanding of the pathogenesis of retinal diseases such as wet AMD.
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Affiliation(s)
- Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- * E-mail:
| | - Stanislava Fialová
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Tanja Himmel
- Core Facility for Research and Technology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Martin Glösmann
- Core Facility for Research and Technology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Theresia Lengheimer
- Division of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Roberto Plasenzotti
- Division of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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29
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Uddin MI, Evans SM, Craft JR, Capozzi ME, McCollum GW, Yang R, Marnett LJ, Uddin MJ, Jayagopal A, Penn JS. In Vivo Imaging of Retinal Hypoxia in a Model of Oxygen-Induced Retinopathy. Sci Rep 2016; 6:31011. [PMID: 27491345 PMCID: PMC4974503 DOI: 10.1038/srep31011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/11/2016] [Indexed: 01/16/2023] Open
Abstract
Ischemia-induced hypoxia elicits retinal neovascularization and is a major component of several blinding retinopathies such as retinopathy of prematurity (ROP), diabetic retinopathy (DR) and retinal vein occlusion (RVO). Currently, noninvasive imaging techniques capable of detecting and monitoring retinal hypoxia in living systems do not exist. Such techniques would greatly clarify the role of hypoxia in experimental and human retinal neovascular pathogenesis. In this study, we developed and characterized HYPOX-4, a fluorescence-imaging probe capable of detecting retinal-hypoxia in living animals. HYPOX-4 dependent in vivo and ex vivo imaging of hypoxia was tested in a mouse model of oxygen-induced retinopathy (OIR). Predicted patterns of retinal hypoxia were imaged by HYPOX-4 dependent fluorescence activity in this animal model. In retinal cells and mouse retinal tissue, pimonidazole-adduct immunostaining confirmed the hypoxia selectivity of HYPOX-4. HYPOX-4 had no effect on retinal cell proliferation as indicated by BrdU assay and exhibited no acute toxicity in retinal tissue as indicated by TUNEL assay and electroretinography (ERG) analysis. Therefore, HYPOX-4 could potentially serve as the basis for in vivo fluorescence-based hypoxia-imaging techniques, providing a tool for investigators to understand the pathogenesis of ischemic retinopathies and for physicians to address unmet clinical needs.
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Affiliation(s)
- Md. Imam Uddin
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Stephanie M. Evans
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jason R. Craft
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Megan E. Capozzi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gary W. McCollum
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Rong Yang
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Lawrence J. Marnett
- A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry and Pharmacology, Vanderbilt Institute of Chemical Biology, Center for Molecular Toxicology and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Md. Jashim Uddin
- A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry and Pharmacology, Vanderbilt Institute of Chemical Biology, Center for Molecular Toxicology and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Ashwath Jayagopal
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - John S. Penn
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
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30
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Scarinci F, Nesper PL, Fawzi AA. Deep Retinal Capillary Nonperfusion Is Associated With Photoreceptor Disruption in Diabetic Macular Ischemia. Am J Ophthalmol 2016; 168:129-138. [PMID: 27173374 PMCID: PMC4969199 DOI: 10.1016/j.ajo.2016.05.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/29/2016] [Accepted: 05/02/2016] [Indexed: 11/23/2022]
Abstract
PURPOSE To report outer retinal structural changes associated with macular capillary nonperfusion at the level of deep capillary plexus (DCP) in diabetic patients. DESIGN Prospective observational cross-sectional study. METHODS The study included 14 eyes of 10 patients who were diagnosed as having diabetic retinopathy. To study the outer retina and localize areas of capillary nonperfusion at the superficial (SCP) or DCP, we used the spectral-domain optical coherence tomography (SDOCT) device (RTVue-XR Avanti; Optovue Inc, Fremont, California, USA) with split-spectrum amplitude-decorrelation angiography (SSADA) software for optical coherence tomography angiography (OCTA). Two independent masked graders (F.S. and A.A.F.) qualitatively evaluated SDOCT scans as either normal or having outer retina disruption. The angiographic images were examined to define the presence and location of capillary nonperfusion. RESULTS Eight eyes showed outer retinal disruption on SDOCT that co-localized to areas of enlarged foveal avascular zone, areas of no flow between capillaries, and capillary nonperfusion of the DCP. Six eyes without outer retinal changes on SDOCT showed robust perfusion of the DCP. CONCLUSIONS Using OCTA, this study shows that macular photoreceptor disruption on SDOCT in patients with diabetic retinopathy corresponds to areas of capillary nonperfusion at the level of the DCP. This is important in highlighting the contribution of the DCP to the oxygen requirements of the photoreceptors as well as the outer retina in diabetic macular ischemia.
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Affiliation(s)
- Fabio Scarinci
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; G.B. Bietti Eye Foundation-IRCCS, Rome, Italy
| | - Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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