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Park Y, Shin J, Park J, Kim S, Park JH, Kim J, Kim CS, Chang JW, Schuurmans C, Aubert I, Chang WS, Eom K. Focused Ultrasound as a Novel Non-Invasive Method for the Delivery of Gold Nanoparticles to Retinal Ganglion Cells. Transl Vis Sci Technol 2024; 13:5. [PMID: 38713474 PMCID: PMC11086706 DOI: 10.1167/tvst.13.5.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/22/2024] [Indexed: 05/08/2024] Open
Abstract
Purpose The blood-retinal barrier (BRB) restricts the delivery of intravenous therapeutics to the retina, necessitating innovative approaches for treating retinal disorders. This study sought to explore the potential of focused ultrasound (FUS) to non-invasively deliver intravenously administered gold nanoparticles (AuNPs) across the BRB. FUS-BRB modulation can offer a novel method for targeted retinal therapy. Methods AuNPs of different sizes and shapes were characterized, and FUS parameters were optimized to permeate the BRB without causing retinal damage in a rodent model. The delivery of 70-kDa dextran and AuNPs to the retinal ganglion cell (RGC) layer was visualized using confocal and two-photon microscopy, respectively. Histological and statistical analyses were conducted to assess the effectiveness and safety of the procedure. Results FUS-BRB modulation resulted in the delivery of dextran and AuNPs to the RGC and inner nuclear layer. Smaller AuNPs reached the retinal layers to a greater extent than larger ones. The delivery of dextran and AuNPs across the BRB with FUS was achieved without significant retinal damage. Conclusions This investigation provides the first evidence, to our knowledge, of FUS-mediated AuNP delivery across the BRB, establishing a foundation for a targeted and non-invasive approach to retinal treatment. The results contribute to developing promising non-invasive therapeutic strategies in ophthalmology to treat retinal diseases. Translational Relevance Modifying the BRB with ultrasound offers a targeted and non-invasive delivery strategy of intravenous therapeutics to the retina.
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Affiliation(s)
- Younghoon Park
- Department of Electronics Engineering, College of Engineering, Pusan National University, Busan, Republic of Korea
| | - Jaewoo Shin
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation (K-MEDI Hub), Daegu, Republic of Korea
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Junwon Park
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seulbi Kim
- Department of Science Education, Ewha Womans University, Seoul, Republic of Korea
| | - Ji Hun Park
- Department of Science Education, Ewha Womans University, Seoul, Republic of Korea
| | - Jaeheung Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
| | - Chang Seok Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Carol Schuurmans
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Isabelle Aubert
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Won Seok Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyungsik Eom
- Department of Electronics Engineering, College of Engineering, Pusan National University, Busan, Republic of Korea
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Yao X, Son T, Kim TH, Le D. Interpretation of anatomic correlates of outer retinal bands in optical coherence tomography. Exp Biol Med (Maywood) 2021; 246:2140-2150. [PMID: 34111984 DOI: 10.1177/15353702211022674] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
By providing the sectioning capability to differentiate individual retinal layers, optical coherence tomography (OCT) is revolutionizing eye disease diagnosis and treatment evaluation. A better understanding of the hyper- and hypo-reflective bands in retinal OCT is essential for accurate interpretation of clinical outcomes. In this article, we summarize the interpretations of clinical OCT and adaptive optics (AO) OCT (AO-OCT) of the outer retina in the human eye, and briefly review OCT investigation of the outer retina in animal models. Quantitative analysis of outer retinal OCT bands is compared to established parameters of retinal histology. The literature review and comparative analysis support that both inner/outer segment (IS/OS) junction and IS ellipsoid zone nonexclusively contribute to the second band; and OS, OS tips, and retinal pigment epithelium apical processes contribute to the third band in conventional OCT. In contrast, AO-OCT might predominantly detect the IS/OS junction and OS tip signals at the second and third bands due to its improved sectioning capability and possible AO effect on the sensitivities for recording ballistic and diffusive photons from different regions of the outer retina.
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Affiliation(s)
- Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - David Le
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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Bueno JM, Cruz-Castillo R, Avilés-Trigueros M, Bautista-Elivar N. Arrangement of the photoreceptor mosaic in a diabetic rat model imaged with multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:4901-4914. [PMID: 33014589 PMCID: PMC7510868 DOI: 10.1364/boe.399835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Diabetic retinopathy (DR) is defined as a microvascular pathology. However, some data have suggested that the retinal photoreceptors (PRs) might be important in the pathogenesis of this ocular disease. In this study the organization of the PRs in control and diabetic-induced rats was compared using multiphoton microscopy. The PR mosaic was imaged at different locations in non-stained retinas. The density of PRs was directly quantified from cell counting. The spatially resolved density presents a double-slope pattern (from the central retina towards the periphery) in both healthy and pathological samples, although the values for the latter were significantly lower all across the retina. Moreover, Voronoi analysis was performed to explore changes in PR topography. In control specimens a hexagonally packed structure was dominant. However, despite the non-controlled effects of the disease in retinal structures, this PR regularity was fairly maintained in diabetic retinas.
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Affiliation(s)
- Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Murcia, Spain
| | - Ricardo Cruz-Castillo
- Área Académica de Matemáticas y Física, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, Mexico
| | - Marcelino Avilés-Trigueros
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca, “Campus Mare Nostrum” de Excelencia International, Murcia, Spain
| | - Nazario Bautista-Elivar
- Departamento de Ingeniería Eléctrica, Tecnológico Nacional de México, Instituto Tecnológico de Pachuca, Hidalgo, Mexico
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4
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Batista A, Breunig HG, König A, Morgado AM, König K. Assessment of the metabolism and morphology of the porcine cornea, lens and retina by 2-photon imaging. JOURNAL OF BIOPHOTONICS 2018; 11:e201700324. [PMID: 29575612 DOI: 10.1002/jbio.201700324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
Two-photon imaging is a noninvasive imaging technique with increasing importance in the biological and medical fields since it allows intratissue cell imaging with high resolution. We demonstrate the feasibility of using a single 2-photon instrument to evaluate the cornea, the crystalline lens and the retina based on their autofluorescence (AF). Image acquisition was performed using a custom-built 2-photon microscope for 5-dimensional microscopy with a near infrared broadband sub-15 femtosecond laser centered at 800 nanometers. Signals were detected using a spectral photomultiplier tube. The spectral ranges for the analysis of each tissue/layer AF were determined based on the spectra of each tissue as well as of pure endogenous fluorophores. The cornea, lens and retina are characterized at multiple depths with subcellular resolution based on their morphology and AF lifetime. Additionally, the AF lifetime of NAD(P)H was used to assess the metabolic activity of the cornea epithelium, endothelium and keratocytes. The feasibility to evaluate the metabolic activity of lens epithelial cells was also demonstrated, which may be used to further investigate the pathogenesis of cataracts. The results illustrate the potential of multimodal multiphoton imaging as a novel ophthalmologic technique as well as its potential as a diagnostic tool.
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Affiliation(s)
- Ana Batista
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - Hans G Breunig
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - Aisada König
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - António M Morgado
- Department of Physics, University of Coimbra, Coimbra, Portugal
- Coimbra Institute for Biomedical Imaging and Translational Research/Institute of Nuclear Sciences Applied to Heath (CIBIT/ICNAS), University of Coimbra, Coimbra, Portugal
| | - Karsten König
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
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Liu C, Zhi Y, Wang B, Thapa D, Chen Y, Alam M, Lu Y, Yao X. In vivo super-resolution retinal imaging through virtually structured detection. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:120502. [PMID: 27992630 PMCID: PMC5167560 DOI: 10.1117/1.jbo.21.12.120502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/28/2016] [Indexed: 06/01/2023]
Abstract
High resolution is important for sensitive detection of subtle distortions of retinal morphology at an early stage of eye diseases. We demonstrate virtually structured detection (VSD) as a feasible method to achieve in vivo super-resolution ophthalmoscopy. A line-scanning strategy was employed to achieve a super-resolution imaging speed up to 127 ?? frames / s with a frame size of 512 × 512 ?? pixels . The proof-of-concept experiment was performed on anesthetized frogs. VSD-based super-resolution images reveal individual photoreceptors and nerve fiber bundles unambiguously. Both image contrast and signal-to-noise ratio are significantly improved due to the VSD implementation.
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Affiliation(s)
- Changgeng Liu
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Yanan Zhi
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Benquan Wang
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Damber Thapa
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Yanjun Chen
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Minhaj Alam
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Yiming Lu
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
| | - Xincheng Yao
- University of Illinois at Chicago, Department of Bioengineering, 851 South Morgen Street, Chicago, Illinois 60607, United States
- University of Illinois at Chicago, Department of Ophthalmology and Visual Sciences, 1905 West Taylor Street, Chicago, Illinois 60612, United States
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Sharma R, Williams DR, Palczewska G, Palczewski K, Hunter JJ. Two-Photon Autofluorescence Imaging Reveals Cellular Structures Throughout the Retina of the Living Primate Eye. Invest Ophthalmol Vis Sci 2016; 57:632-46. [PMID: 26903224 PMCID: PMC4771181 DOI: 10.1167/iovs.15-17961] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 12/30/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Although extrinsic fluorophores can be introduced to label specific cell types in the retina, endogenous fluorophores, such as NAD(P)H, FAD, collagen, and others, are present in all retinal layers. These molecules are a potential source of optical contrast and can enable noninvasive visualization of all cellular layers. We used a two-photon fluorescence adaptive optics scanning light ophthalmoscope (TPF-AOSLO) to explore the native autofluorescence of various cell classes spanning several layers in the unlabeled retina of a living primate eye. METHODS Three macaques were imaged on separate occasions using a custom TPF-AOSLO. Two-photon fluorescence was evoked by pulsed light at 730 and 920 nm excitation wavelengths, while fluorescence emission was collected in the visible range from several retinal layers and different locations. Backscattered light was recorded simultaneously in confocal modality and images were postprocessed to remove eye motion. RESULTS All retinal layers yielded two-photon signals and the heterogeneous distribution of fluorophores provided optical contrast. Several structural features were observed, such as autofluorescence from vessel walls, Müller cell processes in the nerve fibers, mosaics of cells in the ganglion cell and other nuclear layers of the inner retina, as well as photoreceptor and RPE layers in the outer retina. CONCLUSIONS This in vivo survey of two-photon autofluorescence throughout the primate retina demonstrates a wider variety of structural detail in the living eye than is available through conventional imaging methods, and broadens the use of two-photon imaging of normal and diseased eyes.
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Affiliation(s)
- Robin Sharma
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - David R. Williams
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jennifer J. Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
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7
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Stremplewski P, Komar K, Palczewski K, Wojtkowski M, Palczewska G. Periscope for noninvasive two-photon imaging of murine retina in vivo. BIOMEDICAL OPTICS EXPRESS 2015; 6:3352-61. [PMID: 26417507 PMCID: PMC4574663 DOI: 10.1364/boe.6.003352] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/01/2015] [Accepted: 08/02/2015] [Indexed: 05/18/2023]
Abstract
Two-photon microscopy allows visualization of subcellular structures in the living animal retina. In previously reported experiments it was necessary to apply a contact lens to each subject. Extending this technology to larger animals would require fitting a custom contact lens to each animal and cumbersome placement of the living animal head on microscope stage. Here we demonstrate a new device, periscope, for coupling light energy into mouse eye and capturing emitted fluorescence. Using this periscope we obtained images of the RPE and their subcellular organelles, retinosomes, with larger field of view than previously reported. This periscope provides an interface with a commercial microscope, does not require contact lens and its design could be modified to image retina in larger animals.
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Affiliation(s)
- Patrycjusz Stremplewski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Katarzyna Komar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Maciej Wojtkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
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8
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Zhi Y, Lu R, Wang B, Zhang Q, Yao X. Rapid super-resolution line-scanning microscopy through virtually structured detection. OPTICS LETTERS 2015; 40:1683-6. [PMID: 25872047 PMCID: PMC4426981 DOI: 10.1364/ol.40.001683] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Virtually structured detection (VSD) has been demonstrated to break the diffraction limit in scanning laser microscopy (SLM). VSD provides an easy, low-cost, and phase-artifact-free strategy to achieve super-resolution imaging. However, practical application of this method is challenging due to a limited image acquisition speed. We report here the combination of VSD and line-scanning microscopy (LSM) to improve the image acquisition speed. A motorized dove prism was used to achieve automatic control of four-angle (i.e., 0°, 45°, 90°, and 135°) scanning, thus ensuring isotropic resolution improvement. Both an optical resolution target and a living frog eyecup were used to verify resolution enhancement.
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Affiliation(s)
- Yanan Zhi
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Rongwen Lu
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Benquan Wang
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Qiuxiang Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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9
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Abstract
Light microscopy plays a key role in biological studies and medical diagnosis. The spatial resolution of conventional optical microscopes is limited to approximately half the wavelength of the illumination light as a result of the diffraction limit. Several approaches-including confocal microscopy, stimulated emission depletion microscopy, stochastic optical reconstruction microscopy, photoactivated localization microscopy, and structured illumination microscopy-have been established to achieve super-resolution imaging. However, none of these methods is suitable for the super-resolution ophthalmoscopy of retinal structures because of laser safety issues and inevitable eye movements. We recently experimentally validated virtually structured detection (VSD) as an alternative strategy to extend the diffraction limit. Without the complexity of structured illumination, VSD provides an easy, low-cost, and phase artifact-free strategy to achieve super-resolution in scanning laser microscopy. In this article we summarize the basic principles of the VSD method, review our demonstrated single-point and line-scan super-resolution systems, and discuss both technical challenges and the potential of VSD-based instrumentation for super-resolution ophthalmoscopy of the retina.
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Affiliation(s)
- Yanan Zhi
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL
| | - Benquan Wang
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL
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Bueno JM, Palacios R, Giakoumaki A, Gualda EJ, Schaeffel F, Artal P. Retinal cell imaging in myopic chickens using adaptive optics multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2014; 5:664-674. [PMID: 24688804 PMCID: PMC3959843 DOI: 10.1364/boe.5.000664] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 01/30/2014] [Accepted: 01/31/2014] [Indexed: 06/03/2023]
Abstract
Abnormal eye growth induced by visual deprivation can modify the structure and density of the retinal cells. We have used an adaptive optics multiphoton microscope to image photoreceptors (PRs) and ganglion cells (GCs) at different retinal locations in unstained retinas of chicken eyes with about 10D of myopia and their normal-sighted fellow eyes. In all samples, the local averaged inter-PR distance increased with eccentricity. No significant differences in PR density were found between control and myopic eyes. GC density declined in myopic eyes compared to control eyes and the inter-cell distance increased. In normal eyes, the size of the GC cell bodies increased approximately two-fold between the area centralis and the peripheral retina. In myopic eyes, this trend was preserved but the GC bodies were larger at each retinal location, compared to control eyes. Obviously, GC morphology is changing when the retinal area is enlarged in myopic eyes.
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Affiliation(s)
- Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed.34), 30100 Murcia, Spain
| | | | - Anastasia Giakoumaki
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed.34), 30100 Murcia, Spain
| | - Emilio J. Gualda
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed.34), 30100 Murcia, Spain
| | - Frank Schaeffel
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, Calwerstrasse 7/1, 72076 Tuebingen, Germany
| | - Pablo Artal
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed.34), 30100 Murcia, Spain
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Sharma R, Yin L, Geng Y, Merigan WH, Palczewska G, Palczewski K, Williams DR, Hunter JJ. In vivo two-photon imaging of the mouse retina. BIOMEDICAL OPTICS EXPRESS 2013; 4:1285-93. [PMID: 24009992 PMCID: PMC3756587 DOI: 10.1364/boe.4.001285] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/06/2013] [Accepted: 06/17/2013] [Indexed: 05/18/2023]
Abstract
Though in vivo two-photon imaging has been demonstrated in non-human primates, improvements in the signal-to-noise ratio (SNR) would greatly improve its scientific utility. In this study, extrinsic fluorophores, expressed in otherwise transparent retinal ganglion cells, were imaged in the living mouse eye using a two-photon fluorescence adaptive optics scanning laser ophthalmoscope. We recorded two orders of magnitude greater signal levels from extrinsically labeled cells relative to previous work done in two-photon autofluorescence imaging of primates. Features as small as single dendrites in various layers of the retina could be resolved and predictions are made about the feasibility of measuring functional response from cells. In the future, two-photon imaging in the intact eye may allow us to monitor the function of retinal cell classes with infrared light that minimally excites the visual response.
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Affiliation(s)
- Robin Sharma
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
- The Institute of Optics, University of Rochester, Rochester, New York 14620, USA
| | - Lu Yin
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
| | - Ying Geng
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
- The Institute of Optics, University of Rochester, Rochester, New York 14620, USA
- Currently at: Corning Incorporated, One Riverfront Plaza, Corning, New York 14831, USA
| | - William H. Merigan
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, New York 14642, USA
| | - Grazyna Palczewska
- Polgenix, Inc., 11000 Cedar Avenue, Suite 260, Cleveland, Ohio 44106, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA
| | - David R. Williams
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
- The Institute of Optics, University of Rochester, Rochester, New York 14620, USA
- Flaum Eye Institute, University of Rochester, Rochester, New York 14642, USA
| | - Jennifer J. Hunter
- Center for Visual Science, University of Rochester, Rochester, New York 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, New York 14642, USA
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Johnson Retnaraj Samuel SC, Elaiya Raja S, Beryl Vedha Y, Edith Arul Jane A, Amutha K, Dinesh SM, Jackson Durairaj SC, Kalidas RM, Tharmaraj V, Pitchumani K, Sudhakar S. Autofluorescence in BrdU-positive cells and augmentation of regeneration kinetics by riboflavin. Stem Cells Dev 2012; 21:2071-83. [PMID: 22150027 DOI: 10.1089/scd.2011.0485] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The earthworm, Eudrilus eugeniae, has a prodigious ability to regenerate lost segments. The skin of the worm has an outermost epidermal layer followed by a thick circular muscle layer and an innermost thin longitudinal cell layer. During the process of regeneration, the circular muscle layer decreased in thickness, and longitudinal cell layer increased. The histological analysis of the regenerated worm shows that the longitudinal cell layer forms the regeneration blastema. BrdU-labeling retention assay confirmed that the circular muscle and longitudinal cell layers have BrdU-positive cells, which migrate from the adjacent segments to the regeneration blastema. In addition, it was noted that the cells of the earthworm, E. eugeniae, have the property of autofluorescence. Autofluorescence was found in the cytoplasm, but not in the nucleus. It has been also found that the major source for autofluorescence is riboflavin. Further, it was also demonstrated that supplementation with riboflavin increases the rate of regeneration, while regeneration was hampered by reduced levels of riboflavin. The importance of riboflavin in regeneration was also confirmed by rescue assay. In addition, it was also identified that BrdU-positive cells are highly fluorescent compared to the surrounding cells.
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