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Aeindartehran L, Sadri Z, Rahimi F, Alinejad T. Fluorescence in depth: integration of spectroscopy and imaging with Raman, IR, and CD for advanced research. Methods Appl Fluoresc 2024; 12:032002. [PMID: 38697201 DOI: 10.1088/2050-6120/ad46e6] [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: 12/27/2023] [Accepted: 05/02/2024] [Indexed: 05/04/2024]
Abstract
Fluorescence spectroscopy serves as a vital technique for studying the interaction between light and fluorescent molecules. It encompasses a range of methods, each presenting unique advantages and applications. This technique finds utility in various chemical studies. This review discusses Fluorescence spectroscopy, its branches such as Time-Resolved Fluorescence Spectroscopy (TRFS) and Fluorescence Lifetime Imaging Microscopy (FLIM), and their integration with other spectroscopic methods, including Raman, Infrared (IR), and Circular Dichroism (CD) spectroscopies. By delving into these methods, we aim to provide a comprehensive understanding of the capabilities and significance of fluorescence spectroscopy in scientific research, highlighting its diverse applications and the enhanced understanding it brings when combined with other spectroscopic methods. This review looks at each technique's unique features and applications. It discusses the prospects of their combined use in advancing scientific understanding and applications across various domains.
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Affiliation(s)
- Lida Aeindartehran
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States of America
| | - Zahra Sadri
- Department of Biological Science, Southern Methodist University, Dallas, Texas 75205, United States of America
| | - Fateme Rahimi
- Department of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran
| | - Tahereh Alinejad
- The Key Laboratory of Interventional Pulmonology of Zhejiang Province, Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Wenzhou Medical University, South Baixiang, Ouhai District, Wenzhou 325015, Zhejiang, People's Republic of China
- Institute of Cell Growth Factor, Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision, and Brain Health), Wenzhou Medical University, Wenzhou 325000, People's Republic of China
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Kunala K, Tang JAH, Bowles Johnson KE, Huynh KT, Parkins K, Kim HJ, Yang Q, Sparrow JR, Hunter JJ. Near Infrared Autofluorescence Lifetime Imaging of Human Retinal Pigment Epithelium Using Adaptive Optics Scanning Light Ophthalmoscopy. Invest Ophthalmol Vis Sci 2024; 65:27. [PMID: 38758638 PMCID: PMC11107951 DOI: 10.1167/iovs.65.5.27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 04/23/2024] [Indexed: 05/19/2024] Open
Abstract
Purpose To demonstrate the first near-infrared adaptive optics fluorescence lifetime imaging ophthalmoscopy (NIR-AOFLIO) measurements in vivo of the human retinal pigment epithelial (RPE) cellular mosaic and to visualize lifetime changes at different retinal eccentricities. Methods NIR reflectance and autofluorescence were captured using a custom adaptive optics scanning light ophthalmoscope in 10 healthy subjects (23-64 years old) at seven eccentricities and in two eyes with retinal abnormalities. Repeatability was assessed across two visits up to 8 weeks apart. Endogenous retinal fluorophores and hydrophobic whole retinal extracts of Abca4-/- pigmented and albino mice were imaged to probe the fluorescence origin of NIR-AOFLIO. Results The RPE mosaic was resolved at all locations in five of seven younger subjects (<35 years old). The mean lifetime across near-peripheral regions (8° and 12°) was longer compared to near-foveal regions (0° and 2°). Repeatability across two visits showed moderate to excellent correlation (intraclass correlation: 0.88 [τm], 0.75 [τ1], 0.65 [τ2], 0.98 [a1]). The mean lifetime across drusen-containing eyes was longer than in age-matched healthy eyes. Fluorescence was observed in only the extracts from pigmented Abca4-/- mouse. Conclusions NIR-AOFLIO was repeatable and allowed visualization of the RPE cellular mosaic. An observed signal in only the pigmented mouse extract infers the fluorescence signal originates predominantly from melanin. Variations observed across the retina with intermediate age-related macular degeneration suggest NIR-AOFLIO may act as a functional measure of a biomarker for in vivo monitoring of early alterations in retinal health.
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Affiliation(s)
- Karteek Kunala
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Byers Eye Institute, Stanford University, Palo Alto, California, United States
| | - Janet A. H. Tang
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- The Institute of Optics, University of Rochester, Rochester, New York, United States
| | - Kristen E. Bowles Johnson
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Khang T. Huynh
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, Berkeley, California, United States
| | - Keith Parkins
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Hye-Jin Kim
- College of Pharmacy, Keimyung University, Dalseo-gu, Daegu, South Korea
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, United States
| | - Qiang Yang
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Janet R. Sparrow
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, 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
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Su E, Kesavamoorthy N, Junge JA, Zheng M, Craft CM, Ameri H. Comparison of Retinal Metabolic Activity and Structural Development between rd10 Mice and Normal Mice Using Multiphoton Fluorescence Lifetime Imaging Microscopy. Curr Issues Mol Biol 2024; 46:612-620. [PMID: 38248341 PMCID: PMC10813981 DOI: 10.3390/cimb46010039] [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: 12/11/2023] [Revised: 01/01/2024] [Accepted: 01/04/2024] [Indexed: 01/23/2024] Open
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a technique that analyzes the metabolic state of tissues based on the spatial distribution of fluorescence lifetimes of certain interacting molecules. We used multiphoton FLIM to study the metabolic state of developing C57BL6/J and rd10 retinas based on the fluorescence lifetimes of free versus bound nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate (NAD(P)H), with free NAD(P)H percentages suggesting increased glycolysis and bound NAD(P)H percentages indicating oxidative phosphorylation. The mice were sacrificed and enucleated at various time points throughout their first 3 months of life. The isolated eyecups were fixed, sectioned using a polyacrylamide gel embedding technique, and then analyzed with FLIM. The results suggested that in both C57BL6/J mice and rd10 mice, oxidative phosphorylation initially decreased and then increased, plateauing over time. This trend, however, was accelerated in rd10 mice, with its turning point occurring at p10 versus the p30 turning point in C57BL6/J mice. There was also a noticeable difference in oxidative phosphorylation rates between the outer and inner retinas in both strains, with greater oxidative phosphorylation present in the latter. A greater understanding of rd10 and WT metabolic changes during retinal development may provide deeper insights into retinal degeneration and facilitate the development of future treatments.
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Affiliation(s)
- Erin Su
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (E.S.); (N.K.); (C.M.C.)
| | - Niranjana Kesavamoorthy
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (E.S.); (N.K.); (C.M.C.)
| | - Jason A. Junge
- Department of Biological Sciences, David Dornsife College of Letters Arts and Sciences, University of Southern California Dana, Los Angeles, CA 90089, USA;
| | - Mengmei Zheng
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (E.S.); (N.K.); (C.M.C.)
| | - Cheryl Mae Craft
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (E.S.); (N.K.); (C.M.C.)
| | - Hossein Ameri
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (E.S.); (N.K.); (C.M.C.)
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Sonntag SR, Klein B, Brinkmann R, Grisanti S, Miura Y. Fluorescence Lifetime Imaging Ophthalmoscopy of Mouse Models of Age-related Macular Degeneration. Transl Vis Sci Technol 2024; 13:24. [PMID: 38285461 PMCID: PMC10829802 DOI: 10.1167/tvst.13.1.24] [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: 07/23/2023] [Accepted: 12/21/2023] [Indexed: 01/30/2024] Open
Abstract
Purpose To investigate fluorescence lifetime of mouse models of age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO). Methods Two AMD mouse models, apolipoprotein E knockout (ApoE-/-) mice and NF-E2-related factor-2 knockout (Nrf2-/-) mice, and their wild-type mice underwent monthly ophthalmic examinations including FLIO from 3 months of age. After euthanasia at the age of 6 or 11 months, blood plasma was collected to determine total antioxidant capacity and eyes were enucleated for Oil red O (ORO) lipid staining of chorioretinal tissue. Results In FLIO, the mean fluorescence lifetime (τm) of wild type shortened with age in both spectral channels. In short spectral channel, τm shortening was observed in both AMD models as well, but its rate was more pronounced in ApoE-/- mice and significantly different from the other strains as months of age progressed. In contrast, in long spectral channel, both model strains showed completely opposite trends, with τm becoming shorter in ApoE-/- and longer in Nrf2-/- mice than the others. Oil red O staining at Bruch's membrane was significantly stronger in ApoE-/- mice at 11 months than the other strains. Plasma total antioxidant capacity was highest in ApoE-/- mice at both 6 and 11 months. Conclusions The two AMD mouse models exhibited largely different fundus fluorescence lifetime, which might be related to the different systemic metabolic state. FLIO might be able to indicate different metabolic states of eyes at risk for AMD. Translational Relevance This animal study may provide new insights into the relationship between early AMD-associated metabolic changes and FLIO findings.
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Affiliation(s)
- Svenja Rebecca Sonntag
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Britta Klein
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck, Lübeck, Germany
| | - Ralf Brinkmann
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck, Lübeck, Germany
| | - Salvatore Grisanti
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Yoko Miura
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck, Lübeck, Germany
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Różanowska MB. Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina. Antioxidants (Basel) 2023; 12:2111. [PMID: 38136230 PMCID: PMC10740933 DOI: 10.3390/antiox12122111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK
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Pfau M, Künzel SH, Pfau K, Schmitz-Valckenberg S, Fleckenstein M, Holz FG. Multimodal imaging and deep learning in geographic atrophy secondary to age-related macular degeneration. Acta Ophthalmol 2023; 101:881-890. [PMID: 37933610 PMCID: PMC11044135 DOI: 10.1111/aos.15796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 11/08/2023]
Abstract
Geographic atrophy (GA) secondary to age-related macular degeneration is among the most common causes of irreversible vision loss in industrialized countries. Recently, two therapies have been approved by the US FDA. However, given the nature of their treatment effect, which primarily involves a relative decrease in disease progression, discerning the individual treatment response at the individual level may not be readily apparent. Thus, clinical decision-making may have to rely on the quantification of the slope of GA progression before and during treatment. A panel of imaging modalities and artificial intelligence (AI)-based algorithms are available for such quantifications. This article aims to provide a comprehensive overview of the fundamentals of GA imaging, the procedures for diagnosis and classification using these images, and the cutting-edge role of AI algorithms in automatically deriving diagnostic and prognostic insights from imaging data.
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Affiliation(s)
- Maximilian Pfau
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | | | - Kristina Pfau
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology, University of Bonn, Bonn, Germany
- John A. Moran Eye Center, Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Monika Fleckenstein
- John A. Moran Eye Center, Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Frank G. Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany
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Jaggi D, Solberg Y, Dysli C, Lincke J, Habra O, Wyss A, Wolf S, Zinkernagel M. Fluorescence lifetime imaging ophthalmoscopy and the influence of oral lutein/zeaxanthin supplementation on macular pigment (FLOS) - A pilot study. Clin Nutr ESPEN 2023; 56:127-134. [PMID: 37344061 DOI: 10.1016/j.clnesp.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 04/24/2023] [Accepted: 05/12/2023] [Indexed: 06/23/2023]
Abstract
BACKGROUND & AIMS Oral lutein (L) and zeaxanthin (Z) supplementation enhances macular pigment optical density (MPOD) and plays a protective role in the development of age-related macular degeneration (AMD). Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a novel in vivo retinal imaging method that has been shown to correlate to classical MPOD measurements and might contribute to a metabolic mapping of the retina in the future. Our aim was to show that oral supplementation of L and Z affects the FLIO signal in a positive way in patients with AMD. METHODS This was a prospective, single center, open label cohort study. Patients with early and intermediate AMD received oral L and Z supplementation during three months, and were observed for another three months after therapy termination. All visits included measurements of clinical parameters, serum L and Z concentration, MPOD measurements using heterochromatic flicker photometry, dual wavelength autofluorescence imaging, and FLIO. Correlation analysis between FLIO and MPOD were performed. RESULTS Twenty-one patients completed the follow up period. Serum L and Z concentrations significantly increased during supplementation (mean difference 244.8 ng/ml; 95% CI: 81.26-419.9, and 77.1 ng/ml; 95% CI: 5.3-52.0, respectively). Mean MPOD units significantly increased (mean difference 0.06; 95% CI: 0.02-0.09; at 0.5°, 202; 95% CI: 58-345; at 2°, 1033; 95% CI: 288-1668; at 9° of eccentricity, respectively) after three months of supplementation with macular xanthophylls, which included L and Z. Median FLIO lifetimes in the foveal center significantly decreased from 277.3 ps (interquartile range 230.2-339.1) to 261.0 ps (interquartile range 231.4-334.4, p = 0.027). All parameters returned to near-normal values after termination of the nutritional supplementation. A significant negative correlation was found between FLIO and MPOD (r2 = 0.57, p < 0.0001). CONCLUSIONS FLIO is able to detect subtle changes in MPOD after L and Z supplementation in patients with early and intermediate AMD. Our findings confirm the previous described negative correlation between FLIO and MPOD. Macular xanthophylls seem to contribute to short foveal lifetimes. This study is registered at ClinicalTrials.gov (identifier number NCT04761341).
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Affiliation(s)
- Damian Jaggi
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Yasmin Solberg
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Joel Lincke
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Oussama Habra
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Adrian Wyss
- DSM Nutritional Products Ltd. R&D Human Nutrition and Care, CH-4303 Kaiseraugst, Switzerland.
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
| | - Martin Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of BioMedical Research, University of Bern, Bern, Switzerland.
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García MJ, Kamaid A, Malacrida L. Label-free fluorescence microscopy: revisiting the opportunities with autofluorescent molecules and harmonic generations as biosensors and biomarkers for quantitative biology. Biophys Rev 2023; 15:709-719. [PMID: 37681086 PMCID: PMC10480099 DOI: 10.1007/s12551-023-01083-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/19/2023] [Indexed: 09/09/2023] Open
Abstract
Over the past decade, the utilization of advanced fluorescence microscopy technologies has presented numerous opportunities to study or re-investigate autofluorescent molecules and harmonic generation signals as molecular biomarkers and biosensors for in vivo cell and tissue studies. The label-free approaches benefit from the endogenous fluorescent molecules within the cell and take advantage of their spectroscopy properties to address biological questions. Harmonic generation can be used as a tool to identify the occurrence of fibrillar or lipid deposits in tissues, by using second and third-harmonic generation microscopy. Combining autofluorescence with novel techniques and tools such as fluorescence lifetime imaging microscopy (FLIM) and hyperspectral imaging (HSI) with model-free analysis of phasor plots has revolutionized the understanding of molecular processes such as cellular metabolism. These tools provide quantitative information that is often hidden under classical intensity-based microscopy. In this short review, we aim to illustrate how some of these technologies and techniques may enable investigation without the need to add a foreign fluorescence molecule that can modify or affect the results. We address some of the most important autofluorescence molecules and their spectroscopic properties to illustrate the potential of these combined tools. We discuss using them as biomarkers and biosensors and, under the lens of this new technology, identify some of the challenges and potentials for future advances in the field.
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Affiliation(s)
- María José García
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de La República, Montevideo, Uruguay
- Advanced Bioimaging Unit, Institut Pasteur de Montevideo & Universidad de la República, Montevideo, Uruguay
| | - Andrés Kamaid
- Advanced Bioimaging Unit, Institut Pasteur de Montevideo & Universidad de la República, Montevideo, Uruguay
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de La República, Montevideo, Uruguay
- Advanced Bioimaging Unit, Institut Pasteur de Montevideo & Universidad de la República, Montevideo, Uruguay
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Ferraro G, Gigante Y, Pitea M, Mautone L, Ruocco G, Di Angelantonio S, Leonetti M. A model eye for fluorescent characterization of retinal cultures and tissues. Sci Rep 2023; 13:10983. [PMID: 37415074 PMCID: PMC10326009 DOI: 10.1038/s41598-023-37806-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/28/2023] [Indexed: 07/08/2023] Open
Abstract
Many human neural or neurodegenerative diseases strongly affect the ocular and retinal environment showing peculiar alterations which can be employed as specific disease biomarkers. The noninvasive optical accessibility of the retina makes the ocular investigation a potentially competitive strategy for screening, thus the development of retinal biomarkers is rapidly growing. Nevertheless, a tool to study and image biomarkers or biological samples in a human-like eye environment is still missing. Here we report on a modular and versatile eye model designed to host biological samples, such as retinal cultures differentiated from human induced pluripotent stem cells and ex-vivo retinal tissue, but also suited to host any kind of retinal biomarkers. We characterized the imaging performance of this eye model on standard biomarkers such as Alexa Fluor 532 and Alexa Fluor 594.
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Affiliation(s)
- G Ferraro
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - Y Gigante
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - M Pitea
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - L Mautone
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - G Ruocco
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- Dipartimento di Fisica, Sapienza University, Piazzale Aldo Moro, 5, 00185, Rome, Italy
| | - S Di Angelantonio
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy.
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy.
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - M Leonetti
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy.
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy.
- Institute of Nanotechnology, Soft and Living Matter Laboratory, Consiglio Nazionale delle Ricerche (CNR-NANOTEC), Piazzale Aldo Moro 5, 00185, Rome, Italy.
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Addo EK, Hartnett ME, Bernstein PS. The value of pre-symptomatic genetic risk assessment for age-related macular degeneration: the Moran AMD Genetic Testing Assessment (MAGENTA) study-a study protocol for a randomized controlled trial. Trials 2023; 24:414. [PMID: 37337222 PMCID: PMC10278319 DOI: 10.1186/s13063-023-07436-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is an irreversible blinding eye condition with complex genetic and environmental etiologies. Genetic testing for AMD for previously identified multiple-risk single nucleotide polymorphisms can help determine an individual's future susceptibility. However, such testing has been discouraged until evidence shows that providing such information to symptomatic or pre-symptomatic individuals will alter their disease course. Therefore, we designed this study to investigate whether knowledge of AMD risk could stimulate the adoption of a healthier lifestyle that could lower the incidence of AMD later in life. We hypothesize that pre-symptomatic individuals informed of a high genetic risk of AMD are more likely to make quantifiable, positive lifestyle changes relative to participants informed of lower genetic risk or randomized to deferred disclosure of genetic testing results. METHODS The Moran AMD Genetic Testing Assessment (MAGENTA) study is a phase 2, single-center, prospective, double-masked, randomized controlled trial conducted at the John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Participants are randomized by a 3:1 allocation ratio to immediate and deferred disclosure groups and followed for 12 months. Skin, ocular, and serum carotenoid status, as well as nutritional and social surveys, are assessed at study visits. Skin carotenoid assessment is by resonance Raman spectroscopy and reflectance spectroscopy, ocular carotenoids are measured with Heidelberg Spectralis autofluorescence imaging and fluorescence lifetime imaging ophthalmoscopy (FLIO), and serum carotenoids are quantified using high-performance liquid chromatography. The primary outcome evaluates changes in skin carotenoid status in response to genetic risk disclosure. The secondary outcomes examine changes in ocular and serum carotenoid status in response to genetic risk disclosure. Also, we will correlate AMD genetic risk with baseline ocular and systemic carotenoid status and FLIO. DISCUSSION MAGENTA will provide much-needed evidence on whether pre-symptomatic testing for AMD risk can lead to quantifiable long-term changes in behavior and lifestyle associated with a lower incidence of AMD later in life. Findings from the MAGENTA trial will facilitate the design of a future larger, longer-term, multicenter phase 3 trial that could feature subgroup analysis, expanded measures of lifestyle modification, and potential active nutritional interventions. TRIAL REGISTRATION ClinicalTrials.gov NCT05265624 . Registered on March 3, 2022.
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Affiliation(s)
- Emmanuel K Addo
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - M Elizabeth Hartnett
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Department of Ophthalmology and Visual Sciences, Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA.
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA.
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11
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Abstract
Over the last half century, the autofluorescence of the metabolic cofactors NADH (reduced nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide) has been quantified in a variety of cell types and disease states. With the spread of nonlinear optical microscopy techniques in biomedical research, NADH and FAD imaging has offered an attractive solution to noninvasively monitor cell and tissue status and elucidate dynamic changes in cell or tissue metabolism. Various tools and methods to measure the temporal, spectral, and spatial properties of NADH and FAD autofluorescence have been developed. Specifically, an optical redox ratio of cofactor fluorescence intensities and NADH fluorescence lifetime parameters have been used in numerous applications, but significant work remains to mature this technology for understanding dynamic changes in metabolism. This article describes the current understanding of our optical sensitivity to different metabolic pathways and highlights current challenges in the field. Recent progress in addressing these challenges and acquiring more quantitative information in faster and more metabolically relevant formats is also discussed.
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Affiliation(s)
- Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts, USA;
- Genetics, Molecular and Cellular Biology Program, Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
| | - Kyle P Quinn
- Department of Biomedical Engineering and the Arkansas Integrative Metabolic Research Center, University of Arkansas, Fayetteville, Arkansas, USA
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12
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Jin K, Shen W, Liang Y, He M. Epidemiology, Translation and Clinical Research of Ophthalmology. J Clin Med 2023; 12:jcm12113819. [PMID: 37298014 DOI: 10.3390/jcm12113819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
The human eye is a complex and vital organ that plays a significant role in maintaining a high quality of human life [...].
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Affiliation(s)
- Kai Jin
- Eye Center, The Second Affiliated Hospital School of Medicine Zhejiang University, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, China
| | - Wenyue Shen
- Eye Center, The Second Affiliated Hospital School of Medicine Zhejiang University, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Hangzhou 310009, China
| | - Yuanbo Liang
- National Clinical Research Center for Ocular Diseases, Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Mingguang He
- Centre for Eye Research Australia, Royal Victorian, Eye and Ear Hospital, University of Melbourne, Melbourne 3002, Australia
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13
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Cheung R, Ho S, Ly A. Optometrists' attitudes toward using OCT angiography lag behind other retinal imaging types. Ophthalmic Physiol Opt 2023. [PMID: 37082888 DOI: 10.1111/opo.13149] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/14/2023] [Accepted: 04/07/2023] [Indexed: 04/22/2023]
Abstract
PURPOSE While optometrists' attitudes toward established retinal imaging types are generally positive, they are unknown for optical coherence tomography angiography (OCTA). We performed a cross-sectional survey to estimate attitudes toward OCTA and identify clinician and/or practice characteristics that influence them. METHODS A paper-based survey was mailed to 252 randomly selected optometrists in Australia. Five-point Likert-scale items from a previous survey assessing attitudes toward new technology were included to probe respondent characteristics and attitudes toward retinal imaging. Performance expectancy attitudes toward OCTA were elicited by the statement 'I believe OCTA is useful in daily practice'. Mean scores out of five (mean [SD]) were rounded and mapped to appropriate descriptive statements. RESULTS The response rate was 47% (118/252). The mean (SD) age of respondents was 44.0 (13.8) years and 50.8% (60/118) were female. Optometrists had 19.9 (14.0) years of clinical experience and 66.9% (79/118) worked at independent practices. In total, 8.5% (10/118) of respondents used OCTA to provide clinical care. Optometrists agreed that optical coherence tomography (OCT), colour fundus imaging, ultra-wide field imaging and fundus autofluorescence (mean scores 3.6-4.7 out of 5) were useful in daily practice but felt neutral about whether OCTA was useful (3.4 [0.8]). Optometrists believed that OCTA was less enjoyable to use (p < 0.0001), less endorsed by peers (p < 0.0001) and felt less confident that they had the knowledge to interpret OCTA (p < 0.0001) compared to other retinal imaging types. CONCLUSIONS Optometrists are undecided on whether OCTA is useful in daily practice and had lower expectations that using OCTA would confer job performance benefits compared to other retinal imaging types. Further work is needed to advocate the benefits of using OCTA across the profession.
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Affiliation(s)
- Rene Cheung
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
- Centre for Eye Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Sharon Ho
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
- Centre for Eye Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Angelica Ly
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
- Centre for Eye Health, University of New South Wales, Sydney, New South Wales, Australia
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14
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Hegde KR, Puche AC, Szmacinski H, Fuller K, Ray K, Patel N, Lengyel I, Thompson RB. Fluorescence Lifetime Imaging of Human Sub-RPE Calcification In Vitro Following Chlortetracycline Infusion. Int J Mol Sci 2023; 24:6421. [PMID: 37047392 PMCID: PMC10094693 DOI: 10.3390/ijms24076421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/10/2023] [Accepted: 03/23/2023] [Indexed: 04/14/2023] Open
Abstract
We have shown that all sub-retinal pigment epithelial (sub-RPE) deposits examined contain calcium phosphate minerals: hydroxyapatite (HAP), whitlockite (Wht), or both. These typically take the form of ca. 1 μm diameter spherules or >10 μm nodules and appear to be involved in the development and progression of age-related macular degeneration (AMD). Thus, these minerals may serve as useful biomarkers the for early detection and monitoring of sub-RPE changes in AMD. We demonstrated that HAP deposits could be imaged in vitro by fluorescence lifetime imaging microscopy (FLIM) in flat-mounted retinas using legacy tetracycline antibiotics as selective sensors for HAP. As the contrast on a FLIM image is based on the difference in fluorescence lifetime and not intensity of the tetracycline-stained HAP, distinguishing tissue autofluorescence from the background is significantly improved. The focus of the present pilot study was to assess whether vascular perfusion of the well tolerated and characterized chlortetracycline (widely used as an orally bioavailable antibiotic) can fluorescently label retinal HAP using human cadavers. We found that the tetracycline delivered through the peripheral circulation can indeed selectively label sub-RPE deposits opening the possibility for its use for ophthalmic monitoring of a range of diseases in which deposit formation is reported, such as AMD and Alzheimer disease (AD).
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Affiliation(s)
- Kavita R. Hegde
- Department of Natural Sciences, Coppin State University, Baltimore, MD 21216, USA
| | - Adam C. Puche
- Department of Anatomy and Neurobiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Henryk Szmacinski
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Kristina Fuller
- Department of Anatomy and Neurobiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Krishanu Ray
- Institute for Human Virology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Nikita Patel
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
- Department of Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY 11794, USA
| | - Imre Lengyel
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Richard B. Thompson
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
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15
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Schwanengel LS, Weber S, Simon R, Lehmann T, Augsten R, Meller D, Hammer M. Changes in drusen-associated autofluorescence over time observed by fluorescence lifetime imaging ophthalmoscopy in age-related macular degeneration. Acta Ophthalmol 2023; 101:e154-e166. [PMID: 36017579 DOI: 10.1111/aos.15238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/26/2022] [Accepted: 08/14/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE To observe fundus autofluorescence (FAF) lifetimes and peak emission wavelength (PEW) of drusen with respect to the pathology of the overlying RPE in the follow-up of AMD-patients. METHODS Forty eyes of 38 patients (age: 75.1 ± 7.1 years) with intermediate AMD were included. FAF lifetimes and PEW were recorded by fluorescence lifetime imaging ophthalmoscopy (FLIO). Twenty-six eyes had a follow-up investigation between months 12 and 36, and 10 at months 37-72. AMD progression was retrieved from color fundus photography (CFP) and OCT. Drusen were classified with respect to changes in the overlying RPE into groups no, questionable or faint, and apparent hyperpigmentation based on CFP. RESULTS Among the 210 hyperautofluorescent drusen found at baseline, those with hyperpigmentation had longer lifetimes and shorter PEW than those without. Drusen without hyperpigmentation had shorter lifetimes and PEW than neighboring RPE (all p < 0.001) at baseline, but drusen lifetimes increased, and PEW shortened further over follow-up. Eyes, showing AMD progression, had significantly longer FAF lifetimes at baseline than non-progressing eyes: 282 ± 102 ps versus 245 ± 98 ps, p < 0.001 and 365 ± 44 ps vs. 336 ± 48 ps, p = 0.025 for short and long wavelength FLIO channel, respectively. CONCLUSIONS Depending on hyperpigmentation properties, drusen show lifetimes and PEW different from that of adjacent RPE which change over the natural history of AMD. This difference and change, however, might reflect progressive dysmorphia of the RPE rather than representing fluorescence of drusen material itself. Nevertheless, the observed FAF changes could make FLIO a useful tool for the early detection of AMD progression risk.
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Affiliation(s)
| | - Sebastian Weber
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Rowena Simon
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Thomas Lehmann
- Institute for Medical Statistics, Informatics, und Data Sciences, University Hospital Jena, Jena, Germany
| | - Regine Augsten
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Daniel Meller
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany.,Center for Medical Optics and Photonics, University of Jena, Jena, Germany
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16
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Palczewska G, Wojtkowski M, Palczewski K. From mouse to human: Accessing the biochemistry of vision in vivo by two-photon excitation. Prog Retin Eye Res 2023; 93:101170. [PMID: 36787681 PMCID: PMC10463242 DOI: 10.1016/j.preteyeres.2023.101170] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023]
Abstract
The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly transparent to infrared (IR) light. The interface between the retina and the retinal pigment epithelium (RPE) is especially informative, because it reflects the health of the visual (retinoid) cycle and its changes in response to external stress, genetic manipulations, and drug treatments. Vitamin A-derived retinoids, like retinyl esters, are natural fluorophores that respond to multi-photon excitation with near IR light, bypassing the filter-like properties of the cornea, lens, and macular pigments. Also, during natural aging some retinoids form bisretinoids, like diretinoid-pyridiniumethanolamine (A2E), that are highly fluorescent. These bisretinoids appear to be elevated concurrently with aging. Vitamin A-derived retinoids and bisretinoidss are detected by two-photon ophthalmoscopy (2PO), using a new class of light sources with adjustable spatial, temporal, and spectral properties. Furthermore, the two-photon (2P) absorption of IR light by the visual pigments in rod and cone photoreceptors can initiate visual transduction by cis-trans isomerization of retinal, enabling parallel functional studies. Recently we overcame concerns about safety, data interpretation and complexity of the 2P-based instrumentation, the major roadblocks toward advancing this modality to the clinic. These imaging and retina-function assessment advancements have enabled us to conduct the first 2P studies with humans.
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Affiliation(s)
- Grazyna Palczewska
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Polgenix, Inc., Department of Medical Devices, Cleveland, OH, USA; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
| | - Maciej Wojtkowski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland; Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; Department of Physiology & Biophysics, School of Medicine, And Chemistry, Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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17
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Rispoli M, Cennamo G, Antonio LD, Lupidi M, Parravano M, Pellegrini M, Veritti D, Vujosevic S, Savastano MC. Practical guidance for imaging biomarkers in exudative age-related macular degeneration. Surv Ophthalmol 2023:S0039-6257(23)00039-5. [PMID: 36854371 DOI: 10.1016/j.survophthal.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 02/17/2023] [Accepted: 02/21/2023] [Indexed: 02/27/2023]
Abstract
We provide an overview of current macular imaging techniques and identify and describe biomarkers that may be of use in the routine management of macular diseases, particularly exudative age-related macular degeneration (n-AMD). This perspective includes sections on macular imaging techniques including optical coherence tomography (OCT) and OCT angiography (OCTA), classification of exudative AMD, and biomarkers in structural OCT and OCTA. Fluorescein angiography remains a vital tool for assessing the activity of neovascular lesion, while indocyanine green angiography is the preferred option for choroidal vessels imaging in neovascular AMD. OCT provides a non-invasive three-dimensional visualization of retinal architecture in vivo and is useful in the diagnosis of many imaging biomarkers of AMD-related neovascular lesions including lesion activity. OCTA is a recent advance in OCT technology that allows accurate visualization of retinal and choroidal vascular flow. OCT and OCTA have led to an updated classification of exudative AMD lesions and provide several biomarkers that help to establish a diagnosis and the disease activity status of neovascular lesions. Individualization of therapy guided by OCT and OCTA biomarkers has the potential to further improve visual outcomes in exudative AMD. Moving forwards, integration of technologically advanced imaging equipment with AI software will help ophthalmologists to provide patients with the best possible care.
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Affiliation(s)
| | - Gilda Cennamo
- Eye Clinic, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University; Public Health Department, University of Naples Federico II, Naples, Italy
| | - Luca Di Antonio
- UOC Ophthalmology and Surgery Department, ASL-1 Avezzano-Sulmona, L'Aquila, Italy
| | - Marco Lupidi
- Eye Clinic, Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy.
| | | | - Marco Pellegrini
- Department of Biomedical and Clinical Science "Luigi Sacco", Eye Clinic, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Daniele Veritti
- Department of Medicine-Ophthalmology, University of Udine, Italy
| | - Stela Vujosevic
- University Eye Clinic, IRCCS Multimedica, Milan, Italy; Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Maria Cristina Savastano
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Catholic University "Sacro Cuore", Rome, Italy
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18
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Huynh KT, Walters S, Foley EK, Hunter JJ. Separate lifetime signatures of macaque S cones, M/L cones, and rods observed with adaptive optics fluorescence lifetime ophthalmoscopy. Sci Rep 2023; 13:2456. [PMID: 36774443 PMCID: PMC9922306 DOI: 10.1038/s41598-023-28877-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 01/25/2023] [Indexed: 02/13/2023] Open
Abstract
In the retina, several molecules involved in metabolism, the visual cycle, and other roles exhibit intrinsic fluorescence. The overall properties of retinal fluorescence depend on changes to the composition of these molecules and their environmental interactions due to transient functional shifts, especially in disease. This behooves the understanding of the origins and deviations of these properties within the multilayered retina at high lateral and axial resolution. Of particular interest is the fluorescence lifetime, a potential biomarker of function and disease independent of fluorescence intensity that can be measured in the retina with adaptive optics fluorescence lifetime ophthalmoscopy (AOFLIO). This work demonstrates the utility of the phasor method of analysis, an alternate approach to traditional multiexponential fitting, to evaluate photoreceptor two-photon excited AOFLIO data and separate them based on functional differences. Phasor analysis on fluorescence lifetime decay data allowed the repeatable segregation of S from M/L cones, likely from differences in functional or metabolic demands. Furthermore, it is possible to track the lifetime changes in S cones after photodamage. Phasor analysis increases the sensitivity of AOFLIO to functional differences between cells and has the potential to improve our understanding of pathways involved in normal and diseased conditions at the cellular scale throughout the retina.
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Affiliation(s)
- Khang T Huynh
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA.
- Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA.
| | - Sarah Walters
- Currently with IDEX Health & Science, West Henrietta, NY, 14586, USA
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA
| | - Emma K Foley
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
| | - Jennifer J Hunter
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
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19
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Cui ML, Zhang GS, Kang ZW, Zhang XY, Xie QF, Huang ML, Wang BQ, Yang DP. Iridium nanoclusters for highly efficient p-nitroaniline fluorescence sensor. Microchem J 2023. [DOI: 10.1016/j.microc.2023.108520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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20
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Peng X, Huang J, Li M, Chen Z, Yan W, Qu J. Lipid Membrane Alterations in Tumor Spheroids Revealed by Fluorescence Lifetime Microscopy Imaging. Anal Chem 2023; 95:575-580. [PMID: 36576346 DOI: 10.1021/acs.analchem.2c05126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Three-dimensional (3D) cultured tumor spheroid models, as one type of in vitro model, have been proven to have more physiological similarities to in vivo animal models than cells in 2D cultures. Tumor spheroids have been widely used in preclinical experiments of anticancer drug treatments, providing reliable data in pathogenetic research. Currently, different 3D cell culture conditions, even in the same cell line, generate heterogeneous spheroids in morphology and size, resulting in different growth rates or drug-killing responses. Therefore, the measurement and evaluation of the properties of tumor spheroids have become highly demanding tasks with huge challenges. For functional characterization of tumor spheroids, the microenvironment sensitivity and quantitative properties of the fluorescence lifetime microscopy imaging (FLIM) technique have great advantages for improving the reliability of cell physiological testing. In this paper, we have proposed a FLIM-based approach to observe the lipid components labeled with Nile red of cells in both 3D and 2D cultures. The imaging data and analysis provided basic information on the sizes, morphologies, and cell membrane fluorescence lifetime values of the tumor spheroids. FLIM data showed that the microenvironment of the cell membrane in the 3D model was largely altered compared to that in the 2D culture. Next, a series of parameters that may influence the lipid components of tumor cells and tumor spheroids were tested by FLIM, including pH, viscosity, and polarity. The results showed that pH and viscosity contributed little to the change in fluorescence lifetime values, while the change in cell membrane polarity was the main cause of the alterations in fluorescence lifetime data, suggesting that cell membrane polarity should be considered a marker in distinguishing tumor spheroids from cellular physiological status. In conclusion, this FLIM-based testing process has been proven to be a quantitative method for measuring the differences between the cells of the 3D model from the 2D cultured cells with satisfactory sensitivity and accuracy, providing a high potential standard assay in the quality evaluation and control of tumor spheroids for future anticancer drug development.
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Affiliation(s)
- Xiao Peng
- College of Physics and Optoelectronic Engineering, Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen518060, P. R. China
| | - Jingwen Huang
- College of Physics and Optoelectronic Engineering, Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen518060, P. R. China
| | - Mingyue Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Sipailou #2, Nanjing, Jiangsu210096, P. R. China
| | - Zaozao Chen
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Sipailou #2, Nanjing, Jiangsu210096, P. R. China
| | - Wei Yan
- College of Physics and Optoelectronic Engineering, Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen518060, P. R. China
| | - Junle Qu
- College of Physics and Optoelectronic Engineering, Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen518060, P. R. China
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21
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Dysli C, Dysli M, Wolf S, Zinkernagel M. Fluorescence lifetime distribution in phakic and pseudophakic healthy eyes. PLoS One 2023; 18:e0279158. [PMID: 36608033 PMCID: PMC9821472 DOI: 10.1371/journal.pone.0279158] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 11/14/2022] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To investigate the influence of the lens status and to describe fundus autofluorescence lifetimes (FLT) in a large cohort of healthy eyes across a wide age range. MATERIALS AND METHODS FLT data were acquired from healthy phakic and pseudophakic eyes using fluorescence lifetime imaging ophthalmoscopy (FLIO). Retinal autofluorescence was excited with a 473 nm laser and emitted autofluorescence was detected in a short and a long spectral channel (SSC: 498-560 nm; LSC: 560-720 nm). RESULTS 141 healthy eyes from 141 participants (56 ± 18 years) were included. The shortest mean FLTs were measured within the macular center, followed by the temporal inner and outer ETDRS (Early Treatment Diabetic Retinopathy Study) grid segments, and the remaining areas of the inner and the outer ETDRS ring. In phakic participants (81%), mean, short and long FLTs correlated with the age (SSC: r2 = 0.54; LSC: r2 = 0.7; both p<0.0001) with an increase of about 33 ps in the SSC resp. 28 ps in the LSC per decade. In pseudophakic subjects (19%), mean FLTs only correlated with age in the long spectral channel (r2 = 0.44; p = 0.0002) but not in the short spectral channel (r2 = 0.066; p = 0.2). CONCLUSIONS Fundus autofluorescence lifetimes are age dependent. FLTs in the SSC are more susceptible to lens opacities but less dependent on age changes, whereas FLTs in the LSC are largely independent of the lens status but display a higher degree of age dependency. STUDY REGISTRY ClinicalTrials.gov NCT01981148.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Muriel Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital and Department of BioMedical Research, University of Bern, Bern, Switzerland
- * E-mail:
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22
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Arrigo A, Aragona E, Battaglia Parodi M, Bandello F. Quantitative approaches in multimodal fundus imaging: State of the art and future perspectives. Prog Retin Eye Res 2023; 92:101111. [PMID: 35933313 DOI: 10.1016/j.preteyeres.2022.101111] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/16/2022] [Accepted: 07/19/2022] [Indexed: 02/01/2023]
Abstract
When it first appeared, multimodal fundus imaging revolutionized the diagnostic workup and provided extremely useful new insights into the pathogenesis of fundus diseases. The recent addition of quantitative approaches has further expanded the amount of information that can be obtained. In spite of the growing interest in advanced quantitative metrics, the scientific community has not reached a stable consensus on repeatable, standardized quantitative techniques to process and analyze the images. Furthermore, imaging artifacts may considerably affect the processing and interpretation of quantitative data, potentially affecting their reliability. The aim of this survey is to provide a comprehensive summary of the main multimodal imaging techniques, covering their limitations as well as their strengths. We also offer a thorough analysis of current quantitative imaging metrics, looking into their technical features, limitations, and interpretation. In addition, we describe the main imaging artifacts and their potential impact on imaging quality and reliability. The prospect of increasing reliance on artificial intelligence-based analyses suggests there is a need to develop more sophisticated quantitative metrics and to improve imaging technologies, incorporating clear, standardized, post-processing procedures. These measures are becoming urgent if these analyses are to cross the threshold from a research context to real-life clinical practice.
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Affiliation(s)
- Alessandro Arrigo
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
| | - Emanuela Aragona
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Maurizio Battaglia Parodi
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
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23
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Jaggi D, Solberg Y, Dysli C, Lincke J, Habra O, Wolf S, Zinkernagel M. FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY AS PREDICTOR OF LONG-TERM FUNCTIONAL OUTCOME IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT. Retina 2022; 42:2388-2394. [PMID: 36394892 PMCID: PMC9665949 DOI: 10.1097/iae.0000000000003612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To assess whether macular fluorescence lifetimes may serve as a predictor for long-term outcomes in macula-off rhegmatogenous retinal detachment. METHODS A single-center observational study was conducted. Patients with pseudophakic macula-off rhegmatogenous retinal detachment were included and evaluated 1 and 6 months after successful reattachment surgery. Fluorescence lifetime imaging ophthalmoscopy lifetimes in the central Early Treatment Diabetic Retinopathy Study grid subfield, in two distinct channels (short spectral channel and long spectral channel) were analyzed. Best-corrected visual acuity optical coherence tomography of the macula and fluorescence lifetimes were measured at month 1 and month 6. RESULTS Nineteen patients were analyzed. Lifetimes of the previously detached retinas were prolonged compared with the healthy fellow eyes. Short lifetimes at month 1 were associated with better best-corrected visual acuity improvement (short spectral channel: r2 = 0.27, P < 0.05, long spectral channel: r2 = 0.23, P < 0.05) and with good final best-corrected visual acuity (short spectral channel: r2 = 0.43, P < 0.01, long spectral channel: r2 = 0.25, P < 0.05). Lifetimes were prolonged in some cases of outer retinal damage in optical coherence tomography scans. CONCLUSION Fluorescence lifetime imaging ophthalmoscopy might serve as a prediction tool for functional recovery in pseudophakic macula-off rhegmatogenous retinal detachment. Retinal fluorescence lifetimes could give insight in molecular processes after rhegmatogenous retinal detachment.
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Affiliation(s)
- Damian Jaggi
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Yasmin Solberg
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Joel Lincke
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Oussama Habra
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
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24
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Simon R, Jentsch M, Karimimousivandi P, Cao D, Messinger JD, Meller D, Curcio CA, Hammer M. Prolonged Lifetimes of Histologic Autofluorescence in Ectopic Retinal Pigment Epithelium in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2022; 63:5. [PMID: 36469025 PMCID: PMC9730734 DOI: 10.1167/iovs.63.13.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Purpose The purpose of this study was to investigate histologic autofluorescence lifetimes and spectra of retinal pigment epithelium (RPE) on the transition from normal aging to RPE activation and migration in age-related macular degeneration (AMD). Methods Autofluorescence lifetimes and spectra of 9 donor eyes were analyzed in cryosections by means of 2-photon excited fluorescence at 960 nm. Spectra were detected at 483 to 665 nm. Lifetimes were measured using time-correlated single photon counting in 2 spectral channels: 500 to 550 nm (short-wavelength spectral channel [SSC]) and 550 to 700 nm (long-wavelength spectral channel [LSC]). Fluorescence decays over time were approximated by a series of three exponential functions. The amplitude-weighted mean fluorescence lifetime was determined. Markers for retinoid activity (RPE65) and immune function (CD68) were immunolocalized in selected neighboring sections. Results We identified 9 RPE morphology phenotypes resulting in 399 regions of interest (ROIs) for spectral and 497 ROIs for lifetime measurements. RPE dysmorphia results in a shorter wavelength peak of spectral emission: normal aging versus RPE migrated into the retina (intraELM) = 601.7 (9.5) nm versus 581.6 (7.3) nm, P < 0.001, whereas autofluorescence lifetimes increase: normal aging versus intraELM: SSC 180 (44) picosecond (ps) versus 320 (86) ps, P < 0.001; and LSC 250 (55) ps versus 441 (76) ps, P < 0.001. Ectopic RPE within the neurosensory retina is strongly CD68 positive and RPE65 negative. Conclusions In the process of RPE degeneration, comprising different steps of dysmorphia and migration, lengthening of autofluorescence lifetimes and a hypsochromic shift of emission spectra can be observed. These autofluorescence changes might provide early biomarkers for AMD progression and contribute to our understanding of RPE-driven pathology.
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Affiliation(s)
- Rowena Simon
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Marius Jentsch
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | | | - Dongfeng Cao
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jeffrey D Messinger
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Daniel Meller
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Christine A Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany.,Center for Medical Optics and Photonics, University of Jena, Jena, Germany
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25
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Ochoa M, Smith JT, Gao S, Intes X. Computational macroscopic lifetime imaging and concentration unmixing of autofluorescence. JOURNAL OF BIOPHOTONICS 2022; 15:e202200133. [PMID: 36546622 PMCID: PMC10026351 DOI: 10.1002/jbio.202200133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 06/17/2023]
Abstract
Single-pixel computational imaging can leverage highly sensitive detectors that concurrently acquire data across spectral and temporal domains. For molecular imaging, such methodology enables to collect rich intensity and lifetime multiplexed fluorescence datasets. Herein we report on the application of a single-pixel structured light-based platform for macroscopic imaging of tissue autofluorescence. The super-continuum visible excitation and hyperspectral single-pixel detection allow for parallel characterization of autofluorescence intensity and lifetime. Furthermore, we exploit a deep learning based data processing pipeline, to perform autofluorescence unmixing while yielding the autofluorophores' concentrations. The full scheme (setup and processing) is validated in silico and in vitro with clinically relevant autofluorophores flavin adenine dinucleotide, riboflavin, and protoporphyrin. The presented results demonstrate the potential of the methodology for macroscopically quantifying the intensity and lifetime of autofluorophores, with higher specificity for cases of mixed emissions, which are ubiquitous in autofluorescence and multiplexed in vivo imaging.
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Affiliation(s)
- Marien Ochoa
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Jason T Smith
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Shan Gao
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Xavier Intes
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York, USA
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26
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Schweitzer D, Haueisen J, Klemm M. Suppression of natural lens fluorescence in fundus autofluorescence measurements: review of hardware solutions. BIOMEDICAL OPTICS EXPRESS 2022; 13:5151-5170. [PMID: 36425615 PMCID: PMC9664869 DOI: 10.1364/boe.462559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/25/2022] [Accepted: 07/25/2022] [Indexed: 06/16/2023]
Abstract
Fluorescence lifetime imaging ophthalmoscopy (FLIO), a technique for investigating metabolic changes in the eye ground, can reveal the first signs of diseases related to metabolism. The fluorescence of the natural lens overlies the fundus fluorescence. Although the influence of natural lens fluorescence can be somewhat decreased with mathematical models, excluding this influence during the measurement by using hardware enables more exact estimation of the fundus fluorescence. Here, we analyze four 1-photon excitation hardware solutions to suppress the influence of natural lens fluorescence: aperture stop separation, confocal scanning laser ophthalmoscopy, combined confocal scanning laser ophthalmoscopy and aperture stop separation, and dual point confocal scanning laser ophthalmoscopy. The effect of each principle is demonstrated in examples. The best suppression is provided by the dual point principle, realized with a confocal scanning laser ophthalmoscope. In this case, in addition to the fluorescence of the whole eye, the fluorescence of the anterior part of the eye is detected from a non-excited spot of the fundus. The intensity and time-resolved fluorescence spectral data of the fundus are derived through the subtraction of the simultaneously measured fluorescence of the excited and non-excited spots. Advantages of future 2-photon fluorescence excitation are also discussed. This study provides the first quantitative evaluation of hardware principles to suppress the fluorescence of the natural lens during measurements of fundus autofluorescence.
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Affiliation(s)
- D. Schweitzer
- Department of Ophthalmology, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - J. Haueisen
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
| | - M. Klemm
- Institute of Biomedical Engineering and Informatics, POB 100565, 98694 Ilmenau, Germany
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27
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Hammer M, Simon R, Meller D, Klemm M. Combining fluorescence lifetime with spectral information in fluorescence lifetime imaging ophthalmoscopy (FLIO). BIOMEDICAL OPTICS EXPRESS 2022; 13:5483-5494. [PMID: 36425633 PMCID: PMC9664887 DOI: 10.1364/boe.457946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 06/01/2023]
Abstract
Fluorescence lifetime imaging ophthalmoscopy (FLIO) provides information on fluorescence lifetimes in two spectral channels as well as the peak emission wavelength (PEW) of the fluorescence. Here, we combine these measures in an integral three-dimensional lifetime-PEW metric vector and determine a normal range for this vector from measurements in young healthy subjects. While for these control subjects 97 (±8) % (median (interquartile range)) of all para-macular pixels were covered by this normal vector range, it was 67 (±55) % for the elderly healthy, 38 (±43) % for age-related macular degeneration (AMD)-suspect subjects, and only 6 (±4) % for AMD patients. The vectors were significantly different for retinal pigment epithelium (RPE) lesions in AMD patients from that of non-affected tissue (p < 0.001). Lifetime- PEW plots allowed to identify possibly pathologic fundus areas by fluorescence parameters outside a 95% quantile per subject. In a patient follow-up, changes in fluorescence parameters could be traced in the lifetime-PEW metric, showing their change over disease progression.
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Affiliation(s)
- Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
- Center for Medical Optics and Photonics, Univ. of Jena, Jena, Germany
| | - Rowena Simon
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Daniel Meller
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Matthias Klemm
- Institute of Biomedical Engineering and Informatics, Technical Univ. Ilmenau, Ilmenau, Germany
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28
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Nanegrungsunk O, Patikulsila D, Sadda SR. Ophthalmic imaging in diabetic retinopathy: A review. Clin Exp Ophthalmol 2022; 50:1082-1096. [PMID: 36102668 PMCID: PMC10088017 DOI: 10.1111/ceo.14170] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/01/2022] [Accepted: 09/09/2022] [Indexed: 11/30/2022]
Abstract
Retinal imaging has been a key tool in the diagnosis, evaluation, management and documentation of diabetic retinopathy (DR) and diabetic macular oedema (DMO) for many decades. Imaging technologies have rapidly evolved over the last few decades, yielding images with higher resolution and contrast with less time, effort and invasiveness. While many retinal imaging technologies provide detailed insight into retinal structure such as colour reflectance photography and optical coherence tomography (OCT), others such as fluorescein or OCT angiography and oximetry provide dynamic and functional information. Many other novel imaging technologies are in development and are poised to further enhance our evaluation of patients with DR.
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Affiliation(s)
- Onnisa Nanegrungsunk
- Doheny Imaging Reading Center Doheny Eye Institute Pasadena California USA
- David Geffen School of Medicine University of California‐Los Angeles Los Angeles California USA
- Retina Division, Department of Ophthalmology Chiang Mai University Chiang Mai Thailand
| | - Direk Patikulsila
- Retina Division, Department of Ophthalmology Chiang Mai University Chiang Mai Thailand
| | - Srinivas R. Sadda
- Doheny Imaging Reading Center Doheny Eye Institute Pasadena California USA
- David Geffen School of Medicine University of California‐Los Angeles Los Angeles California USA
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29
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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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30
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Jeevakumar V, Sefton R, Chan J, Gopinath B, Liew G, Shah TM, Siette J. Association between retinal markers and cognition in older adults: a systematic review. BMJ Open 2022; 12:e054657. [PMID: 35728906 PMCID: PMC9214387 DOI: 10.1136/bmjopen-2021-054657] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To appraise the existing literature reporting an association between retinal markers and cognitive impairment in adults aged 65 years and over and to provide directions for future use of retinal scanning as a potential tool for dementia diagnosis. DESIGN Systematic review of peer-reviewed empirical articles investigating the association of retinal markers in assessing cognitive impairment. DATA SOURCES Three electronic databases, Medline, PsycINFO and EMBASE were searched from inception until March 2022. ELIGIBILITY CRITERIA All empirical articles in English investigating the association between retinal markers and cognition in humans aged ≥65 years using various retinal scanning methodologies were included. Studies with no explicit evaluation of retinal scanning and cognitive outcomes were excluded. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. DATA EXTRACTION AND SYNTHESIS Data extraction was conducted by two authors (VJ, RS) and reviewed by another author (JS). Results were synthesised and described narratively. RESULTS Sixty-seven eligible studies examining 6815 older adults were included. Majority of studies were cross-sectional (n=60; 89.6%). Optical coherence tomography (OCT) was the most commonly used retinal scanning methodology to measure the thickness of retinal nerve fibre layer, the ganglion cell complex, choroid and macula. 51.1% of cross-sectional studies using OCT reported an association between the thinning of at least one retinal parameter and poor cognition. Longitudinal studies (n=6) using OCT also mostly identified significant reductions in retinal nerve fibre layer thickness with cognitive decline. Study quality was overall moderate. CONCLUSION Retinal nerve fibre layer thickness is linked with cognitive performance and therefore may have the potential to detect cognitive impairment in older adults. Further longitudinal studies are required to validate our synthesis and understand underlying mechanisms before recommending implementation of OCT as a dementia screening tool in clinical practice. PROSPERO REGISTRATION NUMBER CRD42020176757.
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Affiliation(s)
- Varshanie Jeevakumar
- Australian Institute of Health Innovation, Macquarie University, Macquarie Park, New South Wales, Australia
| | - Rebekah Sefton
- Australian Institute of Health Innovation, Macquarie University, Macquarie Park, New South Wales, Australia
| | - Joyce Chan
- New Look Eyewear, Maitland, New South Wales, Australia
| | - Bamini Gopinath
- Department of Linguistics, Australian Hearing Hub, Macquarie University, Macquarie Park, New South Wales, Australia
| | - Gerald Liew
- Centre for Vision Research, The University of Sydney, Sydney, New South Wales, Australia
| | - Tejal M Shah
- Macquarie Medical School, Macquarie University, North Ryde, New South Wales, Australia
| | - Joyce Siette
- Australian Institute of Health Innovation, Macquarie University, Macquarie Park, New South Wales, Australia
- MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Westmead, New South Wales, Australia
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31
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Bindewald-Wittich A, Holz FG, Ach T, Fiorentzis M, Bechrakis NE, Willerding GD. Fundus Autofluorescence Imaging in Patients with Choroidal Melanoma. Cancers (Basel) 2022; 14:cancers14071809. [PMID: 35406581 PMCID: PMC8997882 DOI: 10.3390/cancers14071809] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 12/15/2022] Open
Abstract
Simple Summary The ocular fundus contains molecules that emit fluorescence when excited with light of an appropriate wavelength. Fundus autofluorescence imaging is based on the in vivo detection of intrinsic fluorescence and results in topographic autofluorescence mapping of the ocular fundus. In contrast to fluorescence angiography, where the fluorescing agents need to be administered intravenously, autofluorescence imaging is a non-invasive technique. Even though choroidal melanomas do not contain significant autofluorescent molecules themselves, they may lead to secondary alterations in neighbouring tissues with an impact on the autofluorescence signal recording. Fundus autofluorescence imaging in the context of choroidal melanoma is helpful for differential diagnosis and for monitoring variations over time in affected patients before and after treatment. Abstract Choroidal melanocytic lesions require reliable and precise clinical examination and diagnosis to differentiate benign choroidal nevi from choroidal melanoma, as the latter may become life-threatening through metastatic disease. To come to an accurate diagnosis, as well as for monitoring, and to assess the efficacy of therapy, various imaging modalities may be used, one of which is non-invasive fundus autofluorescence (FAF) imaging using novel high-resolution digital imaging technology. FAF imaging is based on the visualization of intrinsic fluorophores in the ocular fundus. Lipofuscin and melanolipofuscin within the postmitotic retinal pigment epithelium (RPE) cells represent the major fluorophores that contribute to the FAF signal. In addition, the presence or loss of absorbing molecular constituents may have an impact on the FAF signal. A choroidal melanoma can cause secondary retinal and RPE alterations that affect the FAF signal (e.g., occurrence of orange pigment). Therefore, FAF imaging supports multimodal imaging and gives additional information over and above conventional imaging modalities regarding retinal metabolism and RPE health status. This article summarises the features of FAF imaging and the role of FAF imaging in the context of choroidal melanoma, both before and following therapeutic intervention.
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Affiliation(s)
- Almut Bindewald-Wittich
- Augenkompetenz Zentren Heidenheim, 89518 Heidenheim, Germany
- Augenkompetenz Zentren Bopfingen, 73441 Bopfingen, Germany
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
- Correspondence:
| | - Frank G. Holz
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
| | - Thomas Ach
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
| | - Miltiadis Fiorentzis
- Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (M.F.); (N.E.B.)
| | - Nikolaos E. Bechrakis
- Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (M.F.); (N.E.B.)
| | - Gregor D. Willerding
- Department of Ophthalmology, DRK Kliniken Berlin Westend, 14050 Berlin, Germany;
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32
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Tang JAH, Granger CE, Kunala K, Parkins K, Huynh KT, Bowles-Johnson K, Yang Q, Hunter JJ. Adaptive optics fluorescence lifetime imaging ophthalmoscopy of in vivo human retinal pigment epithelium. BIOMEDICAL OPTICS EXPRESS 2022; 13:1737-1754. [PMID: 35414970 PMCID: PMC8973160 DOI: 10.1364/boe.451628] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 05/18/2023]
Abstract
The intrinsic fluorescence properties of lipofuscin - naturally occurring granules that accumulate in the retinal pigment epithelium - are a potential biomarker for the health of the eye. A new modality is described here which combines adaptive optics technology with fluorescence lifetime detection, allowing for the investigation of functional and compositional differences within the eye and between subjects. This new adaptive optics fluorescence lifetime imaging ophthalmoscope was demonstrated in 6 subjects. Repeated measurements between visits had a minimum intraclass correlation coefficient of 0.59 Although the light levels were well below maximum permissible exposures, the safety of the imaging paradigm was tested using clinical measures; no concerns were raised. This new technology allows for in vivo adaptive optics fluorescence lifetime imaging of the human RPE mosaic.
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Affiliation(s)
- Janet A. H. Tang
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Contributed equally
| | - Charles E. Granger
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Contributed equally
| | - Karteek Kunala
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Keith Parkins
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Khang T. Huynh
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14627, USA
| | - Kristen Bowles-Johnson
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14627, USA
| | - Qiang Yang
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Jennifer J. Hunter
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14627, USA
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33
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Christinaki E, Kulenovic H, Hadoux X, Baldassini N, Van Eijgen J, De Groef L, Stalmans I, van Wijngaarden P. Retinal imaging biomarkers of neurodegenerative diseases. Clin Exp Optom 2022; 105:194-204. [PMID: 34751086 DOI: 10.1080/08164622.2021.1984179] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The timely detection of neurodegenerative diseases is central to improving clinical care as well as enabling the development and deployment of disease-modifying therapies. Retinal imaging is emerging as a method to detect features of a number of neurodegenerative diseases, given the anatomical and functional similarities between the retina and the brain. This review provides an overview of the current status of retinal imaging biomarkers of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Lewy body dementia, frontotemporal dementia, Huntington's disease and multiple sclerosis. Whilst research findings are promising, efforts to harmonise study designs and imaging methods will be important in translating these findings into clinical care. Doing so may mean that eye care providers will play important roles in the detection of a variety of neurodegenerative diseases in future.
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Affiliation(s)
- Eirini Christinaki
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Hana Kulenovic
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Nicole Baldassini
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Jan Van Eijgen
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | - Lies De Groef
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium
| | - Ingeborg Stalmans
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.,Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Parkville, Australia
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34
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Yahav G, Weber Y, Duadi H, Pawar S, Fixler D. Classification of fluorescent anisotropy decay based on the distance approach in the frequency domain. OPTICS EXPRESS 2022; 30:6176-6192. [PMID: 35209559 DOI: 10.1364/oe.453108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Frequency-domain (FD) fluorometry is a widely utilized tool to probe unique features of complex biological structures, which may serve medical diagnostic purposes. The conventional data analysis approaches used today to extract the fluorescence intensity or fluorescence anisotropy (FA) decay data suffer from several drawbacks and are inherently limited by the characteristics and complexity of the decay models. This paper presents the squared distance (D2) technique, which categorized samples based on the direct frequency response data (FRD) of the FA decay. As such, it improves the classification ability of the FD measurements of the FA decay as it avoids any distortion that results from the challenged translation into time domain data. This paper discusses the potential use of the D2 approach to classify biological systems. Mathematical formulation of D2 technique adjusted to the FRD of the FA decay is described. In addition, it validates the D2 approach using 2 simulated data sets of 6 groups with similar widely and closely spaced FA decay data as well as in experimental data of 4 samples of a fluorophore-solvent (fluorescein-glycerol) system. In the simulations, the classification accuracy was above 95% for all 6 groups. In the experimental data, the classification accuracy was 100%. The D2 approach can help classify samples whose FA decay data are difficult to extract making FA in the FD a realistic diagnostic tool. The D2 approach offers an advanced method for sorting biological samples with differences beyond the practical temporal resolution limit in a reliable and efficient manner based on the FRD of their time-resolved fluorescence measurements thereby achieving better diagnostic quality in a shorter time.
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Chen YI, Chang YJ, Liao SC, Nguyen TD, Yang J, Kuo YA, Hong S, Liu YL, Rylander HG, Santacruz SR, Yankeelov TE, Yeh HC. Generative adversarial network enables rapid and robust fluorescence lifetime image analysis in live cells. Commun Biol 2022; 5:18. [PMID: 35017629 PMCID: PMC8752789 DOI: 10.1038/s42003-021-02938-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 11/24/2021] [Indexed: 11/09/2022] Open
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a powerful tool to quantify molecular compositions and study molecular states in complex cellular environment as the lifetime readings are not biased by fluorophore concentration or excitation power. However, the current methods to generate FLIM images are either computationally intensive or unreliable when the number of photons acquired at each pixel is low. Here we introduce a new deep learning-based method termed flimGANE (fluorescence lifetime imaging based on Generative Adversarial Network Estimation) that can rapidly generate accurate and high-quality FLIM images even in the photon-starved conditions. We demonstrated our model is up to 2,800 times faster than the gold standard time-domain maximum likelihood estimation (TD_MLE) and that flimGANE provides a more accurate analysis of low-photon-count histograms in barcode identification, cellular structure visualization, Förster resonance energy transfer characterization, and metabolic state analysis in live cells. With its advantages in speed and reliability, flimGANE is particularly useful in fundamental biological research and clinical applications, where high-speed analysis is critical.
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Affiliation(s)
- Yuan-I Chen
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yin-Jui Chang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Shih-Chu Liao
- ISS, Inc., 1602 Newton Drive, Champaign, IL, 61822, USA
| | - Trung Duc Nguyen
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jianchen Yang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yu-An Kuo
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Soonwoo Hong
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yen-Liang Liu
- Master Program for Biomedical Engineering, China Medical University, Taichung, 406040, Taiwan
- Research Center for Cancer Biology, China Medical University, Taichung, 406040, Taiwan
| | - H Grady Rylander
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Samantha R Santacruz
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
- Institute for Neuroscience, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Thomas E Yankeelov
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Diagnostic Medicine, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Oncology, The University of Texas at Austin, Austin, TX, 78712, USA
- Livestrong Cancer Institutes, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
- Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
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36
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Utilization of Spectrochemical Analysis and Diffuse Optical Techniques to Reveal Adulteration of Alike Fish Species and Their Microbial Contamination. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-021-02212-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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37
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Terry J, Geddes D, Ochoa-Gutierrez V, Yang Z, Smith KJ, Harvey AR. Trans-scleral Illumination - The Future of Retinal Imaging? EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226602007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We report how illumination of the retina through the sclera enables the recording of high-contrast reflectance and fluorescence images of the retina, free of the cornea and lens glare and autofluoresence that degrades images recorded using traditional illumination through the pupil.
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Xue Y, Browne AW, Tang WC, Delgado J, McLelland BT, Nistor G, Chen JT, Chew K, Lee N, Keirstead HS, Seiler MJ. Retinal Organoids Long-Term Functional Characterization Using Two-Photon Fluorescence Lifetime and Hyperspectral Microscopy. Front Cell Neurosci 2021; 15:796903. [PMID: 34955757 PMCID: PMC8707055 DOI: 10.3389/fncel.2021.796903] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/26/2021] [Indexed: 12/31/2022] Open
Abstract
Pluripotent stem cell-derived organoid technologies have opened avenues to preclinical basic science research, drug discovery, and transplantation therapy in organ systems. Stem cell-derived organoids follow a time course similar to species-specific organ gestation in vivo. However, heterogeneous tissue yields, and subjective tissue selection reduce the repeatability of organoid-based scientific experiments and clinical studies. To improve the quality control of organoids, we introduced a live imaging technique based on two-photon microscopy to non-invasively monitor and characterize retinal organoids’ (RtOgs’) long-term development. Fluorescence lifetime imaging microscopy (FLIM) was used to monitor the metabolic trajectory, and hyperspectral imaging was applied to characterize structural and molecular changes. We further validated the live imaging experimental results with endpoint biological tests, including quantitative polymerase chain reaction (qPCR), single-cell RNA sequencing, and immunohistochemistry. With FLIM results, we analyzed the free/bound nicotinamide adenine dinucleotide (f/b NADH) ratio of the imaged regions and found that there was a metabolic shift from glycolysis to oxidative phosphorylation. This shift occurred between the second and third months of differentiation. The total metabolic activity shifted slightly back toward glycolysis between the third and fourth months and stayed relatively stable between the fourth and sixth months. Consistency in organoid development among cell lines and production lots was examined. Molecular analysis showed that retinal progenitor genes were expressed in all groups between days 51 and 159. Photoreceptor gene expression emerged around the second month of differentiation, which corresponded to the shift in the f/b NADH ratio. RtOgs between 3 and 6 months of differentiation exhibited photoreceptor gene expression levels that were between the native human fetal and adult retina gene expression levels. The occurrence of cone opsin expression (OPN1 SW and OPN1 LW) indicated the maturation of photoreceptors in the fourth month of differentiation, which was consistent with the stabilized level of f/b NADH ratio starting from 4 months. Endpoint single-cell RNA and immunohistology data showed that the cellular compositions and lamination of RtOgs at different developmental stages followed those in vivo.
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Affiliation(s)
- Yuntian Xue
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States.,Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States
| | - Andrew W Browne
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States.,Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,Institute for Clinical and Translational Science, University of California, Irvine, Irvine, CA, United States
| | - William C Tang
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States
| | - Jeffrey Delgado
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States
| | | | | | - Jacqueline T Chen
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States.,Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Kaylee Chew
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States
| | - Nicolas Lee
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, United States
| | | | - Magdalene J Seiler
- Stem Cell Research Center, University of California, Irvine, Irvine, CA, United States.,Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,Department of Physical Medicine & Rehabilitation, University of California, Irvine, Irvine, CA, United States.,Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, CA, United States
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Boguslawski J, Palczewska G, Tomczewski S, Milkiewicz J, Kasprzycki P, Stachowiak D, Komar K, Marzejon MJ, Sikorski BL, Hudzikowski A, Głuszek A, Łaszczych Z, Karnowski K, Soboń G, Palczewski K, Wojtkowski M. In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope. J Clin Invest 2021; 132:154218. [PMID: 34847075 PMCID: PMC8759795 DOI: 10.1172/jci154218] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans are currently beyond the reach of even the most modern ocular imaging modalities. METHODS We present a compact fluorescence scanning laser ophthalmoscope (TPEF-SLO) and spectrally resolved images of the human retina based on two-photon excitation (TPE) with near-infrared (IR) light. A custom Er:fiber laser with integrated pulse selection, along with intelligent post-processing of data, enables excitation with low laser power and precise measurement of weak signals. RESULTS We demonstrate spectrally resolved TPE fundus images of human subjects. Comparison of TPE data between human and mouse models of retinal diseases revealed similarity with mouse models that rapidly accumulate bisretinoid condensation products. Thus, visual cycle intermediates and toxic byproducts of this metabolic pathway can be measured and quantified by TPE imaging. CONCLUSION Our work establishes a TPE instrument and measurement method for noninvasive metabolic assessment of the human retina. This approach opens the possibility for monitoring eye diseases in the earliest stages before structural damage to the retina occurs. FUNDING NIH, Research to Prevent Blindness, Foundation for Polish Science, European Regional Development Fund, Polish National Agency for Academic Exchange and Polish Ministry of Science and Higher Education.
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Affiliation(s)
- Jakub Boguslawski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Grazyna Palczewska
- Department of Medical Devices, Polgenix, Inc., Cleveland, United States of America
| | - Slawomir Tomczewski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Jadwiga Milkiewicz
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Kasprzycki
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Dorota Stachowiak
- Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland
| | - Katarzyna Komar
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Marcin J Marzejon
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Bartosz L Sikorski
- Department of Ophthalmology, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Arkadiusz Hudzikowski
- Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland
| | - Aleksander Głuszek
- Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland
| | - Zbigniew Łaszczych
- Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland
| | - Karol Karnowski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland
| | - Grzegorz Soboń
- Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland
| | - Krzysztof Palczewski
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Maciej Wojtkowski
- Physical Chemistry of Biological Systems, Polish Academy of Sciences, Warsaw, Poland
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40
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Dysli C, Dysli M, Lincke J, Jaggi D, Wolf S, Zinkernagel MS. IMAGING ARTIFACTS IN FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY. Retina 2021; 41:2378-2390. [PMID: 34111887 DOI: 10.1097/iae.0000000000003235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate and quantify the influence of imaging artifacts on retinal fluorescence lifetime (FLIO) values and to provide helpful hints and tricks to avoid imaging artifacts and to improve FLIO image acquisition quality. METHODS A systematic analysis of potential parameters influencing FLIO quality and/or fluorescence lifetime values was performed in a prospective systematic experimental imaging study in five eyes of five healthy subjects. For image acquisition, a fluorescence lifetime imaging ophthalmoscope (Heidelberg Engineering) was used. Quantitative analysis of FLIO lifetime changes due to imaging artifacts was performed. RESULTS Imaging artifacts with significant influence on fluorescence lifetimes included too short image acquisition time, insufficient illumination, ocular surface problems, and image defocus. Prior use of systemic or topical fluorescein makes analysis of retinal fluorescence lifetimes impossible. CONCLUSION Awareness of possible sources of imaging artifacts is important for FLIO image acquisition and analysis. Therefore, standardized imaging and analysis procedure in FLIO is crucial for high-quality image acquisition and the possibility for systematic quantitative fluorescence lifetime analysis.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Muriel Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Joel Lincke
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Damian Jaggi
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland; and
- Department of BioMedical Research, University of Bern, Bern, Switzerland
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41
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Attiku Y, He Y, Nittala MG, Sadda SR. Current status and future possibilities of retinal imaging in diabetic retinopathy care applicable to low- and medium-income countries. Indian J Ophthalmol 2021; 69:2968-2976. [PMID: 34708731 PMCID: PMC8725126 DOI: 10.4103/ijo.ijo_1212_21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness among adults and the numbers are projected to rise. There have been dramatic advances in the field of retinal imaging since the first fundus image was captured by Jackman and Webster in 1886. The currently available imaging modalities in the management of DR include fundus photography, fluorescein angiography, autofluorescence imaging, optical coherence tomography, optical coherence tomography angiography, and near-infrared reflectance imaging. These images are obtained using traditional fundus cameras, widefield fundus cameras, handheld fundus cameras, or smartphone-based fundus cameras. Fluorescence lifetime ophthalmoscopy, adaptive optics, multispectral and hyperspectral imaging, and multicolor imaging are the evolving technologies which are being researched for their potential applications in DR. Telemedicine has gained popularity in recent years as remote screening of DR has been made possible. Retinal imaging technologies integrated with artificial intelligence/deep-learning algorithms will likely be the way forward in the screening and grading of DR. We provide an overview of the current and upcoming imaging modalities which are relevant to the management of DR.
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Affiliation(s)
- Yamini Attiku
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, California
| | - Ye He
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, California; Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | | | - SriniVas R Sadda
- Doheny Image Reading Center, Doheny Eye Institute; Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY: Findings After Surgical Reattachment of Macula-Off Rhegmatogenous Retinal Detachment. Retina 2021; 40:1929-1937. [PMID: 31860523 PMCID: PMC7505146 DOI: 10.1097/iae.0000000000002718] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study confirms that fluorescence lifetime imaging ophthalmoscopy is able to identify and quantify macular alterations after surgical reattachment of macula-off rhegmatogenous retinal detachment that relate to visual acuity. Fluorescence lifetime imaging ophthalmoscopy could be a useful noninvasive diagnostic tool to assess eyes after rhegmatogenous retinal detachment repair. Purpose: The purpose of this study was to investigate fluorescence lifetime imaging ophthalmoscopy lifetimes after macula-off rhegmatogenous retinal detachment (RRD) repair. Methods: Fifty-eight patients with successful macula-off RRD reattachment surgery were included. Retinal autofluorescence was excited with 470 nm, and amplitude-weighted mean fluorescence lifetimes (Tm) were measured in a short spectral channel (SSC, 498–560 nm) and a long spectral channel (LSC, 560–720 nm). Tm were obtained within a standardized Early Treatment Diabetic Retinopathy Study grid and correlated with Tm. The unaffected fellow eye served as control. Results: Fifty-eight patients (age: 65 ± 1.6 years, 11 women) were imaged at median 1.5 months postoperatively. Tm were significantly prolongxxxed within areas of previously detached retina in the long spectral channel and particularly in the central subfield in the short spectral channel. Short lifetimes in the center of the Early Treatment Diabetic Retinopathy Study grid correlated with better visual acuity (short spectral channel; r2 = 0.18, P = 0.001, long spectral channel; r2 = 0.08, P = 0.03). Areas of residual subretinal fluid pockets in four RRD eyes displayed short fluorescence lifetimes. Conclusion: Areas of previously detached retina exhibit significant fluorescence lifetime changes. We found a significant correlation of fluorescence lifetimes within the fovea with visual acuity after successful RRD repair. Our data suggests that the prolongation of fluorescence lifetimes in the fovea is mainly driven by loss of macular pigment. Therefore, fluorescence lifetime imaging ophthalmoscopy may be useful in the prediction of long-term functional outcomes after macula-off RRD surgery.
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Hammer M, Jakob-Girbig J, Schwanengel L, Curcio CA, Hasan S, Meller D, Schultz R. Progressive Dysmorphia of Retinal Pigment Epithelium in Age-Related Macular Degeneration Investigated by Fluorescence Lifetime Imaging. Invest Ophthalmol Vis Sci 2021; 62:2. [PMID: 34491262 PMCID: PMC8431975 DOI: 10.1167/iovs.62.12.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Purpose The purpose of this study was to observe changes of the retinal pigment epithelium (RPE) on the transition from dysmorphia to atrophy in age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO). Methods Multimodal imaging including color fundus photography (CFP), optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, and FLIO was performed in 40 eyes of 37 patients with intermediate AMD and no evidence for geographic atrophy or macular neovascularization (mean age = 74.2 ± 7.0 years). Twenty-three eyes were followed for 28.3 ± 18.3 months. Seven eyes had a second follow-up after 46.6 ± 9.0 months. Thickened RPE on OCT, hyperpigmentation on CFP, hyper-reflective foci (HRF) on OCT, attributed to single or clustered intraretinal RPE, were identified. Fluorescence lifetimes in two spectral channels (short-wavelength spectral channel [SSC] = 500–560 nm, long-wavelength spectral channel [LSC] = 560–720 nm) as well as emission spectrum intensity ratio (ESIR) of the lesions were measured by FLIO. Results As hyperpigmented areas form and RPE migrates into the retina, FAF lifetimes lengthen and ESRI of RPE cells increase. Thickened RPE showed lifetimes of 256 ± 49 ps (SSC) and 336 ± 35 ps (LSC) and an ESIR of 0.552 ± 0.079. For hyperpigmentation, these values were 317 ± 68 ps (p < 0.001), 377 ± 56 ps (P < 0.001), and 0.609 ± 0.081 (P = 0.001), respectively, and for HRF 337 ± 79 ps (P < 0.001), 414 ± 50 ps (P < 0.001), and 0.654 ± 0.075 (P < 0.001). Conclusions In the process of RPE degeneration, comprising different steps of dysmorphia, hyperpigmentation, and migration, lengthening of FAF lifetimes and a hypsochromic shift of emission spectra can be observed by FLIO. Thus, FLIO might provide early biomarkers for AMD progression and contribute to our understanding of RPE pathology.
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Affiliation(s)
- Martin Hammer
- Department of Ophthalmology, University Hospital Jena, Jena, Germany.,Center for Medical Optics and Photonics, Univ. of Jena, Jena, Germany
| | | | - Linda Schwanengel
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Christine A Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Somar Hasan
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Daniel Meller
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
| | - Rowena Schultz
- Department of Ophthalmology, University Hospital Jena, Jena, Germany
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44
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Podlipec R, Mur J, Petelin J, Štrancar J, Petkovšek R. Method for controlled tissue theranostics using a single tunable laser source. BIOMEDICAL OPTICS EXPRESS 2021; 12:5881-5893. [PMID: 34692222 PMCID: PMC8515989 DOI: 10.1364/boe.428467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/07/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
Tissue diseases and related disorders need to be first recognized using diagnostic methods and then later treated by therapeutic methods-a joint procedure called theranostics. One of the main challenges in the field of retinal therapies remains in the success of the treatment, typically improving the local metabolism, by sparing the surrounding tissue and with the immediate information of the laser effect. In our study, we present a concept for real-time controlled tissue theranostics on a proof-of-concept study capable of using a single tunable ps laser source (in terms of irradiance, fluence, and repetition rate), done on ex-vivo human retinal pigment epithelium. We have found autofluorescence intensity and lifetime imaging diagnostics very promising for the recognition and quantification of laser effects ranging from selective non-destructive molecular tissue modification to complete tissue ablation. The main novelty of our work presents the developed algorithm for optimized theranostics based on the model function used to quantify laser-induced tissue changes through the diagnostics descriptors, fluorescence lifetime and fluorescence intensity parameters. This approach, together with the operation of the single adaptable laser source, can serve as a new theranostics method in personalized medicine in the future not only limited to treat retinal diseases.
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Affiliation(s)
- Rok Podlipec
- Laboratory of Biophysics, Condensed Matter Physics Department, Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Ion Beam Center, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Jaka Mur
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, Ljubljana, Slovenia
| | - Jaka Petelin
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, Ljubljana, Slovenia
| | - Janez Štrancar
- Laboratory of Biophysics, Condensed Matter Physics Department, Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia
| | - Rok Petkovšek
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, Ljubljana, Slovenia
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45
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Nguyen VP, Li Y, Henry J, Zhang W, Wang X, Paulus YM. Gold Nanorod Enhanced Photoacoustic Microscopy and Optical Coherence Tomography of Choroidal Neovascularization. ACS APPLIED MATERIALS & INTERFACES 2021; 13:40214-40228. [PMID: 34403578 PMCID: PMC8924911 DOI: 10.1021/acsami.1c03504] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Visualization and evaluation of choroidal neovascularization (CNV) are major challenges to improve treatment outcomes for patients with age-related macular degeneration (AMD). Limitations of current imaging techniques include the limited penetration depth, spatial resolution, and sensitivity and difficulty visualizing CNV from the healthy microvasculature. In this study, a custom-built multimodal photoacoustic microscopy (PAM) and optical coherence tomography (OCT) system was developed to distinguish the margin of CNV in living rabbits with the assistance of functionalized gold nanorods conjugating with RGD ligands (GNR-RGD). Intravenous administration of GNR-RGD into rabbits in a CNV model resulted in signal enhancements of 27.2-fold in PAM and 171.4% in OCT. This molecular imaging technique of contrast-enhanced PAM and OCT is a promising tool for the precise imaging of CNV as well as the evaluation of the pathophysiology in vivo without destruction of tissue.
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Affiliation(s)
- Van-Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yanxiu Li
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Jessica Henry
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Wei Zhang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
| | - Xueding Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yannis M Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
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Exploring the systemic delivery of a poorly water-soluble model drug to the retina using PLGA nanoparticles. Eur J Pharm Sci 2021; 164:105905. [PMID: 34116175 DOI: 10.1016/j.ejps.2021.105905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/29/2021] [Accepted: 06/01/2021] [Indexed: 12/18/2022]
Abstract
During the drug development process, many pharmacologically active compounds are discarded because of poor water solubility, but nanoparticle-based formulations are increasingly proposed as a solution for this problem. We therefore studied the distribution of nanoparticulate carriers and the delivery of their poorly water-soluble cargo to a structure of the central nervous system, the retina, under naive and pathological conditions. The lipophilic fluorescent dye coumarin 6 (Cou6) was encapsulated into poly(lactic-co-glycolic acid) PLGA nanoparticles (NPs). After intravenous administration in rats, we analyzed the distribution of cargo Cou6 and of the NP carrier covalently labeled with Cy5.5 in healthy animals and animals with optic nerve crush (ONC). In vivo real-time retina imaging revealed that Cou6 was rapidly released from PLGA NPs and penetrated the inner blood-retina barrier (BRB) within 15 min and PLGA NPs were gradually eliminated from the retinal blood circulation. Ex vivo microscopy of retinal flat mounts indicated that the Cou6 accumulated predominantly in the extracellular space and to a lesser extent in neurons. While the distribution of Cou6 in healthy animals and post ONC was comparable at early time point post-operation, the elimination of the NPs from the vessels was faster on day 7 post ONC. These results demonstrate the importance of considering different kinetics of nano-carrier and poorly water-soluble cargo, emphasizing the critical role of their parenchymal distribution, i.e. cellular/extracellular, and function of different physiological and pathological conditions.
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Pole C, Ameri H. Fundus Autofluorescence and Clinical Applications. J Ophthalmic Vis Res 2021; 16:432-461. [PMID: 34394872 PMCID: PMC8358768 DOI: 10.18502/jovr.v16i3.9439] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/01/2021] [Indexed: 12/20/2022] Open
Abstract
Fundus autofluorescence (FAF) has allowed in vivo mapping of retinal metabolic derangements and structural changes not possible with conventional color imaging. Incident light is absorbed by molecules in the fundus, which are excited and in turn emit photons of specific wavelengths that are captured and processed by a sensor to create a metabolic map of the fundus. Studies on the growing number of FAF platforms has shown each may be suited to certain clinical scenarios. Scanning laser ophthalmoscopes, fundus cameras, and modifications of these each have benefits and drawbacks that must be considered before and after imaging to properly interpret the images. Emerging clinical evidence has demonstrated the usefulness of FAF in diagnosis and management of an increasing number of chorioretinal conditions, such as age-related macular degeneration, central serous chorioretinopathy, retinal drug toxicities, and inherited retinal degenerations such as retinitis pigmentosa and Stargardt disease. This article reviews commercial imaging platforms, imaging techniques, and clinical applications of FAF.
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Affiliation(s)
- Cameron Pole
- Retina Division, USC Roski Eye Institute, Keck School of Medicine, University of South California, Los Angeles, CA, USA
| | - Hossein Ameri
- Retina Division, USC Roski Eye Institute, Keck School of Medicine, University of South California, Los Angeles, CA, USA
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Past, present and future role of retinal imaging in neurodegenerative disease. Prog Retin Eye Res 2021; 83:100938. [PMID: 33460813 PMCID: PMC8280255 DOI: 10.1016/j.preteyeres.2020.100938] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 02/08/2023]
Abstract
Retinal imaging technology is rapidly advancing and can provide ever-increasing amounts of information about the structure, function and molecular composition of retinal tissue in humans in vivo. Most importantly, this information can be obtained rapidly, non-invasively and in many cases using Food and Drug Administration-approved devices that are commercially available. Technologies such as optical coherence tomography have dramatically changed our understanding of retinal disease and in many cases have significantly improved their clinical management. Since the retina is an extension of the brain and shares a common embryological origin with the central nervous system, there has also been intense interest in leveraging the expanding armamentarium of retinal imaging technology to understand, diagnose and monitor neurological diseases. This is particularly appealing because of the high spatial resolution, relatively low-cost and wide availability of retinal imaging modalities such as fundus photography or OCT compared to brain imaging modalities such as magnetic resonance imaging or positron emission tomography. The purpose of this article is to review and synthesize current research about retinal imaging in neurodegenerative disease by providing examples from the literature and elaborating on limitations, challenges and future directions. We begin by providing a general background of the most relevant retinal imaging modalities to ensure that the reader has a foundation on which to understand the clinical studies that are subsequently discussed. We then review the application and results of retinal imaging methodologies to several prevalent neurodegenerative diseases where extensive work has been done including sporadic late onset Alzheimer's Disease, Parkinson's Disease and Huntington's Disease. We also discuss Autosomal Dominant Alzheimer's Disease and cerebrovascular small vessel disease, where the application of retinal imaging holds promise but data is currently scarce. Although cerebrovascular disease is not generally considered a neurodegenerative process, it is both a confounder and contributor to neurodegenerative disease processes that requires more attention. Finally, we discuss ongoing efforts to overcome the limitations in the field and unmet clinical and scientific needs.
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LONGITUDINAL FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY ANALYSIS IN PATIENTS WITH MACULAR TELANGIECTASIA TYPE 2 (MacTel). Retina 2021; 41:1416-1427. [PMID: 34137386 DOI: 10.1097/iae.0000000000003055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Fluorescence lifetime imaging ophthalmoscopy (FLIO) shows characteristic patterns in macular telangiectasia Type 2 (MacTel). This study investigates FLIO changes over time to better understand disease progression. METHODS Thirty-three patients with MacTel (age 60 ± 15 years) were followed at the Moran Eye Center with a prototype Heidelberg Engineering FLIO. The mean follow-up time was 19 ± 8 months (range 6-34 months). Fundus autofluorescence was excited at 473 nm, and FLIO lifetimes were recorded in in short (498-560 nm) and long (560-720 nm) spectral wavelengths channels. RESULTS Autofluorescence lifetimes imaging ophthalmoscopy lifetimes from the MacTel area prolonged significantly over time (subfield T1, baseline: short spectral channel 210 ± 54 ps, long spectral channel 269 ± 58 ps; follow-up: short spectral channel 225 ± 59 ps, P < 0.001, long spectral channel 282 ± 64 ps, P < 0.01). The average 12-months prolongation of FLIO lifetimes was 9 ps (short spectral channel) and 8 ps (long spectral channel). Autofluorescence lifetimes changes correlated positively with ellipsoid zone loss and negatively with changes in retinal thickness. CONCLUSION Autofluorescence lifetimes in MacTel slowly prolong over time, and temporal patterns progress to full rings. Detailed knowledge about FLIO changes will aid in understanding disease development and progression.
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Goerdt L, Sauer L, Vitale AS, Modersitzki NK, Fleckenstein M, Bernstein PS. Comparing Fluorescence Lifetime Imaging Ophthalmoscopy in Atrophic Areas of Retinal Diseases. Transl Vis Sci Technol 2021; 10:11. [PMID: 34110387 PMCID: PMC8196421 DOI: 10.1167/tvst.10.7.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Purpose Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a non-invasive imaging modality to investigate the human retina. This study compares FLIO lifetimes in different degenerative retinal diseases. Methods Included were eyes with retinal pigment epithelium (RPE) and/or photoreceptor atrophy due to Stargardt disease (n = 66), pattern dystrophy (n = 18), macular telangiectasia type 2 (n = 49), retinitis pigmentosa (n = 28), choroideremia (n = 26), and geographic atrophy (n = 32) in age-related macular degeneration, as well as 37 eyes of 37 age-matched healthy controls. Subjects received Heidelberg Engineering FLIO, autofluorescence intensity, and optical coherence tomography imaging. Amplitude-weighted mean FLIO lifetimes (τm) were calculated and analyzed. Results Retinal FLIO lifetimes show significant differences depending on the disease. Atrophic areas in geographic atrophy and choroideremia showed longest mean FLIO lifetimes. τm values within areas of RPE and outer nuclear layer atrophy were significantly longer than within areas with preserved outer nuclear layer (P < 0.001) or non-atrophic areas (P < 0.001). Conclusions FLIO is able to contribute additional information regarding differences in chronic degenerative retinal diseases. Although it cannot replace conventional autofluorescence imaging, FLIO adds to the knowledge in these diseases and may help with the correct differentiation between them. This may lead to a more in-depth understanding of the pathomechanisms related to atrophy and types of progression. Translational Relevance Differences between atrophic retinal diseases highlighted by FLIO may indicate separate pathomechanisms leading to atrophy and disease progression.
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Affiliation(s)
- Lukas Goerdt
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Lydia Sauer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | | | | | | | - Paul S Bernstein
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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