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Yakimov B, Rovnyagina N, Hasan A, Zhang J, Wang H, Fadeev V, Urusova L, Khoroshilov E, Sharkov A, Mokrysheva N, Shirshin E. Fluorescence saturation imaging microscopy: molecular fingerprinting with a standard confocal microscope. BIOMEDICAL OPTICS EXPRESS 2024; 15:3755-3769. [PMID: 38867799 PMCID: PMC11166444 DOI: 10.1364/boe.512188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 06/14/2024]
Abstract
Molecular specificity in fluorescence imaging of cells and tissues can be increased by measuring parameters other than intensity. For instance, fluorescence lifetime imaging became a widespread modality for biomedical optics. Previously, we suggested using the fluorescence saturation effect at pulsed laser excitation to map the absorption cross-section as an additional molecular contrast in two-photon microscopy [Opt. Lett.47(17), 4455 (2022).10.1364/OL.465605]. Here, it is shown that, somewhat counterintuitive, fluorescence saturation can be observed under cw excitation in a standard confocal microscopy setup. Mapping the fluorescence saturation parameter allows obtaining additional information about the fluorophores in the system, as demonstrated by the example of peptide hydrogel, stained cells and unstained thyroid gland. The suggested technique does not require additional equipment and can be implemented on confocal systems as is.
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Affiliation(s)
- Boris Yakimov
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University, Trubetskaya 8, Moscow 119048, Russia
- Vorohobov’s City Clinical Hospital №67 MHD Moscow, 2/44 Salam Adil St., Moscow 123423, Russia
| | - Natalia Rovnyagina
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University, Trubetskaya 8, Moscow 119048, Russia
| | - Afraa Hasan
- HSE University, Faculty of Physics, Myasnitskaya St., 20, Moscow 101100, Russia
| | - Juntao Zhang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 4300023, China
| | - Haibo Wang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 4300023, China
| | - Victor Fadeev
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, 119991 Moscow, Russia
| | - Liliya Urusova
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
| | - Evgeny Khoroshilov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991 Moscow, Russia
| | - Andrey Sharkov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991 Moscow, Russia
| | - Nataliya Mokrysheva
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
| | - Evgeny Shirshin
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, 119991 Moscow, Russia
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
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Nguyen TD, Chen YI, Nguyen AT, Yonas S, Sripati MP, Kuo YA, Hong S, Litvinov M, He Y, Yeh HC, Grady Rylander H. Two-photon autofluorescence lifetime assay of rabbit photoreceptors and retinal pigment epithelium during light-dark visual cycles in rabbit retina. BIOMEDICAL OPTICS EXPRESS 2024; 15:3094-3111. [PMID: 38855698 PMCID: PMC11161359 DOI: 10.1364/boe.511806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 06/11/2024]
Abstract
Two-photon excited fluorescence (TPEF) is a powerful technique that enables the examination of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle. Although previous intensity-based TPEF studies in non-human primates have successfully imaged several classes of retinal cells and elucidated aspects of both rod and cone photoreceptor function, fluorescence lifetime imaging (FLIM) of the retinal cells under light-dark visual cycle has yet to be fully exploited. Here we demonstrate a FLIM assay of photoreceptors and retinal pigment epithelium (RPE) that reveals key insights into retinal physiology and adaptation. We found that photoreceptor fluorescence lifetimes increase and decrease in sync with light and dark exposure, respectively. This is likely due to changes in all-trans-retinol and all-trans-retinal levels in the outer segments, mediated by phototransduction and visual cycle activity. During light exposure, RPE fluorescence lifetime was observed to increase steadily over time, as a result of all-trans-retinol accumulation during the visual cycle and decreasing metabolism caused by the lack of normal perfusion of the sample. Our system can measure the fluorescence lifetime of intrinsic retinal fluorophores on a cellular scale, revealing differences in lifetime between retinal cell classes under different conditions of light and dark exposure.
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Affiliation(s)
- Trung Duc Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yuan-I Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Anh-Thu Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Siem Yonas
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Manasa P Sripati
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yu-An Kuo
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Soonwoo Hong
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Mitchell Litvinov
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yujie He
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
- Texas Materials Institute, University of Texas at Austin, Austin, TX, USA
| | - H Grady Rylander
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
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3
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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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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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5
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Suchand Sandeep CS, Khairyanto A, Aung T, Vadakke Matham M. Bessel Beams in Ophthalmology: A Review. MICROMACHINES 2023; 14:1672. [PMID: 37763835 PMCID: PMC10536271 DOI: 10.3390/mi14091672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023]
Abstract
The achievable resolution of a conventional imaging system is inevitably limited due to diffraction. Dealing with precise imaging in scattering media, such as in the case of biomedical imaging, is even more difficult owing to the weak signal-to-noise ratios. Recent developments in non-diffractive beams such as Bessel beams, Airy beams, vortex beams, and Mathieu beams have paved the way to tackle some of these challenges. This review specifically focuses on non-diffractive Bessel beams for ophthalmological applications. The theoretical foundation of the non-diffractive Bessel beam is discussed first followed by a review of various ophthalmological applications utilizing Bessel beams. The advantages and disadvantages of these techniques in comparison to those of existing state-of-the-art ophthalmological systems are discussed. The review concludes with an overview of the current developments and the future perspectives of non-diffractive beams in ophthalmology.
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Affiliation(s)
- C. S. Suchand Sandeep
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Ahmad Khairyanto
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
| | - Murukeshan Vadakke Matham
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
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Duncan JL, Carroll J. Adaptive Optics Imaging of Inherited Retinal Disease. Cold Spring Harb Perspect Med 2023; 13:a041285. [PMID: 36220331 PMCID: PMC10317068 DOI: 10.1101/cshperspect.a041285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The human retina is amenable to direct, noninvasive visualization using a wide array of imaging modalities. In the ∼140 years since the publication of the first image of the living human retina, there has been a continued evolution of retinal imaging technology. Advances in image acquisition and processing speed now allow real-time visualization of retinal structure, which has revolutionized the diagnosis and management of eye disease. Enormous advances have come in image resolution, with adaptive optics (AO)-based systems capable of imaging the retina with single-cell resolution. In addition, newer functional imaging techniques provide the ability to assess function with exquisite spatial and temporal resolution. These imaging advances have had an especially profound impact on the field of inherited retinal disease research. Here we will review some of the advances and applications of AO retinal imaging in patients with inherited retinal disease.
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Affiliation(s)
- Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, California 94143-4081, USA
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin Eye Institute, Milwaukee, Wisconsin 53226, USA
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Cheong KX, Ong CJT, Chandrasekaran PR, Zhao J, Teo KYC, Mathur R. Review of Retinal Imaging Modalities for Hydroxychloroquine Retinopathy. Diagnostics (Basel) 2023; 13:diagnostics13101752. [PMID: 37238236 DOI: 10.3390/diagnostics13101752] [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: 04/04/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
This review provides an overview of conventional and novel retinal imaging modalities for hydroxychloroquine (HCQ) retinopathy. HCQ retinopathy is a form of toxic retinopathy resulting from HCQ use for a variety of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Each imaging modality detects a different aspect of HCQ retinopathy and shows a unique complement of structural changes. Conventionally, spectral-domain optical coherence tomography (SD-OCT), which shows loss or attenuation of the outer retina and/or retinal pigment epithelium-Bruch's membrane complex, and fundus autofluorescence (FAF), which shows parafoveal or pericentral abnormalities, are used to assess HCQ retinopathy. Additionally, several variations of OCT (retinal and choroidal thickness measurements, choroidal vascularity index, widefield OCT, en face imaging, minimum intensity analysis, and artificial intelligence techniques) and FAF techniques (quantitative FAF, near-infrared FAF, fluorescence lifetime imaging ophthalmoscopy, and widefield FAF) have been applied to assess HCQ retinopathy. Other novel retinal imaging techniques that are being studied for early detection of HCQ retinopathy include OCT angiography, multicolour imaging, adaptive optics, and retromode imaging, although further testing is required for validation.
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Affiliation(s)
- Kai Xiong Cheong
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Charles Jit Teng Ong
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Priya R Chandrasekaran
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Jinzhi Zhao
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Kelvin Yi Chong Teo
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore 169857, Singapore
| | - Ranjana Mathur
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore 169857, Singapore
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Sandali O, Tahiri Joutei Hassani R, Armia Balamoun A, Franklin A, Sallam AB, Borderie V. Operative Digital Enhancement of Macular Pigment during Macular Surgery. J Clin Med 2023; 12:jcm12062300. [PMID: 36983301 PMCID: PMC10051350 DOI: 10.3390/jcm12062300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Purpose: To describe the feasibility of intraoperative digital visualization and its contribution to the enhancement of macular pigmentation visualization in a prospective series of macular surgery interventions. Materials and Methods: A prospective, single-center, single-surgeon study was performed on a series of 21 consecutive cases of vitrectomy for various types of macular surgery using a 3D visualization system. Two optimized filters were applied to enhance the visualization of the macular pigment (MP). For filter 1, cyan, yellow, and magenta color saturations were increased. Filter 2 differed from filter 1 only in having a lower level of magenta saturation for the green-magenta color channel. Results: Optimized digital filters enhanced the visualization of the MP and the pigmented epiretinal tissue associated with the lamellar and macular holes. In vitreomacular traction surgery, the filters facilitated the assessment of MP integrity at the end of surgery. Filter 1 enhanced MP visualization most strongly, with the MP appearing green and slightly fluorescent. Filter 2 enhanced MP visualization less effectively but gave a clearer image of the retinal surface, facilitating safe macular peeling. Conclusion: Optimized digital filters could be used to enhance MP and pigmented epiretinal tissue visualization during macular surgery. These filters open new horizons for future research and should be evaluated in larger series and correlated with intraoperative OCT.
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Affiliation(s)
- Otman Sandali
- Centre Hospitalier National d’Ophtalmologie des XV-XX 28, Rue de Charenton, 75012 Paris, France
- Service de Chirurgie Ambulatoire, Hôpital Guillaume-de-Varye, 18230 Bourges, France
- Correspondence: ; Tel.: +33-1-4002-1508
| | | | - Ashraf Armia Balamoun
- Watany Eye Hospital, Cairo 11775, Egypt
- Watany Research and Development Centre, Cairo 11775, Egypt
- Ashraf Armia Eye Clinic, Giza 12655, Egypt
| | - Alan Franklin
- Diagnostic and Medical Clinic, 1720 SpringHill Ave Suite 300, Mobile, AL 36604, USA
| | - Ahmed B. Sallam
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR 72205, USA
| | - Vincent Borderie
- Centre Hospitalier National d’Ophtalmologie des XV-XX 28, Rue de Charenton, 75012 Paris, France
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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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10
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Stability of retinol in liposomes as measured by fluorescence lifetime spectroscopy and FLIM. BBA ADVANCES 2023. [DOI: 10.1016/j.bbadva.2023.100088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
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11
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Aleman TS, O'Neil EC, Uyhazi KE, Parchinski KM, Santos AJ, Weber ML, Colclough SP, Billek AS, Zhu X, Leroy BP, Bedoukian EC. Fleck-like lesions in CEP290-associated leber congenital amaurosis: a case series. Ophthalmic Genet 2022; 43:824-833. [PMID: 36469661 DOI: 10.1080/13816810.2022.2147960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To provide a detailed ophthalmic phenotype of a small cohort of patients with Leber Congenital Amaurosis (LCA) caused by mutations in CEP290 (CEP290-LCA) with a focus on elucidating the origin of yellow-white lesions observed in 30% of patients with this condition. METHODS This is a retrospective review of records of five patients with CEP290-LCA. Patients had comprehensive ophthalmic evaluations. Visual function was assessed with full-field electroretinograms (ffERGs) and full-field sensitivity testing (FST). Multimodal imaging was performed with spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) with short- (SW) and near-infrared (NIR) excitation wavelengths. RESULTS All patients showed relative structural preservation of the foveal and near midperipheral retina separated by a pericentral area of photoreceptor loss. Yellow-white, fleck-like lesions in an annular distribution around the near midperiphery co-localized with hyperreflective lesions on SD-OCT. The lesions located between the inner segment ellipsoid signal and the apical retinal pigment epithelium (RPE). The inner retina was normal. Longitudinal observations in one of the patients indicates the abnormalities may represent an intermediate stage in the degenerative process between the near normal appearing retina previously documented in young CEP290-LCA patients and the pigmentary retinopathy observed along the same region in older individuals. CONCLUSIONS We speculate that fleck-like lesions in CEP290-LCA correspond to malformed, rudimentary or degenerated, including shed, photoreceptor outer segments. The topography and possible origin of the abnormalities may inform the planning of evolving genetic therapies for this disease.
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Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C O'Neil
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katherine E Uyhazi
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kelsey M Parchinski
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arlene J Santos
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariejel L Weber
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sherice P Colclough
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew S Billek
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiaosong Zhu
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bart P Leroy
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Head & Skin, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Emma C Bedoukian
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Individualized Medical Genetics Center of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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12
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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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13
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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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14
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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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15
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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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16
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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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17
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Marchese A, Cicinelli MV, Amato A, Bandello F, Gupta V, Miserocchi E, Agarwal A. The Next Steps in Ocular Imaging in Uveitis. Ocul Immunol Inflamm 2022; 31:785-792. [PMID: 35412936 DOI: 10.1080/09273948.2022.2055579] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE To describe the future steps and advances in the field of ocular imaging in uveitis. METHODS Narrative review. RESULTS There have been numerous advances in the field of imaging in uveitis in the past decade. Advanced techniques of imaging of the vitreous, vitreo-retinal interface, retinochoroid, and the sclera can provide significant information that helps in understanding the disease pathogenesis and manifestations. Imaging also helps in establishing a diagnosis in challenging cases, along with the laboratory and other assays. Notable developments in ocular imaging include wide-field and ultra-wide field imaging (including angiographies), automated quantification of the retinochoroidal vasculature using optical coherence tomography (OCT) and OCT angiography, quantification of vitreous cells, and intraoperative use of imaging in uveitis, among others. CONCLUSIONS We have summarized several technological achievements in ocular imaging in the field of uveitis and provided insights into the potential future developments.
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Affiliation(s)
- Alessandro Marchese
- Department of Ophthalmology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.,Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Vittoria Cicinelli
- Department of Ophthalmology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.,Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessia Amato
- Department of Ophthalmology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.,Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.,Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Vishali Gupta
- Department of Ophthalmology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | | | - Aniruddha Agarwal
- Department of Ophthalmology, The Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates (UAE)
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18
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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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19
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Xiao D, Zang Z, Xie W, Sapermsap N, Chen Y, Uei Li DD. Spatial resolution improved fluorescence lifetime imaging via deep learning. OPTICS EXPRESS 2022; 30:11479-11494. [PMID: 35473091 DOI: 10.1364/oe.451215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
We present a deep learning approach to obtain high-resolution (HR) fluorescence lifetime images from low-resolution (LR) images acquired from fluorescence lifetime imaging (FLIM) systems. We first proposed a theoretical method for training neural networks to generate massive semi-synthetic FLIM data with various cellular morphologies, a sizeable dynamic lifetime range, and complex decay components. We then developed a degrading model to obtain LR-HR pairs and created a hybrid neural network, the spatial resolution improved FLIM net (SRI-FLIMnet) to simultaneously estimate fluorescence lifetimes and realize the nonlinear transformation from LR to HR images. The evaluative results demonstrate SRI-FLIMnet's superior performance in reconstructing spatial information from limited pixel resolution. We also verified SRI-FLIMnet using experimental images of bacterial infected mouse raw macrophage cells. Results show that the proposed data generation method and SRI-FLIMnet efficiently achieve superior spatial resolution for FLIM applications. Our study provides a solution for fast obtaining HR FLIM images.
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20
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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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21
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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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22
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Yusuf IH, Charbel Issa P, Ahn SJ. Novel imaging techniques for hydroxychloroquine retinopathy. Front Med (Lausanne) 2022; 9:1026934. [PMID: 36314000 PMCID: PMC9606779 DOI: 10.3389/fmed.2022.1026934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
Hydroxychloroquine retinopathy is an increasingly recognized cause of iatrogenic, irreversible visual impairment due to the expanding use of hydroxychloroquine in combination with improvements in disease detection following advances in retinal imaging techniques. The prevalence of disease is estimated to be greater than 5% amongst individuals who have used the drug for 5 years or more. In addition to conventional imaging modalities, such as spectral-domain optical coherence tomography (OCT) and fundus autofluorescence (FAF), novel retinal imaging techniques such as en face OCT, OCT angiography, fluorescence lifetime imaging ophthalmoscopy, quantitative autofluorescence, and retromode imaging are capable of detecting structural changes in the retina. These novel retinal imaging techniques have shown promise in detecting earlier disease than is possible with current mainstream imaging modalities. Moreover, these techniques may identify disease progression as well as enabling functional correlation. In the future, these novel imaging techniques may further reduce the risk of visual loss from hydroxychloroquine retinopathy through the earlier detection of pre-clinical disease.
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Affiliation(s)
- Imran H Yusuf
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Peter Charbel Issa
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Seong Joon Ahn
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, South Korea
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23
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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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Datta R, Gillette A, Stefely M, Skala MC. Recent innovations in fluorescence lifetime imaging microscopy for biology and medicine. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210093-PER. [PMID: 34247457 PMCID: PMC8271181 DOI: 10.1117/1.jbo.26.7.070603] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/11/2021] [Indexed: 05/05/2023]
Abstract
SIGNIFICANCE Fluorescence lifetime imaging microscopy (FLIM) measures the decay rate of fluorophores, thus providing insights into molecular interactions. FLIM is a powerful molecular imaging technique that is widely used in biology and medicine. AIM This perspective highlights some of the major advances in FLIM instrumentation, analysis, and biological and clinical applications that we have found impactful over the last year. APPROACH Innovations in FLIM instrumentation resulted in faster acquisition speeds, rapid imaging over large fields of view, and integration with complementary modalities such as single-molecule microscopy or light-sheet microscopy. There were significant developments in FLIM analysis with machine learning approaches to enhance processing speeds, fit-free techniques to analyze images without a priori knowledge, and open-source analysis resources. The advantages and limitations of these recent instrumentation and analysis techniques are summarized. Finally, applications of FLIM in the last year include label-free imaging in biology, ophthalmology, and intraoperative imaging, FLIM of new fluorescent probes, and lifetime-based Förster resonance energy transfer measurements. CONCLUSIONS A large number of high-quality publications over the last year signifies the growing interest in FLIM and ensures continued technological improvements and expanding applications in biomedical research.
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Affiliation(s)
- Rupsa Datta
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Amani Gillette
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Matthew Stefely
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
- Address all correspondence to Melissa C. Skala,
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