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Torm MEW, Pircher M, Bonnin S, Johannesen J, Klefter ON, Schmidt MF, Frederiksen JL, Lefaudeux N, Andilla J, Valdes C, Loza-Alvarez P, Brea LS, De Jesus DA, Grieve K, Paques M, Larsen M, Gocho K. Detection of capillary abnormalities in early diabetic retinopathy using scanning laser ophthalmoscopy and optical coherence tomography combined with adaptive optics. Sci Rep 2024; 14:13450. [PMID: 38862584 PMCID: PMC11166634 DOI: 10.1038/s41598-024-63749-7] [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: 02/01/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024] Open
Abstract
This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The study examined 11 patients with very mild to moderate non-proliferative diabetic retinopathy (NPDR) and 10 healthy subjects using fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), adaptive optics scanning laser ophthalmoscopy (AO-SLO), adaptive optics OCT and OCTA (AO-OCT(A)). Of 21 eyes of 11 patients, 11 had very mild NPDR, 8 had mild NPDR, 2 had moderate NPDR, and 1 had no retinopathy. Using AO-SLO, capillary looping, inflections and dilations were detected in 8 patients with very mild or mild NPDR, and microaneurysms containing hyperreflective granular elements were visible in 9 patients with mild or moderate NPDR. Most of the abnormalities were seen to be perfused in the corresponding OCTA scans while a few capillary loops appeared to be occluded or perfused at a non-detectable flow rate, possibly because of hypoperfusion. In one patient with moderate NPDR, non-perfused capillaries, also called ghost vessels, were identified by alignment of corresponding en face AO-OCT and AO-OCTA images. The combination of multiple non-invasive imaging methods could identify prominent microscopic abnormalities in diabetic retinopathy earlier and more detailed than conventional fundus imaging devices.
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Affiliation(s)
- Marie Elise Wistrup Torm
- Department of Ophthalmology, Center for Research in Eye Diseases, Rigshospitalet, Section 37, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark.
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Sophie Bonnin
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, 28 Rue de Charenton, 75012, Paris, France
- INSERM, CNRS, Institut de La Vision, Sorbonne Université, 17 Rue Moreau, 75012, Paris, France
- Foundation Rothschild Hospital, 25-29, Rue Manin, 75019, Paris, France
| | - Jesper Johannesen
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
- Department of Pediatrics, Herlev-Gentofte Hospital, Borgmester Ib Juuls Vej 25C, Herlev, Denmark
- Department of Clinical Research, Steno Diabetes Center Copenhagen, Borgmester Ib Juuls Vej 83, Herlev, Denmark
| | - Oliver Niels Klefter
- Department of Ophthalmology, Center for Research in Eye Diseases, Rigshospitalet, Section 37, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
| | - Mathias Falck Schmidt
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
- Department of Neurology, Clinic of Optic Neuritis, The Danish Multiple Sclerosis Center (DMSC), Rigshospitalet, Valdemar Hansens Vej 13, Glostrup, Denmark
| | - Jette Lautrup Frederiksen
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
- Department of Neurology, Clinic of Optic Neuritis, The Danish Multiple Sclerosis Center (DMSC), Rigshospitalet, Valdemar Hansens Vej 13, Glostrup, Denmark
| | | | - Jordi Andilla
- The Barcelona Institute of Science and Technology, ICFO-Institut de Ciencies Fotoniques, 08860, Castelldefels, Barcelona, Spain
| | - Claudia Valdes
- The Barcelona Institute of Science and Technology, ICFO-Institut de Ciencies Fotoniques, 08860, Castelldefels, Barcelona, Spain
| | - Pablo Loza-Alvarez
- The Barcelona Institute of Science and Technology, ICFO-Institut de Ciencies Fotoniques, 08860, Castelldefels, Barcelona, Spain
| | - Luisa Sanchez Brea
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Dr. Molewaterplein 40, Rotterdam, The Netherlands
- Department of Ophthalmology, Erasmus Medical Center, Dr. Molewaterplein 40, Rotterdam, The Netherlands
- The Rotterdam Eye Hospital, The Rotterdam Ophthalmic Institute, Schiedamse Vest 160, Rotterdam, The Netherlands
| | - Danilo Andrade De Jesus
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Dr. Molewaterplein 40, Rotterdam, The Netherlands
- Department of Ophthalmology, Erasmus Medical Center, Dr. Molewaterplein 40, Rotterdam, The Netherlands
- The Rotterdam Eye Hospital, The Rotterdam Ophthalmic Institute, Schiedamse Vest 160, Rotterdam, The Netherlands
| | - Kate Grieve
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, 28 Rue de Charenton, 75012, Paris, France
- INSERM, CNRS, Institut de La Vision, Sorbonne Université, 17 Rue Moreau, 75012, Paris, France
| | - Michel Paques
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, 28 Rue de Charenton, 75012, Paris, France
- INSERM, CNRS, Institut de La Vision, Sorbonne Université, 17 Rue Moreau, 75012, Paris, France
| | - Michael Larsen
- Department of Ophthalmology, Center for Research in Eye Diseases, Rigshospitalet, Section 37, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N, Denmark
| | - Kiyoko Gocho
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, 28 Rue de Charenton, 75012, Paris, France
- INSERM, CNRS, Institut de La Vision, Sorbonne Université, 17 Rue Moreau, 75012, Paris, France
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Bozuyuk U, Wrede P, Yildiz E, Sitti M. Roadmap for Clinical Translation of Mobile Microrobotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2311462. [PMID: 38380776 DOI: 10.1002/adma.202311462] [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: 10/31/2023] [Revised: 01/24/2024] [Indexed: 02/22/2024]
Abstract
Medical microrobotics is an emerging field to revolutionize clinical applications in diagnostics and therapeutics of various diseases. On the other hand, the mobile microrobotics field has important obstacles to pass before clinical translation. This article focuses on these challenges and provides a roadmap of medical microrobots to enable their clinical use. From the concept of a "magic bullet" to the physicochemical interactions of microrobots in complex biological environments in medical applications, there are several translational steps to consider. Clinical translation of mobile microrobots is only possible with a close collaboration between clinical experts and microrobotics researchers to address the technical challenges in microfabrication, safety, and imaging. The clinical application potential can be materialized by designing microrobots that can solve the current main challenges, such as actuation limitations, material stability, and imaging constraints. The strengths and weaknesses of the current progress in the microrobotics field are discussed and a roadmap for their clinical applications in the near future is outlined.
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Affiliation(s)
- Ugur Bozuyuk
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Paul Wrede
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, 8093, Switzerland
| | - Erdost Yildiz
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- School of Medicine and College of Engineering, Koc University, Istanbul, 34450, Turkey
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Cai Y, Thouvenin O, Grieve K, Mecê P. Influence of static and dynamic ocular aberrations on full-field optical coherence tomography for in vivo high-resolution retinal imaging. OPTICS LETTERS 2024; 49:2209-2212. [PMID: 38691681 DOI: 10.1364/ol.515749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/21/2024] [Indexed: 05/03/2024]
Abstract
Under spatially incoherent illumination, time-domain full-field optical coherence tomography (FFOCT) offers the possibility to achieve in vivo retinal imaging at cellular resolution over a wide field of view. Such performance is possible, albeit there is the presence of ocular aberrations even without the use of classical adaptive optics. While the effect of aberrations in FFOCT has been debated these past years, mostly on low-order and static aberrations, we present, for the first time to our knowledge, a method enabling a quantitative study of the effect of statistically representative static and dynamic ocular aberrations on FFOCT image metrics, such as SNR, resolution, and image similarity. While we show that ocular aberrations can decrease FFOCT SNR and resolution by up to 14 dB and fivefold, we take advantage of such quantification to discuss different possible compromises between performance gain and adaptive optics complexity and speed, to optimize both sensor-based and sensorless FFOCT high-resolution retinal imaging.
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Das V, Zhang F, Bower AJ, Li J, Liu T, Aguilera N, Alvisio B, Liu Z, Hammer DX, Tam J. Revealing speckle obscured living human retinal cells with artificial intelligence assisted adaptive optics optical coherence tomography. COMMUNICATIONS MEDICINE 2024; 4:68. [PMID: 38600290 PMCID: PMC11006674 DOI: 10.1038/s43856-024-00483-1] [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: 04/18/2023] [Accepted: 03/13/2024] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND In vivo imaging of the human retina using adaptive optics optical coherence tomography (AO-OCT) has transformed medical imaging by enabling visualization of 3D retinal structures at cellular-scale resolution, including the retinal pigment epithelial (RPE) cells, which are essential for maintaining visual function. However, because noise inherent to the imaging process (e.g., speckle) makes it difficult to visualize RPE cells from a single volume acquisition, a large number of 3D volumes are typically averaged to improve contrast, substantially increasing the acquisition duration and reducing the overall imaging throughput. METHODS Here, we introduce parallel discriminator generative adversarial network (P-GAN), an artificial intelligence (AI) method designed to recover speckle-obscured cellular features from a single AO-OCT volume, circumventing the need for acquiring a large number of volumes for averaging. The combination of two parallel discriminators in P-GAN provides additional feedback to the generator to more faithfully recover both local and global cellular structures. Imaging data from 8 eyes of 7 participants were used in this study. RESULTS We show that P-GAN not only improves RPE cell contrast by 3.5-fold, but also improves the end-to-end time required to visualize RPE cells by 99-fold, thereby enabling large-scale imaging of cells in the living human eye. RPE cell spacing measured across a large set of AI recovered images from 3 participants were in agreement with expected normative ranges. CONCLUSIONS The results demonstrate the potential of AI assisted imaging in overcoming a key limitation of RPE imaging and making it more accessible in a routine clinical setting.
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Affiliation(s)
- Vineeta Das
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Furu Zhang
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Andrew J Bower
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Joanne Li
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Tao Liu
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nancy Aguilera
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Bruno Alvisio
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Zhuolin Liu
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Daniel X Hammer
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Johnny Tam
- National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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Nolte DD. Coherent light scattering from cellular dynamics in living tissues. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:036601. [PMID: 38433567 DOI: 10.1088/1361-6633/ad2229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/24/2024] [Indexed: 03/05/2024]
Abstract
This review examines the biological physics of intracellular transport probed by the coherent optics of dynamic light scattering from optically thick living tissues. Cells and their constituents are in constant motion, composed of a broad range of speeds spanning many orders of magnitude that reflect the wide array of functions and mechanisms that maintain cellular health. From the organelle scale of tens of nanometers and upward in size, the motion inside living tissue is actively driven rather than thermal, propelled by the hydrolysis of bioenergetic molecules and the forces of molecular motors. Active transport can mimic the random walks of thermal Brownian motion, but mean-squared displacements are far from thermal equilibrium and can display anomalous diffusion through Lévy or fractional Brownian walks. Despite the average isotropic three-dimensional environment of cells and tissues, active cellular or intracellular transport of single light-scattering objects is often pseudo-one-dimensional, for instance as organelle displacement persists along cytoskeletal tracks or as membranes displace along the normal to cell surfaces, albeit isotropically oriented in three dimensions. Coherent light scattering is a natural tool to characterize such tissue dynamics because persistent directed transport induces Doppler shifts in the scattered light. The many frequency-shifted partial waves from the complex and dynamic media interfere to produce dynamic speckle that reveals tissue-scale processes through speckle contrast imaging and fluctuation spectroscopy. Low-coherence interferometry, dynamic optical coherence tomography, diffusing-wave spectroscopy, diffuse-correlation spectroscopy, differential dynamic microscopy and digital holography offer coherent detection methods that shed light on intracellular processes. In health-care applications, altered states of cellular health and disease display altered cellular motions that imprint on the statistical fluctuations of the scattered light. For instance, the efficacy of medical therapeutics can be monitored by measuring the changes they induce in the Doppler spectra of livingex vivocancer biopsies.
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Affiliation(s)
- David D Nolte
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, United States of America
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Heitkotter H, Allphin MT, Untaroiu A, Min H, Warr E, Wynne N, Cooper RF, Carroll J. Peak Cone Density Predicted from Outer Segment Length Measured on Optical Coherence Tomography. Curr Eye Res 2024; 49:314-324. [PMID: 38146597 PMCID: PMC10922793 DOI: 10.1080/02713683.2023.2289853] [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: 07/24/2023] [Accepted: 11/27/2023] [Indexed: 12/27/2023]
Abstract
PURPOSE To compare peak cone density predicted from outer segment length measured on optical coherence tomography with direct measures of peak cone density from adaptive optics scanning light ophthalmoscopy. METHODS Data from 42 healthy participants with direct peak cone density measures and optical coherence tomography line scans available were used in this study. Longitudinal reflectivity profiles were analyzed using two methods of identifying the boundaries of the ellipsoid and interdigitation zones to estimate maximum outer segment length: peak-to-peak and the slope method. These maximum outer segment length values were then used to predict peak cone density using a previously described geometrical model. A comparison between predicted and direct peak cone density measures was then performed. RESULTS The mean bias between observers for estimating maximum outer segment length across methods was less than 2 µm. Cone density predicted from the peak-to-peak method against direct cone density measures showed a mean bias of 6,812 cones/mm2 with 50% of participants displaying a 10% difference or less between predicted and direct cone density values. Cone density derived from the slope method showed a mean bias of -17,929 cones/mm2 relative to direct cone density measures, with only 41% of participants demonstrating less than a 10% difference between direct and predicted cone density values. CONCLUSION Predicted foveal cone density derived from peak-to-peak outer segment length measurements using commercial optical coherence tomography show modest agreement with direct measures of peak cone density from adaptive optics scanning light ophthalmoscopy. The methods used here are imperfect predictors of cone density, however, further exploration of this relationship could reveal a clinically relevant marker of cone structure.
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Affiliation(s)
- Heather Heitkotter
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, USA
| | - Mitchell T. Allphin
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, USA
| | - Ana Untaroiu
- School of Medicine, Medical College of Wisconsin, Milwaukee, USA
| | - Heun Min
- School of Medicine, Medical College of Wisconsin, Milwaukee, USA
| | - Emma Warr
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, USA
| | - Niamh Wynne
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert F. Cooper
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, USA
- Joint Department of Biomedical Engineering Marquette University and Medical College of Wisconsin, Milwaukee, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, USA
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, USA
- Joint Department of Biomedical Engineering Marquette University and Medical College of Wisconsin, Milwaukee, USA
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Kurokawa K, Nemeth M. Multifunctional adaptive optics optical coherence tomography allows cellular scale reflectometry, polarimetry, and angiography in the living human eye. BIOMEDICAL OPTICS EXPRESS 2024; 15:1331-1354. [PMID: 38404344 PMCID: PMC10890865 DOI: 10.1364/boe.505395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 02/27/2024]
Abstract
Clinicians are unable to detect glaucoma until substantial loss or dysfunction of retinal ganglion cells occurs. To this end, novel measures are needed. We have developed an optical imaging solution based on adaptive optics optical coherence tomography (AO-OCT) to discern key clinical features of glaucoma and other neurodegenerative diseases at the cellular scale in the living eye. Here, we test the feasibility of measuring AO-OCT-based reflectance, retardance, optic axis orientation, and angiogram at specifically targeted locations in the living human retina and optic nerve head. Multifunctional imaging, combined with focus stacking and global image registration algorithms, allows us to visualize cellular details of retinal nerve fiber bundles, ganglion cell layer somas, glial septa, superior vascular complex capillaries, and connective tissues. These are key histologic features of neurodegenerative diseases, including glaucoma, that are now measurable in vivo with excellent repeatability and reproducibility. Incorporating this noninvasive cellular-scale imaging with objective measurements will significantly enhance existing clinical assessments, which is pivotal in facilitating the early detection of eye disease and understanding the mechanisms of neurodegeneration.
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Affiliation(s)
- Kazuhiro Kurokawa
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Research Institute, Legacy Health, Portland, OR 97232, USA
| | - Morgan Nemeth
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Research Institute, Legacy Health, Portland, OR 97232, USA
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Cheng AMS, Chalam KV, Brar VS, Yang DTY, Bhatt J, Banoub RG, Gupta SK. Recent Advances in Imaging Macular Atrophy for Late-Stage Age-Related Macular Degeneration. Diagnostics (Basel) 2023; 13:3635. [PMID: 38132220 PMCID: PMC10742961 DOI: 10.3390/diagnostics13243635] [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: 09/30/2023] [Revised: 12/02/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. In late-stage AMD, geographic atrophy (GA) of dry AMD or choroidal neovascularization (CNV) of neovascular AMD eventually results in macular atrophy (MA), leading to significant visual loss. Despite the development of innovative therapies, there are currently no established effective treatments for MA. As a result, early detection of MA is critical in identifying later central macular involvement throughout time. Accurate and early diagnosis is achieved through a combination of clinical examination and imaging techniques. Our review of the literature depicts advances in retinal imaging to identify biomarkers of progression and risk factors for late AMD. Imaging methods like fundus photography; dye-based angiography; fundus autofluorescence (FAF); near-infrared reflectance (NIR); optical coherence tomography (OCT); and optical coherence tomography angiography (OCTA) can be used to detect and monitor the progression of retinal atrophy. These evolving diverse imaging modalities optimize detection of pathologic anatomy and measurement of visual function; they may also contribute to the understanding of underlying mechanistic pathways, particularly the underlying MA changes in late AMD.
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Affiliation(s)
- Anny M. S. Cheng
- Department of Ophthalmology, Broward Health, Fort Lauderdale, FL 33064, USA; (A.M.S.C.); (R.G.B.)
- Specialty Retina Center, Coral Springs, FL 33067, USA;
- Department of Ophthalmology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
| | - Kakarla V. Chalam
- Department of Ophthalmology, Loma Linda University, Loma Linda, CA 92350, USA;
| | - Vikram S. Brar
- Department of Ophthalmology, Virginia Commonwealth University, Richmond, VA 23298, USA;
| | - David T. Y. Yang
- College of Biological Science, University of California, Davis, Sacramento, CA 95616, USA;
| | - Jineel Bhatt
- Specialty Retina Center, Coral Springs, FL 33067, USA;
| | - Raphael G. Banoub
- Department of Ophthalmology, Broward Health, Fort Lauderdale, FL 33064, USA; (A.M.S.C.); (R.G.B.)
- Specialty Retina Center, Coral Springs, FL 33067, USA;
| | - Shailesh K. Gupta
- Department of Ophthalmology, Broward Health, Fort Lauderdale, FL 33064, USA; (A.M.S.C.); (R.G.B.)
- Specialty Retina Center, Coral Springs, FL 33067, USA;
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Shiga Y, Nishida T, Jeoung JW, Di Polo A, Fortune B. Optical Coherence Tomography and Optical Coherence Tomography Angiography: Essential Tools for Detecting Glaucoma and Disease Progression. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1217125. [PMID: 37982032 PMCID: PMC10655832 DOI: 10.3389/fopht.2023.1217125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/03/2023] [Indexed: 11/21/2023]
Abstract
Early diagnosis and detection of disease progression are critical to successful therapeutic intervention in glaucoma, the leading cause of irreversible blindness worldwide. Optical coherence tomography (OCT) is a non-invasive imaging technique that allows objective quantification in vivo of key glaucomatous structural changes in the retina and the optic nerve head (ONH). Advances in OCT technology have increased the scan speed and enhanced image quality, contributing to early glaucoma diagnosis and monitoring, as well as the visualization of critically important structures deep within the ONH, such as the lamina cribrosa. OCT angiography (OCTA) is a dye-free technique for noninvasively assessing ocular microvasculature, including capillaries within each plexus serving the macula, peripapillary retina and ONH regions, as well as the deeper vessels of the choroid. This layer-specific assessment of the microvasculature has provided evidence that retinal and choroidal vascular impairments can occur during early stages of glaucoma, suggesting that OCTA-derived measurements could be used as biomarkers for enhancing detection of glaucoma and its progression, as well as to reveal novel insights about pathophysiology. Moreover, these innovations have demonstrated that damage to the macula, a critical region for the vision-related quality of life, can be observed in the early stages of glaucomatous eyes, leading to a paradigm shift in glaucoma monitoring. Other advances in software and hardware, such as artificial intelligence-based algorithms, adaptive optics, and visible-light OCT, may further benefit clinical management of glaucoma in the future. This article reviews the utility of OCT and OCTA for glaucoma diagnosis and disease progression detection, emphasizes the importance of detecting macula damage in glaucoma, and highlights the future perspective of OCT and OCTA. We conclude that the OCT and OCTA are essential glaucoma detection and monitoring tools, leading to clinical and economic benefits for patients and society.
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Affiliation(s)
- Yukihiro Shiga
- Neuroscience Division, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec H2X 0A9, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Takashi Nishida
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California 92093, USA
| | - Jin Wook Jeoung
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Adriana Di Polo
- Neuroscience Division, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec H2X 0A9, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, 1225 NE Second Avenue, Portland, Oregon 97232, USA
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Williams DR, Burns SA, Miller DT, Roorda A. Evolution of adaptive optics retinal imaging [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:1307-1338. [PMID: 36950228 PMCID: PMC10026580 DOI: 10.1364/boe.485371] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/02/2023] [Indexed: 05/02/2023]
Abstract
This review describes the progress that has been achieved since adaptive optics (AO) was incorporated into the ophthalmoscope a quarter of a century ago, transforming our ability to image the retina at a cellular spatial scale inside the living eye. The review starts with a comprehensive tabulation of AO papers in the field and then describes the technological advances that have occurred, notably through combining AO with other imaging modalities including confocal, fluorescence, phase contrast, and optical coherence tomography. These advances have made possible many scientific discoveries from the first maps of the topography of the trichromatic cone mosaic to exquisitely sensitive measures of optical and structural changes in photoreceptors in response to light. The future evolution of this technology is poised to offer an increasing array of tools to measure and monitor in vivo retinal structure and function with improved resolution and control.
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Affiliation(s)
- David R. Williams
- The Institute of Optics and the Center for
Visual Science, University of Rochester,
Rochester NY, USA
| | - Stephen A. Burns
- School of Optometry, Indiana
University at Bloomington, Bloomington IN, USA
| | - Donald T. Miller
- School of Optometry, Indiana
University at Bloomington, Bloomington IN, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and
Vision Science, University of California at Berkeley, Berkeley CA, USA
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Zhao J, Vleck AV, Winetraub Y, Du L, Han Y, Aasi S, Sarin KY, de la Zerda A. Rapid Cellular-Resolution Skin Imaging with Optical Coherence Tomography Using All-Glass Multifocal Metasurfaces. ACS NANO 2023; 17:3442-3451. [PMID: 36745734 PMCID: PMC10619470 DOI: 10.1021/acsnano.2c09542] [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] [Indexed: 06/18/2023]
Abstract
Cellular-resolution optical coherence tomography (OCT) is a powerful tool offering noninvasive histology-like imaging. However, like other optical microscopy tools, a high numerical aperture (N.A.) lens is required to generate a tight focus, generating a narrow depth of field, which necessitates dynamic focusing and limiting the imaging speed. To overcome this limitation, we developed a metasurface platform that generates multiple axial foci, which multiplies the volumetric OCT imaging speed by offering several focal planes. This platform offers accurate and flexible control over the number, positions, and intensities of axial foci generated. All-glass metasurface optical elements 8 mm in diameter are fabricated from fused-silica wafers and implemented into our scanning OCT system. With a constant lateral resolution of 1.1 μm over all depths, the multifocal OCT triples the volumetric acquisition speed for dermatological imaging, while still clearly revealing features of stratum corneum, epidermal cells, and dermal-epidermal junctions and offering morphological information as diagnostic criteria for basal cell carcinoma. The imaging speed can be further improved in a sparse sample, e.g., 7-fold with a seven-foci beam. In summary, this work demonstrates the concept of metasurface-based multifocal OCT for rapid virtual biopsy, further providing insights for developing rapid volumetric imaging systems with high resolution and compact volume.
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Affiliation(s)
- Jingjing Zhao
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Aidan Van Vleck
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Yonatan Winetraub
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, United States; Biophysics Program at Stanford, Molecular Imaging Program at Stanford, and The Bio-X Program, Stanford University, Stanford, California 94305, United States
| | - Lin Du
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley 94720, United States
| | - Yong Han
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Sumaira Aasi
- Department of Dermatology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Kavita Yang Sarin
- Department of Dermatology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, United States; Biophysics Program at Stanford, Molecular Imaging Program at Stanford, and The Bio-X Program, Stanford University, Stanford, California 94305, United States; The Chan Zuckerberg Biohub, San Francisco, California 94158, United States
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12
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Zhou L, Lin D, Xu G, Wang X, Chen Z, Wang D, Fan H. Alteration of neurofilament heavy chain and its phosphoforms reveals early subcellular damage beyond the optic nerve head in glaucoma. Front Neurol 2023; 14:1091697. [PMID: 37034083 PMCID: PMC10073422 DOI: 10.3389/fneur.2023.1091697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/20/2023] [Indexed: 04/11/2023] Open
Abstract
Background Retinal ganglion cells (RGCs) axon loss at the site of optic nerve head (ONH) is long believed as the common pathology in glaucoma since different types of glaucoma possessing different characteristic of intraocular pressure, and this damage was only detected at the later stage. Methods To address these disputes and detect early initiating events underlying RGCs, we firstly detected somatic or axonal change and compared their difference in acute and chronic phase of primary angle-closed glaucoma (PACG) patient using optical coherence tomography (OCT), then an axonal-enriched cytoskeletal protein neurofilament heavy chain and its phosphoforms (NF-H, pNF-H) were utilized to reveal spatio-temporal undetectable damage insulted by acute and chronic ocular hypertension (AOH, COH) in two well characterized glaucoma mice models. Results In clinic, we detected nonhomogeneous changes such as ONH and soma of RGCs presenting edema in acute phase but atrophy in chronic one by OCT. In AOH animal models, an increase expression of NF-H especially its phosphorylation modification was observed as early as 4 h before RGCs loss, which presented as somatic accumulation in the peripheral retina and at the sites of ONH. In contrast, in microbeads induced COH model, NF-H and pNF-H reduced significantly, these changes firstly occurred as NF-H or pNF-H disconnection at ONH and optic nerve after 2 weeks when the intraocular pressure reaching the peak; Meanwhile, we detected aqueous humor pNF-H elevation after AOH and slight reduction in the COH. Conclusion Together, our data supports that early alteration of NF-H and its phosphoforms would reveal undetectable subcellular damage consisting of peripheral somatic neurofilament compaction, impaired axonal transport and distal axonal disorganization of cytoskeleton beyond the ONH, and identifies two distinct axonal degeneration which were Wallerian combination with retrograde degeneration in acute PACG and retrograde degeneration in the chronic one.
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Affiliation(s)
- Lan Zhou
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Dongyue Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Guihua Xu
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
| | - Xiaoyi Wang
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
| | - Zilin Chen
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
| | - Dingding Wang
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
| | - Huiya Fan
- Ophthalmological Center of Huizhou Central People's Hospital, Huizhou, Guangdong, China
- *Correspondence: Huiya Fan
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13
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Zhang J, Boccara C, Grieve K, Jia Y, Xiao P. Editorial: The development and clinical application of innovative optical ophthalmic imaging techniques. Front Med (Lausanne) 2022; 9:1058069. [DOI: 10.3389/fmed.2022.1058069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022] Open
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14
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Liu Z, Zhang F, Zucca K, Agrawal A, Hammer DX. Ultrahigh-speed multimodal adaptive optics system for microscopic structural and functional imaging of the human retina. BIOMEDICAL OPTICS EXPRESS 2022; 13:5860-5878. [PMID: 36733751 PMCID: PMC9872887 DOI: 10.1364/boe.462594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/16/2022] [Accepted: 09/20/2022] [Indexed: 05/02/2023]
Abstract
We describe the design and performance of a multimodal and multifunctional adaptive optics (AO) system that combines scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) for simultaneous retinal imaging at 13.4 Hz. The high-speed AO-OCT channel uses a 3.4 MHz Fourier-domain mode-locked (FDML) swept source. The system achieves exquisite resolution and sensitivity for pan-macular and transretinal visualization of retinal cells and structures while providing a functional assessment of the cone photoreceptors. The ultra-high speed also enables wide-field scans for clinical usability and angiography for vascular visualization. The FDA FDML-AO system is a powerful platform for studying various retinal and neurological diseases for vision science research, retina physiology investigation, and biomarker development.
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Affiliation(s)
- Zhuolin Liu
- Center for Devices and Radiological Health
(CDRH), U. S. Food and Drug Administration (FDA), Silver Spring, Maryland 20993, USA
| | - Furu Zhang
- Center for Devices and Radiological Health
(CDRH), U. S. Food and Drug Administration (FDA), Silver Spring, Maryland 20993, USA
- Co-first author
| | - Kelvy Zucca
- Center for Devices and Radiological Health
(CDRH), U. S. Food and Drug Administration (FDA), Silver Spring, Maryland 20993, USA
| | - Anant Agrawal
- Center for Devices and Radiological Health
(CDRH), U. S. Food and Drug Administration (FDA), Silver Spring, Maryland 20993, USA
| | - Daniel X. Hammer
- Center for Devices and Radiological Health
(CDRH), U. S. Food and Drug Administration (FDA), Silver Spring, Maryland 20993, USA
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15
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Wei X, Hormel TT, Pi S, Wang B, Morrison JC, Jia Y. Wide-field sensorless adaptive optics swept-source optical coherence tomographic angiography in rodents. OPTICS LETTERS 2022; 47:5060-5063. [PMID: 36181186 DOI: 10.1364/ol.472387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/04/2022] [Indexed: 06/16/2023]
Abstract
In this study, we present a sensorless adaptive optics swept-source optical coherence tomographic angiography (sAO-SS-OCTA) imaging system for mice. Real-time graphics processing unit (GPU)-based OCTA image acquisition and processing software were applied to guide wavefront correction using a deformable mirror based on signal strength index (SSI) from both OCT and OCTA images. High-resolution OCTA images with aberrations corrected and contrast enhanced were successfully acquired. Fifty-degree field of view high-resolution montaged OCTA images were also acquired.
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16
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Srinivasan VJ, Kho AM, Chauhan P. Visible Light Optical Coherence Tomography Reveals the Relationship of the Myoid and Ellipsoid to Band 2 in Humans. Transl Vis Sci Technol 2022; 11:3. [PMID: 36053140 PMCID: PMC9440607 DOI: 10.1167/tvst.11.9.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose We employ visible light optical coherence tomography (OCT) to investigate the relationship between the myoid, ellipsoid, and band 2 in the living human retina. Rather than refute existing theories, we aim to reveal new bands and better delineate the structures at hand. Methods An upgraded spectral/Fourier domain visible light OCT prototype, with 1.0-µm axial resolution, imaged 13 eyes of 13 young adult human subjects (23–40 years old) without a history of ocular pathology. The external limiting membrane (band 1) and band 2 edges were segmented. Reflectivity was examined along the inner segment (IS), defined as extending from band 1 to the band 2 center, and within band 2 itself. Results Images highlight a nearly continuously resolved extrafoveal internal limiting membrane, the peripheral single-cell thick ganglion cell layer, and the peripheral photoreceptor axonal fiber layer, a peripheral division of band 2 into bands 2a and 2b, and a reflectivity-based division of the IS into “m” and “e” zones. Discussion Topography and transverse intensity variations of the outermost band 2b suggest an association with rods. The “m” and “e” zone border is consistent with the myoid–ellipsoid boundary, even recapitulating the well-documented distribution of mitochondria throughout the IS at the foveal center. Theories of outer retinal reflectivity in OCT must adequately explain these observations. Translational Relevance Findings support that band 2 does partially overlap with the ellipsoid in transversally averaged OCT images due to photoreceptor IS length dispersion but argue that the inner ellipsoid must be inner to band 2, as suggested by prior quantitative measurements.
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Affiliation(s)
- Vivek J Srinivasan
- Department of Ophthalmology, NYU Langone Health, New York, NY, USA.,Department of Radiology, NYU Langone Health, New York, NY, USA.,Tech4Health Institute, NYU Langone Health, New York, NY, USA.,Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Aaron M Kho
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Pooja Chauhan
- Department of Radiology, NYU Langone Health, New York, NY, USA.,Tech4Health Institute, NYU Langone Health, New York, NY, USA
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17
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Ong J, Zarnegar A, Corradetti G, Singh SR, Chhablani J. Advances in Optical Coherence Tomography Imaging Technology and Techniques for Choroidal and Retinal Disorders. J Clin Med 2022; 11:jcm11175139. [PMID: 36079077 PMCID: PMC9457394 DOI: 10.3390/jcm11175139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/27/2022] [Accepted: 08/28/2022] [Indexed: 11/16/2022] Open
Abstract
Optical coherence tomography (OCT) imaging has played a pivotal role in the field of retina. This light-based, non-invasive imaging modality provides high-quality, cross-sectional analysis of the retina and has revolutionized the diagnosis and management of retinal and choroidal diseases. Since its introduction in the early 1990s, OCT technology has continued to advance to provide quicker acquisition times and higher resolution. In this manuscript, we discuss some of the most recent advances in OCT technology and techniques for choroidal and retinal diseases. The emerging innovations discussed include wide-field OCT, adaptive optics OCT, polarization sensitive OCT, full-field OCT, hand-held OCT, intraoperative OCT, at-home OCT, and more. The applications of these rising OCT systems and techniques will allow for a closer monitoring of chorioretinal diseases and treatment response, more robust analysis in basic science research, and further insights into surgical management. In addition, these innovations to optimize visualization of the choroid and retina offer a promising future for advancing our understanding of the pathophysiology of chorioretinal diseases.
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Affiliation(s)
- Joshua Ong
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Arman Zarnegar
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Giulia Corradetti
- Department of Ophthalmology, Doheny Eye Institute, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at the University of California, Los Angeles, CA 90033, USA
| | | | - Jay Chhablani
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- Correspondence:
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18
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The Role of Medical Image Modalities and AI in the Early Detection, Diagnosis and Grading of Retinal Diseases: A Survey. Bioengineering (Basel) 2022; 9:bioengineering9080366. [PMID: 36004891 PMCID: PMC9405367 DOI: 10.3390/bioengineering9080366] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 11/16/2022] Open
Abstract
Traditional dilated ophthalmoscopy can reveal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), diabetic macular edema (DME), retinal tear, epiretinal membrane, macular hole, retinal detachment, retinitis pigmentosa, retinal vein occlusion (RVO), and retinal artery occlusion (RAO). Among these diseases, AMD and DR are the major causes of progressive vision loss, while the latter is recognized as a world-wide epidemic. Advances in retinal imaging have improved the diagnosis and management of DR and AMD. In this review article, we focus on the variable imaging modalities for accurate diagnosis, early detection, and staging of both AMD and DR. In addition, the role of artificial intelligence (AI) in providing automated detection, diagnosis, and staging of these diseases will be surveyed. Furthermore, current works are summarized and discussed. Finally, projected future trends are outlined. The work done on this survey indicates the effective role of AI in the early detection, diagnosis, and staging of DR and/or AMD. In the future, more AI solutions will be presented that hold promise for clinical applications.
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19
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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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20
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Marsh-Armstrong B, Murrell KS, Valente D, Jonnal RS. Using directional OCT to analyze photoreceptor visibility over AMD-related drusen. Sci Rep 2022; 12:9763. [PMID: 35697705 PMCID: PMC9192709 DOI: 10.1038/s41598-022-13106-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 05/20/2022] [Indexed: 02/03/2023] Open
Abstract
Investigators have reported reduced visibility of the cone photoreceptors overlying drusen using adaptive optics (AO) imaging techniques. Two hypotheses have been proposed to explain this phenomenon. First, the disease-related deformation of the photoreceptor outer segment (OS) may reduce its ability to act as a wave guide, thus decreasing the cell's familiar reflectance pattern. Second, drusen could disorient the photoreceptors away from the eye's pupil, reducing the amount of light reflected back out the pupil. In this work, we use directional OCT (dOCT) images of drusen in AMD patients to measure the respective contributions of these deforming and disorienting factors.
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Affiliation(s)
| | - Kelly S. Murrell
- grid.27860.3b0000 0004 1936 9684University of California, Davis Eye Center, Sacramento, USA
| | - Denise Valente
- grid.27860.3b0000 0004 1936 9684University of California, Davis Eye Center, Sacramento, USA
| | - Ravi S. Jonnal
- grid.27860.3b0000 0004 1936 9684University of California, Davis Eye Center, Sacramento, USA
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21
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Multi-modal and multi-scale clinical retinal imaging system with pupil and retinal tracking. Sci Rep 2022; 12:9577. [PMID: 35688890 PMCID: PMC9187716 DOI: 10.1038/s41598-022-13631-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT) and OCT angiography (OCTA) imaging modalities and provides multi-scale fields of view. For high resolution, and high lateral resolution in particular, cellular imaging correction of aberrations by adaptive optics (AO) is employed. The entire instrument has a compact design and the scanning head is mounted on motorized translation stages that enable 3D self-alignment with respect to the subject's eye by tracking the pupil position. Retinal tracking, based on the information provided by SLO, is incorporated in the instrument to compensate for retinal motion during OCT imaging. The imaging capabilities of the multi-modal and multi-scale instrument were tested by imaging healthy volunteers and patients.
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22
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Kim TH, Ma G, Son T, Yao X. Functional Optical Coherence Tomography for Intrinsic Signal Optoretinography: Recent Developments and Deployment Challenges. Front Med (Lausanne) 2022; 9:864824. [PMID: 35445037 PMCID: PMC9013890 DOI: 10.3389/fmed.2022.864824] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Intrinsic optical signal (IOS) imaging of the retina, also termed as optoretinogram or optoretinography (ORG), promises a non-invasive method for the objective assessment of retinal function. By providing the unparalleled capability to differentiate individual retinal layers, functional optical coherence tomography (OCT) has been actively investigated for intrinsic signal ORG measurements. However, clinical deployment of functional OCT for quantitative ORG is still challenging due to the lack of a standardized imaging protocol and the complication of IOS sources and mechanisms. This article aims to summarize recent developments of functional OCT for ORG measurement, OCT intensity- and phase-based IOS processing. Technical challenges and perspectives of quantitative IOS analysis and ORG interpretations are discussed.
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Affiliation(s)
- Tae-Hoon Kim
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Guangying Ma
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Taeyoon Son
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Xincheng Yao
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
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23
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Sampson DM, Dubis AM, Chen FK, Zawadzki RJ, Sampson DD. Towards standardizing retinal optical coherence tomography angiography: a review. LIGHT, SCIENCE & APPLICATIONS 2022; 11:63. [PMID: 35304441 PMCID: PMC8933532 DOI: 10.1038/s41377-022-00740-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 05/11/2023]
Abstract
The visualization and assessment of retinal microvasculature are important in the study, diagnosis, monitoring, and guidance of treatment of ocular and systemic diseases. With the introduction of optical coherence tomography angiography (OCTA), it has become possible to visualize the retinal microvasculature volumetrically and without a contrast agent. Many lab-based and commercial clinical instruments, imaging protocols and data analysis methods and metrics, have been applied, often inconsistently, resulting in a confusing picture that represents a major barrier to progress in applying OCTA to reduce the burden of disease. Open data and software sharing, and cross-comparison and pooling of data from different studies are rare. These inabilities have impeded building the large databases of annotated OCTA images of healthy and diseased retinas that are necessary to study and define characteristics of specific conditions. This paper addresses the steps needed to standardize OCTA imaging of the human retina to address these limitations. Through review of the OCTA literature, we identify issues and inconsistencies and propose minimum standards for imaging protocols, data analysis methods, metrics, reporting of findings, and clinical practice and, where this is not possible, we identify areas that require further investigation. We hope that this paper will encourage the unification of imaging protocols in OCTA, promote transparency in the process of data collection, analysis, and reporting, and facilitate increasing the impact of OCTA on retinal healthcare delivery and life science investigations.
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Affiliation(s)
- Danuta M Sampson
- Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, GU2 7XH, UK.
| | - Adam M Dubis
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, London, EC1V 2PD, UK
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, Western Australia, 6009, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, 6000, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, 3002, Australia
| | - Robert J Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, 95817, USA
| | - David D Sampson
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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24
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Abstract
Optical coherence tomography (OCT) is an imaging technique based on interferometry of backscattered lights from materials and biological samples. For the quantitative evaluation of an OCT system, artificial optical samples or phantoms are commonly used. They mimic the structure of biological tissues and can provide a quality standard for comparison within and across devices. Phantoms contain medium matrix and scattering particles within the dimension range of target biological structures such as the retina. The aim was to determine if changes in speckle derived optical texture could be employed to classify the OCT phantoms based on their structural composition. Four groups of phantom types were prepared and imaged. These comprise different concentrations of a medium matrix (gelatin solution), different sized polystyrene beads (PBs), the volume of PBs and different refractive indices of scatterers (PBs and SiO2). Texture analysis was applied to detect subtle optical differences in OCT image intensity, surface coarseness and brightness of regions of interest. A semi-automated classifier based on principal component analysis (PCA) and support vector machine (SVM) was applied to discriminate the various texture models. The classifier detected correctly different phantom textures from 82% to 100%, demonstrating that analysis of the texture of OCT images can be potentially used to discriminate biological structure based on subtle changes in light scattering.
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25
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Affiliation(s)
- Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA 94720
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26
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Brunner E, Shatokhina J, Shirazi MF, Drexler W, Leitgeb R, Pollreisz A, Hitzenberger CK, Ramlau R, Pircher M. Retinal adaptive optics imaging with a pyramid wavefront sensor. BIOMEDICAL OPTICS EXPRESS 2021; 12:5969-5990. [PMID: 34745716 PMCID: PMC8548025 DOI: 10.1364/boe.438915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/04/2021] [Indexed: 05/25/2023]
Abstract
The pyramid wavefront sensor (P-WFS) has replaced the Shack-Hartmann (SH-) WFS as the sensor of choice for high-performance adaptive optics (AO) systems in astronomy. Many advantages of the P-WFS, such as its adjustable pupil sampling and superior sensitivity, are potentially of great benefit for AO-supported imaging in ophthalmology as well. However, so far no high quality ophthalmic AO imaging was achieved using this novel sensor. Usually, a P-WFS requires modulation and high precision optics that lead to high complexity and costs of the sensor. These factors limit the competitiveness of the P-WFS with respect to other WFS devices for AO correction in visual science. Here, we present a cost-effective realization of AO correction with a non-modulated P-WFS based on standard components and apply this technique to human retinal in vivo imaging using optical coherence tomography (OCT). P-WFS based high quality AO imaging was successfully performed in 5 healthy subjects and smallest retinal cells such as central foveal cone photoreceptors are visualized. The robustness and versatility of the sensor is demonstrated in the model eye under various conditions and in vivo by high-resolution imaging of other structures in the retina using standard and extended fields of view. As a quality benchmark, the performance of conventional SH-WFS based AO was used and successfully met. This work may trigger a paradigm shift with respect to the wavefront sensor of choice for AO in ophthalmic imaging.
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Affiliation(s)
- Elisabeth Brunner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Julia Shatokhina
- Johann Radon Institute for Computational and Applied Mathematics, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Muhammad Faizan Shirazi
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Rainer Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Andreas Pollreisz
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Ronny Ramlau
- Johann Radon Institute for Computational and Applied Mathematics, Altenbergerstrasse 69, A-4040 Linz, Austria
- Johannes Kepler University Linz, Industrial Mathematics Institute, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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Valente D, Vienola KV, Zawadzki RJ, Jonnal RS. Simultaneous directional full-field OCT using path-length and carrier multiplexing. OPTICS EXPRESS 2021; 29:32179-32195. [PMID: 34615295 PMCID: PMC8687100 DOI: 10.1364/oe.435761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Full-field swept-source optical coherence tomography (FF-SS-OCT) is an emerging technology with potential applications in ophthalmic imaging, microscopy, metrology, and other domains. Here we demonstrate a novel method of multiplexing FF-SS-OCT signals using carrier modulation (CM). The principle of CM could be used to inspect various properties of the scattered light, e.g. its spectrum, polarization, Doppler shift, or distribution in the pupil. The last of these will be explored in this work, where CM was used to acquire images passing through two different optical pupils. The two pupils contained semicircular optical windows with perpendicular orientations, with each window permitting measurement of scattering anisotropy in one dimension by inducing an optical delay between the images formed by the two halves of the pupil. Together, the two forms of multiplexing permit measurement of differential scattering anisotropy in the x and y dimensions simultaneously. To demonstrate the feasibility of this technique our carrier multiplexed directional FF-OCT (CM-D-FF-OCT) system was used to acquire images of a microlens array, human hair, onion skin and in vivo human retina. The results of these studies are presented and briefly discussed in the context of future development and application of this technique.
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Affiliation(s)
- Denise Valente
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Kari V. Vienola
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Robert J. Zawadzki
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
- EyePod Small Animal Ocular Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, CA 95616, USA
| | - Ravi S. Jonnal
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
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Abstract
Advances in retinal imaging are enabling researchers and clinicians to make precise noninvasive measurements of the retinal vasculature in vivo. This includes measurements of capillary blood flow, the regulation of blood flow, and the delivery of oxygen, as well as mapping of perfused blood vessels. These advances promise to revolutionize our understanding of vascular regulation, as well as the management of retinal vascular diseases. This review provides an overview of imaging and optical measurements of the function and structure of the ocular vasculature. We include general characteristics of vascular systems with an emphasis on the eye and its unique status. The functions of vascular systems are discussed, along with physical principles governing flow and its regulation. Vascular measurement techniques based on reflectance and absorption are briefly introduced, emphasizing ways of generating contrast. One of the prime ways to enhance contrast within vessels is to use techniques sensitive to the motion of cells, allowing precise measurements of perfusion and blood velocity. Finally, we provide a brief introduction to retinal vascular diseases.
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Affiliation(s)
- Stephen A Burns
- Indiana University School of Optometry, Bloomington, Indiana 47405, USA; , ,
| | - Ann E Elsner
- Indiana University School of Optometry, Bloomington, Indiana 47405, USA; , ,
| | - Thomas J Gast
- Indiana University School of Optometry, Bloomington, Indiana 47405, USA; , ,
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29
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Kadomoto S, Muraoka Y, Uji A, Ooto S, Kawai K, Ishikura M, Nishigori N, Akagi T, Tsujikawa A. Human Foveal Cone and Müller Cells Examined by Adaptive Optics Optical Coherence Tomography. Transl Vis Sci Technol 2021; 10:17. [PMID: 34559184 PMCID: PMC8475288 DOI: 10.1167/tvst.10.11.17] [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: 01/28/2023] Open
Abstract
Purpose The purpose of this study was to image and investigate the foveal microstructure of human cone and Müller cells using adaptive optics-optical coherence tomography. Methods Six healthy subjects underwent the prototype adaptive optics-optical coherence tomography imaging, which allowed an axial resolution of 3.4 µm and a transverse resolution of approximately 3 µm. The morphological features of the individual retinal cells observed in the foveola were qualitatively and quantitatively evaluated. Results In the six healthy subjects, the image B-scans showed hyper-reflective dots that were densely packed in the outer nuclear layer. The mean number, diameter, and density of hyper-reflective dots in the foveola were 250.8 ± 59.6, 12.7 ± 59.6 µm, and 6966 ± 1833/mm2, respectively. These qualitative and quantitative findings regarding the hyper-reflective dots were markedly consistent with the morphological features of the foveal cone cell nuclei. Additionally, the images showed the funnel-shaped hyporeflective bodies running vertically and obliquely between the inner and external limiting membranes, illustrating the cell morphology of the foveal Müller cells. Conclusions Using adaptive optics, we succeeded in visualizing cross-sectional images of the individual cone and Müller cells of the human retina in vivo. Translational Relevance Adaptive optics-optical coherence tomography would help to improve our understanding of the pathogenesis of macular diseases.
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Affiliation(s)
- Shin Kadomoto
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuki Muraoka
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihito Uji
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sotaro Ooto
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kentaro Kawai
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masaharu Ishikura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Naomi Nishigori
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tadamichi Akagi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
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30
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Chen W, Tsissios G, Sallese A, Smucker B, Nguyen AT, Chen J, Wang H, Del Rio-Tsonis K. In Vivo Imaging of Newt Lens Regeneration: Novel Insights Into the Regeneration Process. Transl Vis Sci Technol 2021; 10:4. [PMID: 34383878 PMCID: PMC8362625 DOI: 10.1167/tvst.10.10.4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose To establish optical coherence tomography (OCT) as an in vivo imaging modality for investigating the process of newt lens regeneration. Methods Spectral-domain OCT was employed for in vivo imaging of the newt lens regeneration process. A total of 37 newts were lentectomized and followed by OCT imaging over the course of 60 to 80 days. Histological images were obtained at several time points to compare with the corresponding OCT images. Volume measurements were also acquired. Results OCT can identify the key features observed in corresponding histological images based on the scattering differences from various eye tissues, such as the cornea, intact and regenerated lens, and the iris. Lens volume measurements from three-dimensional OCT images showed that the regenerating lens size increased linearly until 60 days post-lentectomy. Conclusions Using OCT imaging, we were able to track the entire process of newt lens regeneration in vivo for the first time. Three-dimensional OCT images allowed us to volumetrically quantify and visualize the dynamic spatial relationships between tissues during the regeneration process. Our results establish OCT as anin vivo imaging modality to track/analyze the entire lens regeneration process from the same animal. Translational Relevance Lens regeneration in newts represents a unique example of vertebrate tissue plasticity. Investigating the cellular and morphological events that govern this extraordinary process in vivo will advance our understanding and shed light on developing new therapies to treat blinding disorders in higher vertebrates.
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Affiliation(s)
- Weihao Chen
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, USA
| | - Georgios Tsissios
- Department of Biology Miami University, Oxford, OH, USA.,Center for Visual Sciences at Miami University, Oxford, OH, USA.,Cellular Molecular and Structural Biology Program, Miami University, Oxford, OH, USA
| | - Anthony Sallese
- Department of Biology Miami University, Oxford, OH, USA.,Center for Visual Sciences at Miami University, Oxford, OH, USA
| | - Byran Smucker
- Center for Visual Sciences at Miami University, Oxford, OH, USA.,Department of Statistics, Miami University, Oxford, OH, USA
| | - Anh-Thu Nguyen
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, USA
| | - Junfan Chen
- Department of Chemistry and Biochemistry, Miami University, Oxford OH, USA
| | - Hui Wang
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, USA.,Center for Visual Sciences at Miami University, Oxford, OH, USA
| | - Katia Del Rio-Tsonis
- Department of Biology Miami University, Oxford, OH, USA.,Center for Visual Sciences at Miami University, Oxford, OH, USA.,Cellular Molecular and Structural Biology Program, Miami University, Oxford, OH, USA
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31
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Jonnal RS. Toward a clinical optoretinogram: a review of noninvasive, optical tests of retinal neural function. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1270. [PMID: 34532407 PMCID: PMC8421939 DOI: 10.21037/atm-20-6440] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 07/12/2021] [Indexed: 11/17/2022]
Abstract
The past few years have witnessed rapid development of the optoretinogram-a noninvasive, optical measurement of neural function in the retina, and especially the photoreceptors (Ph). While its recent development has been rapid, it represents the culmination of hundreds of experiments spanning decades. Early work showed measurable and reproducible changes in the optical properties of retinal explants and suspensions of Ph, and uncovered some of the biophysical and biochemical mechanisms underlying them. That work thus provided critical motivation for more recent work based on clinical imaging platforms, whose eventual goal is the improvement of ophthalmic care and streamlining the discovery of novel therapeutics. The first part of this review consists of a selective summary of the early work, and identifies four kinds of stimulus-evoked optical signals that have emerged from it: changes in light scattered from the membranous discs of the Ph's outer segment (OS), changes in light scattered by the front and back boundaries of the OS, rearrangement of scattering material in and near the OS, and changes in the OS length. In the past decade, all four of these signals have continued to be investigated using imaging systems already used in the clinic or intended for clinical and translational use. The second part of this review discusses these imaging modalities, their potential to detect and quantify the signals of interest, and other factors influencing their translational promise. Particular attention is paid to phase-sensitive optical coherence tomography (OCT) with adaptive optics (AO), a method in which both the amplitude and the phase of light reflected from individual Ph is monitored as visible stimuli are delivered to them. The record of the light's phase is decoded to reveal a reproducible pattern of deformation in the OS, while the amplitude reveals changes in scattering and structural rearrangements. The method has been demonstrated in a few labs and has been used to measure responses from both rods and cones. With the ability to detect responses to stimuli isomerizing less than 0.01% of photopigment, this technique may prove to be a quick, noninvasive, and objective way to measure subtle disease-related dysfunction at the cellular level, and thus to provide an entirely new and complementary biomarker for retinal disease and recovery.
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32
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Wynne N, Carroll J, Duncan JL. Promises and pitfalls of evaluating photoreceptor-based retinal disease with adaptive optics scanning light ophthalmoscopy (AOSLO). Prog Retin Eye Res 2021; 83:100920. [PMID: 33161127 PMCID: PMC8639282 DOI: 10.1016/j.preteyeres.2020.100920] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 12/15/2022]
Abstract
Adaptive optics scanning light ophthalmoscopy (AOSLO) allows visualization of the living human retina with exquisite single-cell resolution. This technology has improved our understanding of normal retinal structure and revealed pathophysiological details of a number of retinal diseases. Despite the remarkable capabilities of AOSLO, it has not seen the widespread commercial adoption and mainstream clinical success of other modalities developed in a similar time frame. Nevertheless, continued advancements in AOSLO hardware and software have expanded use to a broader range of patients. Current devices enable imaging of a number of different retinal cell types, with recent improvements in stimulus and detection schemes enabling monitoring of retinal function, microscopic structural changes, and even subcellular activity. This has positioned AOSLO for use in clinical trials, primarily as exploratory outcome measures or biomarkers that can be used to monitor disease progression or therapeutic response. AOSLO metrics could facilitate patient selection for such trials, to refine inclusion criteria or to guide the choice of therapy, depending on the presence, absence, or functional viability of specific cell types. Here we explore the potential of AOSLO retinal imaging by reviewing clinical applications as well as some of the pitfalls and barriers to more widespread clinical adoption.
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Affiliation(s)
- Niamh Wynne
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA, USA.
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33
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Abstract
The high power of the eye and optical components used to image it result in "static" distortion, remaining constant across acquired retinal images. In addition, raster-based systems sample points or lines of the image over time, suffering from "dynamic" distortion due to the constant motion of the eye. We recently described an algorithm which corrects for the latter problem but is entirely blind to the former. Here, we describe a new procedure termed "DIOS" (Dewarp Image by Oblique Shift) to remove static distortion of arbitrary type. Much like the dynamic correction method, it relies on locating the same tissue in multiple frames acquired as the eye moves through different gaze positions. Here, the resultant maps of pixel displacement are used to form a sparse system of simultaneous linear equations whose solution gives the common warp seen by all frames. We show that the method successfully handles torsional movement of the eye. We also show that the output of the previously described dynamic correction procedure may be used as input for this new procedure, recovering an image of the tissue that is, in principle, a faithful replica free of any type of distortion. The method could be extended beyond ocular imaging, to any kind of imaging system in which the image can move or be made to move across the detector.
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Affiliation(s)
- Phillip Bedggood
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Andrew Metha
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
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34
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Wu S, Okada R, Liu Y, Fang Y, Yan F, Wang C, Li H, Kobayashi H, Chen Y, Tang Q. Quantitative analysis of vascular changes during photoimmunotherapy using speckle variance optical coherence tomography (SV-OCT). BIOMEDICAL OPTICS EXPRESS 2021; 12:1804-1820. [PMID: 33996199 PMCID: PMC8086455 DOI: 10.1364/boe.419163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Near-infrared (NIR) photoimmunotherapy (NIR-PIT) is an emerging cancer therapy based on a monoclonal antibody and phthalocyanine dye conjugate. Direct tumor necrosis and immunogenic cell death occur during NIR irradiation. However, the alteration of tumor blood vessels and blood volume inside the blood vessels induced by the NIR-PIT process is still unknown. In our study, a speckle variance (SV) algorithm combined with optical coherence tomography (OCT) technology was applied to monitor the change of blood vessels and the alterations of the blood volume inside the blood vessels during and after NIR-PIT treatment. Vascular density and the measurable diameter of the lumen in the blood vessel (the diameter of the region filled with blood) were extracted for quantitively uncovering the alterations of blood vessels and blood volume induced by NIR-PIT treatment. The results indicate that both the density and the diameter of the lumen in the blood vessels decrease during the NIR-PIT process, while histological results indicated the blood vessels were dilated. The increase of permeability of blood vessels could lead to the increase of the blood pool volume within the tumor (shown in histology) and results in the decrease of free-moving red blood cells inside the blood vessels (shown in SV-OCT).
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Affiliation(s)
- Shulian Wu
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- These authors contributed equally to this work
| | - Ryuhei Okada
- National Institute of Health, National Cancer Institute, Molecular Imaging Program, Bldg 10, Room B3B47, Bethesda, Maryland 20892-1088, USA
- These authors contributed equally to this work
| | - Yi Liu
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Yuhong Fang
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
| | - Feng Yan
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Chen Wang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Hui Li
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
| | - Hisataka Kobayashi
- National Institute of Health, National Cancer Institute, Molecular Imaging Program, Bldg 10, Room B3B47, Bethesda, Maryland 20892-1088, USA
| | - Yu Chen
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Department of Biomedical Engineering, University of Massachusetts, Amherst, MA 01003, USA
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
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Zhang S, Phu J, Xu P, Wang H, Kalloniatis M, Zangerl B. The performance and confidence of clinicians in training in the analysis of ophthalmic images within a work-integrated teaching model. Ophthalmic Physiol Opt 2021; 41:768-781. [PMID: 33682940 DOI: 10.1111/opo.12795] [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: 10/23/2020] [Accepted: 01/08/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE A fundamental clinical skill is the recognition of artefacts within the outputs of advanced imaging modalities. However, current teaching programmes of healthcare practitioners are becoming increasingly challenged to provide practical exposure within an already crowded curriculum. This study evaluates the impact of a novel work-integrated teaching model on the confidence and competence of clinicians in the use of optical coherence tomography (OCT) and the recognition of its artefacts. The outcomes were then used to develop a model to predict performance and guide teaching strategies. METHODS We prospectively evaluated a 6-week clinical placement for final year optometry students within a diagnostic eye clinic in 2018-2020. Participants completed a quiz on the identification of common OCT artefacts and rated their confidence levels on key areas of OCT application using a five-point Likert scale. Both were completed before (pre-rotation) and after (post-rotation) the placement. The cohort was divided into two groups; the first group was used to assess the impact of the placement and derive the prediction model for post-placement performance, which was then validated against the second group. RESULTS A significant improvement in detecting OCT imaging artefacts was seen upon completion of the placement, which was greater in participants with lower entry level performance. Across all OCT artefact subtypes, there was an improvement in detecting segmentation error, delineation error and media opacities. A model predicting post-placement student performance was developed using entry level knowledge base as the key dependent variable. Self-rated confidence improved across all domains of OCT application but was not found to be a direct predictor of actual performance. CONCLUSIONS These results highlight the benefit of a work-integrated learning programme on both academic performance and confidence whilst identifying entry level knowledge base as the key variable predicting improvement. Tailored teaching incorporating entering knowledge is the best predictor of improvement during clinical placements. Integrating clinicians into a work-integrated setting with tailored teaching and comprehensive practical exposure can be an effective method for training future or current healthcare professionals.
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Affiliation(s)
- Sophia Zhang
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Jack Phu
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Pauline Xu
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Henrietta Wang
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Michael Kalloniatis
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Barbara Zangerl
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.,School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
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36
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Zhang T, Kho AM, Yiu G, Srinivasan VJ. Visible Light Optical Coherence Tomography (OCT) Quantifies Subcellular Contributions to Outer Retinal Band 4. Transl Vis Sci Technol 2021; 10:30. [PMID: 34003965 PMCID: PMC7998011 DOI: 10.1167/tvst.10.3.30] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/17/2021] [Indexed: 01/07/2023] Open
Abstract
Purpose To use visible light optical coherence tomography (OCT) to investigate subcellular reflectivity contributions to the outermost (4th) of the retinal hyperreflective bands visualized by current clinical near-infrared (NIR) OCT. Methods Visible light OCT, with 1.0 µm axial resolution, was performed in 28 eyes of 19 human subjects (21-57 years old) without history of ocular pathology. Two foveal and three extrafoveal hyperreflective zones were consistently depicted within band 4 in all eyes. The two outermost hyperreflective bands, occasionally visualized by NIR OCT, were presumed to be the retinal pigment epithelium (RPE) and Bruch's membrane (BM). RPE thickness, BM thickness, and RPE interior reflectivity were quantified topographically across the macula. Results A method for correcting RPE multiple scattering tails was found to both improve the Gaussian goodness-of-fit for the BM intensity profile and reduce the coefficient of variation of BM thickness in vivo. No major topographical differences in macular BM thickness were noted. RPE thickness decreased with increasing eccentricity. Visible light OCT signal intensity in the RPE was weighted to the apical side and attenuated more across the RPE in the fovea than peripherally. Conclusions Morphometry of the presumed RPE and BM bands is consistent with known anatomy. Weighting of RPE reflectivity toward the apical side suggests that melanosomes are the predominant contributors to RPE backscattering and signal attenuation in young eyes. Translational Relevance By enabling morphometric analysis of the RPE and BM, visible light OCT deciphers the main reflectivity contributions to outer retinal band 4, commonly visualized by commercial OCT systems.
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Affiliation(s)
- Tingwei Zhang
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Aaron M. Kho
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Glenn Yiu
- Department of Ophthalmology and Vision Science, University of California Davis, Davis School of Medicine, Sacramento, California, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
- Department of Ophthalmology and Vision Science, University of California Davis, Davis School of Medicine, Sacramento, California, USA
- Department of Ophthalmology, New York University Langone Health, New York, New York, USA
- Department of Radiology, New York University Langone Health, New York, New York, USA
- Tech4Health Institute, New York University Langone Health, New York, New York, USA
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37
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Liu Z, Saeedi O, Zhang F, Villanueva R, Asanad S, Agrawal A, Hammer DX. Quantification of Retinal Ganglion Cell Morphology in Human Glaucomatous Eyes. Invest Ophthalmol Vis Sci 2021; 62:34. [PMID: 33760041 PMCID: PMC7995922 DOI: 10.1167/iovs.62.3.34] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Purpose To characterize retinal ganglion cell morphological changes in patients with primary open-angle glaucoma associated with hemifield defect (HD) using adaptive optics–optical coherence tomography (AO-OCT). Methods Six patients with early to moderate primary open-angle glaucoma with an average age of 58 years associated with HD and six age-matched healthy controls with an average age of 61 years were included. All participants underwent in vivo retinal ganglion cell (RGC) imaging at six primary locations across the macula with AO-OCT. Ganglion cell layer (GCL) somas were manually counted, and morphological parameters of GCL soma density, size, and symmetry were calculated. RGC cellular characteristics were correlated with functional visual field measurements. Results GCL soma density was 12,799 ± 7747 cells/mm2, 9370 ± 5572 cells/mm2, and 2134 ± 1494 cells/mm2 at 3°, 6°, and 12°, respectively, in glaucoma patients compared with 25,058 ± 4649 cells/mm2, 15,551 ± 2301 cells/mm2, and 3891 ± 1105 cells/mm2 (P < 0.05 for all locations) at the corresponding retinal locations in healthy participants. Mean soma diameter was significantly larger in glaucoma patients (14.20 ± 2.30 µm) compared with the health controls (12.32 ± 1.94 µm, P < 0.05 for all locations); symmetry was 0.36 ± 0.32 and 0.86 ± 0.13 in glaucoma and control cohorts, respectively. Conclusions Glaucoma patients had lower GCL soma density and symmetry, greater soma size, and increased variation of GCL soma reflectance compared with age-matched control subjects. The morphological changes corresponded with HD, and the cellular level structural loss correlated with visual function loss in glaucoma. AO-based morphological parameters could be potential sensitive biomarkers for glaucoma.
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Affiliation(s)
- Zhuolin Liu
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Osamah Saeedi
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore Maryland, United States
| | - Furu Zhang
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Ricardo Villanueva
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore Maryland, United States
| | - Samuel Asanad
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore Maryland, United States
| | - Anant Agrawal
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Daniel X Hammer
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, Silver Spring, Maryland, United States
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Bower AJ, Liu T, Aguilera N, Li J, Liu J, Lu R, Giannini JP, Huryn LA, Dubra A, Liu Z, Hammer DX, Tam J. Integrating adaptive optics-SLO and OCT for multimodal visualization of the human retinal pigment epithelial mosaic. BIOMEDICAL OPTICS EXPRESS 2021; 12:1449-1466. [PMID: 33796365 PMCID: PMC7984802 DOI: 10.1364/boe.413438] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 05/03/2023]
Abstract
In vivo imaging of human retinal pigment epithelial (RPE) cells has been demonstrated through multiple adaptive optics (AO)-based modalities. However, whether consistent and complete information regarding the cellular structure of the RPE mosaic is obtained across these modalities remains uncertain due to limited comparisons performed in the same eye. Here, an imaging platform combining multimodal AO-scanning light ophthalmoscopy (AO-SLO) with AO-optical coherence tomography (AO-OCT) is developed to make a side-by-side comparison of the same RPE cells imaged across four modalities: AO-darkfield, AO-enhanced indocyanine green (AO-ICG), AO-infrared autofluorescence (AO-IRAF), and AO-OCT. Co-registered images were acquired in five subjects, including one patient with choroideremia. Multimodal imaging provided multiple perspectives of the RPE mosaic that were used to explore variations in RPE cell contrast in a subject-, location-, and even cell-dependent manner. Estimated cell-to-cell spacing and density were found to be consistent both across modalities and with normative data. Multimodal images from a patient with choroideremia illustrate the benefit of using multiple modalities to infer the cellular structure of the RPE mosaic in an affected eye, in which disruptions to the RPE mosaic may locally alter the signal strength, visibility of individual RPE cells, or even source of contrast in unpredictable ways.
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Affiliation(s)
- Andrew J. Bower
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tao Liu
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nancy Aguilera
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joanne Li
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jianfei Liu
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rongwen Lu
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - John P. Giannini
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Laryssa A. Huryn
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
| | - Zhuolin Liu
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA
| | - Daniel X. Hammer
- Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA
| | - Johnny Tam
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Three-dimensional composition of the photoreceptor cone layers in healthy eyes using adaptive-optics optical coherence tomography (AO-OCT). PLoS One 2021; 16:e0245293. [PMID: 33412568 PMCID: PMC7790532 DOI: 10.1371/journal.pone.0245293] [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] [Received: 09/15/2020] [Accepted: 12/25/2020] [Indexed: 12/18/2022] Open
Abstract
Purpose To assess the signal composition of cone photoreceptors three-dimensionally in healthy retinas using adaptive optics optical coherence tomography (AO-OCT). Methods Study population. Twenty healthy eyes of ten subjects (age 23 to 67). Procedures. After routine ophthalmological assessments, eyes were examined using AO-OCT. Three-dimensional volumes were acquired at 2.5° and 6.5° foveal eccentricity in four main meridians (superior, nasal, inferior, temporal). Cone densities and signal compositions were investigated in four different planes: the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST) and full en-face plane (FEF) combining signals from all mentioned cone layers. Additionally, reliability of a simple semi-automated approach for assessment of cone density was tested. Main outcome measures. Cone density of IS/OS, IS/OS+, COST and FEF. Qualitative depiction and composition of each cone layer. Inter-rater agreement of cone density measurements. Results Mean overall cone density at all eccentricities was highest at the FEF plane (21.160/mm2), followed by COST (20.450/mm2), IS/OS+ (19.920/mm2) and IS/OS (19.530/mm2). The different meridians and eccentricities had a significant impact on cone density, with lower eccentricity resulting in higher cone densities (p≤.001), which were highest at the nasal, then temporal, then inferior and then superior meridian. Depiction of the cone mosaic differed between all 4 layers regarding signal size and packing density. Therefore, different cone layers showed evident but not complete signal overlap. Using the semi-automated technique for counting of cone signals achieved high inter-rater reliability (ICC > .99). Conclusions In healthy individuals qualitative and quantitative changes in cone signals are found not only in different eccentricities and meridians, but also within different photoreceptor layers. The variation between cone planes has to be considered when assessing the integrity of cone photoreceptors in healthy and diseased eyes using adaptive optics technology.
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Kurokawa K, Crowell JA, Do N, Lee JJ, Miller DT. Multi-reference global registration of individual A-lines in adaptive optics optical coherence tomography retinal images. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200266R. [PMID: 33410310 PMCID: PMC7787477 DOI: 10.1117/1.jbo.26.1.016001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/10/2020] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Adaptive optics optical coherence tomography (AO-OCT) technology enables non-invasive, high-resolution three-dimensional (3D) imaging of the retina and promises earlier detection of ocular disease. However, AO-OCT data are corrupted by eye-movement artifacts that must be removed in post-processing, a process rendered time-consuming by the immense quantity of data. AIM To efficiently remove eye-movement artifacts at the level of individual A-lines, including those present in any individual reference volume. APPROACH We developed a registration method that cascades (1) a 3D B-scan registration algorithm with (2) a global A-line registration algorithm for correcting torsional eye movements and image scaling and generating global motion-free coordinates. The first algorithm corrects 3D translational eye movements to a single reference volume, accelerated using parallel computing. The second algorithm combines outputs of multiple runs of the first algorithm using different reference volumes followed by an affine transformation, permitting registration of all images to a global coordinate system at the level of individual A-lines. RESULTS The 3D B-scan algorithm estimates and corrects 3D translational motions with high registration accuracy and robustness, even for volumes containing microsaccades. Averaging registered volumes improves our image quality metrics up to 22 dB. Implementation in CUDA™ on a graphics processing unit registers a 512 × 512 × 512 volume in only 10.6 s, 150 times faster than MATLAB™ on a central processing unit. The global A-line algorithm minimizes image distortion, improves regularity of the cone photoreceptor mosaic, and supports enhanced visualization of low-contrast retinal cellular features. Averaging registered volumes improves our image quality up to 9.4 dB. It also permits extending the imaging field of view (∼2.1 × ) and depth of focus (∼5.6 × ) beyond what is attainable with single-reference registration. CONCLUSIONS We can efficiently correct eye motion in all 3D at the level of individual A-lines using a global coordinate system.
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Affiliation(s)
- Kazuhiro Kurokawa
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - James A. Crowell
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Nhan Do
- Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States
- Google, Mountain View, California, United States
| | - John J. Lee
- Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States
| | - Donald T. Miller
- Indiana University, School of Optometry, Bloomington, Indiana, United States
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Abstract
Adaptive optics (AO) is a technique that corrects for optical aberrations. It was originally proposed to correct for the blurring effect of atmospheric turbulence on images in ground-based telescopes and was instrumental in the work that resulted in the Nobel prize-winning discovery of a supermassive compact object at the centre of our galaxy. When AO is used to correct for the eye's imperfect optics, retinal changes at the cellular level can be detected, allowing us to study the operation of the visual system and to assess ocular health in the microscopic domain. By correcting for sample-induced blur in microscopy, AO has pushed the boundaries of imaging in thick tissue specimens, such as when observing neuronal processes in the brain. In this primer, we focus on the application of AO for high-resolution imaging in astronomy, vision science and microscopy. We begin with an overview of the general principles of AO and its main components, which include methods to measure the aberrations, devices for aberration correction, and how these components are linked in operation. We present results and applications from each field along with reproducibility considerations and limitations. Finally, we discuss future directions.
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Hormel TT, Jia Y, Jian Y, Hwang TS, Bailey ST, Pennesi ME, Wilson DJ, Morrison JC, Huang D. Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography. Prog Retin Eye Res 2021; 80:100878. [PMID: 32712135 PMCID: PMC7855241 DOI: 10.1016/j.preteyeres.2020.100878] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022]
Abstract
Optical coherence tomographic angiography (OCTA) is a novel technology capable of imaging retinal vasculature three-dimensionally at capillary scale without the need to inject any extrinsic dye contrast. However, projection artifacts cause superficial retinal vascular patterns to be duplicated in deeper layers, thus interfering with the clean visualization of some retinal plexuses and vascular pathologies. Projection-resolved OCTA (PR-OCTA) uses post-processing algorithms to reduce projection artifacts. With PR-OCTA, it is now possible to resolve up to 4 distinct retinal vascular plexuses in the living human eye. The technology also allows us to detect and distinguish between various retinal and optic nerve diseases. For example, optic nerve diseases such as glaucoma primarily reduces the capillary density in the superficial vascular complex, which comprises the nerve fiber layer plexus and the ganglion cell layer plexus. Outer retinal diseases such as retinitis pigmentosa primarily reduce the capillary density in the deep vascular complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Retinal vascular diseases such as diabetic retinopathy and vein occlusion affect all plexuses, but with different patterns of capillary loss and vascular malformations. PR-OCTA is also useful in distinguishing various types of choroidal neovascularization and monitoring their response to anti-angiogenic medications. In retinal angiomatous proliferation and macular telangiectasia type 2, PR-OCTA can trace the pathologic vascular extension into deeper layers as the disease progress through stages. Plexus-specific visualization and measurement of retinal vascular changes are improving our ability to diagnose, stage, monitor, and assess treatment response in a wide variety of optic nerve and retinal diseases. These applications will be further enhanced with the continuing improvement of the speed and resolution of the OCT platforms, as well as the development of software algorithms to reduce artifacts, improve image quality, and make quantitative measurements.
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Affiliation(s)
- Tristan T Hormel
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Thomas S Hwang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Steven T Bailey
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - David J Wilson
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - John C Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA.
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Kanngiesser J, Roth B. Wavefront Shaping Concepts for Application in Optical Coherence Tomography-A Review. SENSORS (BASEL, SWITZERLAND) 2020; 20:E7044. [PMID: 33316998 PMCID: PMC7763956 DOI: 10.3390/s20247044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 01/10/2023]
Abstract
Optical coherence tomography (OCT) enables three-dimensional imaging with resolution on the micrometer scale. The technique relies on the time-of-flight gated detection of light scattered from a sample and has received enormous interest in applications as versatile as non-destructive testing, metrology and non-invasive medical diagnostics. However, in strongly scattering media such as biological tissue, the penetration depth and imaging resolution are limited. Combining OCT imaging with wavefront shaping approaches significantly leverages the capabilities of the technique by controlling the scattered light field through manipulation of the field incident on the sample. This article reviews the main concepts developed so far in the field and discusses the latest results achieved with a focus on signal enhancement and imaging.
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Affiliation(s)
- Jonas Kanngiesser
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
| | - Bernhard Roth
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
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Reumueller A, Wassermann L, Salas M, Schranz M, Told R, Kostolna K, Drexler W, Pircher M, Schmidt-Erfurth U, Pollreisz A. Three-dimensional assessment of para- and perifoveal photoreceptor densities and the impact of meridians and age in healthy eyes with adaptive-optics optical coherence tomography (AO-OCT). OPTICS EXPRESS 2020; 28:36723-36739. [PMID: 33379760 DOI: 10.1364/oe.409076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
An adaptive optics optical coherence tomography (AO-OCT) system is used to assess sixty healthy eyes of thirty subjects (age 22 to 75) to evaluate how the outer retinal layers, foveal eccentricity and age effect the mean cone density. The cone mosaics of different retinal planes (the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST), and the full en-face plane (FEF)) at four main meridians (superior, nasal, inferior, temporal) and para- and perifoveal eccentricities (ecc 2.5° and 6.5°) were analyzed quantitatively. The mean overall cone density was 19,892/mm2 at ecc 2.5° and 13,323/mm2 at ecc 6.5°. A significant impact on cone density was found for eccentricity (up to 6,700/mm2 between ecc 2.5° and 6.5°), meridian (up to 3,700/mm2 between nasal and superior meridian) and layer (up to 1,400/mm2 between FEF and IS/OS). Age showed only a weak negative effect. These factors as well as inter-individual variability have to be taken into account when comparing cone density measurements between healthy and pathologically changed eyes, as their combined effect on density can easily exceed several thousand cones per mm2 even in parafoveal regions.
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45
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Scholler J, Groux K, Grieve K, Boccara C, Mecê P. Adaptive-glasses time-domain FFOCT for wide-field high-resolution retinal imaging with increased SNR. OPTICS LETTERS 2020; 45:5901-5904. [PMID: 33137028 DOI: 10.1364/ol.403135] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/15/2020] [Indexed: 05/18/2023]
Abstract
The highest three-dimensional (3D) resolution possible in in vivo retinal imaging is achieved by combining optical coherence tomography (OCT) and adaptive optics. However, this combination brings important limitations, such as small field-of-view and complex, cumbersome systems, preventing so far the translation of this technology from the research lab to clinics. In this Letter, we mitigate these limitations by combining our compact time-domain full-field OCT (FFOCT) with a multi-actuator adaptive lens positioned just in front of the eye, in a technique we call the adaptive-glasses wavefront sensorless approach. Through this approach, we demonstrate that ocular aberrations can be corrected, increasing the FFOCT signal-to-noise ratio (SNR) and enabling imaging of different retinal layers with a 3D cellular resolution over a 5∘×5∘ field-of-view, without apparent anisoplanatism.
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46
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Bonati C, Laforest T, Kunzi M, Moser C. Phase sensitivity in differential phase contrast microscopy: limits and strategies to improve it. OPTICS EXPRESS 2020; 28:33767-33783. [PMID: 33115036 DOI: 10.1364/oe.409890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
The phase sensitivity limit of Differential Phase Contrast (DPC) with partially coherent light is analyzed in details. The parameters to tune phase sensitivity, such as the diameter of illumination, the numerical aperture of the objective, and the noise of the camera are taken into account to determine the minimum phase contrast that can be detected. We found that a priori information about the sample can be used to fine-tune these parameters to increase phase contrast. Based on this information, we propose a simple algorithm to predict phase sensitivity of a DPC setup, which can be performed before the setup is built. Experiments confirm the theoretical findings.
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47
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Valente D, Vienola KV, Zawadzki RJ, Jonnal RS. Kilohertz retinal FF-SS-OCT and flood imaging with hardware-based adaptive optics. BIOMEDICAL OPTICS EXPRESS 2020; 11:5995-6011. [PMID: 33150001 PMCID: PMC7587251 DOI: 10.1364/boe.403509] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 05/18/2023]
Abstract
A retinal imaging system was designed for full-field (FF) swept-source (SS) optical coherence tomography (OCT) with cellular resolution. The system incorporates a real-time adaptive optics (AO) subsystem and a very high-speed CMOS sensor, and is capable of acquiring volumetric images of the retina at rates up to 1 kHz. While digital aberration correction (DAC) is an attractive potential alternative to AO, it has not yet been shown to provide resolution allowing visualization of cones in the fovea, where early detection of functional deficits is most critical. Here we demonstrate that FF-SS-OCT with hardware AO permits resolution of foveal cones, imaged at eccentricities of 1° and 2°, with volume rates adequate to measure light-evoked changes in photoreceptors. With the reference arm blocked, the system can operate as a kilohertz AO flood illumination fundus camera with adjustable temporal coherence and is expected to allow measurement of light-evoked changes caused by common path interference in photoreceptor outer segments (OS). In this paper, we describe the system's optical design, characterize its performance, and demonstrate its ability to produce images of the human photoreceptor mosaic.
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Affiliation(s)
- Denise Valente
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Kari V. Vienola
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Robert J. Zawadzki
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
- EyePod Small Animal Ocular Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, CA 95616, USA
| | - Ravi S. Jonnal
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
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Huckenpahler AL, Lookfong NA, Warr E, Heffernan E, Carroll J, Collery RF. Noninvasive Imaging of Cone Ablation and Regeneration in Zebrafish. Transl Vis Sci Technol 2020; 9:18. [PMID: 32983626 PMCID: PMC7500127 DOI: 10.1167/tvst.9.10.18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
Purpose To observe and characterize cone degeneration and regeneration in a selective metronidazole-mediated ablation model of ultraviolet-sensitive (UV) cones in zebrafish using in vivo optical coherence tomography (OCT) imaging. Methods Twenty-six sws1:nfsB-mCherry;sws2:eGFP zebrafish were imaged with OCT, treated with metronidazole to selectively kill UV cones, and imaged at 1, 3, 7, 14, 28, or 56 days after ablation. Regions 200 × 200 µm were cropped from volume OCT scans to count individual UV cones before and after ablation. Fish eyes were fixed, and immunofluorescence staining was used to corroborate cone density measured from OCT and to track monocyte response. Results Histology shows significant loss of UV cones after metronidazole treatment with a slight increase in observable blue cone density one day after treatment (Kruskal, Wallis, P = 0.0061) and no significant change in blue cones at all other timepoints. Regenerated UV cones measured from OCT show significantly lower density than pre-cone-ablation at 14, 28, and 56 days after ablation (analysis of variance, P < 0.01, P < 0.0001, P < 0.0001, respectively, 15.9% of expected nonablated levels). Histology shows significant changes to monocyte morphology (mixed-effects analysis, P < 0.0001) and retinal position (mixed-effects analysis, P < 0.0001). Conclusions OCT can be used to observe loss of individual cones selectively ablated by metronidazole prodrug activation and to quantify UV cone loss and regeneration in zebrafish. OCT images also show transient changes to the blue cone mosaic and inner retinal layers that occur concomitantly with selective UV cone ablation. Translational Relevance Profiling cone degeneration and regeneration using in vivo imaging enables experiments that may lead to a better understanding of cone regeneration in vertebrates.
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Affiliation(s)
- Alison L Huckenpahler
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Emma Warr
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Elizabeth Heffernan
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ross F Collery
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
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Miller DT, Kurokawa K. Cellular-Scale Imaging of Transparent Retinal Structures and Processes Using Adaptive Optics Optical Coherence Tomography. Annu Rev Vis Sci 2020; 6:115-148. [PMID: 32609578 PMCID: PMC7864592 DOI: 10.1146/annurev-vision-030320-041255] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High-resolution retinal imaging is revolutionizing how scientists and clinicians study the retina on the cellular scale. Its exquisite sensitivity enables time-lapse optical biopsies that capture minute changes in the structure and physiological processes of cells in the living eye. This information is increasingly used to detect disease onset and monitor disease progression during early stages, raising the possibility of personalized eye care. Powerful high-resolution imaging tools have been in development for more than two decades; one that has garnered considerable interest in recent years is optical coherence tomography enhanced with adaptive optics. State-of-the-art adaptive optics optical coherence tomography (AO-OCT) makes it possible to visualize even highly transparent cells and measure some of their internal processes at all depths within the retina, permitting reconstruction of a 3D view of the living microscopic retina. In this review, we report current AO-OCT performance and its success in visualizing and quantifying these once-invisible cells in human eyes.
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Affiliation(s)
- Donald T Miller
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA; ,
| | - Kazuhiro Kurokawa
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA; ,
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50
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Mecê P, Groux K, Scholler J, Thouvenin O, Fink M, Grieve K, Boccara C. Coherence gate shaping for wide field high-resolution in vivo retinal imaging with full-field OCT. BIOMEDICAL OPTICS EXPRESS 2020; 11:4928-4941. [PMID: 33014591 PMCID: PMC7510855 DOI: 10.1364/boe.400522] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/20/2020] [Accepted: 07/29/2020] [Indexed: 05/05/2023]
Abstract
Allying high-resolution with a large field-of-view (FOV) is of great importance in the fields of biology and medicine, but it is particularly challenging when imaging non-flat living samples such as the human retina. Indeed, high-resolution is normally achieved with adaptive optics (AO) and scanning methods, which considerably reduce the useful FOV and increase the system complexity. An alternative technique is time-domain full-field optical coherence tomography (FF-OCT), which has already shown its potential for in-vivo high-resolution retinal imaging. Here, we introduce coherence gate shaping for FF-OCT, to optically shape the coherence gate geometry to match the sample curvature, thus achieving a larger FOV than previously possible. Using this instrument, we obtained high-resolution images of living human photoreceptors close to the foveal center without AO and with a 1 mm × 1 mm FOV in a single shot. This novel advance enables the extraction of photoreceptor-based biomarkers with ease and spatiotemporal monitoring of individual photoreceptors. We compare our findings with AO-assisted ophthalmoscopes, highlighting the potential of FF-OCT, as a compact system, to become a routine clinical imaging technique.
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Affiliation(s)
- Pedro Mecê
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
| | - Kassandra Groux
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
| | - Jules Scholler
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
| | - Olivier Thouvenin
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
| | - Mathias Fink
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
| | - Kate Grieve
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012, Paris, France
- Quinze-Vingts National Eye Hospital, 28 Rue de Charenton, Paris, 75012, France
| | - Claude Boccara
- Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France
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