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Mbagwu M, Chu Z, Borkar D, Koshta A, Shah N, Torres A, Kalvaria H, Lum F, Leng T. Feasibility of cross-vendor linkage of ophthalmic images with electronic health record data: an analysis from the IRIS Registry ®. JAMIA Open 2024; 7:ooae005. [PMID: 38283883 PMCID: PMC10811449 DOI: 10.1093/jamiaopen/ooae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 10/02/2023] [Accepted: 01/05/2024] [Indexed: 01/30/2024] Open
Abstract
Purpose To link compliant, universal Digital Imaging and Communications in Medicine (DICOM) ophthalmic imaging data at the individual patient level with the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight). Design A retrospective study using de-identified EHR registry data. Subjects Participants Controls IRIS Registry records. Materials and Methods DICOM files of several imaging modalities were acquired from two large retina ophthalmology practices. Metadata tags were extracted and harmonized to facilitate linkage to the IRIS Registry using a proprietary, heuristic patient-matching algorithm, adhering to HITRUST guidelines. Linked patients and images were assessed by image type and clinical diagnosis. Reasons for failed linkage were assessed by examining patients' records. Main Outcome Measures Success rate of linking clinicoimaging and EHR data at the patient level. Results A total of 2 287 839 DICOM files from 54 896 unique patients were available. Of these, 1 937 864 images from 46 196 unique patients were successfully linked to existing patients in the registry. After removing records with abnormal patient names and invalid birthdates, the success linkage rate was 93.3% for images. 88.2% of all patients at the participating practices were linked to at least one image. Conclusions and Relevance Using identifiers from DICOM metadata, we created an automated pipeline to connect longitudinal real-world clinical data comprehensively and accurately to various imaging modalities from multiple manufacturers at the patient and visit levels. The process has produced an enriched and multimodal IRIS Registry, bridging the gap between basic research and clinical care by enabling future applications in artificial intelligence algorithmic development requiring large linked clinicoimaging datasets.
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Affiliation(s)
- Michael Mbagwu
- Verana Health, San Francisco, CA 94107, United States
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA 94303, United States
| | - Zhongdi Chu
- Verana Health, San Francisco, CA 94107, United States
| | - Durga Borkar
- Verana Health, San Francisco, CA 94107, United States
- Duke Eye Center, Duke University School of Medicine, Durham, NC 27705, United States
| | - Alex Koshta
- Verana Health, San Francisco, CA 94107, United States
| | - Nisarg Shah
- Verana Health, San Francisco, CA 94107, United States
| | | | | | - Flora Lum
- American Academy of Ophthalmology, San Francisco, CA 94109, United States
| | - Theodore Leng
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA 94303, United States
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Orr S, Hatamnejad A, Sodhi S, Golding J, Pattathil N, Choudhry N. Novel features of degenerative retinoschisis identified using ultra-widefield multicolor channels: A review of 139 eyes. Acta Ophthalmol 2024. [PMID: 38533620 DOI: 10.1111/aos.16683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 03/28/2024]
Abstract
BACKGROUND/OBJECTIVE To utilize ultra-widefield multimodal imaging (Optos PLC) to describe novel findings in degenerative retinoschisis. METHODS This retrospective, non-comparative case series of degenerative retinoschisis received a waiver of consent from Advarra IRB, Protocol 00066379. Initial ultra-widefield pseudocolour, colour-separated, autofluorescence, and peripheral OCT imaging were analysed for characterizing features. RESULTS In total, 139 eyes were included. A hyporeflective reticular pattern associated with retinoschisis was seen on pseudocolour images in 39% of cases, but visible in 53% on green-separated images. Fine hyper-reflective foci were observed in 49%. In 27%, retinoschisis was confirmed with OCT. CONCLUSIONS Ultra-widefield pseudocolour and green-separated images are valuable for the diagnosis and characterization of degenerative retinoschisis. The findings described may prompt the evaluation of subtle retinoschisis with peripheral OCT.
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Affiliation(s)
- Samantha Orr
- Vitreous Retina Macula Specialists of Toronto, Toronto, Ontario, Canada
- Octane Imaging Lab, Toronto, Ontario, Canada
| | - Amin Hatamnejad
- Octane Imaging Lab, Toronto, Ontario, Canada
- McMaster University, Hamilton, Ontario, Canada
| | - Simrat Sodhi
- Octane Imaging Lab, Toronto, Ontario, Canada
- University of Cambridge, Cambridge, UK
| | - John Golding
- Vitreous Retina Macula Specialists of Toronto, Toronto, Ontario, Canada
- Octane Imaging Lab, Toronto, Ontario, Canada
| | - Niveditha Pattathil
- Vitreous Retina Macula Specialists of Toronto, Toronto, Ontario, Canada
- Octane Imaging Lab, Toronto, Ontario, Canada
| | - Netan Choudhry
- Vitreous Retina Macula Specialists of Toronto, Toronto, Ontario, Canada
- Octane Imaging Lab, Toronto, Ontario, Canada
- Department of Ophthalmology & Visual Sciences, University of Toronto, Toronto, Ontario, Canada
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3
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Ong AY, Hogg HDJ, Kale AU, Taribagil P, Kras A, Dow E, Macdonald T, Liu X, Keane PA, Denniston AK. AI as a Medical Device for Ophthalmic Imaging in Europe, Australia, and the United States: Protocol for a Systematic Scoping Review of Regulated Devices. JMIR Res Protoc 2024; 13:e52602. [PMID: 38483456 PMCID: PMC10979335 DOI: 10.2196/52602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 02/10/2024] [Accepted: 02/20/2024] [Indexed: 04/01/2024] Open
Abstract
BACKGROUND Artificial intelligence as a medical device (AIaMD) has the potential to transform many aspects of ophthalmic care, such as improving accuracy and speed of diagnosis, addressing capacity issues in high-volume areas such as screening, and detecting novel biomarkers of systemic disease in the eye (oculomics). In order to ensure that such tools are safe for the target population and achieve their intended purpose, it is important that these AIaMD have adequate clinical evaluation to support any regulatory decision. Currently, the evidential requirements for regulatory approval are less clear for AIaMD compared to more established interventions such as drugs or medical devices. There is therefore value in understanding the level of evidence that underpins AIaMD currently on the market, as a step toward identifying what the best practices might be in this area. In this systematic scoping review, we will focus on AIaMD that contributes to clinical decision-making (relating to screening, diagnosis, prognosis, and treatment) in the context of ophthalmic imaging. OBJECTIVE This study aims to identify regulator-approved AIaMD for ophthalmic imaging in Europe, Australia, and the United States; report the characteristics of these devices and their regulatory approvals; and report the available evidence underpinning these AIaMD. METHODS The Food and Drug Administration (United States), the Australian Register of Therapeutic Goods (Australia), the Medicines and Healthcare products Regulatory Agency (United Kingdom), and the European Database on Medical Devices (European Union) regulatory databases will be searched for ophthalmic imaging AIaMD through a snowballing approach. PubMed and clinical trial registries will be systematically searched, and manufacturers will be directly contacted for studies investigating the effectiveness of eligible AIaMD. Preliminary regulatory database searches, evidence searches, screening, data extraction, and methodological quality assessment will be undertaken by 2 independent review authors and arbitrated by a third at each stage of the process. RESULTS Preliminary searches were conducted in February 2023. Data extraction, data synthesis, and assessment of methodological quality commenced in October 2023. The review is on track to be completed and submitted for peer review by April 2024. CONCLUSIONS This systematic review will provide greater clarity on ophthalmic imaging AIaMD that have achieved regulatory approval as well as the evidence that underpins them. This should help adopters understand the range of tools available and whether they can be safely incorporated into their clinical workflow, and it should also support developers in navigating regulatory approval more efficiently. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/52602.
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Affiliation(s)
- Ariel Yuhan Ong
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Henry David Jeffry Hogg
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, United Kingdom
| | - Aditya U Kale
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Priyal Taribagil
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | | | - Eliot Dow
- Retinal Consultants Medical Group, Sacramento, CA, United States
| | - Trystan Macdonald
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom
| | - Xiaoxuan Liu
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom
- Centre for Regulatory Science and Innovation, Birmingham Health Partners, Birmingham, United Kingdom
| | - Pearse A Keane
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
- NIHR Moorfields Biomedical Research Centre, London, United Kingdom
| | - Alastair K Denniston
- Department of Ophthalmology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom
- Centre for Regulatory Science and Innovation, Birmingham Health Partners, Birmingham, United Kingdom
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Vohra M, Gour A, Rajput J, Sangwan B, Chauhan M, Goel K, Kamath A, Mathur U, Chandru A, Sangwan VS, Bhowmick T, Tiwari A. Chemical (Alkali) Burn-Induced Neurotrophic Keratitis Model in New Zealand Rabbit Investigated Using Medical Clinical Readouts and In Vivo Confocal Microscopy (IVCM). Cells 2024; 13:379. [PMID: 38474343 DOI: 10.3390/cells13050379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 03/14/2024] Open
Abstract
PURPOSE Chemical eye injury is an acute emergency that can result in vision loss. Neurotrophic keratitis (NK) is the most common long-term manifestation of chemical injury. NK due to alkali burn affects ocular surface health and is one of its most common causes. Here, we established a rabbit model of corneal alkali burns to evaluate the severity of NK-associated changes. MATERIAL METHODS Alkali burns were induced in NZ rabbits by treating the cornea with (i) a 5 mm circular filter paper soaked in 0.75 N NaOH for 10 s (Mild NK) and (ii) trephination using a guarded trephine (5 mm diameter and 150-micron depth), followed by alkali burn, with a 5 mm circular filter paper soaked in 0.75 N NaOH for 10 s (a severe form of NK). Immediately after, the cornea was rinsed with 10 mL of normal saline to remove traces of NaOH. Clinical features were evaluated on Day 0, Day 1, Day 7, Day 15, and Day 21 post-alkali burn using a slit lamp, Pentacam, and anterior segment optical coherence tomography (AS-OCT). NK-like changes in epithelium, sub-basal nerve plexus, and stroma were observed using in vivo confocal microscopy (IVCM), and corneal sensation were measured using an aesthesiometer post alkali injury. After 21 days, pro-inflammatory cytokines were evaluated for inflammation through ELISA. RESULTS Trephination followed by alkali burn resulted in the loss of epithelial layers (manifested using fluorescein stain), extensive edema, and increased corneal thickness (550 µm compared to 380 µm thickness of control) evaluated through AS-OCT and increased opacity score in alkali-treated rabbit (80 compared to 16 controls). IVCM images showed complete loss of nerve fibers, which failed to regenerate over 30 days, and loss of corneal sensation-conditions associated with NK. Cytokines evaluation of IL6, VEGF, and MMP9 indicated an increased angiogenic and pro-inflammatory milieu compared to the milder form of NK and the control. DISCUSSION Using clinical parameters, we demonstrated that the alkali-treated rabbit model depicts features of NK. Using IVCM in the NaOH burn animal model, we demonstrated a complete loss of nerve fibers with poor self-healing capability associated with sub-basal nerve degeneration and compromised corneal sensation. This pre-clinical rabbit model has implications for future pre-clinical research in neurotrophic keratitis.
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Affiliation(s)
- Mehak Vohra
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Abha Gour
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
| | - Jyoti Rajput
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Bharti Sangwan
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Monika Chauhan
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Kartik Goel
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Ajith Kamath
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Umang Mathur
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
| | - Arun Chandru
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Virender Singh Sangwan
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
| | - Tuhin Bhowmick
- Pandorum Technologies Pvt. Ltd., Bangalore 560100, India
| | - Anil Tiwari
- Shroff-Pandorum Center for Ocular Regeneration, Dr. Shroff's Charity Eye Hospital, New Delhi 110002, India
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Nguyen VP, Hu J, Zhe J, Ramasamy S, Ahmed U, Paulus YM. Advanced nanomaterials for imaging of eye diseases. ADMET DMPK 2024; 12:269-298. [PMID: 38720929 PMCID: PMC11075159 DOI: 10.5599/admet.2182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/16/2024] [Indexed: 05/12/2024] Open
Abstract
Background and purpose Vision impairment and blindness present significant global challenges, with common causes including age-related macular degeneration, diabetes, retinitis pigmentosa, and glaucoma. Advanced imaging tools, such as optical coherence tomography, fundus photography, photoacoustic microscopy, and fluorescence imaging, play a crucial role in improving therapeutic interventions and diagnostic methods. Contrast agents are often employed with these tools to enhance image clarity and signal detection. This review aims to explore the commonly used contrast agents in ocular disease imaging. Experimental approach The first section of the review delves into advanced ophthalmic imaging techniques, outlining their importance in addressing vision-related issues. The emphasis is on the efficacy of therapeutic interventions and diagnostic methods, establishing a foundation for the subsequent exploration of contrast agents. Key results This review focuses on the role of contrast agents, with a specific emphasis on gold nanoparticles, particularly gold nanorods. The discussion highlights how these contrast agents optimize imaging in ocular disease diagnosis and monitoring, emphasizing their unique properties that enhance signal detection and imaging precision. Conclusion The final section, we explores both organic and inorganic contrast agents and their applications in specific conditions such as choroidal neovascularization, retinal neovascularization, and stem cell tracking. The review concludes by addressing the limitations of current contrast agent usage and discussing potential future clinical applications. This comprehensive exploration contributes to advancing our understanding of contrast agents in ocular disease imaging and sets the stage for further research and development in the field.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Justin Hu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Josh Zhe
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Sanjay Ramasamy
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Umayr Ahmed
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yannis M. Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
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Edgar AK, Connor HRM, Kamarelddin S, Musich J, Mclouta S, Choi E, Thamer A, Salcedo A, Nazarian A, Chong LX. Anterior segment optical coherence tomography meibography compared with keratograph meibography. Ophthalmic Physiol Opt 2024; 44:115-123. [PMID: 37697893 DOI: 10.1111/opo.13231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/13/2023]
Abstract
PURPOSE The aim of this study was to determine the feasibility of using readily accessible technology, anterior segment optical coherence tomography (AS-OCT), to detect and grade meibomian gland dropout and examine its interchangeability with the Oculus Keratograph 5M (K5M). METHODS A total of 30 participants (30 eyes) with a median age of 21 (range = 19-28 years) were recruited. Meibography was performed using two commercially available imaging devices to look at the structure of the meibomian glands and grade them subjectively in real time, and image analysis was used to quantify meibomian gland loss objectively. Gland loss as imaged by the two techniques was graded using the meiboscore grading schema. Test-retest reliability was determined with intraclass correlation coefficients (ICCs). Weighted kappa was used to evaluate agreement between the two imaging devices and four methods of image analysis. Spearman and Pearson correlation coefficients were used to determine the association of structural measurements between each of the techniques. The agreement between the two imaging techniques was determined with the Bland-Altman analysis. RESULTS Reliability of subjective grading was strong for AS-OCT (ICC: 0.92, 95% CI: 0.83-0.96, p < 0.001) and K5M (ICC: 0.96, 95% CI: 0.96-0.91, p = 0.001). Image analysis with ImageJ reliability was strong between the imaging devices (ICC: 0.84, 95% CI: 0.55-0.94, p < 0.001). Agreement between each subjective technique was fair, κ = 0.45 (95% CI: 0.17-0.73, p < 0.001) and a positive Spearman correlation was also observed (r = 0.52, p < 0.001). There was no significant difference between the mean meibomian gland loss measured with ImageJ between AS-OCT and K5M (0.92 ± 6.28, p = 0.26). The 95% limits of agreement were -12.45% to +14.04%. CONCLUSION These findings suggest subjective real-time grading of meibomian gland loss could be performed using readily available AS-OCT technology and that this method was interchangeable with the K5M.
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Affiliation(s)
- Amanda K Edgar
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
- Digital Learning, Deakin Learning Futures, Deakin University, Geelong, Victoria, Australia
| | - Heather R M Connor
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Shayma Kamarelddin
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Jack Musich
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Stefanos Mclouta
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Evelyn Choi
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Afnan Thamer
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Adrian Salcedo
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Aram Nazarian
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
| | - Luke X Chong
- School of Medicine (Optometry), Faculty of Health, Deakin University, Waurn Ponds, Victoria, Australia
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Suchand Sandeep CS, Khairyanto A, Aung T, Vadakke Matham M. Bessel Beams in Ophthalmology: A Review. Micromachines (Basel) 2023; 14:1672. [PMID: 37763835 PMCID: PMC10536271 DOI: 10.3390/mi14091672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023]
Abstract
The achievable resolution of a conventional imaging system is inevitably limited due to diffraction. Dealing with precise imaging in scattering media, such as in the case of biomedical imaging, is even more difficult owing to the weak signal-to-noise ratios. Recent developments in non-diffractive beams such as Bessel beams, Airy beams, vortex beams, and Mathieu beams have paved the way to tackle some of these challenges. This review specifically focuses on non-diffractive Bessel beams for ophthalmological applications. The theoretical foundation of the non-diffractive Bessel beam is discussed first followed by a review of various ophthalmological applications utilizing Bessel beams. The advantages and disadvantages of these techniques in comparison to those of existing state-of-the-art ophthalmological systems are discussed. The review concludes with an overview of the current developments and the future perspectives of non-diffractive beams in ophthalmology.
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Affiliation(s)
- C. S. Suchand Sandeep
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Ahmad Khairyanto
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
| | - Murukeshan Vadakke Matham
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore
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Zhang J, Mazlin V, Fei K, Boccara AC, Yuan J, Xiao P. Time-domain full-field optical coherence tomography (TD-FF-OCT) in ophthalmic imaging. Ther Adv Chronic Dis 2023; 14:20406223231170146. [PMID: 37152350 PMCID: PMC10161339 DOI: 10.1177/20406223231170146] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 03/29/2023] [Indexed: 05/09/2023] Open
Abstract
Ocular imaging plays an irreplaceable role in the evaluation of eye diseases. Developing cellular-resolution ophthalmic imaging technique for more accurate and effective diagnosis and pathogenesis analysis of ocular diseases is a hot topic in the cross-cutting areas of ophthalmology and imaging. Currently, ocular imaging with traditional optical coherence tomography (OCT) is limited in lateral resolution and thus can hardly resolve cellular structures. Conventional OCT technology obtains ultra-high resolution at the expense of a certain imaging range and cannot achieve full field of view imaging. In the early years, Time-domain full-field OCT (TD-FF-OCT) has been mainly used for ex vivo ophthalmic tissue studies, limited by the low speed and low full-well capacity of existing two-dimensional (2D) cameras. The recent improvements in system design opened new imaging possibilities for in vivo applications thanks to its distinctive optical properties of TD-FF-OCT such as a spatial resolution almost insensitive to aberrations, and the possibility to control the curvature of the optical slice. This review also attempts to look at the future directions of TD-FF-OCT evolution, for example, the potential transfer of the functional-imaging dynamic TD-FF-OCT from the ex vivo into in vivo use and its expected benefit in basic and clinical ophthalmic research. Through non-invasive, wide-field, and cellular-resolution imaging, TD-FF-OCT has great potential to be the next-generation imaging modality to improve our understanding of human eye physiology and pathology.
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Affiliation(s)
- Jinze Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Viacheslav Mazlin
- ESPCI Paris, PSL University, CNRS, Langevin Institute, Paris, France
| | - Keyi Fei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | | | - Jin Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Jinsui Road 7, Guangzhou 510060, Guangdong, China
| | - Peng Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Jinsui Road 7, Guangzhou 510060, Guangdong, China
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9
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Moramarco A, di Geronimo N, Airaldi M, Gardini L, Semeraro F, Iannetta D, Romano V, Fontana L. Intraoperative OCT for Lamellar Corneal Surgery: A User Guide. J Clin Med 2023; 12:jcm12093048. [PMID: 37176489 PMCID: PMC10179477 DOI: 10.3390/jcm12093048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 04/07/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Intraoperative OCT is an innovative and promising technology which allows anterior and posterior segment ocular surgeons to obtain a near-histologic cross-sectional and tomographic image of the tissues. Intraoperative OCT has several applications in ocular surgery which are particularly interesting in the context of corneal transplantation. Indeed, iOCT images provide a direct and meticulous visualization of the anatomy, which could guide surgical decisions. In particular, during both big-bubble and manual DALK, the visualization of the relationship between the corneal layers and instruments allows the surgeon to obtain a more desirable depth of the trephination, thus achieving more type 1 bubbles, better regularity of the plane, and a reduced risk of DM perforation. During EK procedures, iOCT supplies information about proper descemetorhexis, graft orientation, and interface quality in order to optimize the postoperative adhesion and reduce the need for re-bubbling. Finally, mushroom PK, a challenging technique for many surgeons, can be aided through the use of iOCT since it guides the correct apposition of the lamellae and their centration. The technology of iOCT is still evolving: a larger field of view could allow for the visualization of all surgical fields, and automated tracking and iOCT autofocusing guarantee the continued centration of the image.
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Affiliation(s)
- Antonio Moramarco
- Ophthalmology Unit, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum-University of Bologna, 40126 Bologna, Italy
- Ophthalmology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40126 Bologna, Italy
| | - Natalie di Geronimo
- Ophthalmology Unit, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum-University of Bologna, 40126 Bologna, Italy
- Ophthalmology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40126 Bologna, Italy
| | - Matteo Airaldi
- Eye Unit, ASST Spedali Civili di Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy
- Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Viale Europa 15, 25123 Brescia, Italy
| | - Lorenzo Gardini
- Ophthalmology Unit, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum-University of Bologna, 40126 Bologna, Italy
- Ophthalmology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40126 Bologna, Italy
| | - Francesco Semeraro
- Eye Unit, ASST Spedali Civili di Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy
- Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Viale Europa 15, 25123 Brescia, Italy
| | - Danilo Iannetta
- Ophthalmology Unit, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum-University of Bologna, 40126 Bologna, Italy
- Ophthalmology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40126 Bologna, Italy
| | - Vito Romano
- Eye Unit, ASST Spedali Civili di Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy
- Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Viale Europa 15, 25123 Brescia, Italy
| | - Luigi Fontana
- Ophthalmology Unit, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum-University of Bologna, 40126 Bologna, Italy
- Ophthalmology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40126 Bologna, Italy
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10
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Rico-Jimenez JJ, Jovanovic J, Nolen SL, Malone JD, Rao G, Levine EM, Tao YK. MURIN: Multimodal Retinal Imaging and Navigated-laser-delivery for dynamic and longitudinal tracking of photodamage in murine models. Front Ophthalmol (Lausanne) 2023; 3:1141070. [PMID: 37275441 PMCID: PMC10238074 DOI: 10.3389/fopht.2023.1141070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Laser-induced photodamage is a robust method for investigating retinal pathologies in small animals. However, aiming of the photocoagulation laser is often limited by manual alignment and lacks real-time feedback on lesion location and severity. Here, we demonstrate a multimodality OCT and SLO ophthalmic imaging system with an image-guided scanning laser lesioning module optimized for the murine retina. The proposed system enables targeting of focal and extended area lesions under OCT guidance to benefit visualization of photodamage response and the precision and repeatability of laser lesion models of retinal injury.
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Affiliation(s)
- Jose J. Rico-Jimenez
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN 37208, USA
| | - Joel Jovanovic
- Vanderbilt University Medical Center, Vanderbilt Eye Institute, Nashville, TN 37208, USA
- Vanderbilt University, Dept. of Ophthalmology and Visual Sciences, Nashville, TN 37208, USA
- Vanderbilt University, Dept. of Cell and Developmental Biology, Nashville, TN 37208, USA
| | - Stephanie L. Nolen
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN 37208, USA
| | - Joseph D. Malone
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN 37208, USA
| | - Gopikrishna Rao
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN 37208, USA
| | - Edward M. Levine
- Vanderbilt University Medical Center, Vanderbilt Eye Institute, Nashville, TN 37208, USA
- Vanderbilt University, Dept. of Ophthalmology and Visual Sciences, Nashville, TN 37208, USA
- Vanderbilt University, Dept. of Cell and Developmental Biology, Nashville, TN 37208, USA
| | - Yuankai K. Tao
- Vanderbilt University, Dept. of Biomedical Engineering, Nashville, TN 37208, USA
- Vanderbilt University Medical Center, Vanderbilt Eye Institute, Nashville, TN 37208, USA
- Vanderbilt University, Dept. of Ophthalmology and Visual Sciences, Nashville, TN 37208, USA
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11
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Paul SK, Pan I, Sobol WM. Efficient labeling of retinal fundus photographs using deep active learning. J Med Imaging (Bellingham) 2022; 9:064001. [PMID: 36405815 PMCID: PMC9667889 DOI: 10.1117/1.jmi.9.6.064001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 10/31/2022] [Indexed: 11/18/2023] Open
Abstract
Purpose To compare the performance of four deep active learning (DAL) approaches to optimize label efficiency for training diabetic retinopathy (DR) classification deep learning models. Approach 88,702 color retinal fundus photographs from 44,351 patients with DR grades from the publicly available EyePACS dataset were used. Four DAL approaches [entropy sampling (ES), Bayesian active learning by disagreement (BALD), core set, and adversarial active learning (ADV)] were compared to conventional naive random sampling. Models were compared at various dataset sizes using Cohen's kappa (CK) and area under the receiver operating characteristic curve on an internal test set of 10,000 images. An independent test set of 3662 fundus photographs was used to assess generalizability. Results On the internal test set, 3 out of 4 DAL methods resulted in statistically significant performance improvements ( p < 1 × 10 - 4 ) compared to random sampling for multiclass classification, with the largest observed differences in CK ranging from 0.051 for BALD to 0.053 for ES. Improvements in multiclass classification generalized to the independent test set, with the largest differences in CK ranging from 0.126 to 0.135. However, no statistically significant improvements were seen for binary classification. Similar performance was seen across DAL methods, except ADV, which performed similarly to random sampling. Conclusions Uncertainty-based and feature descriptor-based deep active learning methods outperformed random sampling on both the internal and independent test sets at multiclass classification. However, binary classification performance remained similar across random sampling and active learning methods.
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Affiliation(s)
- Samantha K. Paul
- University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Ophthalmology, Cleveland, Ohio, United States
| | - Ian Pan
- Brigham and Women’s Hospital, Harvard Medical School, Department of Radiology, Boston, Massachusetts, United States
| | - Warren M. Sobol
- University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Ophthalmology, Cleveland, Ohio, United States
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12
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Majeed A, Marwick B, Yu H, Fadavi H, Tavakoli M. Ophthalmic Biomarkers for Alzheimer's Disease: A Review. Front Aging Neurosci 2021; 13:720167. [PMID: 34566623 PMCID: PMC8461312 DOI: 10.3389/fnagi.2021.720167] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/11/2021] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by neuronal loss, extracellular amyloid-β (Aβ) plaques, and intracellular neurofibrillary tau tangles. A diagnosis is currently made from the presenting symptoms, and the only definitive diagnosis can be done post-mortem. Over recent years, significant advances have been made in using ocular biomarkers to diagnose various neurodegenerative diseases, including AD. As the eye is an extension of the central nervous system (CNS), reviewing changes in the eye's biology could lead to developing a series of non-invasive, differential diagnostic tests for AD that could be further applied to other diseases. Significant changes have been identified in the retinal nerve fiber layer (RNFL), cornea, ocular vasculature, and retina. In the present paper, we review current research and assess some ocular biomarkers' accuracy and reliability that could potentially be used for diagnostic purposes. Additionally, we review the various imaging techniques used in the measurement of these biomarkers.
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Affiliation(s)
- Ayesha Majeed
- Medical School, University of Exeter, Exeter, United Kingdom
| | - Ben Marwick
- Medical School, University of Exeter, Exeter, United Kingdom
| | - Haoqing Yu
- Medical School, University of Exeter, Exeter, United Kingdom
| | | | - Mitra Tavakoli
- Medical School, University of Exeter, Exeter, United Kingdom
- Exeter Centre of Excellence for Diabetes Research, University of Exeter, Exeter, United Kingdom
- National Institute for Health Research, Exeter Clinical Research Facility, Exeter, United Kingdom
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13
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Lim HG, Kim HH, Yoon C. Synthetic Aperture Imaging Using High-Frequency Convex Array for Ophthalmic Ultrasound Applications. Sensors (Basel) 2021; 21:s21072275. [PMID: 33805048 PMCID: PMC8036709 DOI: 10.3390/s21072275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 11/16/2022]
Abstract
High-frequency ultrasound (HFUS) imaging has emerged as an essential tool for pre-clinical studies and clinical applications such as ophthalmic and dermatologic imaging. HFUS imaging systems based on array transducers capable of dynamic receive focusing have considerably improved the image quality in terms of spatial resolution and signal-to-noise ratio (SNR) compared to those by the single-element transducer-based one. However, the array system still suffers from low spatial resolution and SNR in out-of-focus regions, resulting in a blurred image and a limited penetration depth. In this paper, we present synthetic aperture imaging with a virtual source (SA-VS) for an ophthalmic application using a high-frequency convex array transducer. The performances of the SA-VS were evaluated with phantom and ex vivo experiments in comparison with the conventional dynamic receive focusing method. Pre-beamformed radio-frequency (RF) data from phantoms and excised bovine eye were acquired using a custom-built 64-channel imaging system. In the phantom experiments, the SA-VS method showed improved lateral resolution (>10%) and sidelobe level (>4.4 dB) compared to those by the conventional method. The SNR was also improved, resulting in an increased penetration depth: 16 mm and 23 mm for the conventional and SA-VS methods, respectively. Ex vivo images with the SA-VS showed improved image quality at the entire depth and visualized structures that were obscured by noise in conventional imaging.
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Affiliation(s)
- Hae Gyun Lim
- Department of Biomedical Engineering, Pukyong National University, Busan 48513, Korea;
| | - Hyung Ham Kim
- Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
- Correspondence: (H.H.K.); or (C.Y.)
| | - Changhan Yoon
- Department of Biomedical Engineering, Inje University, Gimhae 50834, Korea
- Department of Nanoscience and Engineering, Inje University, Gimhae 50834, Korea
- Correspondence: (H.H.K.); or (C.Y.)
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14
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Abstract
Obtaining a clear assessment of the anterior segment is critical for disease diagnosis and management in ophthalmic telemedicine. The anterior segment can be imaged with slit lamp cameras, robotic remote controlled slit lamps, cell phones, cell phone adapters, digital cameras, and webcams, all of which can enable remote care. The ability of these devices to identify various ophthalmic diseases has been studied, including cataracts, as well as abnormalities of the ocular adnexa, cornea, and anterior chamber. This article reviews the current state of anterior segment imaging for the purpose of ophthalmic telemedical care.
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Affiliation(s)
- Grayson W Armstrong
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Gagan Kalra
- Department of Ophthalmology, Government Medical College and Hospital, Chandigarh, India
| | - Sofia De Arrigunaga
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - David S Friedman
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Alice C Lorch
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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15
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Hao Q, Zhou K, Yang J, Hu Y, Chai Z, Ma Y, Liu G, Zhao Y, Gao S, Liu J. High signal-to-noise ratio reconstruction of low bit-depth optical coherence tomography using deep learning. J Biomed Opt 2020; 25:JBO-200220SSR. [PMID: 33191687 PMCID: PMC7666869 DOI: 10.1117/1.jbo.25.12.123702] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/26/2020] [Indexed: 05/10/2023]
Abstract
SIGNIFICANCE Reducing the bit depth is an effective approach to lower the cost of an optical coherence tomography (OCT) imaging device and increase the transmission efficiency in data acquisition and telemedicine. However, a low bit depth will lead to the degradation of the detection sensitivity, thus reducing the signal-to-noise ratio (SNR) of OCT images. AIM We propose using deep learning to reconstruct high SNR OCT images from low bit-depth acquisition. APPROACH The feasibility of our approach is evaluated by applying this approach to the quantized 3- to 8-bit data from native 12-bit interference fringes. We employ a pixel-to-pixel generative adversarial network (pix2pixGAN) architecture in the low-to-high bit-depth OCT image transition. RESULTS Extensively, qualitative and quantitative results show our method could significantly improve the SNR of the low bit-depth OCT images. The adopted pix2pixGAN is superior to other possible deep learning and compressed sensing solutions. CONCLUSIONS Our work demonstrates that the proper integration of OCT and deep learning could benefit the development of healthcare in low-resource settings.
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Affiliation(s)
- Qiangjiang Hao
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
- University of Science and Technology of China, Nano Science and Technology Institute, Suzhou, China
| | - Kang Zhou
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
- ShanghaiTech University, School of Information Science and Technology, Shanghai, China
| | - Jianlong Yang
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
- Address all correspondence to Jianlong Yang,
| | - Yan Hu
- Southern University of Science and Technology, Department of Computer Science and Engineering, Shenzhen, China
| | - Zhengjie Chai
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
- ShanghaiTech University, School of Information Science and Technology, Shanghai, China
| | - Yuhui Ma
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
| | | | - Yitian Zhao
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
| | - Shenghua Gao
- ShanghaiTech University, School of Information Science and Technology, Shanghai, China
| | - Jiang Liu
- Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Ningbo, China
- Southern University of Science and Technology, Department of Computer Science and Engineering, Shenzhen, China
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16
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Lee S, Jiang K, McIlmoyle B, To E, Xu QA, Hirsch-Reinshagen V, Mackenzie IR, Hsiung GYR, Eadie BD, Sarunic MV, Beg MF, Cui JZ, Matsubara JA. Amyloid Beta Immunoreactivity in the Retinal Ganglion Cell Layer of the Alzheimer's Eye. Front Neurosci 2020; 14:758. [PMID: 32848548 PMCID: PMC7412634 DOI: 10.3389/fnins.2020.00758] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/29/2020] [Indexed: 01/04/2023] Open
Abstract
Alzheimer’s disease (AD) is the most prevalent form of dementia, accounting for 60–70% of all dementias. AD is often under-diagnosed and recognized only at a later, more advanced stage, and this delay in diagnosis has been suggested as a contributing factor in the numerous unsuccessful AD treatment trials. Although there is no known cure for AD, early diagnosis is important for disease management and care. A hallmark of AD is the deposition of amyloid-β (Aβ)-containing senile neuritic plaques and neurofibrillary tangles composed of hyperphosporylated tau in the brain. However, current in vivo methods to quantify Aβ in the brain are invasive, requiring radioactive tracers and positron emission tomography. Toward development of alternative methods to assess AD progression, we focus on the retinal manifestation of AD pathology. The retina is an extension of the central nervous system uniquely accessible to light-based, non-invasive ophthalmic imaging. However, earlier studies in human retina indicate that the literature is divided on the presence of Aβ in the AD retina. To help resolve this disparity, this study assessed retinal tissues from neuropathologically confirmed AD cases to determine the regional distribution of Aβ in retinal wholemounts and to inform on future retinal image studies targeting Aβ. Concurrent post-mortem brain tissues were also collected. Neuropathological cortical assessments including neuritic plaque (NP) scores and cerebral amyloid angiopathy (CAA) were correlated with retinal Aβ using immunohistochemistry, confocal microscopy, and quantitative image analysis. Aβ load was compared between AD and control (non-AD) eyes. Our results indicate that levels of intracellular and extracellular Aβ retinal deposits were significantly higher in AD than controls. Mid-peripheral Aβ levels were greater than central retina in both AD and control eyes. In AD retina, higher intracellular Aβ was associated with lower NP score, while higher extracellular Aβ was associated with higher CAA score. Our data support the feasibility of using the retinal tissue to assess ocular Aβ as a surrogate measure of Aβ in the brain of individuals with AD. Specifically, mid-peripheral retina possesses more Aβ deposition than central retina, and thus may be the optimal location for future in vivo ocular imaging.
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Affiliation(s)
- Sieun Lee
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.,School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Kailun Jiang
- Department of Surgery, Division of Ophthalmology, University of Calgary, Calgary, AB, Canada
| | - Brandon McIlmoyle
- Department of Family Medicine, Queen's University, Kingston, ON, Canada
| | - Eleanor To
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Qinyuan Alis Xu
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Veronica Hirsch-Reinshagen
- Department of Pathology, Vancouver General Hospital, The University of British Columbia, Vancouver, BC, Canada
| | - Ian R Mackenzie
- Department of Pathology, Vancouver General Hospital, The University of British Columbia, Vancouver, BC, Canada
| | - Ging-Yuek R Hsiung
- Division of Neurology, Department of Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Brennan D Eadie
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Mirza Faisal Beg
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Jing Z Cui
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Joanne A Matsubara
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
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17
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Abstract
Quality assurance (QA) is the maintenance of a desired level of quality in a service, by means of attention to every stage of process of delivery. Correct image acquisition along with accurate and reproducible quantification of ophthalmic imaging is crucial for evaluating disease progression/stabilization, response to therapy, and planning proper management of these cases. QA includes development of standard operating procedures for the collection of data for ophthalmic imaging, proper functioning of the ophthalmic imaging equipment, and intensive training of technicians/doctors for the same. QA can be obtained during ophthalmic imaging by not only calibration and setting up of the instrument as per the manufacturer's specifications but also giving proper instructions to the patients in a language which they understand and by acquisition of good quality images. This review article will highlight on how to achieve QA in imaging which is commonly being used in ophthalmic practice.
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Affiliation(s)
- Suneeta Dubey
- Head, Glaucoma Services, Dr. Shroff's Charity Eye Hospital, Delhi, India
| | - Kanika Jain
- Fellow Glaucoma and Anterior Segment, Dr Shroff's Charity Eye Hospital, Delhi, India
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18
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Abstract
A customized Optical Coherence Tomography Angiography (OCTA) algorithm and Orthogonal OCT (en-face and B-Scans) were used for longitudinal assessment of retina murine vascular and tissue remodeling comparing photoreceptor ablation and laser-induced Choroidal Neovascularization (CNV). In the mouse model, we utilized a combined OCTA/OCT technique to image and quantify morphological and vascular features of laser lesions over time. This approach enabled us to monitor and correlate the dynamics of retina vascular and tissue remodeling as evidenced by swelling, edema, and scarring. From the OCT B-Scans, three stages of inflammatory progression were identified: the early response occurring within hours to day 3, the transition phase from 3-7 days, and the late stage of 7-21 days entering either the resolving phase or chronic phase, respectively. For the case of CNV, en-face OCTA revealed a transient non-perfusion of inner retina capillaries, specifically Deep Vascular Plexus (DVP), which corresponded to growth in lesions of a height of 200 μm or greater. Non-perfusion first occurred at 24 hours, persisted during edema and CNV formation days 7-14. In contrast, the acute inflammation induced photoreceptor damage, but no detectable alterations to the microvasculature were observed. We demonstrated that the en-face OCTA system is capable of visualizing capillary networks (~5 μm) and the corresponding tissue remodeling and growth dynamics allowing for separating acute injury from CNV. For the first time, by using OCTA we observed the presence of the 5-10 μm capillary non-perfusion present in DVP as part of CNV formation and the associated wound healing in the retina.
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Affiliation(s)
- Jonathan Luisi
- Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Wei Liu
- Ophthalmology and Visual Science, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Wenbo Zhang
- Ophthalmology and Visual Science, University of Texas Medical Branch, Galveston, TX 77555, USA
- Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Massoud Motamedi
- Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555, USA
- Ophthalmology and Visual Science, University of Texas Medical Branch, Galveston, TX 77555, USA
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19
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Wood EH, Moshfeghi AA, Nudleman ED, Moshfeghi DM. Evaluation of Visunex Medical's PanoCam(TM) LT and PanoCam(TM) Pro wide-field imaging systems for the screening of ROP in newborn infants. Expert Rev Med Devices 2017; 13:705-12. [PMID: 27424884 DOI: 10.1080/17434440.2016.1208560] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Retinopathy of Prematurity (ROP) is a leading cause of childhood blindness. The incidence of ROP is rising, placing greater demands on the healthcare providers that serve these patients and their families. Telemedicine remote digital fundus imaging (TM-RDFI) plays a pivotal role in ROP management, and has allowed for the expansion of ROP care into previously underserved areas. AREAS COVERED A broad literature review through the pubmed index was undertaken with the goal of summarizing the current state of ROP and guidelines for its screening . Furthermore, all currently used telemedicine remote digital fundus imaging devices were analyzed both via the literature and the companies' websites/brochures. Finally, the PanoCam LT™ and PanoCam™ Pro created by Visunex Medical were analyzed via the company website/brochures. Expert commentary: The PanoCam LT™ and PanoCam™ Pro have recently been approved for use within the USA and CE marked for international commercialization in European Union and other countries requiring CE mark. These wide-field imaging systems have the intended use of ophthalmic imaging of all newborn babies and meet the requirements for ROP screening, thereby serving as competition within the ROP screening market previously dominated by one camera imaging system.
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Affiliation(s)
- Edward H Wood
- a Byers Eye Institute, Department of Ophthalmology , Stanford University School of Medicine , Palo Alto , CA , USA
| | - Andrew A Moshfeghi
- b USC Eye Institute, Department of Ophthalmology , University of Southern California Keck School of Medicine , Los Angeles , CA , USA
| | - Eric D Nudleman
- c Shiley Eye Institute, Department of Ophthalmology , University of California San Diego School of Medicine , La Jolla , CA , USA
| | - Darius M Moshfeghi
- a Byers Eye Institute, Department of Ophthalmology , Stanford University School of Medicine , Palo Alto , CA , USA
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20
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Abstract
We demonstrate the usefulness of utilizing a segmentation step for improving the performance of sparsity based image reconstruction algorithms. In specific, we will focus on retinal optical coherence tomography (OCT) reconstruction and propose a novel segmentation based reconstruction framework with sparse representation, termed segmentation based sparse reconstruction (SSR). The SSR method uses automatically segmented retinal layer information to construct layer-specific structural dictionaries. In addition, the SSR method efficiently exploits patch similarities within each segmented layer to enhance the reconstruction performance. Our experimental results on clinical-grade retinal OCT images demonstrate the effectiveness and efficiency of the proposed SSR method for both denoising and interpolation of OCT images.
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21
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Javed A, Aslam T, Ashworth J. Use of new imaging in detecting and monitoring ocular manifestations of the mucopolysaccharidoses. Acta Ophthalmol 2016; 94:e676-e682. [PMID: 27273899 DOI: 10.1111/aos.13098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/24/2016] [Indexed: 12/13/2022]
Abstract
The aim of this review is to summate the eye involvement in patients with mucopolysaccharidoses (MPS) using current ocular imaging techniques, their advantages and disadvantages and how they may aid diagnosis, management and monitoring. We critically reviewed the current literature surrounding MPS and recent imaging technology as well as histology. Primary searches of PubMed and Web of Science were performed. We reviewed all papers on the topic published and summarized the findings of each medical device as well as the advantages and disadvantages of using these for the MPS patient. We discussed the potential of each of these devices to monitor potential ocular pathology in the MPS cohorts in the order of MPS subtype. We reviewed imaging techniques involving use of the Iris Camera, Pentacam, Optical Coherence Tomography (OCT) as well as ultrasound and Heidelberg OCT. The need for reliable objective quantification of eye findings in MPS has led to utilization of new imaging technologies described here, and future use will enhance our understanding of the unique eye features in MPS. In particular, we note that the Pentacam and iris camera are able to provide objective measurements of corneal haze and monitor ocular response to treatment.
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Affiliation(s)
- Ahmed Javed
- Manchester Royal Eye Hospital; Manchester Academic Health Science Centre; Manchester UK
| | - Tariq Aslam
- Manchester Royal Eye Hospital; Manchester Academic Health Science Centre; Manchester UK
- Faculty of Medical and Human Sciences; Centre for Ophthalmology and Vision Sciences; Institute of Human Development; University of Manchester; Manchester UK
| | - Jane Ashworth
- Manchester Royal Eye Hospital; Manchester Academic Health Science Centre; Manchester UK
- Faculty of Medical and Human Sciences; Centre for Ophthalmology and Vision Sciences; Institute of Human Development; University of Manchester; Manchester UK
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22
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Abstract
This review was written for the special issue of IOVS to describe the history of optical coherence tomography (OCT) and its evolution from a nonscientific, historic perspective. Optical coherence tomography has become a standard of care in ophthalmology, providing real-time information on structure and function - diagnosing disease, evaluating progression, and assessing response to therapy, as well as helping to understand disease pathogenesis and create new therapies. Optical coherence tomography also has applications in multiple clinical specialties, fundamental research, and manufacturing. We review the early history of OCT describing how research and development evolves and the important role of multidisciplinary collaboration and expertise. Optical coherence tomography had its origin in femtosecond optics, but used optical communications technologies and required advanced engineering for early OCT prototypes, clinical feasibility studies, entrepreneurship, and corporate development in order to achieve clinical acceptance and clinical impact. Critical advances were made by early career researchers, clinician scientists, engineering experts, and business leaders, which enabled OCT to have a worldwide impact on health care. We introduce the concept of an "ecosystem" consisting of research, government funding, collaboration and competition, clinical studies, innovation, entrepreneurship and industry, and impact - all of which must work synergistically. The process that we recount is long and challenging, but it is our hope that it might inspire early career professionals in science, engineering, and medicine, and that the clinical and research community will find this review of interest.
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Affiliation(s)
- James Fujimoto
- Research Laboratory of Electronics Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Eric Swanson
- Research Laboratory of Electronics Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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Sharma R, Williams DR, Palczewska G, Palczewski K, Hunter JJ. Two-Photon Autofluorescence Imaging Reveals Cellular Structures Throughout the Retina of the Living Primate Eye. Invest Ophthalmol Vis Sci 2016; 57:632-46. [PMID: 26903224 PMCID: PMC4771181 DOI: 10.1167/iovs.15-17961] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 12/30/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Although extrinsic fluorophores can be introduced to label specific cell types in the retina, endogenous fluorophores, such as NAD(P)H, FAD, collagen, and others, are present in all retinal layers. These molecules are a potential source of optical contrast and can enable noninvasive visualization of all cellular layers. We used a two-photon fluorescence adaptive optics scanning light ophthalmoscope (TPF-AOSLO) to explore the native autofluorescence of various cell classes spanning several layers in the unlabeled retina of a living primate eye. METHODS Three macaques were imaged on separate occasions using a custom TPF-AOSLO. Two-photon fluorescence was evoked by pulsed light at 730 and 920 nm excitation wavelengths, while fluorescence emission was collected in the visible range from several retinal layers and different locations. Backscattered light was recorded simultaneously in confocal modality and images were postprocessed to remove eye motion. RESULTS All retinal layers yielded two-photon signals and the heterogeneous distribution of fluorophores provided optical contrast. Several structural features were observed, such as autofluorescence from vessel walls, Müller cell processes in the nerve fibers, mosaics of cells in the ganglion cell and other nuclear layers of the inner retina, as well as photoreceptor and RPE layers in the outer retina. CONCLUSIONS This in vivo survey of two-photon autofluorescence throughout the primate retina demonstrates a wider variety of structural detail in the living eye than is available through conventional imaging methods, and broadens the use of two-photon imaging of normal and diseased eyes.
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Affiliation(s)
- Robin Sharma
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - David R. Williams
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jennifer J. Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
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Fang L, Li S, Kang X, Izatt JA, Farsiu S. 3-D Adaptive Sparsity Based Image Compression With Applications to Optical Coherence Tomography. IEEE Trans Med Imaging 2015; 34:1306-20. [PMID: 25561591 PMCID: PMC4490145 DOI: 10.1109/tmi.2014.2387336] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods.
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Affiliation(s)
- Leyuan Fang
- College of Electrical and Information Engineering, Hunan University, Changsha, 410082, China
| | - Shutao Li
- College of Electrical and Information Engineering, Hunan University, Changsha, 410082, China
| | - Xudong Kang
- College of Electrical and Information Engineering, Hunan University, Changsha, 410082, China
| | - Joseph A. Izatt
- Biomedical Engineering, Duke University, Durham, NC 27708 USA and also with the Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710 USA
| | - Sina Farsiu
- Departments of Biomedical Engineering, and Electrical and Computer Engineering, and Computer Science Duke University, Durham, NC 27708 USA , and also with the Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710 USA
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Jia Y, Bailey ST, Hwang TS, McClintic SM, Gao SS, Pennesi ME, Flaxel CJ, Lauer AK, Wilson DJ, Hornegger J, Fujimoto JG, Huang D. Quantitative optical coherence tomography angiography of vascular abnormalities in the living human eye. Proc Natl Acad Sci U S A 2015; 112:E2395-402. [PMID: 25897021 DOI: 10.1073/pnas.1500185112] [Citation(s) in RCA: 474] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.
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de la Zerda A, Prabhulkar S, Perez VL, Ruggeri M, Paranjape AS, Habte F, Gambhir SS, Awdeh RM. Optical coherence contrast imaging using gold nanorods in living mice eyes. Clin Exp Ophthalmol 2015; 43:358-66. [PMID: 24533647 DOI: 10.1111/ceo.12299] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 02/06/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Optical coherence tomography (OCT) is a powerful imaging modality to visualize tissue structures, with axial image pixel resolution as high as 1.6 μm in tissue. However, OCT is intrinsically limited to providing structural information as the OCT contrast is produced by optically scattering tissues. METHODS Gold nanorods (GNRs) were injected into the anterior chamber (AC) and cornea of mice eyes which could create a significant OCT signal and hence could be used as a contrast agent for in vivo OCT imaging. RESULTS A dose of 30 nM of GNRs (13 nm in diameter and 45 nm in length) were injected to the AC of mice eyes and produced an OCT contrast nearly 50-fold higher than control mice injected with saline. Furthermore, the lowest detectable concentration of GNRs in living mice AC was experimentally estimated to be as low as 120 pM. CONCLUSIONS The high sensitivity and low toxicity of GNRs brings great promise for OCT to uniquely become a high-resolution molecular imaging modality.
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Affiliation(s)
- Adam de la Zerda
- Molecular Imaging Program at Stanford, the Bio-X Program and the Department of Radiology, Stanford University, Palo Alto, California, USA.,Department of Structural Biology, Stanford University, Palo Alto, California, USA
| | | | - Victor L Perez
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | - Marco Ruggeri
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | - Amit S Paranjape
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | - Frezghi Habte
- Molecular Imaging Program at Stanford, the Bio-X Program and the Department of Radiology, Stanford University, Palo Alto, California, USA
| | - Sanjiv S Gambhir
- Molecular Imaging Program at Stanford, the Bio-X Program and the Department of Radiology, Stanford University, Palo Alto, California, USA.,Department of Bioengineering, Stanford University, Palo Alto, California, USA.,Department of Materials Science and Engineering, Stanford University, Palo Alto, California, USA
| | - Richard M Awdeh
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
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Abstract
A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea.
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Affiliation(s)
- Changgeng Liu
- University of South Florida, Department of Physics, Digital Holography and Microscopy Laboratory, Tampa, Florida 33620, United States
| | - Myung K. Kim
- University of South Florida, Department of Physics, Digital Holography and Microscopy Laboratory, Tampa, Florida 33620, United States
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Abstract
PURPOSE Fundus autofluorescence (AF) is characterized not only by its intensity or excitation and emission spectra but also by the lifetimes of the fluorophores. Fluorescence lifetime is influenced by the fluorophore's microenvironment and may provide information about the metabolic tissue state. We report quantitative and qualitative autofluorescence lifetime imaging of the ocular fundus in mice. METHODS A fluorescence lifetime imaging ophthalmoscope (FLIO) was used to measure fluorescence lifetimes of endogenous fluorophores in the murine retina. FLIO imaging was performed in 1-month-old C57BL/6, BALB/c, and C3A.Cg-Pde6b(+)Prph2(Rd2)/J mice. Measurements were repeated at monthly intervals over the course of 6 months. For correlation with structural changes, an optical coherence tomogram was acquired. RESULTS Fundus autofluorescence lifetime images were readily obtained in all mice. In the short spectral channel (498-560 nm), mean ± SEM AF lifetimes were 956 ± 15 picoseconds (ps) in C57BL/6; 801 ± 35 ps in BALB/c mice; and 882 ± 37 ps in C3A.Cg-Pde6b(+)Prph2(Rd2)/J mice. In the long spectral channel (560-720 nm), mean ± SEM AF lifetimes were 298 ± 14 ps in C57BL/6 mice, 241 ± 10 ps in BALB/c mice, and 288 ± 8 ps in C3A.Cg-Pde6b(+)Prph2(Rd2)/J mice. There was a general decrease in mean AF lifetimes with age. CONCLUSIONS Although fluorescence lifetime values differ among mouse strains, we found little variance within the groups. Fundus autofluorescence lifetime imaging in mice may provide additional information for understanding retinal disease processes and may facilitate monitoring of therapeutic effects in preclinical studies.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Muriel Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Volker Enzmann
- Department of Ophthalmology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
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Abstract
INTRODUCTION OR BACKGROUND The last two decades have seen a revolution in ophthalmic imaging. In this review we present an overview of the breadth of ophthalmic imaging modalities in use today and describe how the role of ophthalmic imaging has changed from documenting abnormalities visible on clinical examination to the detection of clinically silent abnormalities which can lead to an earlier and more precise diagnosis. SOURCES OF DATA This review is based on published literature in the fields of ophthalmic imaging and with focus on most commonly used imaging modalities. AREAS OF AGREEMENT New imaging techniques enable non-invasive evaluation of ocular structures at a resolution of a few micrometres. This has led to a re-evaluation of diagnostic criteria for ocular disease, which were previously defined by clinical findings without significant reference to imaging. AREAS OF CONTROVERSY Lack of formal training and clinical guidelines regarding use of new imaging techniques in diagnosing and monitoring various ocular conditions. Lack of large normative databases and interchangeability issues between different commercial machines can hinder the detection of disease progression. GROWING POINTS Imaging devices are being constantly refined with improved image capture and image analysis tools. AREAS TIMELY FOR DEVELOPING RESEARCH Clinical applications of new techniques and devices have yet to be determined using systematic scientific research methods.
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Affiliation(s)
- Tomas Ilginis
- NIHR Moorfields Biomedical Research Centre (Moorfields Eye Hospital and UCL Institute of Ophthalmology), London, UK
| | - Jonathan Clarke
- NIHR Moorfields Biomedical Research Centre (Moorfields Eye Hospital and UCL Institute of Ophthalmology), London, UK
| | - Praveen J Patel
- NIHR Moorfields Biomedical Research Centre (Moorfields Eye Hospital and UCL Institute of Ophthalmology), London, UK
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Ramos de Carvalho JE, Verbraak FD, Aalders MC, van Noorden CJ, Schlingemann RO. Recent advances in ophthalmic molecular imaging. Surv Ophthalmol 2013; 59:393-413. [PMID: 24529711 DOI: 10.1016/j.survophthal.2013.09.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 12/30/2022]
Abstract
The aim of molecular imaging techniques is the visualization of molecular processes and functional changes in living animals and human patients before morphological changes occur at the cellular and tissue level. Ophthalmic molecular imaging is still in its infancy and has mainly been used in small animals for pre-clinical research. The goal of most of these pre-clinical studies is their translation into ophthalmic molecular imaging techniques in clinical care. We discuss various molecular imaging techniques and their applications in ophthalmology.
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Affiliation(s)
- J Emanuel Ramos de Carvalho
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Frank D Verbraak
- Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Maurice C Aalders
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Cornelis J van Noorden
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Reinier O Schlingemann
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Netherlands Institute for Neuroscience, Royal Academy of Sciences, Amsterdam, The Netherlands.
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Kim DY, Fingler J, Zawadzki RJ, Park SS, Morse LS, Schwartz DM, Fraser SE, Werner JS. Optical imaging of the chorioretinal vasculature in the living human eye. Proc Natl Acad Sci U S A 2013; 110:14354-9. [PMID: 23918361 DOI: 10.1073/pnas.1307315110] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Detailed visualization of microvascular changes in the human retina is clinically limited by the capabilities of angiography imaging, a 2D fundus photograph that requires an intravenous injection of fluorescent dye. Whereas current angiography methods enable visualization of some retinal capillary detail, they do not adequately reveal the choriocapillaris or other microvascular features beneath the retina. We have developed a noninvasive microvascular imaging technique called phase-variance optical coherence tomography (pvOCT), which identifies vasculature three dimensionally through analysis of data acquired with OCT systems. The pvOCT imaging method is not only capable of generating capillary perfusion maps for the retina, but it can also use the 3D capabilities to segment the data in depth to isolate vasculature in different layers of the retina and choroid. This paper demonstrates some of the capabilities of pvOCT imaging of the anterior layers of choroidal vasculature of a healthy normal eye as well as of eyes with geographic atrophy (GA) secondary to age-related macular degeneration. The pvOCT data presented permit digital segmentation to produce 2D depth-resolved images of the retinal vasculature, the choriocapillaris, and the vessels in Sattler's and Haller's layers. Comparisons are presented between en face projections of pvOCT data within the superficial choroid and clinical angiography images for regions of GA. Abnormalities and vascular dropout observed within the choriocapillaris for pvOCT are compared with regional GA progression. The capability of pvOCT imaging of the microvasculature of the choriocapillaris and the anterior choroidal vasculature has the potential to become a unique tool to evaluate therapies and understand the underlying mechanisms of age-related macular degeneration progression.
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Zhu D, Shen M, Jiang H, Li M, Wang MR, Wang Y, Ge L, Qu J, Wang J. Broadband superluminescent diode-based ultrahigh resolution optical coherence tomography for ophthalmic imaging. J Biomed Opt 2011; 16:126006. [PMID: 22191923 PMCID: PMC3247935 DOI: 10.1117/1.3660314] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 09/30/2011] [Accepted: 10/24/2011] [Indexed: 05/20/2023]
Abstract
Spectral domain optical coherence tomography (SD-OCT) with ultrahigh resolution can be used to measure precise structures in the context of ophthalmic imaging. We designed an ultrahigh resolution SD-OCT system based on broadband superluminescent diode (SLD) as the light source. An axial resolution of 2.2 μm in tissue, a scan depth of 1.48 mm, and a high sensitivity of 93 dB were achieved by the spectrometer designed. The ultrahigh-resolution SD-OCT system was employed to image the human cornea and retina with a cross-section image of 2048 × 2048 pixels. Our research demonstrated that ultrahigh -resolution SD-OCT can be achieved using broadband SLD in a simple way.
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Affiliation(s)
- Dexi Zhu
- Wenzhou Medical College, School of Ophthalmology and Optometry, Wenzhou, Zhejiang 325000, China
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