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Gaire BP, Koronyo Y, Fuchs DT, Shi H, Rentsendorj A, Danziger R, Vit JP, Mirzaei N, Doustar J, Sheyn J, Hampel H, Vergallo A, Davis MR, Jallow O, Baldacci F, Verdooner SR, Barron E, Mirzaei M, Gupta VK, Graham SL, Tayebi M, Carare RO, Sadun AA, Miller CA, Dumitrascu OM, Lahiri S, Gao L, Black KL, Koronyo-Hamaoui M. Alzheimer's disease pathophysiology in the Retina. Prog Retin Eye Res 2024; 101:101273. [PMID: 38759947 DOI: 10.1016/j.preteyeres.2024.101273] [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: 02/11/2023] [Revised: 04/23/2024] [Accepted: 05/10/2024] [Indexed: 05/19/2024]
Abstract
The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring.
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Affiliation(s)
- Bhakta Prasad Gaire
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Altan Rentsendorj
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ron Danziger
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jean-Philippe Vit
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Nazanin Mirzaei
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jonah Doustar
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Harald Hampel
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Andrea Vergallo
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Miyah R Davis
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ousman Jallow
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Filippo Baldacci
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France; Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | | | - Ernesto Barron
- Department of Ophthalmology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Mehdi Mirzaei
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Vivek K Gupta
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Stuart L Graham
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia; Department of Clinical Medicine, Macquarie University, Sydney, NSW, Australia
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Roxana O Carare
- Department of Clinical Neuroanatomy, University of Southampton, Southampton, UK
| | - Alfredo A Sadun
- Department of Ophthalmology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Carol A Miller
- Department of Pathology Program in Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Shouri Lahiri
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Liang Gao
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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Joseph S, Haystead A, Robbins CB, Threlfall A, MacGillivray TJ, Stinnett S, Grewal DS, Fekrat S. Analysis of the Retinal and Choroidal Vasculature Using Ultrawidefield Fundus Imaging in Mild Cognitive Impairment and Normal Cognition. OPHTHALMOLOGY SCIENCE 2024; 4:100480. [PMID: 38827032 PMCID: PMC11141260 DOI: 10.1016/j.xops.2024.100480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 06/04/2024]
Abstract
Purpose To utilize ultrawidefield (UWF) imaging to evaluate retinal and choroidal vasculature and structure in individuals with mild cognitive impairment (MCI) compared with that of controls with normal cognition. Design Prospective cross sectional study. Participants One hundred thirty-one eyes of 82 MCI patients and 230 eyes of 133 cognitively normal participants from the Eye Multimodal Imaging in Neurodegenerative Disease Study. Methods A scanning laser ophthalmoscope (California, Optos Inc) was used to obtain UWF fundus color images. Images were analyzed with the Vasculature Assessment Platform for Images of the Retina UWF (VAMPIRE-UWF 2.0, Universities of Edinburgh and Dundee) software. Main outcome measures Imaging parameters included vessel width gradient, vessel width intercept, large vessel choroidal vascular density, vessel tortuosity, and vessel fractal dimension. Results Both retinal artery and vein width gradients were less negative in MCI patients compared with controls, demonstrating decreased rates of vessel thinning at the periphery (P < 0.001; P = 0.027). Retinal artery and vein width intercepts, a metric that extrapolates the width of the vessel at the center of the optic disc, were smaller in MCI patients compared with that of controls (P < 0.001; P = 0.017). The large vessel choroidal vascular density, which quantifies the vascular area versus the total choroidal area, was greater in MCI patients compared with controls (P = 0.025). Conclusions When compared with controls with normal cognition, MCI patients had thinner retinal vasculature manifested in both the retinal arteries and the veins. In MCI, these thinner arteries and veins attenuated at a lower rate when traveling toward the periphery. MCI patients also had increased choroidal vascular density. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Suzanna Joseph
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
| | - Alice Haystead
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
| | - Cason B. Robbins
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
| | - Adam Threlfall
- Centre for Clinical Brain Science, University of Edinburgh, Scotland, United Kingdom
| | - Tom J. MacGillivray
- Centre for Clinical Brain Science, University of Edinburgh, Scotland, United Kingdom
| | - Sandra Stinnett
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
| | - Dilraj S. Grewal
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
| | - Sharon Fekrat
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Department of Neurology, Duke University School of Medicine, Durham, North Carolina
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Dumitrascu OM, Doustar J, Fuchs DT, Koronyo Y, Sherman DS, Miller MS, Johnson KO, Carare RO, Verdooner SR, Lyden PD, Schneider JA, Black KL, Koronyo-Hamaoui M. Distinctive retinal peri-arteriolar versus peri-venular amyloid plaque distribution correlates with the cognitive performance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.580733. [PMID: 38464292 PMCID: PMC10925252 DOI: 10.1101/2024.02.27.580733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Introduction The vascular contribution to Alzheimer's disease (AD) is tightly connected to cognitive performance across the AD continuum. We topographically describe retinal perivascular amyloid plaque (AP) burden in subjects with normal or impaired cognition. Methods Using scanning laser ophthalmoscopy, we quantified retinal peri-arteriolar and peri-venular curcumin-positive APs in the first, secondary and tertiary branches in twenty-eight subjects. Perivascular AP burden among cognitive states was correlated with neuroimaging and cognitive measures. Results Peri-arteriolar exceeded peri-venular AP count (p<0.0001). Secondary branch AP count was significantly higher in cognitively impaired (p<0.01). Secondary small and tertiary peri-venular AP count strongly correlated with clinical dementia rating, hippocampal volumes, and white matter hyperintensity count. Discussion Our topographic analysis indicates greater retinal amyloid accumulation in the retinal peri-arteriolar regions overall, and distal peri-venular regions in cognitively impaired individuals. Larger longitudinal studies are warranted to understand the temporal-spatial relationship between vascular dysfunction and perivascular amyloid deposition in AD. Highlights Retinal peri-arteriolar region exhibits more amyloid compared with peri-venular regions.Secondary retinal vascular branches have significantly higher perivascular amyloid burden in subjects with impaired cognition, consistent across sexes.Cognitively impaired individuals have significantly greater retinal peri-venular amyloid deposits in the distal small branches, that correlate with CDR and hippocampal volumes.
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Shi H, Koronyo Y, Fuchs DT, Sheyn J, Jallow O, Mandalia K, Graham SL, Gupta VK, Mirzaei M, Kramerov AA, Ljubimov AV, Hawes D, Miller CA, Black KL, Carare RO, Koronyo-Hamaoui M. Retinal arterial Aβ 40 deposition is linked with tight junction loss and cerebral amyloid angiopathy in MCI and AD patients. Alzheimers Dement 2023; 19:5185-5197. [PMID: 37166032 PMCID: PMC10638467 DOI: 10.1002/alz.13086] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 05/12/2023]
Abstract
INTRODUCTION Vascular amyloid beta (Aβ) protein deposits were detected in retinas of mild cognitively impaired (MCI) and Alzheimer's disease (AD) patients. We tested the hypothesis that the retinal vascular tight junctions (TJs) were compromised and linked to disease status. METHODS TJ components and Aβ expression in capillaries and larger blood vessels were determined in post mortem retinas from 34 MCI or AD patients and 27 cognitively normal controls and correlated with neuropathology. RESULTS Severe decreases in retinal vascular zonula occludens-1 (ZO-1) and claudin-5 correlating with abundant arteriolar Aβ40 deposition were identified in MCI and AD patients. Retinal claudin-5 deficiency was closely associated with cerebral amyloid angiopathy, whereas ZO-1 defects correlated with cerebral pathology and cognitive deficits. DISCUSSION We uncovered deficiencies in blood-retinal barrier markers for potential retinal imaging targets of AD screening and monitoring. Intense retinal arteriolar Aβ40 deposition suggests a common pathogenic mechanism of failed Aβ clearance via intramural periarterial drainage.
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Affiliation(s)
- Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Ousman Jallow
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Krishna Mandalia
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Stuart L. Graham
- Macquarie Medical school, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Vivek K. Gupta
- Macquarie Medical school, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Mehdi Mirzaei
- Macquarie Medical school, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Andrei A. Kramerov
- Department of Biomedical Sciences and Eye Program, Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Alexander V. Ljubimov
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Department of Biomedical Sciences and Eye Program, Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Debra Hawes
- Department of Pathology Program in Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90048, USA
| | - Carol A. Miller
- Department of Pathology Program in Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90048, USA
| | - Keith L. Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Roxana O. Carare
- Department of Clinical Neuroanatomy, University of Southampton, Southampton SO16 6YD, UK
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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Zhang Y, Huang J, Liang Y, Huang J, Fu Y, Chen N, Lu B, Zhao C. Clearance of lipid droplets by chimeric autophagy-tethering compound ameliorates the age-related macular degeneration phenotype in mice lacking APOE. Autophagy 2023; 19:2668-2681. [PMID: 37266932 PMCID: PMC10472852 DOI: 10.1080/15548627.2023.2220540] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 05/10/2023] [Accepted: 05/23/2023] [Indexed: 06/03/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly, and there is currently no clinical treatment targeting the primary impairment of AMD. The earliest clinical hallmark of AMD is drusen, which are yellowish spots mainly composed of lipid droplets (LDs) accumulated under the retinal pigment epithelium (RPE). However, the potential pathogenic role of this excessive LD accumulation in AMD is yet to be determined, partially due to a lack of chemical tools to manipulate LDs specifically. Here, we employed our recently developed Lipid Droplets·AuTophagy Tethering Compounds (LD∙ATTECs) to degrade LDs and to evaluate its consequence on the AMD-like phenotypes in apoe-/- (apolipoprotein E; B6/JGpt-Apoeem1Cd82/Gpt) mouse model. apoe-/- mice fed with high-fat diet (apoe-/--HFD) exhibited excessive LD accumulation in the retina, particularly with AMD-like phenotypes including RPE degeneration, Bruch's membrane (BrM) thickening, drusen-like deposits, and photoreceptor dysfunction. LD·ATTEC treatment significantly cleared LDs in RPE/choroidal tissues without perturbing lipid synthesis-related proteins and rescued RPE degeneration and photoreceptor dysfunction in apoe-/--HFD mice. This observation implied a causal relationship between LD accumulation and AMD-relevant phenotypes. Mechanically, the apoe-/--HFD mice exhibited elevated oxidative stress and inflammatory signals, both of which were mitigated by the LD·ATTEC treatment. Collectively, this study demonstrated that LD accumulation was a trigger for the process of AMD and provided entry points for the treatment of the initial insult of AMD by degrading LDs.Abbreviations: AMD: age-related macular degeneration; APOE: apolipoprotein E; ATTECs: autophagy-tethering compounds; BODIPY: boron-dipyrromethene; BrM: Bruch's membrane; ERG: electroretinogram; HFD: high-fat diet; LD·ATTECs: Lipid Droplets·AuTophagy Tethering Compounds; LDs: lipid droplets; OA: oleic acid; OPL: outer plexiform layer; ROS: reactive oxygen species; RPE: retinal pigment epithelium.
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Affiliation(s)
- Yuelu Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
- Department of Ophthalmology, Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Jiancheng Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
- Department of Ophthalmology, Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Yu Liang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
- Department of Ophthalmology, Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Jiaqiu Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
- Department of Ophthalmology, Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Yuhua Fu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China
| | - Ningxie Chen
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China
| | - Chen Zhao
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
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Brazionis L, Quinn N, Dabbah S, Ryan CD, Møller DM, Richardson H, Keech AC, Januszewski AS, Grauslund J, Rasmussen ML, Peto T, Jenkins AJ. Review and comparison of retinal vessel calibre and geometry software and their application to diabetes, cardiovascular disease, and dementia. Graefes Arch Clin Exp Ophthalmol 2023; 261:2117-2133. [PMID: 36801971 DOI: 10.1007/s00417-023-06002-7] [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: 10/03/2022] [Revised: 01/06/2023] [Accepted: 02/04/2023] [Indexed: 02/20/2023] Open
Abstract
Developments in retinal imaging technologies have enabled the quantitative evaluation of the retinal vasculature. Changes in retinal calibre and/or geometry have been reported in systemic vascular diseases, including diabetes mellitus (DM), cardiovascular disease (CVD), and more recently in neurodegenerative diseases, such as dementia. Several retinal vessel analysis softwares exist, some being disease-specific, others for a broader context. In the research setting, retinal vasculature analysis using semi-automated software has identified associations between retinal vessel calibre and geometry and the presence of or risk of DM and its chronic complications, and of CVD and dementia, including in the general population. In this article, we review and compare the most widely used semi-automated retinal vessel analysis softwares and their associations with ocular imaging findings in common systemic diseases, including DM and its chronic complications, CVD, and dementia. We also provide original data comparing retinal calibre grading in people with Type 1 DM using two softwares, with good concordance.
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Affiliation(s)
- Laima Brazionis
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
| | - Nicola Quinn
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia
- Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Sami Dabbah
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark
| | - Chris D Ryan
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia
| | - Dennis M Møller
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Hilary Richardson
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia
| | - Anthony C Keech
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia
| | - Andrzej S Januszewski
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia.
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia.
| | - Jakob Grauslund
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
| | - Malin Lundberg Rasmussen
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Tunde Peto
- Centre for Public Health, Queen's University Belfast, Belfast, UK.
- Institute of Clinical Science, Royal Victoria Hospital, Belfast, BT12 6BA, UK.
| | - Alicia J Jenkins
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- NHMRC Clinical Trials Centre, The University of Sydney, 92 Parramatta Rd, Camperdown, NSW, 2050, Australia
- Centre for Public Health, Queen's University Belfast, Belfast, UK
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
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Hegde KR, Puche AC, Szmacinski H, Fuller K, Ray K, Patel N, Lengyel I, Thompson RB. Fluorescence Lifetime Imaging of Human Sub-RPE Calcification In Vitro Following Chlortetracycline Infusion. Int J Mol Sci 2023; 24:6421. [PMID: 37047392 PMCID: PMC10094693 DOI: 10.3390/ijms24076421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/10/2023] [Accepted: 03/23/2023] [Indexed: 04/14/2023] Open
Abstract
We have shown that all sub-retinal pigment epithelial (sub-RPE) deposits examined contain calcium phosphate minerals: hydroxyapatite (HAP), whitlockite (Wht), or both. These typically take the form of ca. 1 μm diameter spherules or >10 μm nodules and appear to be involved in the development and progression of age-related macular degeneration (AMD). Thus, these minerals may serve as useful biomarkers the for early detection and monitoring of sub-RPE changes in AMD. We demonstrated that HAP deposits could be imaged in vitro by fluorescence lifetime imaging microscopy (FLIM) in flat-mounted retinas using legacy tetracycline antibiotics as selective sensors for HAP. As the contrast on a FLIM image is based on the difference in fluorescence lifetime and not intensity of the tetracycline-stained HAP, distinguishing tissue autofluorescence from the background is significantly improved. The focus of the present pilot study was to assess whether vascular perfusion of the well tolerated and characterized chlortetracycline (widely used as an orally bioavailable antibiotic) can fluorescently label retinal HAP using human cadavers. We found that the tetracycline delivered through the peripheral circulation can indeed selectively label sub-RPE deposits opening the possibility for its use for ophthalmic monitoring of a range of diseases in which deposit formation is reported, such as AMD and Alzheimer disease (AD).
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Affiliation(s)
- Kavita R. Hegde
- Department of Natural Sciences, Coppin State University, Baltimore, MD 21216, USA
| | - Adam C. Puche
- Department of Anatomy and Neurobiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Henryk Szmacinski
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Kristina Fuller
- Department of Anatomy and Neurobiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Krishanu Ray
- Institute for Human Virology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Nikita Patel
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
- Department of Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY 11794, USA
| | - Imre Lengyel
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Richard B. Thompson
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
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8
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Tsai HR, Lo RY, Liang KH, Chen TL, Huang HK, Wang JH, Lee YC. Risk of Subsequent Dementia or Alzheimer Disease Among Patients With Age-Related Macular Degeneration: A Systematic Review and Meta-analysis. Am J Ophthalmol 2023; 247:161-169. [PMID: 36375591 DOI: 10.1016/j.ajo.2022.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022]
Abstract
PURPOSE Alzheimer disease (AD), a common form of dementia, shares several clinical and pathologic features with age-related macular degeneration (AMD). Epidemiologic reports on the association of AMD with subsequent dementia or AD are inconsistent. DESIGN Systematic review and meta-analysis. METHODS The Meta-analysis of Observational Studies in Epidemiology reporting guidelines were applied. The Newcastle-Ottawa Scale was used to evaluate the risk of bias in the included cohort studies that examined the association of AMD with subsequent dementia or AD. We estimated the pooled hazard ratios (HRs) of dementia or AD using random effects model meta-analysis and subgroup analysis on different follow-up periods, AMD subtype, gender, age, study design, and methods to ascertain dementia or AD. RESULTS A total of 8 223 581 participants were included in 8 studies published during 2000-2021. The meta-analysis showed that AMD was significantly associated with subsequent dementia (pooled HR 1.22, 95% CI 1.01-1.47) or AD (pooled HR 1.21, 95% CI 1.03-1.43). Our secondary analysis revealed that the association was more noticeable in dry AMD than wet AMD. CONCLUSIONS Patients with AMD have higher risks of developing dementia or AD, and therefore identifying related comorbidities and retinal biomarkers is much warranted for older adults with AMD in ophthalmologic practice.
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Affiliation(s)
- Hou-Ren Tsai
- From the Department of Ophthalmology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (H.-R.T., Y.-C.L.), Hualien
| | - Raymond Y Lo
- Division of Cognitive/Geriatric Neurology, Department of Neurology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and Tzu Chi University (R.Y.L.), Hualien; Institute of Medical Sciences, Tzu Chi University (R.Y.L.), Hualien
| | - Kai-Hsiang Liang
- Department of Medical Education, Medical Administration Office, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City
| | - Tai-Li Chen
- Center for Aging and Health, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (T.-L.C.), Hualien; Department of Dermatology, Taipei Veterans General Hospital (T.-L.C.), Taipei
| | - Huei-Kai Huang
- Department of Family medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (H.-K.H.), Hualien; Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (H.-K.H., J.-H.W.), Hualien
| | - Jen-Hung Wang
- Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (H.-K.H., J.-H.W.), Hualien
| | - Yuan-Chieh Lee
- From the Department of Ophthalmology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (H.-R.T., Y.-C.L.), Hualien; Department of Ophthalmology and Visual Science, Tzu Chi University (Y.-C.L.), Hualien.
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9
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Sensi SL, Russo M, Tiraboschi P. Biomarkers of diagnosis, prognosis, pathogenesis, response to therapy: Convergence or divergence? Lessons from Alzheimer's disease and synucleinopathies. HANDBOOK OF CLINICAL NEUROLOGY 2023; 192:187-218. [PMID: 36796942 DOI: 10.1016/b978-0-323-85538-9.00015-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Alzheimer's disease (AD) is the most common disorder associated with cognitive impairment. Recent observations emphasize the pathogenic role of multiple factors inside and outside the central nervous system, supporting the notion that AD is a syndrome of many etiologies rather than a "heterogeneous" but ultimately unifying disease entity. Moreover, the defining pathology of amyloid and tau coexists with many others, such as α-synuclein, TDP-43, and others, as a rule, not an exception. Thus, an effort to shift our AD paradigm as an amyloidopathy must be reconsidered. Along with amyloid accumulation in its insoluble state, β-amyloid is becoming depleted in its soluble, normal states, as a result of biological, toxic, and infectious triggers, requiring a shift from convergence to divergence in our approach to neurodegeneration. These aspects are reflected-in vivo-by biomarkers, which have become increasingly strategic in dementia. Similarly, synucleinopathies are primarily characterized by abnormal deposition of misfolded α-synuclein in neurons and glial cells and, in the process, depleting the levels of the normal, soluble α-synuclein that the brain needs for many physiological functions. The soluble to insoluble conversion also affects other normal brain proteins, such as TDP-43 and tau, accumulating in their insoluble states in both AD and dementia with Lewy bodies (DLB). The two diseases have been distinguished by the differential burden and distribution of insoluble proteins, with neocortical phosphorylated tau deposition more typical of AD and neocortical α-synuclein deposition peculiar to DLB. We propose a reappraisal of the diagnostic approach to cognitive impairment from convergence (based on clinicopathologic criteria) to divergence (based on what differs across individuals affected) as a necessary step for the launch of precision medicine.
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Affiliation(s)
- Stefano L Sensi
- Department of Neuroscience, Imaging, and Clinical Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Molecular Neurology Unit, Center for Advanced Studies and Technology-CAST and ITAB Institute for Advanced Biotechnology, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
| | - Mirella Russo
- Department of Neuroscience, Imaging, and Clinical Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Molecular Neurology Unit, Center for Advanced Studies and Technology-CAST and ITAB Institute for Advanced Biotechnology, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Pietro Tiraboschi
- Division of Neurology V-Neuropathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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10
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Pead E, Thompson AC, Grewal DS, McGrory S, Robbins CB, Ma JP, Johnson KG, Liu AJ, Hamid C, Trucco E, Ritchie CW, Muniz G, Lengyel I, Dhillon B, Fekrat S, MacGillivray T. Retinal Vascular Changes in Alzheimer's Dementia and Mild Cognitive Impairment: A Pilot Study Using Ultra-Widefield Imaging. Transl Vis Sci Technol 2023; 12:13. [PMID: 36622689 PMCID: PMC9838583 DOI: 10.1167/tvst.12.1.13] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose Retinal microvascular abnormalities measured on retinal images are a potential source of prognostic biomarkers of vascular changes in the neurodegenerating brain. We assessed the presence of these abnormalities in Alzheimer's dementia and mild cognitive impairment (MCI) using ultra-widefield (UWF) retinal imaging. Methods UWF images from 103 participants (28 with Alzheimer's dementia, 30 with MCI, and 45 with normal cognition) underwent analysis to quantify measures of retinal vascular branching complexity, width, and tortuosity. Results Participants with Alzheimer's dementia displayed increased vessel branching in the midperipheral retina and increased arteriolar thinning. Participants with MCI displayed increased rates of arteriolar and venular thinning and a trend for decreased vessel branching. Conclusions Statistically significant differences in the retinal vasculature in peripheral regions of the retina were observed among the distinct cognitive stages. However, larger studies are required to establish the clinical importance of our findings. UWF imaging may be a promising modality to assess a larger view of the retinal vasculature to uncover retinal changes in Alzheimer's disease. Translational Relevance This pilot work reports an investigation into which retinal vasculature measurements may be useful surrogate measures of cognitive decline, as well as technical developments (e.g., measurement standardization), that are first required to establish their recommended use and translational potential.
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Affiliation(s)
- Emma Pead
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Atalie C. Thompson
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Dilraj S. Grewal
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Sarah McGrory
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Cason B. Robbins
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Justin P. Ma
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Kim G. Johnson
- Department of Neurology, Duke University School of Medicine, Durham, NC, USA
| | - Andy J. Liu
- Department of Neurology, Duke University School of Medicine, Durham, NC, USA
| | - Charlene Hamid
- Edinburgh Clinical Research Facility, The University of Edinburgh, Edinburgh, UK
| | - Emanuele Trucco
- VAMPIRE Project, Computer Vision and Image Processing, Computing (SSE), The University of Dundee, Dundee, UK
| | - Craig W. Ritchie
- Edinburgh Dementia Prevention, The University of Edinburgh, Edinburgh, UK
| | - Graciela Muniz
- Department of Social Medicine, Ohio University, Athens, OH, USA
| | - Imre Lengyel
- The Welcome-Wolfson Institute for Experimental Medicine, School of Medicine Dentistry and Biomedical Science, Queen's University Belfast, Belfast, UK
| | - Baljean Dhillon
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK,Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, UK
| | - Sharon Fekrat
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Tom MacGillivray
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
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11
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Xu QA, Boerkoel P, Hirsch-Reinshagen V, Mackenzie IR, Hsiung GYR, Charm G, To EF, Liu AQ, Schwab K, Jiang K, Sarunic M, Beg MF, Pham W, Cui J, To E, Lee S, Matsubara JA. Müller cell degeneration and microglial dysfunction in the Alzheimer's retina. Acta Neuropathol Commun 2022; 10:145. [PMID: 36199154 PMCID: PMC9533552 DOI: 10.1186/s40478-022-01448-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/18/2022] [Indexed: 01/26/2023] Open
Abstract
Amyloid beta (Aβ) deposits in the retina of the Alzheimer's disease (AD) eye may provide a useful diagnostic biomarker for AD. This study focused on the relationship of Aβ with macroglia and microglia, as these glial cells are hypothesized to play important roles in homeostasis and clearance of Aβ in the AD retina. Significantly higher Aβ load was found in AD compared to controls, and specifically in the mid-peripheral region. AD retina showed significantly less immunoreactivity against glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) compared to control eyes. Immunoreactivity against ionized calcium binding adapter molecule-1 (IBA-1), a microglial marker, demonstrated a higher level of microgliosis in AD compared to control retina. Within AD retina, more IBA-1 immunoreactivity was present in the mid-peripheral retina, which contained more Aβ than the central AD retina. GFAP co-localized rarely with Aβ, while IBA-1 co-localized with Aβ in more layers of control than AD donor retina. These results suggest that dysfunction of the Müller and microglial cells may be key features of the AD retina.
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Affiliation(s)
- Qinyuan Alis Xu
- grid.17091.3e0000 0001 2288 9830MD Undergraduate Program, University of British Columbia, Vancouver, BC Canada ,grid.17063.330000 0001 2157 2938Postgraduate Medical Education, Department of Family and Community Medicine, University of Toronto, Barrie, ON Canada
| | - Pierre Boerkoel
- grid.17091.3e0000 0001 2288 9830MD Undergraduate Program, University of British Columbia, Vancouver, BC Canada
| | - Veronica Hirsch-Reinshagen
- grid.17091.3e0000 0001 2288 9830Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC Canada
| | - Ian R. Mackenzie
- grid.17091.3e0000 0001 2288 9830Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC Canada
| | - Ging-Yuek Robin Hsiung
- grid.17091.3e0000 0001 2288 9830Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC Canada
| | - Geoffrey Charm
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
| | - Elliott F. To
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
| | - Alice Q. Liu
- grid.17091.3e0000 0001 2288 9830MD Undergraduate Program, University of British Columbia, Vancouver, BC Canada
| | - Katerina Schwab
- grid.17091.3e0000 0001 2288 9830MD Undergraduate Program, University of British Columbia, Vancouver, BC Canada
| | - Kailun Jiang
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
| | - Marinko Sarunic
- grid.61971.380000 0004 1936 7494School of Engineering Sciences, Simon Fraser University, Burnaby, BC Canada
| | - Mirza Faisal Beg
- grid.61971.380000 0004 1936 7494School of Engineering Sciences, Simon Fraser University, Burnaby, BC Canada
| | - Wellington Pham
- grid.152326.10000 0001 2264 7217Vanderbilt University Institute of Imaging Science, Vanderbilt University School of Medicine, Nashville, USA
| | - Jing Cui
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
| | - Eleanor To
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
| | - Sieun Lee
- grid.61971.380000 0004 1936 7494School of Engineering Sciences, Simon Fraser University, Burnaby, BC Canada ,grid.4563.40000 0004 1936 8868Mental Health & Clinical Neurosciences, School of Medicine, University of Nottingham, University of Nottingham, Nottingham, England
| | - Joanne A. Matsubara
- grid.17091.3e0000 0001 2288 9830Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC V5Z3N9 Canada
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12
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Vij R, Arora S. A systematic survey of advances in retinal imaging modalities for Alzheimer's disease diagnosis. Metab Brain Dis 2022; 37:2213-2243. [PMID: 35290546 DOI: 10.1007/s11011-022-00927-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/04/2022] [Indexed: 01/06/2023]
Abstract
Recent advances in retinal imaging pathophysiology have shown a new function for biomarkers in Alzheimer's disease diagnosis and prognosis. The significant improvements in Optical coherence tomography (OCT) retinal imaging have led to significant clinical translation, particularly in Alzheimer's disease detection. This systematic review will provide a comprehensive overview of retinal imaging in clinical applications, with a special focus on biomarker analysis for use in Alzheimer's disease detection. Articles on OCT retinal imaging in Alzheimer's disease diagnosis were identified in PubMed, Google Scholar, IEEE Xplore, and Research Gate databases until March 2021. Those studies using simultaneous retinal imaging acquisition were chosen, while those using sequential techniques were rejected. "Alzheimer's disease" and "Dementia" were searched alone and in combination with "OCT" and "retinal imaging". Approximately 1000 publications were searched, and after deleting duplicate articles, 145 relevant studies focused on the diagnosis of Alzheimer's disease utilizing retinal imaging were chosen for study. OCT has recently been demonstrated to be a valuable technique in clinical practice as according to this survey, 57% of the researchers employed optical coherence tomography, 19% used ocular fundus imaging, 13% used scanning laser ophthalmoscopy, and 11% have used multimodal imaging to diagnose Alzheimer disease. Retinal imaging has become an important diagnostic technique for Alzheimer's disease. Given the scarcity of available literature, it is clear that future prospective trials involving larger and more homogeneous groups are necessary, and the work can be expanded by evaluating its significance utilizing a machine-learning platform rather than simply using statistical methodologies.
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Affiliation(s)
- Richa Vij
- School of Computer Science & Engineering, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Sakshi Arora
- School of Computer Science & Engineering, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India.
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13
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Klyucherev TO, Olszewski P, Shalimova AA, Chubarev VN, Tarasov VV, Attwood MM, Syvänen S, Schiöth HB. Advances in the development of new biomarkers for Alzheimer's disease. Transl Neurodegener 2022; 11:25. [PMID: 35449079 PMCID: PMC9027827 DOI: 10.1186/s40035-022-00296-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 03/28/2022] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is a complex, heterogeneous, progressive disease and is the most common type of neurodegenerative dementia. The prevalence of AD is expected to increase as the population ages, placing an additional burden on national healthcare systems. There is a large need for new diagnostic tests that can detect AD at an early stage with high specificity at relatively low cost. The development of modern analytical diagnostic tools has made it possible to determine several biomarkers of AD with high specificity, including pathogenic proteins, markers of synaptic dysfunction, and markers of inflammation in the blood. There is a considerable potential in using microRNA (miRNA) as markers of AD, and diagnostic studies based on miRNA panels suggest that AD could potentially be determined with high accuracy for individual patients. Studies of the retina with improved methods of visualization of the fundus are also showing promising results for the potential diagnosis of the disease. This review focuses on the recent developments of blood, plasma, and ocular biomarkers for the diagnosis of AD.
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Affiliation(s)
- Timofey O Klyucherev
- Department of Neuroscience, Functional Pharmacology, University of Uppsala, Uppsala, Sweden.,Department of Pharmacology, Institute of Pharmacy, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Pawel Olszewski
- Department of Neuroscience, Functional Pharmacology, University of Uppsala, Uppsala, Sweden
| | - Alena A Shalimova
- Department of Neuroscience, Functional Pharmacology, University of Uppsala, Uppsala, Sweden.,Department of Pharmacology, Institute of Pharmacy, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Vladimir N Chubarev
- Institute of Translational Medicine and Biotechnology, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Vadim V Tarasov
- Department of Pharmacology, Institute of Pharmacy, I. M. Sechenov First Moscow State Medical University, Moscow, Russia.,Institute of Translational Medicine and Biotechnology, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Misty M Attwood
- Department of Neuroscience, Functional Pharmacology, University of Uppsala, Uppsala, Sweden
| | - Stina Syvänen
- Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, University of Uppsala, Uppsala, Sweden.
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14
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Cheung R, Ly A, Katalinic P, Coroneo MT, Chang A, Kalloniatis M, Madigan MC, Nivison-Smith L. Visualisation of peripheral retinal degenerations and anomalies with ocular imaging. Semin Ophthalmol 2022; 37:554-582. [DOI: 10.1080/08820538.2022.2039222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Rene Cheung
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Angelica Ly
- Centre for Eye Health, University of New South Wales, Sydney, Australia
| | - Paula Katalinic
- Centre for Eye Health, University of New South Wales, Sydney, Australia
| | - Minas Theodore Coroneo
- Department of Ophthalmology, Prince of Wales Clinical School, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Andrew Chang
- Sydney Institute of Vision Science, Sydney, Australia
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Michael Kalloniatis
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
- Centre for Eye Health, University of New South Wales, Sydney, Australia
| | - Michele C. Madigan
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Lisa Nivison-Smith
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
- Centre for Eye Health, University of New South Wales, Sydney, Australia
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15
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Dumitrascu OM, Rosenberry R, Sherman DS, Khansari MM, Sheyn J, Torbati T, Sherzai A, Sherzai D, Johnson KO, Czeszynski AD, Verdooner S, Black KL, Frautschy S, Lyden PD, Shi Y, Cheng S, Koronyo Y, Koronyo-Hamaoui M. Retinal Venular Tortuosity Jointly with Retinal Amyloid Burden Correlates with Verbal Memory Loss: A Pilot Study. Cells 2021; 10:cells10112926. [PMID: 34831149 PMCID: PMC8616417 DOI: 10.3390/cells10112926] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/21/2021] [Accepted: 10/25/2021] [Indexed: 12/11/2022] Open
Abstract
Introduction: Retinal imaging is a non-invasive tool to study both retinal vasculature and neurodegeneration. In this exploratory retinal curcumin-fluorescence imaging (RFI) study, we sought to determine whether retinal vascular features combined with retinal amyloid burden correlate with the neurocognitive status. Methods: We used quantitative RFI in a cohort of patients with cognitive impairment to automatically compute retinal amyloid burden. Retinal blood vessels were segmented, and the vessel tortuosity index (VTI), inflection index, and branching angle were quantified. We assessed the correlations between retinal vascular and amyloid parameters, and cognitive domain Z-scores using linear regression models. Results: Thirty-four subjects were enrolled and twenty-nine (55% female, mean age 64 ± 6 years) were included in the combined retinal amyloid and vascular analysis. Eleven subjects had normal cognition and 18 had impaired cognition. Retinal VTI was discriminated among cognitive scores. The combined proximal mid-periphery amyloid count and venous VTI index exhibited significant differences between cognitively impaired and cognitively normal subjects (0.49 ± 1.1 vs. 0.91 ± 1.4, p = 0.006), and correlated with both the Wechsler Memory Scale-IV and SF-36 mental component score Z-scores (p < 0.05). Conclusion: This pilot study showed that retinal venular VTI combined with the proximal mid-periphery amyloid count could predict verbal memory loss. Future research is needed to finesse the clinical application of this retinal imaging-based technology.
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Affiliation(s)
- Oana M. Dumitrascu
- Department of Neurology, Mayo Clinic, Scottsdale, AZ 85251, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
| | - Ryan Rosenberry
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Dale S. Sherman
- Department of Neuropsychology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Maziyar M. Khansari
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Julia Sheyn
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Tania Torbati
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Ayesha Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Dean Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Kenneth O. Johnson
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Alan D. Czeszynski
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Steven Verdooner
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Keith L. Black
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Sally Frautschy
- Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA;
| | - Patrick D. Lyden
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Yonggang Shi
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Susan Cheng
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Yosef Koronyo
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
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16
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Pilgrim MG, Marouf S, Fearn S, Csincsik L, Kortvely E, Knowles JC, Malek G, Thompson RB, Lengyel I. Characterization of Calcium Phosphate Spherical Particles in the Subretinal Pigment Epithelium-Basal Lamina Space in Aged Human Eyes. OPHTHALMOLOGY SCIENCE 2021; 1:100053. [PMID: 36247811 PMCID: PMC9559963 DOI: 10.1016/j.xops.2021.100053] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/21/2021] [Accepted: 08/12/2021] [Indexed: 11/17/2022]
Abstract
Purpose Micrometer-sized spherules formed of hydroxyapatite or whitlockite were identified within extracellular deposits that accumulate in the space between the basal lamina (BL) of retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane (sub-RPE-BL space). This investigation aimed to characterize the morphologic features, structure, and distribution of these spherules in aged human eyes with and without clinical indications of age-related macular degeneration (AMD). Design Experimental study. Participants Five human eyes with varying degrees of sub-RPE-BL deposits were obtained from the University College London Institute of Ophthalmology and Moorfield's Eye Hospital Tissue Repository or the Advancing Sight Network. Two eyes were reported as having clinical indications of AMD (age, 76-87 years), whereas 3 were considered healthy (age, 69-91 years). Methods Cadaveric eyes with sub-RPE-BL deposits were embedded in paraffin wax and sectioned to a thickness of 4-10 μm. Spherules were identified and characterized using high-resolution scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy, and time-of-flight secondary ion mass spectroscopy. Main Outcome Measures High-resolution scanning electron micrographs of spherules, the size-frequency distribution of spherules including average diameter, and the distribution of particles across the central-peripheral axis. Elemental maps and time-of-flight secondary ion mass spectra also were obtained. Results The precipitation of spherules is ubiquitous across the central, mid-peripheral, and far-peripheral axis in aged human eyes. No significant difference was found in the frequency of spherules along this axis. However, statistical analysis indicated that spherules exhibited significantly different sizes in these regions. In-depth analysis revealed that spherules in the sub-RPE-BL space of eyes with clinical signs of AMD were significantly larger (median diameter, 1.64 μm) than those in healthy aged eyes (median diameter, 1.16 μm). Finally, spherules showed great variation in surface topography and internal structure. Conclusions The precipitation of spherules in the sub-RPE-BL space is ubiquitous across the central-peripheral axis in aged human eyes. However, a marked difference exists in the size and frequency of spherules in eyes with clinical signs of AMD compared to those without, suggesting that the size and frequency of spherules may be associated with AMD.
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Key Words
- AMD, age-related macular degeneration
- BL, basal lamina
- BrM, Bruch’s membrane
- C, Calcium
- Choroid
- Drusen
- EDX, Energy dispersive x-ray spectroscopy
- Ectopic calcification
- H, hydrogen
- Mg, Magnesium
- N, Nitrogen
- Na, sodium
- O, oxygen
- P, phosphorus
- RPE, retinal pigment epithelium
- Retina
- SEM, scanning electron microscopy
- Spherical particle
- Sub-retinal pigment epithelium-basal lamina deposit
- Sub-retinal pigment epithelium-basal lamina space
- Sub–retinal pigment epithelium
- ToF-SIMs, time of flight-secondary ion mass spectrometry
- sub-RPE–BL space, sub-retinal pigment epithelium-basal lamina space
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Affiliation(s)
- Matthew G. Pilgrim
- University College London Institute of Ophthalmology, London, United Kingdom
- Division of Biomaterials and Tissue Engineering, University College London Eastman Dental Institute, Royal Free Hospital, London, United Kingdom
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast, United Kingdom
| | - Salma Marouf
- Barts and The London School of Medicine and Dentistry, London, United Kingdom
| | - Sarah Fearn
- Department of Materials, Imperial College London, London, United Kingdom
| | - Lajos Csincsik
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast, United Kingdom
| | - Elod Kortvely
- Roche Pharma Research and Early Development, Immunology, Infectious Diseases and Ophthalmology (I20) Discovery and Translational Area, Roche Innovation Centre Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - Jonathan C. Knowles
- Division of Biomaterials and Tissue Engineering, University College London Eastman Dental Institute, Royal Free Hospital, London, United Kingdom
| | - Goldis Malek
- Department of Ophthalmology, Albert Eye Research Institute, and Department of Pathology, Duke University School of Medicine, Durham, North Carolina
| | - Richard B. Thompson
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Imre Lengyel
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast, United Kingdom
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17
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Cheung CY, Mok V, Foster PJ, Trucco E, Chen C, Wong TY. Retinal imaging in Alzheimer's disease. J Neurol Neurosurg Psychiatry 2021; 92:983-994. [PMID: 34108266 DOI: 10.1136/jnnp-2020-325347] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/27/2021] [Indexed: 12/11/2022]
Abstract
Identifying biomarkers of Alzheimer's disease (AD) will accelerate the understanding of its pathophysiology, facilitate screening and risk stratification, and aid in developing new therapies. Developments in non-invasive retinal imaging technologies, including optical coherence tomography (OCT), OCT angiography and digital retinal photography, have provided a means to study neuronal and vascular structures in the retina in people with AD. Both qualitative and quantitative measurements from these retinal imaging technologies (eg, thinning of peripapillary retinal nerve fibre layer, inner retinal layer, and choroidal layer, reduced capillary density, abnormal vasodilatory response) have been shown to be associated with cognitive function impairment and risk of AD. The development of computer algorithms for respective retinal imaging methods has further enhanced the potential of retinal imaging as a viable tool for rapid, early detection and screening of AD. In this review, we present an update of current retinal imaging techniques and their potential applications in AD research. We also discuss the newer retinal imaging techniques and future directions in this expanding field.
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Affiliation(s)
- Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Vincent Mok
- Gerald Choa Neuroscience Centre, Therese Pei Fong Chow Research Centre for Prevention of Dementia, Lui Che Woo Institute of Innovative Medicine, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Paul J Foster
- National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, NHS Foundation Trust, UCL Institute of Ophthalmology, London, UK
| | - Emanuele Trucco
- VAMPIRE project, Computing, School of Science and Engineering, University of Dundee, Dundee, UK
| | - Christopher Chen
- Pharmacology, National University Singapore Yong Loo Lin School of Medicine, Singapore.,Memory Aging and Cognition Centre, National University Health System, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
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18
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Csincsik L, Quinn N, Yong KXX, Crutch SJ, Peto T, Lengyel I. Retinal phenotyping of variants of Alzheimer's disease using ultra-widefield retinal images. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12232. [PMID: 34458553 PMCID: PMC8377778 DOI: 10.1002/dad2.12232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/25/2021] [Accepted: 07/01/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Posterior cortical atrophy (PCA) is the most common atypical variant of Alzheimer's disease (AD). Changes associated with PCA in the brain affect the visual cortex, but little is known about retinal changes in PCA. In this study, we explored retinal phenotypic variations in typical AD (tAD) and PCA. METHODS Retinal phenotyping was carried out on ultra-widefield (UWF) images of 69 control, 24 tAD, and 25 PCA participants. RESULTS Individuals with tAD (odds ratio [OR] = 2.76 [confidence interval (CI):1.24 to 6.10], P = .012) and PCA (OR = 3.40 [CI:1.25 to 9.22], P = .016) were more likely phenotyped as hard drusen. tAD (OR = 0.34 [CI:0.12 to 0.92], P = .035) were less likely to have soft drusen compared to control. Almost 3-fold increase in reticular pseudodrusen formation in tAD (OR = 2.93 [CI:1.10 to 7.76], P = .030) compared to control was estimated. DISCUSSION Studying the peripheral retina may contribute to a better understanding of differences in retinal phenotypes of different AD variants.
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Affiliation(s)
- Lajos Csincsik
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's University BelfastBelfastUK
| | - Nicola Quinn
- Centre for Public HealthQueen's University BelfastBelfastUK
| | - Keir X. X. Yong
- Dementia Research CentreUCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Sebastian J. Crutch
- Dementia Research CentreUCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Tunde Peto
- Centre for Public HealthQueen's University BelfastBelfastUK
| | - Imre Lengyel
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's University BelfastBelfastUK
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19
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Ngolab J, Donohue M, Belsha A, Salazar J, Cohen P, Jaiswal S, Tan V, Gessert D, Korouri S, Aggarwal NT, Alber J, Johnson K, Jicha G, van Dyck C, Lah J, Salloway S, Sperling RA, Aisen PS, Rafii MS, Rissman RA. Feasibility study for detection of retinal amyloid in clinical trials: The Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12199. [PMID: 34430703 PMCID: PMC8369843 DOI: 10.1002/dad2.12199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 01/03/2023]
Abstract
INTRODUCTION The retina and brain exhibit similar pathologies in patients diagnosed with neurodegenerative diseases. The ability to access the retina through imaging techniques opens the possibility for non-invasive evaluation of Alzheimer's disease (AD) pathology. While retinal amyloid deposits are detected in individuals clinically diagnosed with AD, studies including preclinical individuals are lacking, limiting assessment of the feasibility of retinal imaging as a biomarker for early-stage AD risk detection. METHODS In this small cross-sectional study we compare retinal and cerebral amyloid in clinically normal individuals who screened positive for high amyloid levels through positron emission tomography (PET) from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial as well as a companion cohort of individuals who exhibited low levels of amyloid PET in the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) study. We quantified the number of curcumin-positive fluorescent retinal spots from a small subset of participants from both studies to determine retinal amyloid deposition at baseline. RESULTS The four participants from the A4 trial showed a greater number of retinal spots compared to the four participants from the LEARN study. We observed a positive correlation between retinal spots and brain amyloid, as measured by the standardized uptake value ratio (SUVr). DISCUSSION The results of this small pilot study support the use of retinal fundus imaging for detecting amyloid deposition that is correlated with brain amyloid PET SUVr. A larger sample size will be necessary to fully ascertain the relationship between amyloid PET and retinal amyloid both cross-sectionally and longitudinally.
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Affiliation(s)
- Jennifer Ngolab
- Department of NeurosciencesSan Diego, School of MedicineUniversity of CaliforniaLa JollaCaliforniaUSA
| | - Michael Donohue
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Alison Belsha
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Jennifer Salazar
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Paula Cohen
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Sandhya Jaiswal
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Veasna Tan
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Devon Gessert
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Shaina Korouri
- Department of NeurosciencesSan Diego, School of MedicineUniversity of CaliforniaLa JollaCaliforniaUSA
| | - Neelum T. Aggarwal
- Department of Neurological Sciences and the Rush Alzheimer's Disease CenterRush University Medical CenterChicagoIllinoisUSA
| | - Jessica Alber
- George & Anne Ryan Institute for NeuroscienceUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Ken Johnson
- NeuroVision Imaging IncSacramentoCaliforniaUSA
| | - Gregory Jicha
- Department of Neurology & the Sanders‐Brown Center on AgingUniversity of Kentucky College of MedicineLexingtonKentuckyUSA
| | - Christopher van Dyck
- Alzheimer's Disease Research UnitDepartments of PsychiatryNeurology, and Neuroscience, Yale School of MedicineNew HavenConnecticutUSA
| | - James Lah
- Department of NeurologyEmory Goizueta Alzheimer's Disease Research CenterEmory University School of MedicineAtlantaGeorgiaUSA
| | - Stephen Salloway
- Memory and Aging ProgramButler HospitalProvidenceRhode IslandUSA
| | - Reisa A. Sperling
- Center for Alzheimer Research and TreatmentBrigham and Women's Hospital Massachusetts General HospitalBostonMassachusettsUSA
| | - Paul S. Aisen
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Michael S. Rafii
- Alzheimer's Therapeutic Research InstituteUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Robert A. Rissman
- Department of NeurosciencesSan Diego, School of MedicineUniversity of CaliforniaLa JollaCaliforniaUSA
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20
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Chalkias IN, Tegos T, Topouzis F, Tsolaki M. Ocular biomarkers and their role in the early diagnosis of neurocognitive disorders. Eur J Ophthalmol 2021; 31:2808-2817. [PMID: 34000876 DOI: 10.1177/11206721211016311] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Given the fact that different types of dementia can be diagnosed only postmortem or when the disease has progressed enough to cause irreversible damage to certain brain areas, there has been an increasing need for the development of sensitive and reliable methods that can detect early preclinical forms of dementia, before the symptoms have even appeared. Ideally, such a method would have the following characteristics: to be inexpensive, sensitive and specific, Non-invasive, fast and easily accessible. The ophthalmologic examination and especially the study of the retina, has caught the attention of many researchers, as it can provide a lot of information about the CNS and it fulfills many of the aforementioned criteria. Since the introduction of the non-invasive optical coherence tomography (OCT) and the newly developed modality OCT-angiography (OCT-A) that can demonstrate the structure and the microvasculature of the retina and choroid, respectively, there have been promising results regarding the value of the ophthalmologic examination in the early diagnosis of Alzheimer's disease. In this review paper, we summarize and discuss the ocular findings in patients with cognitive impairment disorders and we highlight the importance of the ophthalmologic examination to the diagnosis of these disorders.
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Affiliation(s)
- Ioannis-Nikolaos Chalkias
- 1st Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Thomas Tegos
- 1st Department of Neurology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Fotis Topouzis
- 1st Department of Ophthalmology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece
| | - Magda Tsolaki
- 1st Department of Neurology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Makedonia Thraki, Greece.,Greek Association of Alzheimer's Disease and Related Disorders, Thessaloniki, Greece
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21
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Scholl HPN. 2020: The Year in Review for Ophthalmic Research. Ophthalmic Res 2021; 64:529-531. [PMID: 33979797 DOI: 10.1159/000517097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Hendrik P N Scholl
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland
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22
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Schwaber EJ, Thompson AC, Smilnak G, Stinnett SS, Whitson HE, Lad EM. Co-Prevalence of Alzheimer's Disease and Age-Related Macular Degeneration Established by Histopathologic Diagnosis. J Alzheimers Dis 2021; 76:207-215. [PMID: 32444545 DOI: 10.3233/jad-200111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Previous epidemiologic studies have suggested an association between AMD and AD, and several therapeutic agents are being developed based on this principle. However, prior studies have provided conflicting results due in part to their reliance on clinical diagnoses that are not based on gold-standard histopathology. OBJECTIVE To use histopathologic standards for diagnosis in order to determine the co-prevalence of AD among patients with and without AMD. METHODS This is a cross-sectional study of 157 autopsy ocular specimens from patients with and without AMD that were greater than 75 years of age at death. Sarks staging was used to document the severity of AMD, and Braak and Braak staging was used to assess the severity of AD in corresponding brain specimens. The prevalence of AD within different severities of AMD was determined using univariable and multivariable logistic regression. RESULTS 58% of autopsy eyes had AMD. The prevalence of AD was lower in AMD subjects (63%) compared to non-AMD subjects (73%), even when grouped by severity (all p > 0.15). The likelihood of AD was significantly less in AMD subjects, even after adjusting for age and sex in multivariable analysis (OR 0.47, p = 0.049). CONCLUSION Histopathologic diagnoses fail to support an increase in prevalence of AD among subjects with AMD, even when disease severity is considered.
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Affiliation(s)
- Eric J Schwaber
- Department of Internal Medicine, Griffin Hospital, Derby, CT, USA
| | - Atalie C Thompson
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Gordon Smilnak
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Sandra S Stinnett
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Heather E Whitson
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.,Department of Medicine, Division of Geriatrics, Duke University Medical Center, Durham, NC, USA
| | - Eleonora M Lad
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
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23
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Multimodal, label-free fluorescence and Raman imaging of amyloid deposits in snap-frozen Alzheimer's disease human brain tissue. Commun Biol 2021; 4:474. [PMID: 33859370 PMCID: PMC8050064 DOI: 10.1038/s42003-021-01981-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 03/11/2021] [Indexed: 02/02/2023] Open
Abstract
Alzheimer's disease (AD) neuropathology is characterized by hyperphosphorylated tau containing neurofibrillary tangles and amyloid-beta (Aβ) plaques. Normally these hallmarks are studied by (immuno-) histological techniques requiring chemical pretreatment and indirect labelling. Label-free imaging enables one to visualize normal tissue and pathology in its native form. Therefore, these techniques could contribute to a better understanding of the disease. Here, we present a comprehensive study of high-resolution fluorescence imaging (before and after staining) and spectroscopic modalities (Raman mapping under pre-resonance conditions and stimulated Raman scattering (SRS)) of amyloid deposits in snap-frozen AD human brain tissue. We performed fluorescence and spectroscopic imaging and subsequent thioflavin-S staining of the same tissue slices to provide direct confirmation of plaque location and correlation of spectroscopic biomarkers with plaque morphology; differences were observed between cored and fibrillar plaques. The SRS results showed a protein peak shift towards the β-sheet structure in cored amyloid deposits. In the Raman maps recorded with 532 nm excitation we identified the presence of carotenoids as a unique marker to differentiate between a cored amyloid plaque area versus a non-plaque area without prior knowledge of their location. The observed presence of carotenoids suggests a distinct neuroinflammatory response to misfolded protein accumulations.
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24
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Song A, Johnson N, Ayala A, Thompson AC. Optical Coherence Tomography in Patients with Alzheimer's Disease: What Can It Tell Us? Eye Brain 2021; 13:1-20. [PMID: 33447120 PMCID: PMC7802785 DOI: 10.2147/eb.s235238] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/09/2020] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Although Alzheimer's disease (AD) is a leading cause of dementia worldwide, its clinical diagnosis remains a challenge. Optical coherence tomography (OCT) and OCT with angiography (OCTA) are non-invasive ophthalmic imaging tools with the potential to detect retinal structural and microvascular changes in patients with AD, which may serve as biomarkers for the disease. In this systematic review, we evaluate whether certain OCT and OCTA parameters are significantly associated with AD and mild cognitive impairment (MCI). METHODS PubMed database was searched using a combination of MeSH terms to identify studies for review. Studies were organized by participant diagnostic groups, type of imaging modality, and OCT/OCTA parameters of interest. Participant demographic data was also collected and baseline descriptive statistics were calculated for the included studies. RESULTS Seventy-one studies were included for review, representing a total of 6757 patients (2350 AD, 793 MCI, 2902 healthy controls (HC), and 841 others with a range of other neurodegenerative diagnoses). The mean baseline ages were 72.78±3.69, 71.52±2.88, 70.55±3.85 years for AD, MCI and HC groups, respectively. The majority of studies noted significant structural and functional decline in AD patients when compared to HC. Although analysis of MCI groups yielded more mixed results, a similar pattern of decline was often noted amongst patients with MCI relative to HC. OCT and OCTA measurements were also shown to correlate with established measures of AD such as neuropsychological testing or neuroimaging. CONCLUSION OCT and OCTA show great potential as non-invasive technologies for the diagnosis of AD. However, further research is needed to determine whether there are AD-specific patterns of structural or microvascular change in the retina and optic nerve that distinguish AD from other neurodegenerative diseases. Development of sensitive and specific OCT/OCTA parameters will be necessary before they can be used to detect AD in clinical settings.
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Affiliation(s)
- Ailin Song
- Duke University School of Medicine, Durham, NC, USA
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25
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Czakó C, Kovács T, Ungvari Z, Csiszar A, Yabluchanskiy A, Conley S, Csipo T, Lipecz A, Horváth H, Sándor GL, István L, Logan T, Nagy ZZ, Kovács I. Retinal biomarkers for Alzheimer's disease and vascular cognitive impairment and dementia (VCID): implication for early diagnosis and prognosis. GeroScience 2020; 42:1499-1525. [PMID: 33011937 PMCID: PMC7732888 DOI: 10.1007/s11357-020-00252-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/10/2020] [Indexed: 12/11/2022] Open
Abstract
Cognitive impairment and dementia are major medical, social, and economic public health issues worldwide with significant implications for life quality in older adults. The leading causes are Alzheimer's disease (AD) and vascular cognitive impairment/dementia (VCID). In both conditions, pathological alterations of the cerebral microcirculation play a critical pathogenic role. Currently, the main pathological biomarkers of AD-β-amyloid peptide and hyperphosphorylated tau proteins-are detected either through cerebrospinal fluid (CSF) or PET examination. Nevertheless, given that they are invasive and expensive procedures, their availability is limited. Being part of the central nervous system, the retina offers a unique and easy method to study both neurodegenerative disorders and cerebral small vessel diseases in vivo. Over the past few decades, a number of novel approaches in retinal imaging have been developed that may allow physicians and researchers to gain insights into the genesis and progression of cerebromicrovascular pathologies. Optical coherence tomography (OCT), OCT angiography, fundus photography, and dynamic vessel analyzer (DVA) are new imaging methods providing quantitative assessment of retinal structural and vascular indicators-such as thickness of the inner retinal layers, retinal vessel density, foveal avascular zone area, tortuosity and fractal dimension of retinal vessels, and microvascular dysfunction-for cognitive impairment and dementia. Should further studies need to be conducted, these retinal alterations may prove to be useful biomarkers for screening and monitoring dementia progression in clinical routine. In this review, we seek to highlight recent findings and current knowledge regarding the application of retinal biomarkers in dementia assessment.
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Affiliation(s)
- Cecilia Czakó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Tibor Kovács
- Department of Neurology, Semmelweis University, Budapest, Hungary
| | - Zoltan Ungvari
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Anna Csiszar
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Andriy Yabluchanskiy
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shannon Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tamas Csipo
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Agnes Lipecz
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Ophthalmology, Josa Andras Hospital, Nyiregyhaza, Hungary
| | - Hajnalka Horváth
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | | | - Lilla István
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Trevor Logan
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary.
- Department of Ophthalmology, Weill Cornell Medical College, New York City, NY, USA.
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Wisely CE, Wang D, Henao R, Grewal DS, Thompson AC, Robbins CB, Yoon SP, Soundararajan S, Polascik BW, Burke JR, Liu A, Carin L, Fekrat S. Convolutional neural network to identify symptomatic Alzheimer’s disease using multimodal retinal imaging. Br J Ophthalmol 2020; 106:388-395. [DOI: 10.1136/bjophthalmol-2020-317659] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Background/AimsTo develop a convolutional neural network (CNN) to detect symptomatic Alzheimer’s disease (AD) using a combination of multimodal retinal images and patient data.MethodsColour maps of ganglion cell-inner plexiform layer (GC-IPL) thickness, superficial capillary plexus (SCP) optical coherence tomography angiography (OCTA) images, and ultra-widefield (UWF) colour and fundus autofluorescence (FAF) scanning laser ophthalmoscopy images were captured in individuals with AD or healthy cognition. A CNN to predict AD diagnosis was developed using multimodal retinal images, OCT and OCTA quantitative data, and patient data.Results284 eyes of 159 subjects (222 eyes from 123 cognitively healthy subjects and 62 eyes from 36 subjects with AD) were used to develop the model. Area under the receiving operating characteristic curve (AUC) values for predicted probability of AD for the independent test set varied by input used: UWF colour AUC 0.450 (95% CI 0.282, 0.592), OCTA SCP 0.582 (95% CI 0.440, 0.724), UWF FAF 0.618 (95% CI 0.462, 0.773), GC-IPL maps 0.809 (95% CI 0.700, 0.919). A model incorporating all images, quantitative data and patient data (AUC 0.836 (CI 0.729, 0.943)) performed similarly to models only incorporating all images (AUC 0.829 (95% CI 0.719, 0.939)). GC-IPL maps, quantitative data and patient data AUC 0.841 (95% CI 0.739, 0.943).ConclusionOur CNN used multimodal retinal images to successfully predict diagnosis of symptomatic AD in an independent test set. GC-IPL maps were the most useful single inputs for prediction. Models including only images performed similarly to models also including quantitative data and patient data.
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Retinal capillary degeneration and blood-retinal barrier disruption in murine models of Alzheimer's disease. Acta Neuropathol Commun 2020; 8:202. [PMID: 33228786 PMCID: PMC7686701 DOI: 10.1186/s40478-020-01076-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/11/2020] [Indexed: 01/17/2023] Open
Abstract
Extensive effort has been made studying retinal pathology in Alzheimer’s disease (AD) to improve early noninvasive diagnosis and treatment. Particularly relevant are vascular changes, which appear prominent in early brain pathogenesis and could predict cognitive decline. Recently, we identified platelet-derived growth factor receptor beta (PDGFRβ) deficiency and pericyte loss associated with vascular Aβ deposition in the neurosensory retina of mild cognitively impaired (MCI) and AD patients. However, the pathological mechanisms of retinal vascular changes and their possible relationships with vascular amyloidosis, pericyte loss, and blood-retinal barrier (BRB) integrity remain unknown. Here, we evaluated the retinas of transgenic APPSWE/PS1ΔE9 mouse models of AD (ADtg mice) and wild-type mice at different ages for capillary degeneration, PDGFRβ expression, vascular amyloidosis, permeability and inner BRB tight-junction molecules. Using a retinal vascular isolation technique followed by periodic acid-Schiff or immunofluorescent staining, we discovered significant retinal capillary degeneration in ADtg mice compared to age- and sex-matched wild-type mice (P < 0.0001). This small vessel degeneration reached significance in 8-month-old mice (P = 0.0035), with males more susceptible than females. Degeneration of retinal capillaries also progressively increased with age in healthy mice (P = 0.0145); however, the phenomenon was significantly worse during AD-like progression (P = 0.0001). A substantial vascular PDGFRβ deficiency (~ 50% reduction, P = 0.0017) along with prominent vascular Aβ deposition was further detected in the retina of ADtg mice, which inversely correlated with the extent of degenerated capillaries (Pearson’s r = − 0.8, P = 0.0016). Importantly, tight-junction alterations such as claudin-1 downregulation and increased BRB permeability, demonstrated in vivo by retinal fluorescein imaging and ex vivo following injection of FITC-dextran (2000 kD) and Texas Red-dextran (3 kD), were found in ADtg mice. Overall, the identification of age- and Alzheimer’s-dependent retinal capillary degeneration and compromised BRB integrity starting at early disease stages in ADtg mice could contribute to the development of novel targets for AD diagnosis and therapy.
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Calcium and hydroxyapatite binding site of human vitronectin provides insights to abnormal deposit formation. Proc Natl Acad Sci U S A 2020; 117:18504-18510. [PMID: 32699145 DOI: 10.1073/pnas.2007699117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human blood protein vitronectin (Vn) is a major component of the abnormal deposits associated with age-related macular degeneration, Alzheimer's disease, and many other age-related disorders. Its accumulation with lipids and hydroxyapatite (HAP) has been demonstrated, but the precise mechanism for deposit formation remains unknown. Using a combination of solution and solid-state NMR experiments, cosedimentation assays, differential scanning fluorimetry (DSF), and binding energy calculations, we demonstrate that Vn is capable of binding both soluble ionic calcium and crystalline HAP, with high affinity and chemical specificity. Calcium ions bind preferentially at an external site, at the top of the hemopexin-like (HX) domain, with a group of four Asp carboxylate groups. The same external site is also implicated in HAP binding. Moreover, Vn acquires thermal stability upon association with either calcium ions or crystalline HAP. The data point to a mechanism whereby Vn plays an active role in orchestrating calcified deposit formation. They provide a platform for understanding the pathogenesis of macular degeneration and other related degenerative disorders, and the normal functions of Vn, especially those related to bone resorption.
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29
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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] [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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Shi H, Koronyo Y, Rentsendorj A, Regis GC, Sheyn J, Fuchs DT, Kramerov AA, Ljubimov AV, Dumitrascu OM, Rodriguez AR, Barron E, Hinton DR, Black KL, Miller CA, Mirzaei N, Koronyo-Hamaoui M. Identification of early pericyte loss and vascular amyloidosis in Alzheimer's disease retina. Acta Neuropathol 2020; 139:813-836. [PMID: 32043162 PMCID: PMC7181564 DOI: 10.1007/s00401-020-02134-w] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/17/2020] [Accepted: 02/02/2020] [Indexed: 01/27/2023]
Abstract
Pericyte loss and deficient vascular platelet-derived growth factor receptor-β (PDGFRβ) signaling are prominent features of the blood-brain barrier breakdown described in Alzheimer's disease (AD) that can predict cognitive decline yet have never been studied in the retina. Recent reports using noninvasive retinal amyloid imaging, optical coherence tomography angiography, and histological examinations support the existence of vascular-structural abnormalities and vascular amyloid β-protein (Aβ) deposits in retinas of AD patients. However, the cellular and molecular mechanisms of such retinal vascular pathology were not previously explored. Here, by modifying a method of enzymatically clearing non-vascular retinal tissue and fluorescent immunolabeling of the isolated blood vessel network, we identified substantial pericyte loss together with significant Aβ deposition in retinal microvasculature and pericytes in AD. Evaluation of postmortem retinas from a cohort of 56 human donors revealed an early and progressive decrease in vascular PDGFRβ in mild cognitive impairment (MCI) and AD compared to cognitively normal controls. Retinal PDGFRβ loss significantly associated with increased retinal vascular Aβ40 and Aβ42 burden. Decreased vascular LRP-1 and early apoptosis of pericytes in AD retina were also detected. Mapping of PDGFRβ and Aβ40 levels in pre-defined retinal subregions indicated that certain geometrical and cellular layers are more susceptible to AD pathology. Further, correlations were identified between retinal vascular abnormalities and cerebral Aβ burden, cerebral amyloid angiopathy (CAA), and clinical status. Overall, the identification of pericyte and PDGFRβ loss accompanying increased vascular amyloidosis in Alzheimer's retina implies compromised blood-retinal barrier integrity and provides new targets for AD diagnosis and therapy.
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Affiliation(s)
- Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Altan Rentsendorj
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Giovanna C Regis
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Andrei A Kramerov
- Department of Biomedical Sciences and Eye Program, Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Alexander V Ljubimov
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
- Department of Biomedical Sciences and Eye Program, Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Oana M Dumitrascu
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Anthony R Rodriguez
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - David R Hinton
- Departments of Pathology and Ophthalmology, Keck School of Medicine, USC Roski Eye Institute, University of Southern California, Los Angeles, CA, USA
| | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Carol A Miller
- Department of Pathology Program in Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Nazanin Mirzaei
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA.
- Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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Danso SO, Muniz-Terrera G, Luz S, Ritchie C. Application of Big Data and Artificial Intelligence technologies to dementia prevention research: an opportunity for low-and-middle-income countries. J Glob Health 2020; 9:020322. [PMID: 32257177 PMCID: PMC7101511 DOI: 10.7189/jogh.09.020322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Samuel O Danso
- Edinburgh Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Graciela Muniz-Terrera
- Edinburgh Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Saturnino Luz
- Usher Institute of Population Health Sciences and Informatics, Edinburgh Medical School, Molecular, Genetic and Population Health Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Craig Ritchie
- Edinburgh Dementia Prevention, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
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32
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Wagner SK, Fu DJ, Faes L, Liu X, Huemer J, Khalid H, Ferraz D, Korot E, Kelly C, Balaskas K, Denniston AK, Keane PA. Insights into Systemic Disease through Retinal Imaging-Based Oculomics. Transl Vis Sci Technol 2020; 9:6. [PMID: 32704412 PMCID: PMC7343674 DOI: 10.1167/tvst.9.2.6] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 10/09/2019] [Indexed: 01/06/2023] Open
Abstract
Among the most noteworthy developments in ophthalmology over the last decade has been the emergence of quantifiable high-resolution imaging modalities, which are typically non-invasive, rapid and widely available. Such imaging is of unquestionable utility in the assessment of ocular disease however evidence is also mounting for its role in identifying ocular biomarkers of systemic disease, which we term oculomics. In this review, we highlight our current understanding of how retinal morphology evolves in two leading causes of global morbidity and mortality, cardiovascular disease and dementia. Population-based analyses have demonstrated the predictive value of retinal microvascular indices, as measured through fundus photography, in screening for heart attack and stroke. Similarly, the association between the structure of the neurosensory retina and prevalent neurodegenerative disease, in particular Alzheimer's disease, is now well-established. Given the growing size and complexity of emerging multimodal datasets, modern artificial intelligence techniques, such as deep learning, may provide the optimal opportunity to further characterize these associations, enhance our understanding of eye-body relationships and secure novel scalable approaches to the risk stratification of chronic complex disorders of ageing.
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Affiliation(s)
- Siegfried K. Wagner
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Dun Jack Fu
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Livia Faes
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
- Department of Ophthalmology, Cantonal Hospital Lucerne, Lucerne, Switzerland
| | - Xiaoxuan Liu
- Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Academic Unit of Ophthalmology, Institute of Inflammation & Ageing, University of Birmingham, Birmingham, UK
| | - Josef Huemer
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Hagar Khalid
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Daniel Ferraz
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Edward Korot
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | | | - Konstantinos Balaskas
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Alastair K. Denniston
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
- Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Academic Unit of Ophthalmology, Institute of Inflammation & Ageing, University of Birmingham, Birmingham, UK
| | - Pearse A. Keane
- NIHR Biomedical Research Center at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
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33
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Lemmens S, Devulder A, Van Keer K, Bierkens J, De Boever P, Stalmans I. Systematic Review on Fractal Dimension of the Retinal Vasculature in Neurodegeneration and Stroke: Assessment of a Potential Biomarker. Front Neurosci 2020; 14:16. [PMID: 32116491 PMCID: PMC7025576 DOI: 10.3389/fnins.2020.00016] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/08/2020] [Indexed: 01/23/2023] Open
Abstract
Introduction: Ocular manifestations in several neurological pathologies accentuate the strong relationship between the eye and the brain. Retinal alterations in particular can serve as surrogates for cerebral changes. Offering a “window to the brain,” the transparent eye enables non-invasive imaging of these changes in retinal structure and vasculature. Fractal dimension (FD) reflects the overall complexity of the retinal vasculature. Changes in FD could reflect subtle changes in the cerebral vasculature that correspond to preclinical stages of neurodegenerative diseases. In this review, the potential of this retinal vessel metric to serve as a biomarker in neurodegeneration and stroke will be explored. Methods: A literature search was conducted, following the PRISMA Statement 2009 criteria, in four large bibliographic databases (Pubmed, Embase, Web Of Science and Cochrane Library) up to 12 October 2019. Articles have been included based upon their relevance. Wherever possible, level of evidence (LOE) has been assessed by means of the Oxford Centre for Evidence-based Medicine Level of Evidence classification. Results: Twenty-one studies were included for qualitative synthesis. We performed a narrative synthesis and produced summary tables of findings of included papers because methodological heterogeneity precluded a meta-analysis. A significant association was found between decreased FD and neurodegenerative disease, mainly addressing cognitive impairment (CI) and dementia. In acute, subacute as well as chronic settings, decreased FD seems to be associated with stroke. Differences in FD between subtypes of ischemic stroke remain unclear. Conclusions: This review provides a summary of the scientific literature regarding the association between retinal FD and neurodegenerative disease and stroke. Central pathology is associated with a decreased FD, as a measure of microvascular network complexity. As retinal FD reflects the global integrity of the cerebral microvasculature, it is an attractive parameter to explore. Despite obvious concerns, mainly due to a lack of methodological standardization, retinal FD remains a promising non-invasive and low-cost diagnostic biomarker for neurodegenerative and cerebrovascular disease. Before FD can be implemented in clinic as a diagnostic biomarker, the research community should strive for uniformization and standardization.
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Affiliation(s)
- Sophie Lemmens
- Department of Ophthalmology, University Hospitals UZ Leuven, Leuven, Belgium.,Research Group Ophthalmology, Biomedical Science Group, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Health Unit, VITO (Flemish Institute for Technological Research), Mol, Belgium
| | - Astrid Devulder
- Department of Ophthalmology, University Hospitals UZ Leuven, Leuven, Belgium.,Research Group Ophthalmology, Biomedical Science Group, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Karel Van Keer
- Department of Ophthalmology, University Hospitals UZ Leuven, Leuven, Belgium.,Research Group Ophthalmology, Biomedical Science Group, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Johan Bierkens
- Health Unit, VITO (Flemish Institute for Technological Research), Mol, Belgium
| | - Patrick De Boever
- Health Unit, VITO (Flemish Institute for Technological Research), Mol, Belgium.,Centre of Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Ingeborg Stalmans
- Department of Ophthalmology, University Hospitals UZ Leuven, Leuven, Belgium.,Research Group Ophthalmology, Biomedical Science Group, Department of Neurosciences, KU Leuven, Leuven, Belgium
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Multimodal imaging characterization of peripheral drusen. Graefes Arch Clin Exp Ophthalmol 2020; 258:543-549. [PMID: 31900644 DOI: 10.1007/s00417-019-04586-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To provide an integrate multimodal imaging characterization of peripheral drusen in the eyes with and without macular signs of age-related macular degeneration (AMD) and to analyze their association with macular findings. METHODS In this retrospective, cross-sectional study, subjects with peripheral drusen were imaged with the Optos (Optos PLC, Dunfermline, Scotland, UK) and Spectralis devices to obtain referenced spectral domain optical coherence tomography (SD-OCT) images. Two experienced graders independently graded the ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) images for the presence of peripheral drusen and analyzed peripheral druse features using OCT. Main outcome measures included quantitative and qualitative assessment of peripheral drusen. RESULTS Fifty-seven eyes (30 subjects) were included in the analysis. Mean ± SD age was 77.6 ± 9.2 years (range 54-97 years). On pseudocolor images, graders identified the presence of drusen in all the enrolled eyes (Cohen's kappa was 1.0). On FAF images, Cohen's kappa was 0.71. In the topographical assessment, peripheral drusen were detected in 23 cases in the temporal region, in 40 cases in the nasal region, in 40 cases in the inferior region, and in 42 cases in the superior region. On SD-OCT images, peripheral drusen had a high reflective core in 97.1% of cases, while remaining drusen were characterized by a low reflective core. The macula was affected by early/intermediate AMD in 23 eyes (43.5%) and late AMD in 6 eyes (10.5%). CONCLUSIONS We provided an integrate multimodal imaging assessment of peripheral drusen in the eyes with and without AMD. Peripheral drusen were characterized by distinguished features that may suggest that these lesions constitute a distinct disease, rather than representing an expansion of AMD.
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Abstract
PURPOSE To assess the thickness of the retinal nerve fiber layer and its morphometric parameters using optical coherent tomography in Alzheimer's disease (AD). MATERIAL AND METHODS The study included 105 patients, among which 45 were with AD and 60 patients without AD (control group). Visual acuity of each eye was measured using Snellen chart, intraocular pressure according to Goldman, and cognitive state on the MMSE scale. All patients underwent optical coherence tomography. RESULTS The average thickness of the nerve fibers of the retina in patients with AD was lower by 27.0%, in the temporal, upper and lower quadrants - by 24.0, 17.9 and 24.9%, respectively. The thickness in the nasal quadrant with AD was reduced by 15.4%. Excavation to diameter ratio, as well as vertical and horizontal excavation to diameter ratios on average exceeded the benchmark by 12.5%, 23.4% and 30.8% (p<0.05), respectively. There was a decrease in the size of the area of the neuroretinal belt and the area of the disk by an average of 28.5% (p<0.05) and 8.8%, respectively. The average thickness, the thickness in the upper and lower segments of the ganglion cell complex is reduced, the indices of focal and global loss of the volume of retinal ganglion cells complex are increased respectively by 1.7 (p<0.05) and 2.8 times (p<0.01). CONCLUSION In patients with moderate AD, the thickness of retinal nerve fibers (RNFL) in the temporal, upper, and lower segments decreases significantly (p<0.001); a statistically significant (p<0.05) increase in the excavation to diameter ratio of the optic nerve head and a decrease in the area of the neuroretinal belt is observed; the increase in the indices of focal and global loss of the volume of ganglion cells complex is statistically significant (p<0.01).
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Affiliation(s)
- R N Guliyeva
- National Ophthalmology Center named after Zarifa Aliyeva, Baku, Republic of Azerbaijan
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36
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Ngolab J, Honma P, Rissman RA. Reflections on the Utility of the Retina as a Biomarker for Alzheimer's Disease: A Literature Review. Neurol Ther 2019; 8:57-72. [PMID: 31833024 PMCID: PMC6908534 DOI: 10.1007/s40120-019-00173-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Indexed: 12/12/2022] Open
Abstract
As a part of the central nervous system, the retina may reflect both physiologic processes and abnormalities related to diseases of the brain. Indeed, a concerted effort has been put forth to understand how Alzheimer's disease (AD) pathology may manifest in the retina as a means to assess the state of the AD brain. The development and refinement of ophthalmologic techniques for studying the retina in vivo have produced evidence of retinal degeneration in AD diagnosed patients. In this review, we will discuss retinal imaging techniques implemented to study the changes in AD retina as well as highlight the recent efforts made to correlate such findings to other clinical hallmarks of AD to assess the viability of the retina as a biomarker for AD.
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Affiliation(s)
- Jennifer Ngolab
- Department of Neurosciences, University of California, San Diego, CA, USA
| | - Patrick Honma
- Department of Neurosciences, University of California, San Diego, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, CA, USA.
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Koychev I, Lawson J, Chessell T, Mackay C, Gunn R, Sahakian B, Rowe JB, Thomas AJ, Rochester L, Chan D, Tom B, Malhotra P, Ballard C, Chessell I, Ritchie CW, Raymont V, Leroi I, Lengyel I, Murray M, Thomas DL, Gallacher J, Lovestone S. Deep and Frequent Phenotyping study protocol: an observational study in prodromal Alzheimer's disease. BMJ Open 2019; 9:e024498. [PMID: 30904851 PMCID: PMC6475176 DOI: 10.1136/bmjopen-2018-024498] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Recent failures of potential novel therapeutics for Alzheimer's disease (AD) have prompted a drive towards clinical studies in prodromal or preclinical states. However, carrying out clinical trials in early disease stages is extremely challenging-a key reason being the unfeasibility of using classical outcome measures of dementia trials (eg, conversion to dementia) and the lack of validated surrogate measures so early in the disease process. The Deep and Frequent Phenotyping (DFP) study aims to resolve this issue by identifying a set of markers acting as indicators of disease progression in the prodromal phase of disease that could be used as indicative outcome measures in proof-of-concept trials. METHODS AND ANALYSIS The DFP study is a repeated measures observational study where participants will be recruited through existing parent cohorts, research interested lists/databases, advertisements and memory clinics. Repeated measures of both established (cognition, positron emission tomography (PET) imaging or cerebrospinal fluid (CSF) markers of pathology, structural MRI markers of neurodegeneration) and experimental modalities (functional MRI, magnetoencephalography and/or electroencephalography, gait measurement, ophthalmological and continuous smartphone-based cognitive and other assessments together with experimental CSF, blood, tear and saliva biomarkers) will be performed. We will be recruiting male and female participants aged >60 years with prodromal AD, defined as absence of dementia but with evidence of cognitive impairment together with AD pathology as assessed using PET imaging or CSF biomarkers. Control participants without evidence of AD pathology will be included at a 1:4 ratio. ETHICS AND DISSEMINATION The study gained favourable ethical opinion from the South Central-Oxford B NHS Research Ethics Committee (REC reference 17/SC/0315; approved on 18 August 2017; amendment 13 February 2018). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.
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Affiliation(s)
- Ivan Koychev
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Tharani Chessell
- IMED Neuroscience, AstraZeneca UK Ltd, Cambridge, Cambridgeshire, UK
| | - Clare Mackay
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Roger Gunn
- Invicro, London, UK
- Department of Medicine, Imperial College London, London, UK
| | - Barbara Sahakian
- Department of Psychiatry, University of Cambridge, Cambridge, Cambridgeshire, UK
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, Cambridgeshire, UK
| | - Alan J Thomas
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Lynn Rochester
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Dennis Chan
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- MRC Cognition and Brain Sciences Unit, Cambridge, Cambridgeshire, UK
| | - Brian Tom
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Paresh Malhotra
- Department of Neurology, Imperial College London Faculty of Medicine, London, UK
| | | | - Iain Chessell
- IMED Neuroscience, AstraZeneca UK Ltd, Cambridge, Cambridgeshire, UK
| | - Craig W Ritchie
- Department of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Vanessa Raymont
- Department of Psychiatry, University of Oxford, Oxford, UK
- Department of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Iracema Leroi
- Manchester Academic Health Sciences Centre, Institute of Brain, Behaviour, and Mental Health, Manchester, UK
| | | | | | - David L Thomas
- Leonard Wolfson Experimental Neurology Centre, University College London Institute of Neurology, London, London, UK
| | - John Gallacher
- Department of Psychiatry, University of Oxford, Oxford, UK
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Pead E, Megaw R, Cameron J, Fleming A, Dhillon B, Trucco E, MacGillivray T. Automated detection of age-related macular degeneration in color fundus photography: a systematic review. Surv Ophthalmol 2019; 64:498-511. [PMID: 30772363 PMCID: PMC6598673 DOI: 10.1016/j.survophthal.2019.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/13/2022]
Abstract
The rising prevalence of age-related eye diseases, particularly age-related macular degeneration, places an ever-increasing burden on health care providers. As new treatments emerge, it is necessary to develop methods for reliably assessing patients' disease status and stratifying risk of progression. The presence of drusen in the retina represents a key early feature in which size, number, and morphology are thought to correlate significantly with the risk of progression to sight-threatening age-related macular degeneration. Manual labeling of drusen on color fundus photographs by a human is labor intensive and is where automatic computerized detection would appreciably aid patient care. We review and evaluate current artificial intelligence methods and developments for the automated detection of drusen in the context of age-related macular degeneration.
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Affiliation(s)
- Emma Pead
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland.
| | - Roly Megaw
- Princess Alexandra Eye Pavilion, Edinburgh, Scotland
| | - James Cameron
- MRC Human Genetics Unit, The University of Edinburgh, Edinburgh, Scotland
| | - Alan Fleming
- Optos plc, Queensferry House, Carnegie Campus, Dunfermline
| | | | - Emanuele Trucco
- VAMPIRE Project, Computing (School of Science and Engineering), University of Dundee, UK
| | - Thomas MacGillivray
- VAMPIRE Project, Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland
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Harrison IF, Whitaker R, Bertelli PM, O’Callaghan JM, Csincsik L, Bocchetta M, Ma D, Fisher A, Ahmed Z, Murray TK, O’Neill MJ, Rohrer JD, Lythgoe MF, Lengyel I. Optic nerve thinning and neurosensory retinal degeneration in the rTg4510 mouse model of frontotemporal dementia. Acta Neuropathol Commun 2019; 7:4. [PMID: 30616676 PMCID: PMC6322294 DOI: 10.1186/s40478-018-0654-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 01/09/2023] Open
Abstract
Visual impairments, such as difficulties in reading and finding objects, perceiving depth and structure from motion, and impaired stereopsis, have been reported in tauopathy disorders, such as frontotemporal dementia (FTD). These impairments however have been previously attributed to cortical pathologies rather than changes in the neurosensory retina or the optic nerve. Here, we examined tau pathology in the neurosensory retina of the rTg(tauP301L)4510 mouse model of FTD. Optic nerve pathology in mice was also assessed using MRI, and corresponding measurements taken in a cohort of five FTD sufferers and five healthy controls. rTg(tauP301L)4510 mice were imaged (T2-weighted MRI) prior to being terminally anesthetized and eyes and brains removed for immunohistochemical and histological analysis. Central and peripheral retinal labelling of tau and phosphorylated tau (pTau) was quantified and retinal layer thicknesses and cell numbers assessed. MR volumetric changes of specific brain regions and the optic nerve were compared to tau accumulation and cell loss in the visual pathway. In addition, the optic nerves of a cohort of healthy controls and behavioural variant FTD patients, were segmented from T1- and T2-weighted images for volumetric study. Accumulation of tau and pTau were observed in both the central and peripheral retinal ganglion cell (RGC), inner plexiform and inner nuclear layers of the neurosensory retina of rTg(tauP301L)4510 mice. This pathology was associated with reduced nuclear density (− 24.9 ± 3.4%) of the central RGC layer, and a reduced volume (− 19.3 ± 4.6%) and elevated T2 signal (+ 27.1 ± 1.8%) in the optic nerve of the transgenic mice. Significant atrophy of the cortex (containing the visual cortex) was observed but not in other area associated with visual processing, e.g. the lateral geniculate nucleus or superior colliculus. Atrophic changes in optic nerve volume were similarly observed in FTD patients (− 36.6 ± 2.6%). The association between tau-induced changes in the neurosensory retina and reduced optic nerve volume in mice, combined with the observation of optic nerve atrophy in clinical FTD suggests that ophthalmic tau pathology may also exist in the eyes of FTD patients. If tau pathology and neurodegeneration in the retina were to reflect the degree of cortical tau burden, then cost-effective and non-invasive imaging of the neurosensory retina could provide valuable biomarkers in tauopathy. Further work should aim to validate whether these observations are fully translatable to a clinical scenario, which would recommend follow-up retinal and optic nerve examination in FTD.
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On the origin of proteins in human drusen: The meet, greet and stick hypothesis. Prog Retin Eye Res 2018; 70:55-84. [PMID: 30572124 DOI: 10.1016/j.preteyeres.2018.12.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/12/2022]
Abstract
Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.
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Cabrera DeBuc D, Somfai GM, Arthur E, Kostic M, Oropesa S, Mendoza Santiesteban C. Investigating Multimodal Diagnostic Eye Biomarkers of Cognitive Impairment by Measuring Vascular and Neurogenic Changes in the Retina. Front Physiol 2018; 9:1721. [PMID: 30574092 PMCID: PMC6291749 DOI: 10.3389/fphys.2018.01721] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 11/15/2018] [Indexed: 12/20/2022] Open
Abstract
Previous studies have demonstrated that cognitive impairment (CI) is not limited to the brain but also affects the retina. In this pilot study, we investigated the correlation between the retinal vascular complexity and neurodegenerative changes in patients with CI using a low-cost multimodal approach. Quantification of the retinal structure and function were conducted for every subject (n = 69) using advanced retinal imaging, full-field electroretinogram (ERG) and visual performance exams. The retinal vascular parameters were calculated using the Singapore Institute Vessel Assessment software. The Montreal Cognitive Assessment was used to measure CI. Pearson product moment correlation was performed between variables. Of the 69 participants, 32 had CI (46%). We found significantly altered microvascular network in individuals with CI (larger venular-asymmetry factor: 0.7 ± 0.2) compared with controls (0.6 ± 0.2). The vascular fractal dimension was lower in individuals with CI (capacity, information and correlation dimensions: D0, D1, and D2 (mean ± SD): 1.57 ± 0.06; 1.56 ± 0.06; 1.55 ± 0.06; age 81 ± 6years) vs. controls (1.61 ± 0.03; 1.59 ± 0.03; 1.58 ± 0.03; age: 80 ± 7 years). Also, drusen-like regions in the peripheral retina along with pigment dispersion were noted in subjects with mild CI. Functional loss in color vision as well as smaller ERG amplitudes and larger peak times were observed in the subjects with CI. Pearson product moment correlation showed significant associations between the vascular parameters (artery-vein ratio, total length-diameter ratio, D0, D1, D2 and the implicit time (IT) of the flicker response but these associations were not significant in the partial correlations. This study illustrates that there are multimodal retinal markers that may be sensitive to CI decline, and adds to the evidence that there is a statistical trend pointing to the correlation between retinal neuronal dysfunction and microvasculature changes suggesting that retinal geometric vascular and functional parameters might be associated with physiological changes in the retina due to CI. We suspect our analysis of combined structural-functional parameters, instead of individual biomarkers, may provide a useful clinical marker of CI that could also provide increased sensitivity and specificity for the differential diagnosis of CI. However, because of our study sample was small, the full extent of clinical applicability of our approach is provocative and still to be determined.
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Affiliation(s)
- Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Gabor Mark Somfai
- Retinology Unit, Pallas Kliniken, Olten, Switzerland.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Edmund Arthur
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Maja Kostic
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Susel Oropesa
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
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The clinical relevance of visualising the peripheral retina. Prog Retin Eye Res 2018; 68:83-109. [PMID: 30316018 DOI: 10.1016/j.preteyeres.2018.10.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 10/01/2018] [Accepted: 10/07/2018] [Indexed: 01/04/2023]
Abstract
Recent developments in imaging technologies now allow the documentation, qualitative and quantitative evaluation of peripheral retinal lesions. As wide field retinal imaging, capturing both the central and peripheral retina up to 200° eccentricity, is becoming readily available the question is: what is it that we gain by imaging the periphery? Based on accumulating evidence it is clear that findings in the periphery do not always associate to those observed in the posterior pole. However, the newly acquired information may provide useful clues to previously unrecognised disease features and may facilitate more accurate disease prognostication. In this review, we explore the anatomy and physiology of the peripheral retina, focusing on how it differs from the posterior pole, recount the history of peripheral retinal imaging, describe various peripheral retinal lesions and evaluate the overall relevance of peripheral retinal findings to different diseases.
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Dumitrascu OM, Qureshi TA. Retinal Vascular Imaging in Vascular Cognitive Impairment: Current and Future Perspectives. J Exp Neurosci 2018; 12:1179069518801291. [PMID: 30262988 PMCID: PMC6149015 DOI: 10.1177/1179069518801291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Vascular cognitive disorders are heterogeneous and increasingly recognized
entities with intricate correlation to neurodegenerative conditions. Retinal
vascular analysis is a noninvasive approach to study cerebrovascular pathology,
with promise to assist particularly during early disease phases. In this
article, we have systematically summarized the current understanding, potential
applications, and inevitable limitations of retinal vascular imaging in patients
with vascular cognitive impairment. In addition, future directions in the field
with support from automated technology using deep learning methods and their
existing challenges are emphasized.
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Affiliation(s)
- Oana M Dumitrascu
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Touseef A Qureshi
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Ocular amyloid imaging at the crossroad of Alzheimer's disease and age-related macular degeneration: implications for diagnosis and therapy. J Neurol 2018; 266:1566-1577. [PMID: 30155741 DOI: 10.1007/s00415-018-9028-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/18/2018] [Accepted: 08/20/2018] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) and age-related macular degeneration (AMD) are important disorders of aging, but significant challenges remain in diagnosis and therapy. Amyloid-beta (Aβ), found in the brain and a defining feature of AD, has also been observed in the retina in both AD and AMD. While current diagnostic modalities for detecting Aβ in the brain are costly or invasive, Aβ in the retina can be noninvasively and conveniently imaged using modern photonic imaging systems such as optical coherence tomography (OCT). Moreover, since many of these retinal changes occur before degenerative changes can be detected in the brain, ocular amyloid biomarkers could be utilized to detect AD as well as AMD in their earliest stages when therapy may be most effective in halting disease progression. Novel technologies to quantify retinal biomarkers have the potential to facilitate early diagnosis and noninvasive monitoring of disease progression with important therapeutic implications.
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46
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Liao H, Zhu Z, Peng Y. Potential Utility of Retinal Imaging for Alzheimer's Disease: A Review. Front Aging Neurosci 2018; 10:188. [PMID: 29988470 PMCID: PMC6024140 DOI: 10.3389/fnagi.2018.00188] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 06/05/2018] [Indexed: 01/18/2023] Open
Abstract
The ensuing upward shift in demographic distribution due to the increase in life expectancy has resulted in a rising prevalence of Alzheimer's disease (AD). The heavy public burden of AD, along with the urgent to prevent and treat the disease before the irreversible damage to the brain, calls for a sensitive and specific screening technology to identify high-risk individuals before cognitive symptoms arise. Even though current modalities, such as positron emission tomography (PET) and cerebrospinal fluid (CSF) biomarker, showed their potential clinical uses in early detection of AD, the high cost, narrow isotope availability of PET probes and invasive characteristics of CSF biomarker limited their broad utility. Therefore, additional tools for detection of AD are needed. As a projection of the central nervous system (CNS), the retina has been described as a "window to the brain" and a novel marker for AD. Low cost, easy accessibility and non-invasive features make retina tests suitable for large-scale population screening and investigations of preclinical AD. Furthermore, a number of novel approaches in retina imaging, such as optical coherence tomography (OCT), have been developed and made it possible to visualize changes in the retina at a very fine resolution. In this review, we outline the background for AD to accelerate the adoption of retina imaging for the diagnosis and management of AD in clinical practice. Then, we focus on recent findings on the application of retina imaging to investigate AD and provide suggestions for future research directions.
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Affiliation(s)
- Huan Liao
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhuoting Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Ying Peng
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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