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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 PMCID: PMC11285518 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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Yousefzadeh N, Tran C, Ramirez-Zamora A, Chen J, Fang R, Thai MT. Neuron-level explainable AI for Alzheimer's Disease assessment from fundus images. Sci Rep 2024; 14:7710. [PMID: 38565579 PMCID: PMC10987553 DOI: 10.1038/s41598-024-58121-8] [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: 05/06/2023] [Accepted: 03/26/2024] [Indexed: 04/04/2024] Open
Abstract
Alzheimer's Disease (AD) is a progressive neurodegenerative disease and the leading cause of dementia. Early diagnosis is critical for patients to benefit from potential intervention and treatment. The retina has emerged as a plausible diagnostic site for AD detection owing to its anatomical connection with the brain. However, existing AI models for this purpose have yet to provide a rational explanation behind their decisions and have not been able to infer the stage of the disease's progression. Along this direction, we propose a novel model-agnostic explainable-AI framework, called Granula ̲ r Neuron-le v ̲ el Expl a ̲ iner (LAVA), an interpretation prototype that probes into intermediate layers of the Convolutional Neural Network (CNN) models to directly assess the continuum of AD from the retinal imaging without the need for longitudinal or clinical evaluations. This innovative approach aims to validate retinal vasculature as a biomarker and diagnostic modality for evaluating Alzheimer's Disease. Leveraged UK Biobank cognitive tests and vascular morphological features demonstrate significant promise and effectiveness of LAVA in identifying AD stages across the progression continuum.
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Affiliation(s)
- Nooshin Yousefzadeh
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville, Florida, USA
| | - Charlie Tran
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, USA
| | | | - Jinghua Chen
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Ruogu Fang
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, USA.
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
- Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, USA.
| | - My T Thai
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville, Florida, USA.
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El Husseini N, Schaich CL, Craft S, Rapp SR, Hayden KM, Sharrett R, Cotch MF, Wong TY, Luchsinger JA, Espeland MA, Baker LD, Bertoni AG, Hughes TM. Retinal vessel caliber and cognitive performance: the multi-ethnic study of atherosclerosis (MESA). Sci Rep 2024; 14:4120. [PMID: 38374377 PMCID: PMC10876697 DOI: 10.1038/s41598-024-54412-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/12/2024] [Indexed: 02/21/2024] Open
Abstract
Retinal vessel calibers share anatomic and physiologic characteristics with the cerebral vasculature and can be visualized noninvasively. In light of the known microvascular contributions to brain health and cognitive function, we aimed to determine if, in a community based-study, retinal vessel calibers and change in caliber over 8 years are associated with cognitive function or trajectory. Participants in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort who completed cognitive testing at Exam 5 (2010-2012) and had retinal vascular caliber measurements (Central Retinal Artery and Vein Equivalents; CRAE and CRVE) at Exam 2 (2002-2004) and Exam 5 were included. Using multivariable linear regression, we evaluated the association of CRAE and CRVE from Exam 2 and Exam 5 and their change between the two exams with scores on tests of global cognitive function (Cognitive Abilities Screening Instrument; CASI), processing speed (Digit Symbol Coding; DSC) and working memory (Digit Span; DS) at Exam 5 and with subsequent change in cognitive scores between Exam 5 and Exam 6 (2016-2018).The main effects are reported as the difference in cognitive test score per SD increment in retinal vascular caliber with 95% confidence intervals (CI). A total of 4334 participants (aged 61.6 ± 9.2 years; 53% female; 41% White) completed cognitive testing and at least one retinal assessment. On multivariable analysis, a 1 SD larger CRAE at exam 5 was associated with a lower concomitant CASI score (- 0.24, 95% CI - 0.46, - 0.02). A 1 SD larger CRVE at exam 2 was associated with a lower subsequent CASI score (- 0.23, 95%CI - 0.45, - 0.01). A 1 SD larger CRVE at exam 2 or 5 was associated with a lower DSC score [(- 0.56, 95% CI - 1.02, - 0.09) and - 0.55 (95% CI - 1.03, - 0.07) respectively]. The magnitude of the associations was relatively small (2.8-3.1% of SD). No significant associations were found between retinal vessel calibers at Exam 2 and 5 with the subsequent score trajectory of cognitive tests performance over an average of 6 years. Wider retinal venular caliber was associated with concomitant and future measures of slower processing speed but not with later cognitive trajectory. Future studies should evaluate the utility of these measures in risk stratification models from a clinical perspective as well as for screening on a population level.
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Affiliation(s)
- Nada El Husseini
- Department of Neurology, Duke University Medical Center, Duke South, Purple Zone, Suite 0109, Durham, NC, 27710, USA.
| | - Christopher L Schaich
- Department of Surgery, Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Suzanne Craft
- Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Stephen R Rapp
- Psychiatry and Behavioral Medicine, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Kathleen M Hayden
- Social Sciences and Health Policy, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Richey Sharrett
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
| | | | - Tien Y Wong
- Department of Ophthalmology and Visual Sciences, National University of Singapore, Singapore, Singapore
- Tsinghua Medicine, Tsinghua University, Beijing, China
| | - Jose A Luchsinger
- Division of General Medicine, Columbia University Medical Center, New York, NY, USA
| | - Mark A Espeland
- Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Laura D Baker
- Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Alain G Bertoni
- Epidemiology and Prevention, Wake Forest University School of Medicine, Winston Salem, NC, USA
| | - Timothy M Hughes
- Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston Salem, NC, USA
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Ong SS, Peavey JJ, Hiatt KD, Whitlow CT, Sappington RM, Thompson AC, Lockhart SN, Chen H, Craft S, Rapp SR, Fitzpatrick AL, Heckbert SR, Luchsinger JA, Klein BEK, Meuer SM, Cotch MF, Wong TY, Hughes TM. Association of fractal dimension and other retinal vascular network parameters with cognitive performance and neuroimaging biomarkers: The Multi-Ethnic Study of Atherosclerosis (MESA). Alzheimers Dement 2024; 20:941-953. [PMID: 37828734 PMCID: PMC10916935 DOI: 10.1002/alz.13498] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/16/2023] [Accepted: 09/09/2023] [Indexed: 10/14/2023]
Abstract
INTRODUCTION Retinal vascular network changes may reflect the integrity of the cerebral microcirculation, and may be associated with cognitive impairment. METHODS Associations of retinal vascular measures with cognitive function and MRI biomarkers were examined amongst Multi-Ethnic Study of Atherosclerosis (MESA) participants in North Carolina who had gradable retinal photographs at Exams 2 (2002 to 2004, n = 313) and 5 (2010 to 2012, n = 306), and detailed cognitive testing and MRI at Exam 6 (2016 to 2018). RESULTS After adjustment for covariates and multiple comparisons, greater arteriolar fractal dimension (FD) at Exam 2 was associated with less isotropic free water of gray matter regions (β = -0.0005, SE = 0.0024, p = 0.01) at Exam 6, while greater arteriolar FD at Exam 5 was associated with greater gray matter cortical volume (in mm3 , β = 5458, SE = 20.17, p = 0.04) at Exam 6. CONCLUSION Greater arteriolar FD, reflecting greater complexity of the branching pattern of the retinal arteries, is associated with MRI biomarkers indicative of less neuroinflammation and neurodegeneration.
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Affiliation(s)
- Sally S. Ong
- Department of OphthalmologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Jeremy J. Peavey
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Kevin D. Hiatt
- Department of RadiologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Christopher T. Whitlow
- Department of RadiologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Rebecca M. Sappington
- Department of OphthalmologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
- Department of BiochemistryWake Forest School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Atalie C. Thompson
- Department of OphthalmologyWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Samuel N. Lockhart
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Haiying Chen
- Department of Psychiatry and Behavioral MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Suzanne Craft
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Stephen R. Rapp
- Biostatistics and Data ScienceWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Annette L. Fitzpatrick
- Department of EpidemiologySchool of Public HealthUniversity of WashingtonSeattleWashingtonUSA
| | - Susan R. Heckbert
- Department of EpidemiologySchool of Public HealthUniversity of WashingtonSeattleWashingtonUSA
| | - José A. Luchsinger
- Departments of Medicine and EpidemiologyColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Barbara E. K. Klein
- Department of Ophthalmology and Visual SciencesUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Stacy M Meuer
- Department of Ophthalmology and Visual SciencesUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | | | - Tien Y. Wong
- Singapore Eye Research InstituteSingapore National Eye CenterOphthalmology and Visual Sciences Academic Clinical ProgramDuke‐NUS Medical SchoolSingapore
- Tsinghua MedicineTsinghua UniversityBeijingChina
| | - Timothy M. Hughes
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
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García-Bermúdez MY, Vohra R, Freude K, van Wijngaarden P, Martin K, Thomsen MS, Aldana BI, Kolko M. Potential Retinal Biomarkers in Alzheimer's Disease. Int J Mol Sci 2023; 24:15834. [PMID: 37958816 PMCID: PMC10649108 DOI: 10.3390/ijms242115834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Alzheimer's disease (AD) represents a major diagnostic challenge, as early detection is crucial for effective intervention. This review examines the diagnostic challenges facing current AD evaluations and explores the emerging field of retinal alterations as early indicators. Recognizing the potential of the retina as a noninvasive window to the brain, we emphasize the importance of identifying retinal biomarkers in the early stages of AD. However, the examination of AD is not without its challenges, as the similarities shared with other retinal diseases introduce complexity in the search for AD-specific markers. In this review, we address the relevance of using the retina for the early diagnosis of AD and the complex challenges associated with the search for AD-specific retinal biomarkers. We provide a comprehensive overview of the current landscape and highlight avenues for progress in AD diagnosis by retinal examination.
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Affiliation(s)
| | - Rupali Vohra
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark
| | - Kristine Freude
- Group of Stem Cell Models and Embryology, Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
| | - Peter van Wijngaarden
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Keith Martin
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Maj Schneider Thomsen
- Neurobiology Research and Drug Delivery, Department of Health, Science and Technology, Aalborg University, 9220 Aalborg, Denmark
| | - Blanca Irene Aldana
- Neurometabolism Research Group, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Miriam Kolko
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark
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Wu TY, Hsieh YT, Wang YH, Chiou JM, Chen TF, Lai LC, Chen JH, Chen YC. The association between retinal vascular fractal dimension and cognitive function in the community-dwelling older adults cohort TIGER. J Formos Med Assoc 2023; 122:1050-1060. [PMID: 37085387 DOI: 10.1016/j.jfma.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 03/12/2023] [Accepted: 04/06/2023] [Indexed: 04/23/2023] Open
Abstract
BACKGROUND/PURPOSE The small retinal vessels reflect cerebral microcirculation and its fractal dimension (Df), representing the complexity of the retinal microcirculation. However, the connection between retinal circulation and cognitive function lacked consistent and longitudinal evidence. This study aimed to explore the association between retinal vascular complexity and cognitive impairment over time in non-demented community-dwelling older adults. METHODS This four-year prospective cohort study (2015-2019) is part of the ongoing Taiwan Initiative for Geriatric Epidemiological Research (TIGER, 2011 to present). Of the 434 older adults (age >65) recruited, 207 participants were included for analysis. The retinal vascular Df was assessed by baseline images from fundus photography (2015-2017). Global (Montreal Cognitive Assessment-Taiwanese version, MoCA-T) and domain-specific cognition were assessed at the baseline and 2-year follow-up (2017-2019). The multivariable linear regression models and generalized linear mixed models were used to evaluate the association of Df with cognitive decline/impairment over time. RESULTS Decreased left retinal vascular complexity was associated with poor attention performance (β = -0.40). As follow-up time increased, decreased vascular complexity was associated with poor memory performance (right: β = -0.25; left: β = -0.19), and decreased right vascular complexity was associated with poor attention performance (β = -0.18). CONCLUSION Low retinal vascular complexity of the right or left eye may be differentially associated with cognitive domains in community-dwelling older adults over two years. The retinal vascular Df of either eye may be served as a screening tool for detecting cognitive impairment in the preclinical phase of dementia.
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Affiliation(s)
- Ting-Yu Wu
- Department of Ophthalmology, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Hsieh
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-Hsin Wang
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Jeng-Min Chiou
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
| | - Ta-Fu Chen
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Liang-Chuan Lai
- Graduate Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Jen-Hau Chen
- Department of Geriatrics and Gerontology, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Yen-Ching Chen
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
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Rebouças SCL, Cougnard‐Gregoire A, Arnould L, Delyfer M, Schweitzer C, Korobelnik J, Foubert‐Samier A, Cheung CY, Wong TY, Delcourt C, Helmer C. Retinal microvasculature and incident dementia over 10 years: The Three-City-Alienor cohort. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2023; 15:e12480. [PMID: 37915467 PMCID: PMC10617985 DOI: 10.1002/dad2.12480] [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: 08/18/2023] [Accepted: 08/24/2023] [Indexed: 11/03/2023]
Abstract
Introduction We explored the longitudinal relationship between retinal vascular features and dementia incidence over 10 years. Methods Among 584 participants from the Three-City-Alienor (3C-Alienor) population-based cohort, quantitative retinal vascular features (caliber, tortuosity, fractal dimension) were measured using semi-automated software. Dementia was actively diagnosed over the follow-up period. Results One hundred twenty-eight participants (21.9%) developed dementia over a median of 7.1 years. In Cox proportional hazards models adjusted for sociodemographic characteristics, apolipoprotein E (APOE) ε4, and vascular factors, increased retinal arteriolar tortuosity was associated with all-cause dementia (hazard ratio per standard deviation increase, 1.21; 95% confidence interval: 1.02-1.44). Wider retinal calibers and a higher venular tortuosity were associated with mixed/vascular dementia, but not Alzheimer's disease. Fractal dimensions were not associated with dementia. Discussion Changes in the retinal microvasculature were associated with dementia risk. More studies are needed to replicate these findings and determine which features might help identify persons at risk at an early stage. HIGHLIGHTS The retinal microvasculature might reflect the brain microvasculatureWe explored the association between retinal vascular features and incident dementia584 participants from the Three-City-Alienor cohort were followed-up over 10 yearsIncreased arteriolar tortuosity and venular calibers were associated with dementia riskRetinal imaging might help identify persons at risk of future dementia.
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Affiliation(s)
| | | | - Louis Arnould
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Department of OphthalmologyDijon University HospitalDijonFrance
| | - Marie‐Noëlle Delyfer
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Department of OphthalmologyBordeaux University HospitalBordeauxFrance
| | - Cédric Schweitzer
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Department of OphthalmologyBordeaux University HospitalBordeauxFrance
| | - Jean‐François Korobelnik
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Department of OphthalmologyBordeaux University HospitalBordeauxFrance
| | - Alexandra Foubert‐Samier
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Institut des Maladies NeurodégénérativesBordeaux University HospitalBordeauxFrance
| | - Carol Y. Cheung
- Department of Ophthalmology and Visual SciencesThe Chinese University of Hong KongHong KongChina
| | - Tien Y. Wong
- Singapore Eye Research InstituteSingapore National Eye CenterSingaporeSingapore
- Tsinghua MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
| | | | - Catherine Helmer
- University of BordeauxINSERM, BPH, U1219BordeauxFrance
- Clinical Investigation Center – Clinical EpidemiologyINSERMBordeauxFrance
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9
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Zou L, Herold F, Ludyga S, Kamijo K, Müller NG, Pontifex MB, Heath M, Kuwamizu R, Soya H, Hillman CH, Ando S, Alderman BL, Cheval B, Kramer AF. Look into my eyes: What can eye-based measures tell us about the relationship between physical activity and cognitive performance? JOURNAL OF SPORT AND HEALTH SCIENCE 2023; 12:568-591. [PMID: 37148971 PMCID: PMC10466196 DOI: 10.1016/j.jshs.2023.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/07/2023] [Accepted: 03/16/2023] [Indexed: 05/08/2023]
Abstract
BACKGROUND There is a growing interest to understand the neurobiological mechanisms that drive the positive associations of physical activity and fitness with measures of cognitive performance. To better understand those mechanisms, several studies have employed eye-based measures (e.g., eye movement measures such as saccades, pupillary measures such as pupil dilation, and vascular measures such as retinal vessel diameter) deemed to be proxies for specific neurobiological mechanisms. However, there is currently no systematic review providing a comprehensive overview of these studies in the field of exercise-cognition science. Thus, this review aimed to address that gap in the literature. METHODS To identify eligible studies, we searched 5 electronic databases on October 23, 2022. Two researchers independently extracted data and assessed the risk of bias using a modified version of the Tool for the assEssment of Study qualiTy and reporting in EXercise (TESTEX scale, for interventional studies) and the critical appraisal tool from the Joanna Briggs Institute (for cross-sectional studies). RESULTS Our systematic review (n = 35 studies) offers the following main findings: (a) there is insufficient evidence available to draw solid conclusions concerning gaze-fixation-based measures; (b) the evidence that pupillometric measures, which are a proxy for the noradrenergic system, can explain the positive effect of acute exercise and cardiorespiratory fitness on cognitive performance is mixed; (c) physical training- or fitness-related changes of the cerebrovascular system (operationalized via changes in retinal vasculature) are, in general, positively associated with cognitive performance improvements; (d) acute and chronic physical exercises show a positive effect based on an oculomotor-based measure of executive function (operationalized via antisaccade tasks); and (e) the positive association between cardiorespiratory fitness and cognitive performance is partly mediated by the dopaminergic system (operationalized via spontaneous eye-blink rate). CONCLUSION This systematic review offers confirmation that eye-based measures can provide valuable insight into the neurobiological mechanisms that may drive positive associations between physical activity and fitness and measures of cognitive performance. However, due to the limited number of studies utilizing specific methods for obtaining eye-based measures (e.g., pupillometry, retinal vessel analysis, spontaneous eye blink rate) or investigating a possible dose-response relationship, further research is necessary before more nuanced conclusions can be drawn. Given that eye-based measures are economical and non-invasive, we hope this review will foster the future application of eye-based measures in the field of exercise-cognition science.
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Affiliation(s)
- Liye Zou
- Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen 518060, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam 14476, Germany.
| | - Fabian Herold
- Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen 518060, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam 14476, Germany
| | - Sebastian Ludyga
- Department of Sport, Exercise, and Health, University of Basel, Basel 4052, Switzerland
| | - Keita Kamijo
- Faculty of Liberal Arts and Sciences, Chukyo University, Nagoya 466-8666, Japan
| | - Notger G Müller
- Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen 518060, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam 14476, Germany
| | - Matthew B Pontifex
- Department of Kinesiology, Michigan State University, East Lansing, MI 48824, USA
| | - Matthew Heath
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London ON N6A 3K7, Canada; Canadian Centre for Activity and Aging, University of Western Ontario, London ON, N6A 3K7, Canada; Graduate Program in Neuroscience, University of Western Ontario, London ON, N6A 3K7, Canada
| | - Ryuta Kuwamizu
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan
| | - Hideaki Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan; Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan
| | - Charles H Hillman
- Center for Cognitive and Brain Health, Department of Psychology, Department of Physical Therapy, Movement, and Rehabilitation Sciences, Northeastern University, Boston, MA 02115, USA
| | - Soichi Ando
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo 182-8585, Japan
| | - Brandon L Alderman
- Department of Kinesiology and Health, Rutgers University-New Brunswick, New Brunswick, NJ 08854, USA
| | - Boris Cheval
- Swiss Center for Affective Sciences, University of Geneva, Geneva 1205, Switzerland; Laboratory for the Study of Emotion Elicitation and Expression (E3Lab), Department of Psychology, University of Geneva, Geneva 1205, Switzerland
| | - Arthur F Kramer
- Department of Psychology, Center for Cognitive and Brain Health, Northeastern University, Boston, MA 02115, USA; Beckman Institute, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
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10
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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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11
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Shi XH, Dong L, Zhang RH, Zhou DJ, Ling SG, Shao L, Yan YN, Wang YX, Wei WB. Relationships between quantitative retinal microvascular characteristics and cognitive function based on automated artificial intelligence measurements. Front Cell Dev Biol 2023; 11:1174984. [PMID: 37416799 PMCID: PMC10322221 DOI: 10.3389/fcell.2023.1174984] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
Introduction: The purpose of this study is to assess the relationship between retinal vascular characteristics and cognitive function using artificial intelligence techniques to obtain fully automated quantitative measurements of retinal vascular morphological parameters. Methods: A deep learning-based semantic segmentation network ResNet101-UNet was used to construct a vascular segmentation model for fully automated quantitative measurement of retinal vascular parameters on fundus photographs. Retinal photographs centered on the optic disc of 3107 participants (aged 50-93 years) from the Beijing Eye Study 2011, a population-based cross-sectional study, were analyzed. The main parameters included the retinal vascular branching angle, vascular fractal dimension, vascular diameter, vascular tortuosity, and vascular density. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Results: The results showed that the mean MMSE score was 26.34 ± 3.64 (median: 27; range: 2-30). Among the participants, 414 (13.3%) were classified as having cognitive impairment (MMSE score < 24), 296 (9.5%) were classified as mild cognitive impairment (MMSE: 19-23), 98 (3.2%) were classified as moderate cognitive impairment (MMSE: 10-18), and 20 (0.6%) were classified as severe cognitive impairment (MMSE < 10). Compared with the normal cognitive function group, the retinal venular average diameter was significantly larger (p = 0.013), and the retinal vascular fractal dimension and vascular density were significantly smaller (both p < 0.001) in the mild cognitive impairment group. The retinal arteriole-to-venular ratio (p = 0.003) and vascular fractal dimension (p = 0.033) were significantly decreased in the severe cognitive impairment group compared to the mild cognitive impairment group. In the multivariate analysis, better cognition (i.e., higher MMSE score) was significantly associated with higher retinal vascular fractal dimension (b = 0.134, p = 0.043) and higher retinal vascular density (b = 0.152, p = 0.023) after adjustment for age, best corrected visual acuity (BCVA) (logMAR) and education level. Discussion: In conclusion, our findings derived from an artificial intelligence-based fully automated retinal vascular parameter measurement method showed that several retinal vascular morphological parameters were correlated with cognitive impairment. The decrease in retinal vascular fractal dimension and decreased vascular density may serve as candidate biomarkers for early identification of cognitive impairment. The observed reduction in the retinal arteriole-to-venular ratio occurs in the late stages of cognitive impairment.
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Affiliation(s)
- Xu Han Shi
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Li Dong
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Rui Heng Zhang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Deng Ji Zhou
- EVision Technology (Beijing) Co., Ltd., Beijing, China
| | | | - Lei Shao
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yan Ni Yan
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ya Xing Wang
- Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Wen Bin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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12
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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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13
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García-Sierra R, López-Lifante VM, Isusquiza Garcia E, Heras A, Besada I, Verde Lopez D, Alzamora MT, Forés R, Montero-Alia P, Ugarte Anduaga J, Torán-Monserrat P. Automated Systems for Calculating Arteriovenous Ratio in Retinographies: A Scoping Review. Diagnostics (Basel) 2022; 12:diagnostics12112865. [PMID: 36428925 PMCID: PMC9689345 DOI: 10.3390/diagnostics12112865] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/29/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022] Open
Abstract
There is evidence of an association between hypertension and retinal arteriolar narrowing. Manual measurement of retinal vessels comes with additional variability, which can be eliminated using automated software. This scoping review aims to summarize research on automated retinal vessel analysis systems. Searches were performed on Medline, Scopus, and Cochrane to find studies examining automated systems for the diagnosis of retinal vascular alterations caused by hypertension using the following keywords: diagnosis; diagnostic screening programs; image processing, computer-assisted; artificial intelligence; electronic data processing; hypertensive retinopathy; hypertension; retinal vessels; arteriovenous ratio and retinal image analysis. The searches generated 433 articles. Of these, 25 articles published from 2010 to 2022 were included in the review. The retinographies analyzed were extracted from international databases and real scenarios. Automated systems to detect alterations in the retinal vasculature are being introduced into clinical practice for diagnosis in ophthalmology and other medical specialties due to the association of such changes with various diseases. These systems make the classification of hypertensive retinopathy and cardiovascular risk more reliable. They also make it possible for diagnosis to be performed in primary care, thus optimizing ophthalmological visits.
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Affiliation(s)
- Rosa García-Sierra
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
- Multidisciplinary Research Group in Health and Society GREMSAS (2017 SGR 917), 08007 Barcelona, Spain
- Nursing Department, Faculty of Medicine, Universitat Autònoma de Barcelona, Campus Bellaterra, 08193 Barcelona, Spain
- Primary Care Group, Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
| | - Victor M. López-Lifante
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
- Palau-solità i Plegamans Primary Healthcare Centre, Palau-solità i Plegamans, Gerència d’Àmbit d’Atenció Primària Metropolitana Nord, Institut Català de la Salut, 08184 Barcelona, Spain
- Correspondence:
| | | | - Antonio Heras
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
- Primary Healthcare Centre Riu Nord-Riu Sud, Gerència d’Àmbit d’Atenció Primària Metropolitana Nord, Institut Català de la Salut, Santa Coloma de Gramenet, 08921 Barcelona, Spain
| | - Idoia Besada
- ULMA Medical Technologies, S. Coop, 20560 Onati, Spain
| | - David Verde Lopez
- Institut Universitari d’Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), 08007 Barcelona, Spain
| | - Maria Teresa Alzamora
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
- Primary Healthcare Centre Riu Nord-Riu Sud, Gerència d’Àmbit d’Atenció Primària Metropolitana Nord, Institut Català de la Salut, Santa Coloma de Gramenet, 08921 Barcelona, Spain
| | - Rosa Forés
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
| | - Pilar Montero-Alia
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
| | | | - Pere Torán-Monserrat
- Research Support Unit Metropolitana Nord, Primary Care Research Institut Jordi Gol (IDIAPJGol), 08303 Mataró, Spain
- Multidisciplinary Research Group in Health and Society GREMSAS (2017 SGR 917), 08007 Barcelona, Spain
- Primary Care Group, Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- Department of Medicine, Faculty of Medicine, Universitat de Girona, 17004 Girona, Spain
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14
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Cheung CY, Wong WLE, Hilal S, Kan CN, Gyanwali B, Tham YC, Schmetterer L, Xu D, Lee ML, Hsu W, Venketasubramanian N, Tan BY, Wong TY, Chen CPLH. Deep-learning retinal vessel calibre measurements and risk of cognitive decline and dementia. Brain Commun 2022; 4:fcac212. [PMID: 36043139 PMCID: PMC9416061 DOI: 10.1093/braincomms/fcac212] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 06/07/2022] [Accepted: 08/16/2022] [Indexed: 10/14/2023] Open
Abstract
Previous studies have explored the associations of retinal vessel calibre, measured from retinal photographs or fundus images using semi-automated computer programs, with cognitive impairment and dementia, supporting the concept that retinal blood vessels reflect microvascular changes in the brain. Recently, artificial intelligence deep-learning algorithms have been developed for the fully automated assessment of retinal vessel calibres. Therefore, we aimed to determine whether deep-learning-based retinal vessel calibre measurements are predictive of risk of cognitive decline and dementia. We conducted a prospective study recruiting participants from memory clinics at the National University Hospital and St. Luke's Hospital in Singapore; all participants had comprehensive clinical and neuropsychological examinations at baseline and annually for up to 5 years. Fully automated measurements of retinal arteriolar and venular calibres from retinal fundus images were estimated using a deep-learning system. Cox regression models were then used to assess the relationship between baseline retinal vessel calibre and the risk of cognitive decline and developing dementia, adjusting for age, gender, ethnicity, education, cerebrovascular disease status, hypertension, hyperlipidemia, diabetes, and smoking. A total of 491 participants were included in this study, of whom 254 developed cognitive decline over 5 years. In multivariable models, narrower retinal arteriolar calibre (hazard ratio per standard deviation decrease = 1.258, P = 0.008) and wider retinal venular calibre (hazard ratio per standard deviation increase = 1.204, P = 0.037) were associated with increased risk of cognitive decline. Among participants with cognitive impairment but no dementia at baseline (n = 212), 44 progressed to have incident dementia; narrower retinal arteriolar calibre was also associated with incident dementia (hazard ratio per standard deviation decrease = 1.624, P = 0.021). In summary, deep-learning-based measurement of retinal vessel calibre was associated with risk of cognitive decline and dementia.
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Affiliation(s)
- Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Win Lee Edwin Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
- Memory Ageing and Cognition Centre, National University Health System, Singapore 119074, Singapore
| | - Saima Hilal
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
- Memory Ageing and Cognition Centre, National University Health System, Singapore 119074, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore 117549, Singapore
| | - Cheuk Ni Kan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
- Memory Ageing and Cognition Centre, National University Health System, Singapore 119074, Singapore
| | - Bibek Gyanwali
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
- Memory Ageing and Cognition Centre, National University Health System, Singapore 119074, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798, Singapore
- Department of Clinical Pharmacology, Medical University Vienna, Vienna 1090, Austria
- Austria Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna 1090, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Dejiang Xu
- School of Computing, National University of Singapore, Singapore 117417, Singapore
| | - Mong Li Lee
- School of Computing, National University of Singapore, Singapore 117417, Singapore
| | - Wynne Hsu
- School of Computing, National University of Singapore, Singapore 117417, Singapore
| | | | - Boon Yeow Tan
- St. Luke's Hospital, Singapore, Singapore 659674, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Christopher P L H Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
- Memory Ageing and Cognition Centre, National University Health System, Singapore 119074, Singapore
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117600, Singapore
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15
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Miller LR, Tarantini S, Nyúl-Tóth Á, Johnston MP, Martin T, Bullen EC, Bickel MA, Sonntag WE, Yabluchanskiy A, Csiszar A, Ungvari ZI, Elliott MH, Conley SM. Increased Susceptibility to Cerebral Microhemorrhages Is Associated With Imaging Signs of Microvascular Degeneration in the Retina in an Insulin-Like Growth Factor 1 Deficient Mouse Model of Accelerated Aging. Front Aging Neurosci 2022; 14:788296. [PMID: 35356301 PMCID: PMC8959924 DOI: 10.3389/fnagi.2022.788296] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 01/31/2022] [Indexed: 01/21/2023] Open
Abstract
Age-related cerebrovascular defects contribute to vascular cognitive impairment and dementia (VCID) as well as other forms of dementia. There has been great interest in developing biomarkers and other tools for studying cerebrovascular disease using more easily accessible tissues outside the brain such as the retina. Decreased circulating insulin-like growth factor 1 (IGF-1) levels in aging are thought to contribute to the development of cerebrovascular impairment, a hypothesis that has been supported by the use of IGF-1 deficient animal models. Here we evaluate vascular and other retinal phenotypes in animals with circulating IGF-1 deficiency and ask whether the retina mimics common age-related vascular changes in the brain such as the development of microhemorrhages. Using a hypertension-induced model, we confirm that IGF-1 deficient mice exhibited worsened microhemorrhages than controls. The retinas of IGF-1 deficient animals do not exhibit microhemorrhages but do exhibit signs of vascular damage and retinal stress such as patterns of vascular constriction and Müller cell activation. These signs of retinal stress are not accompanied by retinal degeneration or impaired neuronal function. These data suggest that the role of IGF-1 in the retina is complex, and while IGF-1 deficiency leads to vascular defects in both the brain and the retina, not all brain pathologies are evident in the retina.
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Affiliation(s)
- Lauren R. Miller
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,Stephenson Cancer Center, University of Oklahoma, Oklahoma City, OK, United States,International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,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, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Morgan P. Johnston
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Teryn Martin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Elizabeth C. Bullen
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Marisa A. Bickel
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - William E. Sonntag
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Zoltan I. Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Michael H. Elliott
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,*Correspondence: Shannon M. Conley,
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16
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Christinaki E, Kulenovic H, Hadoux X, Baldassini N, Van Eijgen J, De Groef L, Stalmans I, van Wijngaarden P. Retinal imaging biomarkers of neurodegenerative diseases. Clin Exp Optom 2022; 105:194-204. [PMID: 34751086 DOI: 10.1080/08164622.2021.1984179] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The timely detection of neurodegenerative diseases is central to improving clinical care as well as enabling the development and deployment of disease-modifying therapies. Retinal imaging is emerging as a method to detect features of a number of neurodegenerative diseases, given the anatomical and functional similarities between the retina and the brain. This review provides an overview of the current status of retinal imaging biomarkers of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Lewy body dementia, frontotemporal dementia, Huntington's disease and multiple sclerosis. Whilst research findings are promising, efforts to harmonise study designs and imaging methods will be important in translating these findings into clinical care. Doing so may mean that eye care providers will play important roles in the detection of a variety of neurodegenerative diseases in future.
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Affiliation(s)
- Eirini Christinaki
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Hana Kulenovic
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Nicole Baldassini
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Jan Van Eijgen
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | - Lies De Groef
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium
| | - Ingeborg Stalmans
- Research Group Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.,Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Parkville, Australia
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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: 43] [Impact Index Per Article: 14.3] [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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Liao C, Xu J, Chen Y, Ip NY. Retinal Dysfunction in Alzheimer's Disease and Implications for Biomarkers. Biomolecules 2021; 11:biom11081215. [PMID: 34439882 PMCID: PMC8394950 DOI: 10.3390/biom11081215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that manifests as cognitive deficits and memory decline, especially in old age. Several biomarkers have been developed to monitor AD progression. Given that the retina and brain share some similarities including features related to anatomical composition and neurological functions, the retina is closely associated with the progression of AD. Herein, we review the evidence of retinal dysfunction in AD, particularly at the early stage, together with the underlying molecular mechanisms. Furthermore, we compared the retinal pathologies of AD and other ophthalmological diseases and summarized potential retinal biomarkers measurable by existing technologies for detecting AD, providing insights for the future development of diagnostic tools.
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Affiliation(s)
- Chunyan Liao
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen 518055, China; (C.L.); (J.X.)
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Jinying Xu
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen 518055, China; (C.L.); (J.X.)
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen 518057, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Chen
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen 518055, China; (C.L.); (J.X.)
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen 518057, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (Y.C.); (N.Y.I.); Tel.: +86-755-2692-5498 (Y.C.); +852-2358-6161 (N.Y.I.)
| | - Nancy Y. Ip
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen 518057, China
- Division of Life Science, Molecular Neuroscience Center, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong 999077, China
- Correspondence: (Y.C.); (N.Y.I.); Tel.: +86-755-2692-5498 (Y.C.); +852-2358-6161 (N.Y.I.)
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19
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O'Neill RA, Maxwell AP, Paterson EN, Kee F, Young I, Hogg RE, Cruise S, Murphy S, McGuinness B, McKay GJ. Retinal microvascular parameters are not significantly associated with mild cognitive impairment in the Northern Ireland Cohort for the Longitudinal Study of Ageing. BMC Neurol 2021; 21:112. [PMID: 33706706 PMCID: PMC7948373 DOI: 10.1186/s12883-021-02137-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 03/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The retinal and cerebral microvasculature share similar embryological origins and physiological characteristics. Improved imaging technologies provide opportunistic non-invasive assessment of retinal microvascular parameters (RMPs) against cognitive outcomes. We evaluated baseline measures for associations between RMPs and mild cognitive impairment (MCI) from participants of the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). METHODS RMPs (central retinal arteriolar / venular equivalents, arteriole to venular ratio, fractal dimension and tortuosity) were measured from optic disc centred fundus images and analysed using semi-automated software. Associations between RMPs and MCI were assessed by multivariable logistic regression with adjustment for potential confounders including age, sex, alcohol consumption, smoking status, educational attainment, physical activity, cardiovascular disease (CVD), hypertension, mean arterial blood pressure, triglycerides, diabetes, body mass index, and high density lipoprotein levels. P < 0.05 was considered statistically significant. RESULTS Data were available for 1431 participants, of which 156 (10.9%) were classified with MCI defined by a Montreal Cognitive Assessment (MoCA) score ≤ 26, with subjective cognitive decline, in the absence of depression or problems with activities of daily living. Participants had a mean age of 62.4 ± 8.5 yrs. and 52% were female. As expected, individuals with MCI had a lower MoCA score than those without (23.5 ± 2.6 versus 26.3 ± 2.7, respectively), were more likely to be female, have a lower level of educational attainment, be less physically active, more likely to have CVD, have higher levels of triglycerides and lower levels of high density lipoprotein. No significant associations between RMPs and MCI were detected in unadjusted, minimally adjusted or fully adjusted regression models or subsequent sensitivity analyses. CONCLUSION Previous studies have reported both increased retinal venular calibre and reduced fractal dimension in association with mild cognitive impairment. Our study failed to detect any associations between RMPs and those individuals at an early stage of cognitive loss in an older community-based cohort.
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Affiliation(s)
- R A O'Neill
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - A P Maxwell
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - E N Paterson
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - F Kee
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - I Young
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - R E Hogg
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - S Cruise
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - S Murphy
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - B McGuinness
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland
| | - G J McKay
- Centre for Public Health, Queens University Belfast, Belfast, Northern Ireland.
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20
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Liew G, Gopinath B, White AJ, Burlutsky G, Yin Wong T, Mitchell P. Retinal Vasculature Fractal and Stroke Mortality. Stroke 2021; 52:1276-1282. [PMID: 33611944 DOI: 10.1161/strokeaha.120.031886] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND PURPOSE Fractal analysis is a method of quantifying the branching complexity and density of the retinal vessels. We hypothesized that reduced fractal dimension, signifying a sparser vascular network, is associated with long-term stroke mortality. METHODS We examined the relationship of fractal dimension and stroke mortality in a prospective, population-based cohort of 3143 participants aged 49 years or older. Fractal dimension was measured from digitized fundus photographs using a computer-automated method. Stroke mortality was documented from Australian National Death Index records. We defined reduced fractal dimension as values in the lowest quartile. RESULTS Over 12 years, there were 132 (4.2%) stroke-related deaths. Stroke-related mortality was higher in participants with reduced fractal dimension (lowest quartile) compared with the highest quartile (7.7% versus 1.3%, P<0.01). After controlling for age, gender, smoking, blood pressure, history of stroke, and other factors, participants with reduced fractal dimension had higher stroke mortality (hazard ratio, 2.42 [95% CI, 1.15-5.07], lowest versus highest quartile). When modeled as a continuous variable, reduced fractal dimension was associated with increased stroke mortality (multivariable-adjusted hazard ratio, 1.26 [95% CI, 1.06-1.51], per SD decrease). CONCLUSIONS Reduced retinal vascular fractal dimension is independently associated with 12-year stroke mortality. Reduced fractal dimension may indicate cerebral tissue hypoxia and increased risk of stroke.
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Affiliation(s)
- Gerald Liew
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Australia (G.L., B.G., A.J.W., G.B.M., P.M.)
| | - Bamini Gopinath
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Australia (G.L., B.G., A.J.W., G.B.M., P.M.)
| | - Andrew J White
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Australia (G.L., B.G., A.J.W., G.B.M., P.M.)
| | - George Burlutsky
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Australia (G.L., B.G., A.J.W., G.B.M., P.M.)
| | - Tien Yin Wong
- Duke-NUS Medical School, National University of Singapore (T.Y.W.).,Singapore Eye Research Institute, Singapore National Eye Center (T.Y.W.)
| | - Paul Mitchell
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Australia (G.L., B.G., A.J.W., G.B.M., P.M.)
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21
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Provost EB, Nawrot TS, Int Panis L, Standaert A, Saenen ND, De Boever P. Denser Retinal Microvascular Network Is Inversely Associated With Behavioral Outcomes and Sustained Attention in Children. Front Neurol 2021; 12:547033. [PMID: 33584528 PMCID: PMC7880124 DOI: 10.3389/fneur.2021.547033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 01/08/2021] [Indexed: 11/25/2022] Open
Abstract
Changes in geometry of the retinal microvascular network, including vessel width, vessel density, and tortuosity, have been associated with neurological disorders in adults. We investigated metrics of the retinal microvasculature in association with behavior and cognition in 8- to 12-year-old children. Digital fundus images of 190 children (48.2% girls, mean age 9.9 years) were used to calculate retinal vessel diameters, fractal dimension, lacunarity, and tortuosity. Parents filled out a Strengths and Difficulties Questionnaire (SDQ) for behavioral screening. Cognitive performance testing included a computerized version of the Stroop test (selective attention), the Continuous Performance (sustained attention), the Digit-Symbol (visual scanning and information-processing speed) and the Pattern Comparison (visuospatial analytic ability) tests from the Neurobehavioral Evaluation System (NES3) battery. Retinal vessel geometry was significantly associated with the SDQ problem score, which increased with 1.1 points (95% CI: 0.3 to 1.9 points) per interquartile (IQR) increment in retinal fractal dimension, and decreased 1.4 points (95% CI: −2.4 to −0.4 points) or decreased 1.0 points (95% CI: −2.1 to 0.1 points) per IQR increment in retinal vascular lacunarity or tortuosity, respectively. Sensitivity analyses showed that results were driven by the hyperactivity/inattention and conduct problem scales of the SDQ. Correspondingly, mean reaction time on the Continuous Performance test increased by 11 ms (95% CI: 4.4 to 17.6 ms) with an IQR increase in fractal dimension. The results indicate that a denser retinal microvascular network, exemplified by a higher fractal dimension and lower lacunarity, are inversely associated with behavioral outcomes and sustained attention in children.
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Affiliation(s)
- Eline B Provost
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium.,Health Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium.,Department of Public Health and Primary Care, Leuven University, Leuven, Belgium
| | - Luc Int Panis
- Health Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium.,School for Mobility, Hasselt University, Diepenbeek, Belgium
| | - Arnout Standaert
- Health Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Nelly D Saenen
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Patrick De Boever
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium.,Health Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium.,Department of Biology, University of Antwerp, Antwerp, Belgium
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22
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Tian J, Smith G, Guo H, Liu B, Pan Z, Wang Z, Xiong S, Fang R. Modular machine learning for Alzheimer's disease classification from retinal vasculature. Sci Rep 2021; 11:238. [PMID: 33420208 PMCID: PMC7794289 DOI: 10.1038/s41598-020-80312-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/15/2020] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease is the leading cause of dementia. The long progression period in Alzheimer's disease provides a possibility for patients to get early treatment by having routine screenings. However, current clinical diagnostic imaging tools do not meet the specific requirements for screening procedures due to high cost and limited availability. In this work, we took the initiative to evaluate the retina, especially the retinal vasculature, as an alternative for conducting screenings for dementia patients caused by Alzheimer's disease. Highly modular machine learning techniques were employed throughout the whole pipeline. Utilizing data from the UK Biobank, the pipeline achieved an average classification accuracy of 82.44%. Besides the high classification accuracy, we also added a saliency analysis to strengthen this pipeline's interpretability. The saliency analysis indicated that within retinal images, small vessels carry more information for diagnosing Alzheimer's diseases, which aligns with related studies.
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Affiliation(s)
- Jianqiao Tian
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611, USA
| | - Glenn Smith
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, 32611, USA
| | - Han Guo
- College of Electrical Engineering, Zhejiang University, Hangzhou, 310000, China
| | - Boya Liu
- School of Information and Telecommunication Engineering, Beijing University of Posts & Telecommunications, Beijing, 100876, China
| | - Zehua Pan
- School of Electrical and Information Engineering, Beijing Jiaotong University, Beijing, 100044, China
| | - Zijie Wang
- School of Mathematical Science, East China Normal University, Shanghai, 200062, China
| | - Shuangyu Xiong
- Department of Data Science, East China Normal University, Shanghai, 200062, China
| | - Ruogu Fang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611, USA. .,Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, 32611, USA. .,Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
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23
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Cabrera DeBuc D, Feuer WJ, Persad PJ, Somfai GM, Kostic M, Oropesa S, Mendoza Santiesteban C. Investigating Vascular Complexity and Neurogenic Alterations in Sectoral Regions of the Retina in Patients With Cognitive Impairment. Front Physiol 2020; 11:570412. [PMID: 33240097 PMCID: PMC7680898 DOI: 10.3389/fphys.2020.570412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 10/08/2020] [Indexed: 12/21/2022] Open
Abstract
Evidence is accumulating that cognitive function, and visual impairment may be related. In this pilot study, we investigated whether multifractal dimension and lacunarity analyses performed in sectoral regions of the retina may reveal changes in patients with cognitive impairment (CI) that may be masked in the study considering the whole retinal branching pattern. Prospective age-matched subjects (n = 69) with and with no CI and without the presence of any ophthalmic history were recruited (age > 55+ years). The Montreal Cognitive Assessment (MoCA) was used to measure CI, and full-field electroretinogram (ERG) was performed. Also, visual performance exams were conducted using the Rabin cone contrast test (CCT). Quantification of the retinal structure was performed in retinal fundus images [45o field of view (FOV), optic disk centered] with excellent quality for all individuals [19 healthy controls (HC) and 20 patients with CI] after evaluating the inclusion and exclusion criteria in all study participants recruited (n = 69). The skeletonized vasculature network that comprised the whole branching pattern observable in the full 45° FOV was obtained for each image and divided into nine equal regions (superotemporal, superior, superonasal, macular, optic disk, nasal, inferotemporal, inferior, and inferonasal). The multifractal behavior was analyzed by calculating the generalized dimension Dq (Do, D1, and D2), the lacunarity parameter (Λ), and singularity spectrum f(α) in the nine sectoral skeletonized images as well as in the skeletons that comprised the whole branching pattern observable in the full 45° FOV. The analyses were performed using the ImageJ program together with the FracLac plug-in. Independent sample t-tests or Mann Whitney U test and Pearson correlation coefficient were used to find associations between all parameters in both groups. The effect size (Cohen’s d) of the difference between both groups was also assessed. A p-value < 0.05 was considered statistically significant. Significant correlations between multifractal and Λ parameters with the MoCA and implicit time ERG-parameter were observed in the regional analysis. In contrast, no trend was found when considering the whole retinal branching pattern. Analysis of combined structural-functional parameters in sectoral regions of the retina, instead of individual retinal biomarkers, may provide a useful clinical marker of CI.
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Affiliation(s)
- Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - William J Feuer
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Patrice J Persad
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Gabor Mark Somfai
- Department of Ophthalmology, City Hospital Waid and Triemli, Zurich, Switzerland.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - 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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Lim ZW, Chee ML, Da Soh Z, Cheung N, Dai W, Sahil T, Tao Y, Majithia S, Sabanayagam C, Chen CLH, Wong TY, Cheng CY, Tham YC. Association Between Visual Impairment and Decline in Cognitive Function in a Multiethnic Asian Population. JAMA Netw Open 2020; 3:e203560. [PMID: 32324240 PMCID: PMC7180417 DOI: 10.1001/jamanetworkopen.2020.3560] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
IMPORTANCE With the rapidly aging population, the burden of visual impairment (VI) and cognitive decline is expected to increase. Previous cross-sectional studies suggest an association between these 2 health outcomes. However, few longitudinal reports have examined this association, and to our knowledge, no studies have been performed in Asian populations. Further investigation on this association may help to better identify individuals at risk of cognitive decline. OBJECTIVE To examine the longitudinal association between VI and decline in cognitive function in a multiethnic Asian population. DESIGN, SETTING, AND PARTICIPANTS In this longitudinal, population-based, prospective cohort study, Chinese, Indian, and Malay adults 60 years or older at baseline were recruited from the Singapore Epidemiology of Eye Diseases (SEED) study. At baseline, participants from the SEED study were recruited under 3 studies: the Singapore Malay Eye Study (SiMES; 2004-2006), the Singapore Indian Eye Study (SINDI; 2007-2009), and the Singapore Chinese Eye Study (SCES; 2009-2011). Eligible participants were reexamined after 6 years (2011-2013 for SiMES, 2013-2015 for SINDI, and 2015-2017 for SCES). Data analysis was performed from November 1 to 24, 2019. EXPOSURES Visual impariment was defined as presenting visual acuity worse than 20/40 based on the better-seeing eye. MAIN OUTCOMES AND MEASURES Cognitive function was assessed using a locally validated Abbreviated Mental Test (AMT). The association between baseline VI and change in AMT score was determined using the multivariable linear regression model adjusting for baseline age; sex; race/ethnicity; presence of diabetes, hyperlipidemia, hypertension, and chronic kidney disease; history of cardiovascular disease; smoking status; alcohol intake; body mass index; educational status; and AMT score. RESULTS A total of 2478 individuals (1256 [50.7%] male; 1073 Chinese, 768 Indian, and 637 Malay adults) with mean (SD) age of 67.6 (5.6) years were evaluated, of whom 489 (19.7%) had reduction in AMT scores over 6 years. Baseline VI was associated with a decrease in AMT score over 6 years (β = -0.27; 95% CI, -0.37 to -0.17; P < .001). When change in vision over 6 years was evaluated, unchanged or deteriorated VI was associated with a decrease in AMT score over 6 years (β = -0.29; 95% CI, -0.40 to -0.18; P < .001). Among individuals with baseline VI and a substantial decrease in AMT score of 3 units or more over 6 years, the leading causes of VI were undercorrected refractive error (14 [45.2%]) and cataract (11 [35.5%]). CONCLUSIONS AND RELEVANCE In this study, poor vision was independently associated with a decline in cognitive function. Causes of visual loss in these cases were mostly preventable, further suggesting that preserving good vision may be an important interventional strategy for mitigating cognitive decline.
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Affiliation(s)
- Zhi Wei Lim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Miao-Li Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Zhi Da Soh
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Ning Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
| | - Wei Dai
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Thakur Sahil
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Yijin Tao
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Shivani Majithia
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
| | - Christopher Li-Hsian Chen
- Memory Aging and Cognition Centre, National University Health System, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Yih-Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
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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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26
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Wu H, Wang C, Chen C, Xu X, Zhu Y, Sang A, Jiang K, Dong J. Association between Retinal Vascular Geometric Changes and Cognitive Impairment: A Systematic Review and Meta-Analysis. J Clin Neurol 2020; 16:19-28. [PMID: 31942754 PMCID: PMC6974814 DOI: 10.3988/jcn.2020.16.1.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/04/2019] [Accepted: 07/04/2019] [Indexed: 01/14/2023] Open
Abstract
Background and Purpose Previous studies have explored the association between retinal vascular changes and cognitive impairment. The retinal vasculature shares some characteristics with the cerebral vasculature, and quantitative changes in it could indicate cognitive impairment. Hence, a comprehensive meta-analysis was performed to clarify the potential relationship between retinal vascular geometric changes and cognitive impairment. Methods Relevant databases were scrupulously and systematically searched for retinal vascular geometric changes including caliber, tortuosity, and fractal dimension (FD), and for cognitive impairment. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of included studies. RevMan was used to perform the meta-analysis and detect publication bias. Sensitivity analyses were also performed. Results Five studies that involved 2,343 subjects were finally included in the meta-analysis. The results showed that there was no significant association between central retinal artery equivalents (Z=1.17) or central retinal venular equivalents (Z=1.74) and cognitive impairment (both p>0.05). Similarly, no significant difference was detected in retinal arteriolar tortuosity (Z=0.91) and venular tortuosity (Z=1.31) (both p>0.05). However, the retinal arteriolar FD (mean difference: −0.03, 95% CI: −0.05, −0.01) and venular FD (mean difference: −0.03, 95% CI: −0.05, −0.02) were associated with cognitive impairment. Conclusions A smaller retinal microvascular FD might be associated with cognitive impairment. Further large-sample and well-controlled original studies are required to confirm the present findings.
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Affiliation(s)
- Huiqun Wu
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Chendong Wang
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Cong Chen
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Xiaotao Xu
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Yi Zhu
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Aimin Sang
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China.
| | - Kui Jiang
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
| | - Jiancheng Dong
- Department of Medical Informatics, Medical School of Nantong University, Nantong, China
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27
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Arthur E, Somfai GM, Kostic M, Oropesa S, Santiesteban CM, DeBuc DC. Distinguishing cognitive impairment by using singularity spectrum and lacunarity analysis of the retinal vascular network. NEUROPHOTONICS 2019; 6:041109. [PMID: 31572744 PMCID: PMC6756485 DOI: 10.1117/1.nph.6.4.041109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 08/27/2019] [Indexed: 06/10/2023]
Abstract
The development of effective therapies for cognitive impairment (CI), especially due to Alzheimer's disease, demands diagnosing the condition during the prodromal phase. The diagnosis of CI involves expensive and invasive methods, such as positron emission tomography and cerebrospinal fluid assessment via spinal tap. Hence, a comparatively lower cost and noninvasive method of diagnosis is imperative. The human retina is an extension of the brain characterized by similarities in vascular and neural structures. The complications of CI are not only limited to the brain but also affect the retina for which the loss of retinal ganglion cells has been associated with neurodegeneration in the brain. The loss of retinal ganglion cells in individuals with CI may be related to reduced vascular demand and a potential remodeling of the retinal vascular branching complexity. Retinal imaging biomarkers may provide a low cost and noninvasive alternative for the diagnosis of CI. In this study, the retinal vascular branching complexity of patients with CI was characterized using the singularity spectrum multifractal dimension and lacunarity parameter. A reduced vascular branching complexity was observed in subjects with CI when compared to age- and sex-matched cognitively healthy controls. Significant associations were also found between retinal vascular and functional parameters.
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Affiliation(s)
- Edmund Arthur
- University of Miami, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
| | - Gabor Mark Somfai
- Pallas Kliniken, Retinology Unit, Olten, Switzerland
- Semmelweis University, Department of Ophthalmology, Budapest, Hungary
| | - Maja Kostic
- University of Miami, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
| | - Susel Oropesa
- University of Miami, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
| | - Carlos Mendoza Santiesteban
- University of Miami, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
| | - Delia Cabrera DeBuc
- University of Miami, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
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28
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Smith PJ, Blumenthal JA, Hinderliter AL, Mabe SM, Schwartz JE, Avorgbedor F, Sherwood A. Neurocognition in treatment-resistant hypertension: profile and associations with cardiovascular biomarkers. J Hypertens 2019; 37:1040-1047. [PMID: 30921110 PMCID: PMC7279118 DOI: 10.1097/hjh.0000000000002002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Hypertension in midlife has been associated with increased risk of stroke and neurocognitive decline. Few studies, however, have examined neurocognition among individuals with treatment-resistant hypertension or potential mechanisms by which treatment-resistant hypertension may impair neurocognition. METHODS We examined the pattern of neurocognitive impairment and potential mechanisms in a sample of 96 overweight adults with treatment-resistant hypertension, aged 41-81 years. Neurocognitive function was assessed using a 45-min test battery consisting of executive function and memory. Vascular and metabolic mechanisms examined included cerebrovascular risk factors (CVRFs: Framingham Stroke Risk Profile), insulin sensitivity (homeostatic model assessment of insulin resistance), waist-to-hip ratio, microvascular function (hyperemic response), and peak oxygen consumption from an exercise treadmill test. Simple path analyses were used to assess the association between potential vascular and metabolic mechanisms and neurocognition. RESULTS Neurocognitive impairments were common, with 70% of the sample exhibiting impaired performance on at least one executive function subtest and 38% on at least one measure of memory. Higher levels of aerobic fitness, greater insulin sensitivity, and better microvascular function, as well as lower CVRFs and waist-to-hip ratio were associated with better neurocognition. In path analyses, aerobic fitness, microvascular function, and CVRFs all were independently associated with neurocognitive performance. Insulin resistance associated with worse executive function but better memory performance among older participants. CONCLUSION Neurocognitive impairments are common in adults with treatment-resistant hypertension, particularly on tests of executive function. Better neurocognition is independently associated with aerobic fitness, microvascular function, and CVRFs.
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Affiliation(s)
- Patrick J. Smith
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
| | - James A. Blumenthal
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
| | - Alan L. Hinderliter
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Stephanie M. Mabe
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
| | - Jeanne E. Schwartz
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
| | - Forgive Avorgbedor
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
| | - Andrew Sherwood
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham
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30
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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: 42] [Impact Index Per Article: 7.0] [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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31
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Jung NY, Han JC, Ong YT, Cheung CYL, Chen CP, Wong TY, Kim HJ, Kim YJ, Lee J, Lee JS, Jang YK, Kee C, Lee KH, Kim EJ, Seo SW, Na DL. Retinal microvasculature changes in amyloid-negative subcortical vascular cognitive impairment compared to amyloid-positive Alzheimer's disease. J Neurol Sci 2018; 396:94-101. [PMID: 30447606 DOI: 10.1016/j.jns.2018.10.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 10/25/2018] [Accepted: 10/29/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE To investigate small vessel abnormalities in patients with cognitive impairment, we compared retinal microvascular alterations between patients with cognitive impairment related to Alzheimer's disease (ADCI) and those with subcortical vascular cognitive impairment (SVCI). METHODS We prospectively recruited 29 amyloid-positive ADCI patients, 28 amyloid-negative SVCI patients that were confirmed by 11C-PiB-PET scan and 34 individuals with normal cognition (NC). The three groups were compared in terms of retinal vascular variables (retinal fractal dimension, vascular caliber, tortuosity and branching angle) by using a semi-automated, computer-assisted analysis of digital fundus photographs. We also investigated the relationship between retinal variables and white matter hyperintensities (WMH) on MRI. RESULTS Compared to NC individuals, the SVCI patients had smaller total and arteriolar fractal dimensions, whereas there was no significant difference of fractal dimension between ADCI and NC. Other retinal variables did not differ among the three groups. A significant correlation existed between fractal dimension and WMH volume. CONCLUSIONS Retinal microvascular alterations, especially retinal fractal dimension, may be useful markers that reflect cerebral microvascular changes in patients with SVCI as opposed to ADCI, who had no definite difference in retinal variables compared to the NC group.
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Affiliation(s)
- Na-Yeon Jung
- Department of Neurology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Yangsan, Republic of Korea; Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Jong Chul Han
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yi Ting Ong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Carol Yim-Lui Cheung
- Department of Ophthalmology & Visual Sciences, Chinese University of Hong Kong, Hong Kong
| | | | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Hee Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Yeo Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea; Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Juyoun Lee
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea; Department of Neurology, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Jin San Lee
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea; Department of Neurology, Kyung Hee University Hospital, Seoul, Republic of Korea
| | - Young Kyoung Jang
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Changwon Kee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyung Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Eun-Joo Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Busan, Republic of Korea
| | - Sang Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Duk L Na
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.
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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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33
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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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Obenaus A, Ng M, Orantes AM, Kinney-Lang E, Rashid F, Hamer M, DeFazio RA, Tang J, Zhang JH, Pearce WJ. Traumatic brain injury results in acute rarefication of the vascular network. Sci Rep 2017; 7:239. [PMID: 28331228 PMCID: PMC5427893 DOI: 10.1038/s41598-017-00161-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 02/13/2017] [Indexed: 01/04/2023] Open
Abstract
The role of the cerebrovascular network and its acute response to TBI is poorly defined and emerging evidence suggests that cerebrovascular reactivity is altered. We explored how cortical vessels are physically altered following TBI using a newly developed technique, vessel painting. We tested our hypothesis that a focal moderate TBI results in global decrements to structural aspects of the vasculature. Rats (naïve, sham-operated, TBI) underwent a moderate controlled cortical impact. Animals underwent vessel painting perfusion to label the entire cortex at 1 day post TBI followed by whole brain axial and coronal images using a wide-field fluorescence microscope. Cortical vessel network characteristics were analyzed for classical angiographic features (junctions, lengths) wherein we observed significant global (both hemispheres) reductions in vessel junctions and vessel lengths of 33% and 22%, respectively. Biological complexity can be quantified using fractal geometric features where we observed that fractal measures were also reduced significantly by 33%, 16% and 13% for kurtosis, peak value frequency and skewness, respectively. Acutely after TBI there is a reduction in vascular network and vascular complexity that are exacerbated at the lesion site and provide structural evidence for the bilateral hemodynamic alterations that have been reported in patients after TBI.
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Affiliation(s)
- Andre Obenaus
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA.
| | - Michelle Ng
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Amanda M Orantes
- Molecular and Integrative Physiology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Eli Kinney-Lang
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Faisal Rashid
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Mary Hamer
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | | | - Jiping Tang
- Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - John H Zhang
- Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA.,Anesthesiology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA.,Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - William J Pearce
- Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA.,Center for Perinatal Biology, Loma Linda University, Loma Linda, CA, 92350, USA
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Cheung CYL, Ikram MK, Chen C, Wong TY. Imaging retina to study dementia and stroke. Prog Retin Eye Res 2017; 57:89-107. [PMID: 28057562 DOI: 10.1016/j.preteyeres.2017.01.001] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/07/2016] [Accepted: 01/01/2017] [Indexed: 02/07/2023]
Abstract
With increase in life expectancy, the number of persons suffering from common age-related brain diseases, including neurodegenerative (e.g., dementia) and cerebrovascular (e.g., stroke) disease is expected to rise substantially. As current neuro-imaging modalities such as magnetic resonance imaging may not be able to detect subtle subclinical changes (resolution <100-500 μm) in dementia and stroke, there is an urgent need for other complementary techniques to probe the pathophysiology of these diseases. The retina - due to its anatomical, embryological and physiological similarities with the brain - offers a unique and accessible "window" to study correlates and consequences of subclinical pathology in the brain. Retinal components such as the microvasculature and retinal ganglion cell axons can now be visualized non-invasively using different retinal imaging techniques e.g., ocular fundus photography and optical coherence tomography. Advances in retinal imaging may provide new and potentially important insights into cerebrovascular neurodegenerative processes in addition to what is currently possible with neuro-imaging. In this review, we present an overview of the current literature on the application of retinal imaging in the study of dementia and stroke. We discuss clinical implications of these studies, novel state-of-the-art retinal imaging techniques and future directions aimed at evaluating whether retinal imaging can be an additional investigation tool in the study of dementia and stroke.
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Affiliation(s)
- Carol Yim-Lui Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
| | - M Kamran Ikram
- Duke-NUS Graduate Medical School, National University of Singapore, Singapore; Departments of Neurology & Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Christopher Chen
- Memory Aging and Cognition Centre, National University Health System, Singapore; Department of Pharmacology, National University of Singapore, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Duke-NUS Graduate Medical School, National University of Singapore, Singapore
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Cabrera DeBuc D, Somfai GM, Koller A. Retinal microvascular network alterations: potential biomarkers of cerebrovascular and neural diseases. Am J Physiol Heart Circ Physiol 2016; 312:H201-H212. [PMID: 27923786 DOI: 10.1152/ajpheart.00201.2016] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 11/04/2016] [Accepted: 11/11/2016] [Indexed: 12/12/2022]
Abstract
Increasing evidence suggests that the conditions of retinal microvessels are indicators to a variety of cerebrovascular, neurodegenerative, psychiatric, and developmental diseases. Thus noninvasive visualization of the human retinal microcirculation offers an exceptional opportunity for the investigation of not only the retinal but also cerebral microvasculature. In this review, we show how the conditions of the retinal microvessels could be used to assess the conditions of brain microvessels because the microvascular network of the retina and brain share, in many aspects, standard features in development, morphology, function, and pathophysiology. Recent techniques and imaging modalities, such as optical coherence tomography (OCT), allow more precise visualization of various layers of the retina and its microcirculation, providing a "microscope" to brain microvessels. We also review the potential role of retinal microvessels in the risk identification of cerebrovascular and neurodegenerative diseases. The association between vision problems and cerebrovascular and neurodegenerative diseases, as well as the possible role of retinal microvascular imaging biomarkers in cerebrovascular and neurodegenerative screening, their potentials, and limitations, are also discussed.
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Affiliation(s)
- Delia Cabrera DeBuc
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida;
| | - Gabor Mark Somfai
- Semmelweis University, Budapest, Hungary.,Augenzentrum, Pallas Kliniken, Olten, Switzerland
| | - Akos Koller
- Institute of Natural Sciences, University of Physical Education, Budapest, Hungary; and.,Department of Physiology, New York Medical College, Valhalla, New York
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37
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McGrory S, Cameron JR, Pellegrini E, Warren C, Doubal FN, Deary IJ, Dhillon B, Wardlaw JM, Trucco E, MacGillivray TJ. The application of retinal fundus camera imaging in dementia: A systematic review. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2016; 6:91-107. [PMID: 28229127 PMCID: PMC5312461 DOI: 10.1016/j.dadm.2016.11.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Introduction The ease of imaging the retinal vasculature, and the evolving evidence suggesting this microvascular bed might reflect the cerebral microvasculature, presents an opportunity to investigate cerebrovascular disease and the contribution of microvascular disease to dementia with fundus camera imaging. Methods A systematic review and meta-analysis was carried out to assess the measurement of retinal properties in dementia using fundus imaging. Results Ten studies assessing retinal properties in dementia were included. Quantitative measurement revealed significant yet inconsistent pathologic changes in vessel caliber, tortuosity, and fractal dimension. Retinopathy was more prevalent in dementia. No association of age-related macular degeneration with dementia was reported. Discussion Inconsistent findings across studies provide tentative support for the application of fundus camera imaging as a means of identifying changes associated with dementia. The potential of fundus image analysis in differentiating between dementia subtypes should be investigated using larger well-characterized samples. Future work should focus on refining and standardizing methods and measurements.
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Affiliation(s)
- Sarah McGrory
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - James R Cameron
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK; Anne Rowling Regenerative Neurology Clinic, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Enrico Pellegrini
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Claire Warren
- College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Fergus N Doubal
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Ian J Deary
- Department of Psychology, University of Edinburgh, Edinburgh, UK; Department of Psychology, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Baljean Dhillon
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK; Department of Psychology, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK; Scottish Imaging Network: A Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK
| | - Emanuele Trucco
- VAMPIRE Project and Computer Vision and Image Processing Group School of Science and Engineering (Computing), University of Dundee, Dundee, UK
| | - Thomas J MacGillivray
- Centre for Clinical Brain Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK; VAMPIRE Project and Edinburgh Clinical Research Facility, University of Edinburgh, Edinburgh, UK
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38
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Li LJ, Ikram MK, Wong TY. Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease. J Physiol 2015; 594:2175-203. [PMID: 26435039 DOI: 10.1113/jp270947] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022] Open
Abstract
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non-invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low-fibre and high-sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre-clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood.
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Affiliation(s)
- Ling-Jun Li
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
| | - Mohammad Kamran Ikram
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
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Williams MA, McGowan AJ, Cardwell CR, Cheung CY, Craig D, Passmore P, Silvestri G, Maxwell AP, McKay GJ. Retinal microvascular network attenuation in Alzheimer's disease. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2015; 1:229-235. [PMID: 26634224 PMCID: PMC4629099 DOI: 10.1016/j.dadm.2015.04.001] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Cerebral small-vessel disease has been implicated in the development of Alzheimer's disease (AD). The retinal microvasculature enables the noninvasive visualization and evaluation of the systemic microcirculation. We evaluated retinal microvascular parameters in a case-control study of AD patients and cognitively normal controls. METHODS Retinal images were computationally analyzed and quantitative retinal parameters (caliber, fractal dimension, tortuosity, and bifurcation) measured. Regression models were used to compute odds ratios (OR) and confidence intervals (CI) for AD with adjustment for confounders. RESULTS Retinal images were available in 213 AD participants and 294 cognitively normal controls. Persons with lower venular fractal dimension (OR per standard deviation [SD] increase, 0.77 [CI: 0.62-0.97]) and lower arteriolar tortuosity (OR per SD increase, 0.78 [CI: 0.63-0.97]) were more likely to have AD after appropriate adjustment. DISCUSSION Patients with AD have a sparser retinal microvascular network and retinal microvascular variation may represent similar pathophysiological events within the cerebral microvasculature of patients with AD.
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Affiliation(s)
| | - Amy J McGowan
- Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Chris R Cardwell
- Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Carol Y Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore ; Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - David Craig
- Southern Health and Social Care Trust, Craigavon Hospital, Craigavon, UK
| | - Peter Passmore
- Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Giuliana Silvestri
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | | | - Gareth J McKay
- Centre for Public Health, Queen's University Belfast, Belfast, UK
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MacCormick IJC, Czanner G, Faragher B. Developing retinal biomarkers of neurological disease: an analytical perspective. Biomark Med 2015; 9:691-701. [PMID: 26174843 PMCID: PMC4822679 DOI: 10.2217/bmm.15.17] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The inaccessibility of the brain poses a problem for neuroscience. Scientists have traditionally responded by developing biomarkers for brain physiology and disease. The retina is an attractive source of biomarkers since it shares many features with the brain. Some even describe the retina as a 'window' to the brain, implying that retinal signs are analogous to brain disease features. However, new analytical methods are needed to show whether or not retinal signs really are equivalent to brain abnormalities, since this requires greater evidence than direct associations between retina and brain. We, therefore propose a new way to think about, and test, how clearly one might see the brain through the retinal window, using cerebral malaria as a case study.
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Affiliation(s)
- Ian JC MacCormick
- Department of Eye & Vision Science, University of Liverpool, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Gabriela Czanner
- Department of Eye & Vision Science, University of Liverpool, Liverpool, UK
- Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom
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