1
|
Cao Q, Yang S, Wang X, Sun H, Chen W, Wang Y, Gao J, Wu Y, Yang Q, Chen X, Yuan S, Xiao M, Nedergaard M, Huo Y, Liu Q. Transport of β-amyloid from brain to eye causes retinal degeneration in Alzheimer's disease. J Exp Med 2024; 221:e20240386. [PMID: 39316084 PMCID: PMC11448872 DOI: 10.1084/jem.20240386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 07/03/2024] [Accepted: 08/12/2024] [Indexed: 09/25/2024] Open
Abstract
The eye is closely connected to the brain, providing a unique window to detect pathological changes in the brain. In this study, we discovered β-amyloid (Aβ) deposits along the ocular glymphatic system in patients with Alzheimer's disease (AD) and 5×FAD transgenic mouse model. Interestingly, Aβ from the brain can flow into the eyes along the optic nerve through cerebrospinal fluid (CSF), causing retinal degeneration. Aβ is mainly observed in the optic nerve sheath, the neural axon, and the perivascular space, which might represent the critical steps of the Aβ transportation from the brain to the eyes. Aquaporin-4 facilitates the influx of Aβ in brain-eye transport and out-excretion of the retina, and its absence or loss of polarity exacerbates brain-derived Aβ induced damage and visual impairment. These results revealed brain-to-eye Aβ transport as a major contributor to AD retinopathy, highlighting a new therapeutic avenue in ocular and neurodegenerative disease.
Collapse
Affiliation(s)
- Qiuchen Cao
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Province Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
- Department of Cellular Biology and Anatomy, Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Shige Yang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaowei Wang
- Faculty of Medical and Health Sciences, Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
- Department of Neurosurgery, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Huaiqing Sun
- Jiangsu Province Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Weijie Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yuliang Wang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Diseases, Nanjing Medical University, Nanjing, China
| | - Junying Gao
- Jiangsu Province Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Yanchi Wu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qiuhua Yang
- Department of Cellular Biology and Anatomy, Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Songtao Yuan
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ming Xiao
- Jiangsu Province Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Nanjing Brain Hospital, Brain Institute, Nanjing Medical University , Nanjing, China
| | - Maiken Nedergaard
- Faculty of Medical and Health Sciences, Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
- Department of Neurosurgery, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Yuqing Huo
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
- Department of Cellular Biology and Anatomy, Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Patterson EJ, Bounds AD, Wagner SK, Kadri-Langford R, Taylor R, Daly D. Oculomics: A Crusade Against the Four Horsemen of Chronic Disease. Ophthalmol Ther 2024; 13:1427-1451. [PMID: 38630354 PMCID: PMC11109082 DOI: 10.1007/s40123-024-00942-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/25/2024] [Indexed: 05/22/2024] Open
Abstract
Chronic, non-communicable diseases present a major barrier to living a long and healthy life. In many cases, early diagnosis can facilitate prevention, monitoring, and treatment efforts, improving patient outcomes. There is therefore a critical need to make screening techniques as accessible, unintimidating, and cost-effective as possible. The association between ocular biomarkers and systemic health and disease (oculomics) presents an attractive opportunity for detection of systemic diseases, as ophthalmic techniques are often relatively low-cost, fast, and non-invasive. In this review, we highlight the key associations between structural biomarkers in the eye and the four globally leading causes of morbidity and mortality: cardiovascular disease, cancer, neurodegenerative disease, and metabolic disease. We observe that neurodegenerative disease is a particularly promising target for oculomics, with biomarkers detected in multiple ocular structures. Cardiovascular disease biomarkers are present in the choroid, retinal vasculature, and retinal nerve fiber layer, and metabolic disease biomarkers are present in the eyelid, tear fluid, lens, and retinal vasculature. In contrast, only the tear fluid emerged as a promising ocular target for the detection of cancer. The retina is a rich source of oculomics data, the analysis of which has been enhanced by artificial intelligence-based tools. Although not all biomarkers are disease-specific, limiting their current diagnostic utility, future oculomics research will likely benefit from combining data from various structures to improve specificity, as well as active design, development, and optimization of instruments that target specific disease signatures, thus facilitating differential diagnoses.
Collapse
Affiliation(s)
| | | | - Siegfried K Wagner
- Moorfields Eye Hospital NHS Trust, 162 City Road, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | | | - Robin Taylor
- Occuity, The Blade, Abbey Square, Reading, Berkshire, RG1 3BE, UK
| | - Dan Daly
- Occuity, The Blade, Abbey Square, Reading, Berkshire, RG1 3BE, UK
| |
Collapse
|
4
|
Jin Z, Chen X, Jiang C, Feng X, Zou D, Lu Y, Li J, Ren Q, Zhou C. Predicting the cognitive impairment with multimodal ophthalmic imaging and artificial neural network for community screening. Br J Ophthalmol 2024:bjo-2023-323283. [PMID: 38697799 DOI: 10.1136/bjo-2023-323283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 04/18/2024] [Indexed: 05/05/2024]
Abstract
BACKGROUND/AIMS To investigate the comprehensive prediction ability for cognitive impairment in a general elder population using the combination of the multimodal ophthalmic imaging and artificial neural networks. METHODS Patients with cognitive impairment and cognitively healthy individuals were recruited. All subjects underwent medical history, blood pressure measurement, the Montreal Cognitive Assessment, medical optometry, intraocular pressure and custom-built multimodal ophthalmic imaging, which integrated pupillary light reaction, multispectral imaging, laser speckle contrast imaging and retinal oximetry. Multidimensional parameters were analysed by Student's t-test. Logistic regression analysis and back-propagation neural network (BPNN) were used to identify the predictive capability for cognitive impairment. RESULTS This study included 104 cognitive impairment patients (61.5% female; mean (SD) age, 68.3 (9.4) years), and 94 cognitively healthy age-matched and sex-matched subjects (56.4% female; mean (SD) age, 65.9 (7.6) years). The variation of most parameters including decreased pupil constriction amplitude (CA), relative CA, average constriction velocity, venous diameter, venous blood flow and increased centred retinal reflectance in 548 nm (RC548) in cognitive impairment was consistent with previous studies while the reduced flow acceleration index and oxygen metabolism were reported for the first time. Compared with the logistic regression model, BPNN had better predictive performance (accuracy: 0.91 vs 0.69; sensitivity: 93.3% vs 61.70%; specificity: 90.0% vs 68.66%). CONCLUSIONS This study demonstrates retinal spectral signature alteration, neurodegeneration and angiopathy occur concurrently in cognitive impairment. The combination of multimodal ophthalmic imaging and BPNN can be a useful tool for predicting cognitive impairment with high performance for community screening.
Collapse
Affiliation(s)
- Zi Jin
- Department of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
| | - Xuhui Chen
- Department of Neurology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Chunxia Jiang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Ximeng Feng
- Department of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, Peking University, Beijing, China
- Institute of Medical Technology, Peking University Health Science Centre, Beijing, China
| | - Da Zou
- Department of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, Peking University, Beijing, China
- Institute of Medical Technology, Peking University Health Science Centre, Beijing, China
| | - Yanye Lu
- Department of Biomedical Engineering, Peking University, Beijing, China
- Institute of Medical Technology, Peking University Health Science Centre, Beijing, China
| | - Jinying Li
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Qiushi Ren
- Department of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, Peking University, Beijing, China
- Institute of Medical Technology, Peking University Health Science Centre, Beijing, China
| | - Chuanqing Zhou
- College of Medical Instruments, Shanghai University of Medicine and Health Sciences, Shanghai, China
| |
Collapse
|
5
|
Wang CY, Sadrieh FK, Shen YT, Chen SE, Kim S, Chen V, Raghavendra A, Wang D, Saeedi O, Tao Y. MEMO: dataset and methods for robust multimodal retinal image registration with large or small vessel density differences. BIOMEDICAL OPTICS EXPRESS 2024; 15:3457-3479. [PMID: 38855695 PMCID: PMC11161385 DOI: 10.1364/boe.516481] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/20/2024] [Accepted: 04/18/2024] [Indexed: 06/11/2024]
Abstract
The measurement of retinal blood flow (RBF) in capillaries can provide a powerful biomarker for the early diagnosis and treatment of ocular diseases. However, no single modality can determine capillary flowrates with high precision. Combining erythrocyte-mediated angiography (EMA) with optical coherence tomography angiography (OCTA) has the potential to achieve this goal, as EMA can measure the absolute RBF of retinal microvasculature and OCTA can provide the structural images of capillaries. However, multimodal retinal image registration between these two modalities remains largely unexplored. To fill this gap, we establish MEMO, the first public multimodal EMA and OCTA retinal image dataset. A unique challenge in multimodal retinal image registration between these modalities is the relatively large difference in vessel density (VD). To address this challenge, we propose a segmentation-based deep-learning framework (VDD-Reg), which provides robust results despite differences in vessel density. VDD-Reg consists of a vessel segmentation module and a registration module. To train the vessel segmentation module, we further designed a two-stage semi-supervised learning framework (LVD-Seg) combining supervised and unsupervised losses. We demonstrate that VDD-Reg outperforms existing methods quantitatively and qualitatively for cases of both small VD differences (using the CF-FA dataset) and large VD differences (using our MEMO dataset). Moreover, VDD-Reg requires as few as three annotated vessel segmentation masks to maintain its accuracy, demonstrating its feasibility.
Collapse
Affiliation(s)
- Chiao-Yi Wang
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | | | - Yi-Ting Shen
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742, USA
| | - Shih-En Chen
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sarah Kim
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Victoria Chen
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Achyut Raghavendra
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Dongyi Wang
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Osamah Saeedi
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Tao
- Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
6
|
Dumitrascu OM, Doustar J, Fuchs DT, Koronyo Y, Sherman DS, Miller MS, Johnson KO, Carare RO, Verdooner SR, Lyden PD, Schneider JA, Black KL, Koronyo-Hamaoui M. Distinctive retinal peri-arteriolar versus peri-venular amyloid plaque distribution correlates with the cognitive performance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.580733. [PMID: 38464292 PMCID: PMC10925252 DOI: 10.1101/2024.02.27.580733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Introduction The vascular contribution to Alzheimer's disease (AD) is tightly connected to cognitive performance across the AD continuum. We topographically describe retinal perivascular amyloid plaque (AP) burden in subjects with normal or impaired cognition. Methods Using scanning laser ophthalmoscopy, we quantified retinal peri-arteriolar and peri-venular curcumin-positive APs in the first, secondary and tertiary branches in twenty-eight subjects. Perivascular AP burden among cognitive states was correlated with neuroimaging and cognitive measures. Results Peri-arteriolar exceeded peri-venular AP count (p<0.0001). Secondary branch AP count was significantly higher in cognitively impaired (p<0.01). Secondary small and tertiary peri-venular AP count strongly correlated with clinical dementia rating, hippocampal volumes, and white matter hyperintensity count. Discussion Our topographic analysis indicates greater retinal amyloid accumulation in the retinal peri-arteriolar regions overall, and distal peri-venular regions in cognitively impaired individuals. Larger longitudinal studies are warranted to understand the temporal-spatial relationship between vascular dysfunction and perivascular amyloid deposition in AD. Highlights Retinal peri-arteriolar region exhibits more amyloid compared with peri-venular regions.Secondary retinal vascular branches have significantly higher perivascular amyloid burden in subjects with impaired cognition, consistent across sexes.Cognitively impaired individuals have significantly greater retinal peri-venular amyloid deposits in the distal small branches, that correlate with CDR and hippocampal volumes.
Collapse
|
7
|
Abdolahi F, Yu V, Varma R, Zhou X, Wang RK, D'Orazio LM, Zhao C, Jann K, Wang DJ, Kashani AH, Jiang X. Retinal perfusion is linked to cognition and brain MRI biomarkers in Black Americans. Alzheimers Dement 2024; 20:858-868. [PMID: 37800578 PMCID: PMC10917050 DOI: 10.1002/alz.13469] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 10/07/2023]
Abstract
INTRODUCTION We investigated whether retinal capillary perfusion is a biomarker of cerebral small vessel disease and impaired cognition among Black Americans, an understudied group at higher risk for dementia. METHODS We enrolled 96 Black Americans without known cognitive impairment. Four retinal perfusion measures were derived using optical coherence tomography angiography. Neurocognitive assessment and brain magnetic resonance imaging (MRI) were performed. Multiple linear regression analyses were performed. RESULTS Lower retinal capillary perfusion was correlated with worse Oral Symbol Digit Test (P < = 0.005) and Fluid Cognition Composite scores (P < = 0.02), but not with the Crystallized Cognition Composite score (P > = 0.41). Lower retinal perfusion was also correlated with higher free water and peak width of skeletonized mean diffusivity, and lower fractional anisotropy (all P < 0.05) on MRI (N = 35). DISCUSSION Lower retinal capillary perfusion is associated with worse information processing, fluid cognition, and MRI biomarkers of cerebral small vessel disease, but is not related to crystallized cognition.
Collapse
Affiliation(s)
- Farzan Abdolahi
- Department of OphthalmologyUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Victoria Yu
- Department of OphthalmologyUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Rohit Varma
- Southern California Eye InstituteCHA Hollywood Presbyterian Medical CenterLos AngelesCaliforniaUSA
| | - Xiao Zhou
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
| | - Ruikang K. Wang
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
- Department of OphthalmologyUniversity of WashingtonSeattleWashingtonUSA
| | - Lina M. D'Orazio
- Department of NeurologyUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Chenyang Zhao
- Laboratory of FMRI TechnologyStevens Neuroimaging and Informatics InstituteUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Kay Jann
- Laboratory of FMRI TechnologyStevens Neuroimaging and Informatics InstituteUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Danny J. Wang
- Department of NeurologyUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
- Laboratory of FMRI TechnologyStevens Neuroimaging and Informatics InstituteUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| | - Amir H. Kashani
- Department of OphthalmologyWilmer Eye InstituteJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Xuejuan Jiang
- Department of OphthalmologyUniversity of Southern California Keck School of MedicineLos AngelesCaliforniaUSA
| |
Collapse
|
8
|
Xu Y, Phu J, Aung HL, Hesam-Shariati N, Keay L, Tully PJ, Booth A, Anderson CS, Anstey KJ, Peters R. Frequency of coexistent eye diseases and cognitive impairment or dementia: a systematic review and meta-analysis. Eye (Lond) 2023; 37:3128-3136. [PMID: 36922645 PMCID: PMC10564749 DOI: 10.1038/s41433-023-02481-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 01/20/2023] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
OBJECTIVE We aim to quantify the co-existence of age-related macular degeneration (AMD), glaucoma, or diabetic retinopathy (DR) and cognitive impairment or dementia. METHOD MEDLINE, EMBASE, PsycINFO and CINAHL were searched (to June 2020). Observational studies reporting incidence or prevalence of AMD, glaucoma, or DR in people with cognitive impairment or dementia, and of cognitive impairment or dementia among people with AMD, glaucoma, or DR were included. RESULTS Fifty-six studies (57 reports) were included but marked by heterogeneities in the diagnostic criteria or definitions of the diseases, study design, and case mix. Few studies reported on the incidence. Evidence was sparse but consistent in individuals with mild cognitive impairment where 7.7% glaucoma prevalence was observed. Prevalence of AMD and DR among people with cognitive impairment ranged from 3.9% to 9.4% and from 11.4% to 70.1%, respectively. Prevalence of AMD and glaucoma among people with dementia ranged from 1.4 to 53% and from 0.2% to 25.9%, respectively. Prevalence of DR among people with dementia was 11%. Prevalence of cognitive impairment in people with AMD, glaucoma, and DR ranged from 8.4% to 52.4%, 12.3% to 90.2%, and 3.9% to 77.8%, respectively, and prevalence of dementia in people with AMD, glaucoma and DR ranged from 9.9% to 62.6%, 2.5% to 3.3% and was 12.5%, respectively. CONCLUSIONS Frequency of comorbid eye disease and cognitive impairment or dementia varied considerably. While more population-based estimations of the co-existence are needed, interdisciplinary collaboration might be helpful in the management of these conditions to meet healthcare needs of an ageing population. TRIAL REGISTRATION PROSPERO registration: CRD42020189484.
Collapse
Affiliation(s)
- Ying Xu
- Neuroscience Research Australia, Sydney, NSW, Australia.
- School of Psychology, Faculty of Science, UNSW, Sydney, NSW, Australia.
- The George Institute for Global Health, Faculty of Medicine, UNSW, Sydney, NSW, Australia.
- Faculty of Medicine, UNSW, Sydney, NSW, Australia.
- Ageing Futures Institute, UNSW, Sydney, NSW, Australia.
| | - Jack Phu
- Centre for Eye Health, UNSW, Sydney, NSW, Australia
- School of Optometry and Vision Science, UNSW, Sydney, NSW, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Concord Clinical School, Concord Repatriation General Hospital, Sydney, NSW, Australia
| | - Htein Linn Aung
- Neuroscience Research Australia, Sydney, NSW, Australia
- Faculty of Medicine, UNSW, Sydney, NSW, Australia
| | - Negin Hesam-Shariati
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, UNSW, Sydney, NSW, Australia
| | - Lisa Keay
- The George Institute for Global Health, Faculty of Medicine, UNSW, Sydney, NSW, Australia
- Ageing Futures Institute, UNSW, Sydney, NSW, Australia
- School of Optometry and Vision Science, UNSW, Sydney, NSW, Australia
| | - Phillip J Tully
- School of Psychology, The University of New England, Armidale, NSW, Australia
| | - Andrew Booth
- School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - Craig S Anderson
- The George Institute for Global Health, Faculty of Medicine, UNSW, Sydney, NSW, Australia
- Faculty of Medicine, UNSW, Sydney, NSW, Australia
- The George Institute for Global Health, Beijing, P.R. China
- Neurology Department, Royal Prince Alfred Hospital, Sydney Local Area Health District, Sydney, NSW, Australia
| | - Kaarin J Anstey
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, UNSW, Sydney, NSW, Australia
- Ageing Futures Institute, UNSW, Sydney, NSW, Australia
| | - Ruth Peters
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, UNSW, Sydney, NSW, Australia
- The George Institute for Global Health, Faculty of Medicine, UNSW, Sydney, NSW, Australia
- Faculty of Medicine, UNSW, Sydney, NSW, Australia
- Ageing Futures Institute, UNSW, Sydney, NSW, Australia
- School of Public Health, Imperial College London, London, UK
| |
Collapse
|
9
|
Papageorgiou E, Tsirelis D, Lazari K, Siokas V, Dardiotis E, Tsironi EE. Visual disorders and driving ability in persons with dementia: A mini review. Front Hum Neurosci 2022; 16:932820. [DOI: 10.3389/fnhum.2022.932820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 11/11/2022] [Indexed: 11/30/2022] Open
Abstract
BackgroundImpaired driving ability in patients with Alzheimer’s disease (AD) is associated with a decline in cognitive processes and a deterioration of their basic sensory visual functions. Although a variety of ocular abnormalities have been described in patients with AD, little is known about the impact of those visual disorders on their driving performance.AimAim of this mini-review is to provide an update on the driving ability of patients with dementia and summarize the primary visual disorders affecting their driving behavior.MethodsDatabases were screened for studies investigating dementia, associated visual abnormalities and driving ability.ResultsThere is consistent evidence that dementia affects driving ability. Patients with dementia present with a variety of visual disorders, such as visual acuity reduction, visual field defects, impaired contrast sensitivity, decline in color vision and age-related pathological changes, that may have a negative impact on their driving ability. However, there is a paucity in studies describing the impact of oculovisual decline on the driving ability of AD subjects. A bidirectional association between cognitive and visual impairment (VI) has been described.ConclusionGiven the bidirectional association between VI and dementia, vision screening and cognitive assessment of the older driver should aim to identify at-risk individuals and employ timely strategies for treatment of both cognitive and ocular problems. Future studies should characterize the basic visual sensory status of AD patients participating in driving studies, and investigate the impact of vision abnormalities on their driving performance.
Collapse
|
10
|
Chiara C, Gilda C, Daniela M, Antonio C, Miriana M, Marcello M, Elena S, Roberta L, Ciro C, Vincenzo BM. A two-year longitudinal study of retinal vascular impairment in patients with amnestic mild cognitive impairment. Front Aging Neurosci 2022; 14:993621. [PMID: 36420311 PMCID: PMC9678013 DOI: 10.3389/fnagi.2022.993621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/19/2022] [Indexed: 11/09/2022] Open
Abstract
ObjectiveTo evaluate the relation between retinal vascular impairment and cognitive decline in patients with amnestic mild cognitive impairment (aMCI) over time.MethodsSpectral domain-optical coherence tomography (SD-OCT) and OCT angiography study was performed in aMCI patients over 2 years follow-up and compared to baseline.ResultsThirty-eight eyes from 19 aMCI patients were evaluated. Structural and vascular OCT measures were reduced at follow-up except for vessel density (VD) of the choriocapillaris, unchanged, and foveal avascular zone, which was increased; no changes in any parameter were found in 18 age-matched healthy controls. Overall, these findings were confirmed when patients were evaluated separately according to progression to dementia. Only non-converters to dementia showed significant VD reduction in the deep capillary plexuses (coeff. β = −4.20; p < 0.001), may be for an initial massive VD depletion becoming less evident with progression of the disease. MMSE reduction was associated with a higher ganglion cell complex reduction (coeff. β = 0.10; p = 0.04) and a higher VD reduction in the radial peripapillary capillary (RPC) plexus (coeff. β = 0.14; p = 0.02) in the whole patient group, while it was associated with a higher VD reduction only in RPC plexus in converters (coeff. β = 0.21; p < 0.001).ConclusionOur data shows vascular impairment progression in the inner retina of aMCI patients and support the hypothesis that vascular changes may contribute to the onset and progression of Alzheimer’s disease. Other follow-up studies, with a larger number of patients, are needed to better define VD as a potential biomarker.
Collapse
|
11
|
Matei N, Leahy S, Blair NP, Burford J, Rahimi M, Shahidi M. Retinal Vascular Physiology Biomarkers in a 5XFAD Mouse Model of Alzheimer's Disease. Cells 2022; 11:2413. [PMID: 35954257 PMCID: PMC9368483 DOI: 10.3390/cells11152413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 07/30/2022] [Accepted: 07/30/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a neurodegenerative disorder that affects the brain and retina and lacks reliable biomarkers for early diagnosis. As amyloid beta (Aβ) manifestations emerge prior to clinical symptoms and plaques of amyloid may cause vascular damage, identification of retinal vascular biomarkers may improve knowledge of AD pathophysiology and potentially serve as therapeutic targets. The purpose of the current study was to test the hypothesis that retinal hemodynamic and oxygen metrics are altered in 5XFAD mice. METHODS Thirty-two male mice were evaluated at 3 months of age: sixteen 5XFAD transgenic and sixteen wild-type mice. Spectral-domain optical coherence tomography, vascular oxygen tension, and blood flow imaging were performed in one eye of each mouse. After imaging, the imaged and fellow retinal tissues were submitted for histological sectioning and amyloid protein analysis, respectively. Protein analysis was also performed on the brain tissues. RESULTS Retinal physiological changes in venous diameter and blood velocity, arterial and venous oxygen contents, coupled with anatomical alterations in the thickness of retinal cell layers were detected in 5XFAD mice. Moreover, an increase in Aβ42 levels in both the retina and brain tissues was observed in 5XFAD mice. Significant changes in retinal oxygen delivery, metabolism, or extraction fraction were not detected. Based on compiled data from both groups, arterial oxygen content was inversely related to venous blood velocity and nerve fiber/ganglion cell layer thickness. CONCLUSIONS Concurrent alterations in retinal hemodynamic and oxygen metrics, thickness, and tissue Aβ42 protein levels in 5XFAD mice at 3 months of age corresponded to previously reported findings in human AD. Overall, these results suggest that this mouse model can be utilized for studying pathophysiology of AD and evaluating potential therapies.
Collapse
Affiliation(s)
- Nathanael Matei
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Norman P. Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - James Burford
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Mansour Rahimi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| |
Collapse
|
12
|
Faldu KG, Shah JS. Alzheimer's disease: a scoping review of biomarker research and development for effective disease diagnosis. Expert Rev Mol Diagn 2022; 22:681-703. [PMID: 35855631 DOI: 10.1080/14737159.2022.2104639] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Alzheimer's disease (AD) is regarded as the foremost reason for neurodegeneration that prominently affects the geriatric population. Characterized by extracellular accumulation of amyloid-beta (Aβ), intracellular aggregation of hyperphosphorylated tau (p-tau), and neuronal degeneration that causes impairment of memory and cognition. Amyloid/tau/neurodegeneration (ATN) classification is utilized for research purposes and involves amyloid, tau, and neuronal injury staging through MRI, PET scanning, and CSF protein concentration estimations. CSF sampling is invasive, and MRI and PET scanning requires sophisticated radiological facilities which limit its widespread diagnostic use. ATN classification lacks effectiveness in preclinical AD. AREAS COVERED This publication intends to collate and review the existing biomarker profile and the current research and development of a new arsenal of biomarkers for AD pathology from different biological samples, microRNA (miRNA), proteomics, metabolomics, artificial intelligence, and machine learning for AD screening, diagnosis, prognosis, and monitoring of AD treatments. EXPERT OPINION It is an accepted observation that AD-related pathological changes occur over a long period of time before the first symptoms are observed providing ample opportunity for detection of biological alterations in various biological samples that can aid in early diagnosis and modify treatment outcomes.
Collapse
Affiliation(s)
- Khushboo Govind Faldu
- Department of Pharmacology, Institute of Pharmacy, Nirma University, Ahmedabad, Gujarat, India
| | - Jigna Samir Shah
- Department of Pharmacology, Institute of Pharmacy, Nirma University, Ahmedabad, Gujarat, India
| |
Collapse
|
13
|
Frank B, Ally M, Tripodis Y, Puzo C, Labriolo C, Hurley L, Martin B, Palmisano J, Chan L, Steinberg E, Turk K, Budson A, O’Connor M, Au R, Qiu WQ, Goldstein L, Kukull W, Kowall N, Killiany R, Stern R, Stein T, McKee A, Mez J, Alosco M. Trajectories of Cognitive Decline in Brain Donors With Autopsy-Confirmed Alzheimer Disease and Cerebrovascular Disease. Neurology 2022; 98:e2454-e2464. [PMID: 35444054 PMCID: PMC9231841 DOI: 10.1212/wnl.0000000000200304] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/16/2022] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Cerebrovascular disease (CBVD) is frequently comorbid with autopsy-confirmed Alzheimer disease (AD), but its contribution to the clinical presentation of AD remains unclear. We leveraged the National Alzheimer's Coordinating Center (NACC) uniform and neuropathology datasets to compare the cognitive and functional trajectories of AD+/CBVD+ and AD+/CBVD- brain donors. METHODS The sample included NACC brain donors with autopsy-confirmed AD (Braak stage ≥3, Consortium to Establish a Registry for Alzheimer's Disease score ≥2) and complete Uniform Data Set (UDS) evaluations between 2005 and 2019, with the most recent UDS evaluation within 2 years of autopsy. CBVD was defined as moderate to severe arteriosclerosis or atherosclerosis. We used propensity score weighting to isolate the effects of comorbid AD and CBVD. This method improved the balance of covariates between the AD+/CBVD+ and AD+/CBVD- groups. Longitudinal mixed-effects models were assessed with robust bayesian estimation. UDS neuropsychological test and the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) scores were primary outcomes. RESULTS Of 2,423 brain donors, 1,476 were classified as AD+/CBVD+. Compared with AD+/CVBD- donors, the AD+/CBVD+ group had accelerated decline (i.e., group × time effects) on measures of processing speed (β = -0.93, 95% CI -1.35, -0.51, Bayes factor [BF] 130.75), working memory (β = 0.05, 95% CI 0.02, 0.07, BF 3.59), verbal fluency (β = 0.10, 95% CI 0.04, 0.15, BF 1.28), naming (β = 0.09, 95% CI 0.03, 0.16, BF = 0.69), and CDR-SB (β = -0.08, 95% CI -0.12, -0.05, BF 18.11). Effects ranged from weak (BFs <3.0) to strong (BFs <150). We also found worse performance in the AD+/CBVD+ group across time on naming (β = -1.04, 95% CI -1.83, -0.25, BF 2.52) and verbal fluency (β = -0.73, 95% CI -1.30, -0.15, BF 1.34) and more impaired CDR-SB scores (β = 0.45, 95% CI 0.01, 0.89, BF 0.33). DISCUSSION In brain donors with autopsy-confirmed AD, comorbid CBVD was associated with an accelerated functional and cognitive decline, particularly on neuropsychological tests of attention, psychomotor speed, and working memory. CBVD magnified effects of AD neuropathology on semantic-related neuropsychological tasks. Findings support a prominent additive and more subtle synergistic effect for comorbid CBVD neuropathology in AD.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Michael Alosco
- From the Boston University Alzheimer's Disease Center and CTE Center (B.F., M. Ally, Y.T., C.P., C.L., B.M., J.P., L.C., E.S., K.T., A.B., M.O., R.A., W.Q.Q., L.G., N.K., R.K., R.S., T.S., A.M., J.M., M. Alosco), Boston University School of Medicine; Veteran Affairs Bedford Healthcare System (B.F., M.O., T.S., A.M.), Bedford; Department of Biostatistics (Y.T.), Boston University School of Public Health, MA; Yale School of Public Health (L.H.), New Haven, CT; Biostatistics and Epidemiology Data Analytics Center (B.M., J.P.), Boston University School of Public Health; Department of Neurology (K.T., A.B., R.A., N.K., R.S., A.M., J.M., M. Alosco), Boston University School of Medicine; Veterans Affairs Boston Healthcare System (K.T., A.B., N.K., T.S., A.M); Department of Anatomy & Neurobiology (R.A., R.K., R.S.), Boston University School of Medicine; MA; Framingham Heart Study (R.A.), National Heart, Lung, and Blood Institute, Bethesda, MD; Department of Epidemiology (R.A.), Boston University School of Public Health; Department of Psychiatry (W.Q.Q.), Boston University School of Medicine; Department of Pharmacology & Experimental Therapeutics (W.Q.Q.), Boston University School of Medicine; Department of Pathology and Laboratory Medicine (L.G.), Boston University School of Medicine; Departments of Psychiatry and Ophthalmology (L.G.), Boston University School of Medicine; Departments of Biomedical, Electrical & Computer Engineering (L.G.), Boston University College of Engineering, MA; National Alzheimer's Coordinating Center (W.K.), Department of Epidemiology, University of Washington, Seattle; Center for Biomedical Imaging (R.K.), and Boston University School of Medicine; Department of Neurosurgery (R.S.), Boston University School of Medicine, MA.
| |
Collapse
|
14
|
Moran C, Xu ZY, Mehta H, Gillies M, Karayiannis C, Beare R, Chen C, Srikanth V. Neuroimaging and cognitive correlates of retinal Optical Coherence Tomography (OCT) measures at late middle age in a twin sample. Sci Rep 2022; 12:9562. [PMID: 35688899 PMCID: PMC9187769 DOI: 10.1038/s41598-022-13662-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/26/2022] [Indexed: 11/09/2022] Open
Abstract
Sharing in embryology and function between the eye and brain has led to interest in whether assessments of the eye reflect brain changes seen in neurodegeneration. We aimed to examine the associations between measures of retinal layer thickness using optical coherence tomography (OCT) and multimodal measures of brain structure and function. Using a convenient sample of twins discordant for type 2 diabetes, we performed cognitive testing, structural brain MRI (tissue volumetry), diffusion tensor imaging (white matter microstructure), and arterial spin labelling (cerebral blood flow). OCT images were recorded and retinal thickness maps generated. We used mixed level modelling to examine the relationship between retinal layer thicknesses and brain measures. We enrolled 35 people (18 pairs, mean age 63.8 years, 63% female). Ganglion cell layer thickness was positively associated with memory, speed, gray matter volume, and altered mean diffusivity. Ganglion cell layer thickness was strongly positively associated with regional cerebral blood flow. We found only a limited number of associations between other retinal layer thickness and measures of brain structure or function. Ganglion cell layer thickness showed consistent associations with a range of brain measures suggesting it may have utility as a marker for future dementia risk.
Collapse
Affiliation(s)
- Chris Moran
- National Centre for Healthy Ageing, Melbourne, Australia.,Department of Geriatric Medicine, Peninsula Health and Central Clinical School, Monash University, Melbourne, Australia.,Department of Aged Care, Alfred Health, Melbourne, Australia
| | - Zheng Yang Xu
- Royal Free London NHS Foundation Trust, London, UK.,UCL Medical School, London, UK
| | - Hemal Mehta
- Royal Free London NHS Foundation Trust, London, UK.,Macular Research Group, University of Sydney, Sydney, Australia
| | - Mark Gillies
- Macular Research Group, University of Sydney, Sydney, Australia
| | - Chris Karayiannis
- National Centre for Healthy Ageing, Melbourne, Australia.,Department of Geriatric Medicine, Peninsula Health and Central Clinical School, Monash University, Melbourne, Australia
| | - Richard Beare
- National Centre for Healthy Ageing, Melbourne, Australia.,Department of Geriatric Medicine, Peninsula Health and Central Clinical School, Monash University, Melbourne, Australia
| | - Christine Chen
- Department of Ophthalmology, Monash Health, Melbourne, Australia
| | - Velandai Srikanth
- National Centre for Healthy Ageing, Melbourne, Australia. .,Department of Geriatric Medicine, Peninsula Health and Central Clinical School, Monash University, Melbourne, Australia.
| |
Collapse
|
15
|
López-Cuenca I, Salobrar-García E, Sánchez-Puebla L, Espejel E, García del Arco L, Rojas P, Elvira-Hurtado L, Fernández-Albarral JA, Ramírez-Toraño F, Barabash A, Salazar JJ, Ramírez JM, de Hoz R, Ramírez AI. Retinal Vascular Study Using OCTA in Subjects at High Genetic Risk of Developing Alzheimer's Disease and Cardiovascular Risk Factors. J Clin Med 2022; 11:3248. [PMID: 35683633 PMCID: PMC9181641 DOI: 10.3390/jcm11113248] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/02/2022] [Accepted: 06/05/2022] [Indexed: 02/01/2023] Open
Abstract
In 103 subjects with a high genetic risk of developing Alzheimer's disease (AD), family history (FH) of AD and ApoE ɛ4 characterization (ApoE ɛ4) were analyzed for changes in the retinal vascular network by OCTA (optical coherence tomography angiography), and AngioTool and Erlangen-Angio-Tool (EA-Tool) as imaging analysis software. Retinal vascularization was analyzed by measuring hypercholesterolemia (HCL) and high blood pressure (HBP). Angio-Tool showed a statistically significant higher percentage of area occupied by vessels in the FH+ ApoE ɛ4- group vs. in the FH+ ApoE ɛ4+ group, and EA-Tool showed statistically significant higher vascular densities in the C3 ring in the FH+ ApoE ɛ4+ group when compared with: i)FH- ApoE ɛ4- in sectors H3, H4, H10 and H11; and ii) FH+ ApoE ɛ4- in sectors H4 and H12. In participants with HCL and HBP, statistically significant changes were found, in particular using EA-Tool, both in the macular area, mainly in the deep plexus, and in the peripapillary area. In conclusion, OCTA in subjects with genetic risk factors for the development of AD showed an apparent increase in vascular density in some sectors of the retina, which was one of the first vascular changes detectable. These changes constitute a promising biomarker for monitoring the progression of pathological neuronal degeneration.
Collapse
Affiliation(s)
- Inés López-Cuenca
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - Elena Salobrar-García
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| | - Lidia Sánchez-Puebla
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - Eva Espejel
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - Lucía García del Arco
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - Pilar Rojas
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Madrid Eye Institute, Gregorio Marañón General University Hospital, 28007 Madrid, Spain
| | - Lorena Elvira-Hurtado
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - José A. Fernández-Albarral
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
| | - Federico Ramírez-Toraño
- Laboratory of Cognitive and Computational Neuroscience, Center for Biomedical Technology, Technical University of Madrid, 28233 Madrid, Spain;
- Department of Experimental Psychology, Complutense University of Madrid, 28223 Madrid, Spain
| | - Ana Barabash
- Department of Endocrinology and Nutrition, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain;
- Diabetes and Associated Metabolic Diseases Networking Biomedical Research Centre, Carlos III Health Institute, 28029 Madrid, Spain
- Department of Medicine II, School of Medicine, Complutense University of Madrid, 28040 Madrid, Spain
| | - Juan J. Salazar
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| | - José M. Ramírez
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Department of Immunology, Ophthalmology and ENT, School of Medicine, Complutense University of Madrid, 28040 Madrid, Spain
| | - Rosa de Hoz
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| | - Ana I. Ramírez
- Ramon Castroviejo Institute of Ophthalmologic Research, Group UCM 920105, Health Research Institute of the Hospital Clínico San Carlos (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain; (I.L.-C.); (E.S.-G.); (L.S.-P.); (E.E.); (L.G.d.A.); (P.R.); (L.E.-H.); (J.A.F.-A.); (J.J.S.); (J.M.R.)
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| |
Collapse
|
16
|
Zhang J, Shi L, Shen Y. The retina: A window in which to view the pathogenesis of Alzheimer's disease. Ageing Res Rev 2022; 77:101590. [PMID: 35192959 DOI: 10.1016/j.arr.2022.101590] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 01/14/2022] [Accepted: 02/12/2022] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) is the most familiar type of dementia affecting elderly populations worldwide. Studies of AD patients and AD transgenic mice have revealed alterations in the retina similar to alterations which occur in the AD brain. Moreover, AD retinal pathology occurs even earlier than AD brain pathology. Importantly, non-invasive imaging techniques can be utilized for retinal observation due to the unique optical transparency of the eye, which acts as a convenient window in which preclinical pathology in the AD brain can be monitored. In this review, we overview the existing literature covering different forms of AD retinal pathology and propose a basis for the clinical application of using the retina as a window to view AD during preclinical and clinical stages.
Collapse
Affiliation(s)
- Jie Zhang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disorder Research Center, School of Life Science, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Lei Shi
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disorder Research Center, School of Life Science, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yong Shen
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disorder Research Center, School of Life Science, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230026, China; Center for Excellence in Brain Sciences and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
| |
Collapse
|
17
|
Mirzania D, Thompson AC, Robbins CB, Soundararajan S, Lee JM, Agrawal R, Liu AJ, Johnson KG, Grewal DS, Fekrat S. Retinal and Choroidal Changes in Men Compared with Women with Alzheimer’s Disease. OPHTHALMOLOGY SCIENCE 2022; 2:100098. [PMID: 36246183 PMCID: PMC9559893 DOI: 10.1016/j.xops.2021.100098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 12/01/2022]
Abstract
Purpose To evaluate differences in the retinal microvasculature and structure and choroidal structure among men and women with Alzheimer’s disease (AD) compared with age-matched cognitively normal male and female controls. Design Case-control study of participants ≥ 50 years of age. Participants A total of 202 eyes of 139 subjects (101 cases and 101 controls). Methods All participants and controls underwent OCT and OCT angiography (OCTA), and parameters of subjects with AD were compared with those of cognitively normal controls. Main Outcome Measures The foveal avascular zone (FAZ) area, vessel density (VD), and perfusion density (PD) in the superficial capillary plexus within the 3- and 6-mm circle and ring using Early Treatment Diabetic Retinopathy Study (ETDRS) grid overlay on OCTA; central subfield thickness (CST), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, and choroidal vascularity index (CVI) on OCT. Results No significant sex differences in VD or PD were found in the AD or control cohorts; however, there were greater differences in VD and PD among AD female participants than AD male participants compared with their respective controls. The CST and FAZ area were not different between male and female AD participants. Among controls, men had a thicker CST (P < 0.001) and smaller FAZ area (P = 0.003) compared with women. The RNFL thickness, GCIPL thickness, and CVI were similar among male and female AD participants and controls. Conclusions There may be a loss of the physiologic sex-related differences in retinal structure and microvasculature in those with AD compared with controls. Further studies are needed to elucidate the pathophysiological basis for these findings.
Collapse
Affiliation(s)
- Delaram Mirzania
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
| | - Atalie C. Thompson
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
| | - Cason B. Robbins
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
| | - Srinath Soundararajan
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
| | - Jia Min Lee
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | - Rupesh Agrawal
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | - Andy J. Liu
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Neurology, Durham, North Carolina
| | - Kim G. Johnson
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Neurology, Durham, North Carolina
| | - Dilraj S. Grewal
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
| | - Sharon Fekrat
- iMIND Research Group, Duke University School of Medicine, Durham, North Carolina
- Duke Department of Ophthalmology, Durham, North Carolina
- Correspondence: Sharon Fekrat, MD, Duke University Department of Ophthalmology, 2351 Erwin Road, Box 3802, Durham, NC 27710. .
| |
Collapse
|
18
|
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: 12] [Impact Index Per Article: 6.0] [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.
Collapse
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
| |
Collapse
|
19
|
Alzheimer's Disease Seen through the Eye: Ocular Alterations and Neurodegeneration. Int J Mol Sci 2022; 23:ijms23052486. [PMID: 35269629 PMCID: PMC8910735 DOI: 10.3390/ijms23052486] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s Disease (AD) is one of the main neurodegenerative diseases worldwide. Unfortunately, AD shares many similarities with other dementias at early stages, which impedes an accurate premortem diagnosis. Therefore, it is urgent to find biomarkers to allow for early diagnosis of the disease. There is increasing scientific evidence highlighting the similarities between the eye and other structures of the CNS, suggesting that knowledge acquired in eye research could be useful for research and diagnosis of AD. For example, the retina and optic nerve are considered part of the central nervous system, and their damage can result in retrograde and anterograde axon degeneration, as well as abnormal protein aggregation. In the anterior eye segment, the aqueous humor and tear film may be comparable to the cerebrospinal fluid. Both fluids are enriched with molecules that can be potential neurodegenerative biomarkers. Indeed, the pathophysiology of AD, characterized by cerebral deposits of amyloid-beta (Aβ) and tau protein, is also present in the eyes of AD patients, besides numerous structural and functional changes observed in the structure of the eyes. Therefore, all this evidence suggests that ocular changes have the potential to be used as either predictive values for AD assessment or as diagnostic tools.
Collapse
|
20
|
Adejumo T, Kim TH, Le D, Son T, Ma G, Yao X. Depth-resolved vascular profile features for artery-vein classification in OCT and OCT angiography of human retina. BIOMEDICAL OPTICS EXPRESS 2022; 13:1121-1130. [PMID: 35284164 PMCID: PMC8884205 DOI: 10.1364/boe.450913] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/22/2022] [Accepted: 01/23/2022] [Indexed: 05/11/2023]
Abstract
This study is to characterize reflectance profiles of retinal blood vessels in optical coherence tomography (OCT), and to test the potential of using these vascular features to guide artery-vein classification in OCT angiography (OCTA) of the human retina. Depth-resolved OCT reveals unique features of retinal arteries and veins. Retinal arteries show hyper-reflective boundaries at both upper (inner side towards the vitreous) and lower (outer side towards the choroid) walls. In contrast, retinal veins reveal hyper-reflectivity at the upper boundary only. Uniform lumen intensity was observed in both small and large arteries. However, the venous lumen intensity was dependent on the vessel size. Small veins exhibit a hyper-reflective zone at the bottom half of the lumen, while large veins show a hypo-reflective zone at the bottom half of the lumen.
Collapse
Affiliation(s)
- Tobiloba Adejumo
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - Tae-Hoon Kim
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Guangying Ma
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| |
Collapse
|
21
|
El Haj M, Chapelet G, Moustafa AA, Boutoleau-Bretonnière C. Pupil size as an indicator of cognitive activity in mild Alzheimer's disease. EXCLI JOURNAL 2022; 21:307-316. [PMID: 35382454 PMCID: PMC8977451 DOI: 10.17179/excli2021-4568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 12/07/2021] [Indexed: 12/15/2022]
Abstract
It is well established that pupil activity indexes cognitive processing. For instance, research has consistently demonstrated that the pupil reacts to working memory span task performance. However, little is known about pupil reaction to cognitive processing in Alzheimer's Disease (AD). We thus investigated whether span tasks can modulate pupil size in patients with AD. We invited 24 patients with AD and 24 healthy older adults to perform backward and forward spans, as well as to count aloud in a control condition, while their pupil activity was recorded with eye tracking glasses. In patients with AD, analysis demonstrated larger pupil size during backward spans (M = 2.12, SD = .39) than during forward spans (M = 1.98, SD = .36) [t(23) = 3.22, p = .004], larger pupil size during forward spans than during counting (M = 1.67, SD = .33) [t(23) = 4.75, p < .001], as well as larger pupil size during backward spans than during counting [t(23) = 10.60, p < .001]. In control participants, analysis demonstrated larger pupil size during backward spans (M = 3.36, SD = .49) than during forward spans (M = 2.85, SD = .68) [t(23) = 5.82, p < .001], larger pupil size during forward spans than during counting (M = 2.09, SD = .62) [t(23) = 5.42, < .001], as well as larger pupil size during backward spans than during counting [t(23) = 9.70, p < .001]. Results also demonstrated a significant interaction effect between groups and conditions [F(2,92) = 16.63, p < .001]; in other words, patients with AD have shown fewer variations on the pupil size across the conditions compared to the control participants. The larger pupil size during backward spans, compared with forward spans or counting, can be attributed to the high cognitive load of backward spans. The modulation of pupil size, as observed across backward/forward spans and counting, can possibly be attributed to sympathetic/adrenergic and parasympathetic/cholinergic activities. Our study demonstrates the value of pupillometry as a potential biomarker of cognitive processing in AD.
Collapse
Affiliation(s)
- Mohamad El Haj
- Nantes Université, Univ. Angers, Laboratoire de Psychologie des Pays de la Loire (LPPL - EA 4638), F-44000 Nantes, France,Unité de Gériatrie, Centre Hospitalier de Tourcoing, Tourcoing, France,Institut Universitaire de France, Paris, France,*To whom correspondence should be addressed: Mohamad El Haj, Faculté de Psychologie, LPPL – Laboratoire de Psychologie des Pays de la Loire, Université de Nantes, Chemin de la Censive du Tertre, BP 81227, 44312 Nantes Cedex 3, France, E-mail:
| | - Guillaume Chapelet
- CHU Nantes, Clinical Gerontology Department, Bd Jacques Monod, F44093, Nantes, France,Université de Nantes, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Ahmed A. Moustafa
- School of Psychology, Faculty of Society and Design, Bond University, Gold Coast, Queensland, Australia,Department of Human Anatomy and Physiology, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
| | | |
Collapse
|
22
|
van der Heide FCT, van Sloten TT, Willekens N, Stehouwer CDA. Neurovascular coupling unit dysfunction and dementia: Retinal measurements as tools to move towards population-based evidence. Front Endocrinol (Lausanne) 2022; 13:1014287. [PMID: 36506058 PMCID: PMC9727310 DOI: 10.3389/fendo.2022.1014287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/31/2022] [Indexed: 11/24/2022] Open
Abstract
Dysfunction of the neurovascular coupling unit may be an important contributor to dementia. The neurovascular coupling unit comprises neuronal structures (e.g. astrocytes) and vascular structures (e.g. endothelial cells) that functionally interact both at the level of the arterioles as well as at the capillary level (blood-brain barrier) to regulate optimal metabolic conditions in the brain. However, it remains unclear how and to what extent dysfunction of the neurovascular coupling unit contributes to the early-stage pathobiology of dementia. Currently, limited data are available on the association between neurovascular coupling unit dysfunction, as quantified by cerebral imaging techniques, and cognitive performance. In particular, there is a lack of population-based human data (defined as studies with a sample size ~n>500). This is an important limitation because population-based studies, in comparison with smaller clinical studies, provide data which is better representative of the general population; are less susceptible to selection bias; and have a larger statistical power to detect small associations. To acquire population-based data, however, alternative imaging techniques than cerebral imaging techniques may be required. Disadvantages of cerebral imaging techniques, which limit use in population-based studies, are that these techniques are relatively expensive, time-consuming, and/or invasive. In this review, we propose that retinal imaging techniques can be used for population-based studies: on the one hand the retina and brain have many anatomical and physiological similarities; and on the other hand retinal imaging techniques are non-invasive, highly accurate, relatively inexpensive, and require relatively short measurement time. To provide support for this concept, we provide an overview on the human (population-based) evidence on the associations of retinal indices of neurodegeneration, microvascular dysfunction, and dysfunction of the neurovascular coupling unit with magnetic resonance imaging (MRI) features of structural brain abnormalities and cognitive performance.
Collapse
Affiliation(s)
- Frank C. T. van der Heide
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
- Department of Psychiatry and Neuropsychology, MUMC+, Maastricht, Netherlands
- School of Mental Health and Neuroscience, MUMC+, Maastricht, Netherlands
- *Correspondence: Frank C. T. van der Heide,
| | - Thomas T. van Sloten
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| | - Nele Willekens
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| | - Coen D. A. Stehouwer
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| |
Collapse
|
23
|
Marino MJ, Gehlbach PL, Rege A, Jiramongkolchai K. Current and novel multi-imaging modalities to assess retinal oxygenation and blood flow. Eye (Lond) 2021; 35:2962-2972. [PMID: 34117399 PMCID: PMC8526664 DOI: 10.1038/s41433-021-01570-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/28/2021] [Accepted: 04/20/2021] [Indexed: 02/05/2023] Open
Abstract
Retinal ischemia characterizes the underlying pathology in a multitude of retinal diseases that can ultimately lead to vision loss. A variety of novel imaging modalities have been developed to characterize retinal ischemia by measuring retinal oxygenation and blood flow in-vivo. These technologies offer valuable insight into the earliest pathophysiologic changes within the retina and provide physicians and researchers with new diagnostic and monitoring capabilities. Future retinal imaging technologies with the capability to provide affordable, noninvasive, and comprehensive data on oxygen saturation, vasculature, and blood flow mechanics are needed. This review will highlight current and future trends in multimodal imaging to assess retinal blood flow and oxygenation.
Collapse
Affiliation(s)
- Michael J. Marino
- grid.415233.20000 0004 0444 3298Department of Medicine, MedStar Union Memorial Hospital, Baltimore, MD USA
| | - Peter L. Gehlbach
- grid.21107.350000 0001 2171 9311Retina Division, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Abhishek Rege
- grid.505446.6Vasoptic Medical, Inc., Baltimore, MD USA
| | | |
Collapse
|
24
|
Shi H, Koronyo Y, Rentsendorj A, Fuchs DT, Sheyn J, Black KL, Mirzaei N, Koronyo-Hamaoui M. Retinal Vasculopathy in Alzheimer's Disease. Front Neurosci 2021; 15:731614. [PMID: 34630020 PMCID: PMC8493243 DOI: 10.3389/fnins.2021.731614] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
The retina has been increasingly investigated as a site of Alzheimer’s disease (AD) manifestation for over a decade. Early reports documented degeneration of retinal ganglion cells and their axonal projections. Our group provided the first evidence of the key pathological hallmarks of AD, amyloid β-protein (Aβ) plaques including vascular Aβ deposits, in the retina of AD and mild cognitively impaired (MCI) patients. Subsequent studies validated these findings and further identified electroretinography and vision deficits, retinal (p)tau and inflammation, intracellular Aβ accumulation, and retinal ganglion cell-subtype degeneration surrounding Aβ plaques in these patients. Our data suggest that the brain and retina follow a similar trajectory during AD progression, probably due to their common embryonic origin and anatomical proximity. However, the retina is the only CNS organ feasible for direct, repeated, and non-invasive ophthalmic examination with ultra-high spatial resolution and sensitivity. Neurovascular unit integrity is key to maintaining normal CNS function and cerebral vascular abnormalities are increasingly recognized as early and pivotal factors driving cognitive impairment in AD. Likewise, retinal vascular abnormalities such as changes in vessel density and fractal dimensions, blood flow, foveal avascular zone, curvature tortuosity, and arteriole-to-venule ratio were described in AD patients including early-stage cases. A rapidly growing number of reports have suggested that cerebral and retinal vasculopathy are tightly associated with cognitive deficits in AD patients and animal models. Importantly, we recently identified early and progressive deficiency in retinal vascular platelet-derived growth factor receptor-β (PDGFRβ) expression and pericyte loss that were associated with retinal vascular amyloidosis and cerebral amyloid angiopathy in MCI and AD patients. Other studies utilizing optical coherence tomography (OCT), retinal amyloid-fluorescence imaging and retinal hyperspectral imaging have made significant progress in visualizing and quantifying AD pathology through the retina. With new advances in OCT angiography, OCT leakage, scanning laser microscopy, fluorescein angiography and adaptive optics imaging, future studies focusing on retinal vascular AD pathologies could transform non-invasive pre-clinical AD diagnosis and monitoring.
Collapse
Affiliation(s)
- Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Altan Rentsendorj
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Nazanin Mirzaei
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| |
Collapse
|
25
|
Majeed A, Marwick B, Yu H, Fadavi H, Tavakoli M. Ophthalmic Biomarkers for Alzheimer's Disease: A Review. Front Aging Neurosci 2021; 13:720167. [PMID: 34566623 PMCID: PMC8461312 DOI: 10.3389/fnagi.2021.720167] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/11/2021] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by neuronal loss, extracellular amyloid-β (Aβ) plaques, and intracellular neurofibrillary tau tangles. A diagnosis is currently made from the presenting symptoms, and the only definitive diagnosis can be done post-mortem. Over recent years, significant advances have been made in using ocular biomarkers to diagnose various neurodegenerative diseases, including AD. As the eye is an extension of the central nervous system (CNS), reviewing changes in the eye's biology could lead to developing a series of non-invasive, differential diagnostic tests for AD that could be further applied to other diseases. Significant changes have been identified in the retinal nerve fiber layer (RNFL), cornea, ocular vasculature, and retina. In the present paper, we review current research and assess some ocular biomarkers' accuracy and reliability that could potentially be used for diagnostic purposes. Additionally, we review the various imaging techniques used in the measurement of these biomarkers.
Collapse
Affiliation(s)
- Ayesha Majeed
- Medical School, University of Exeter, Exeter, United Kingdom
| | - Ben Marwick
- Medical School, University of Exeter, Exeter, United Kingdom
| | - Haoqing Yu
- Medical School, University of Exeter, Exeter, United Kingdom
| | | | - Mitra Tavakoli
- Medical School, University of Exeter, Exeter, United Kingdom
- Exeter Centre of Excellence for Diabetes Research, University of Exeter, Exeter, United Kingdom
- National Institute for Health Research, Exeter Clinical Research Facility, Exeter, United Kingdom
| |
Collapse
|
26
|
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: 15] [Impact Index Per Article: 5.0] [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.
Collapse
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.)
| |
Collapse
|
27
|
Wong MNK, Lai DWL, Chan HHL, Lam BYH. Neural and Retinal Characteristics in Relation to Working Memory in Older Adults with Mild Cognitive Impairment. Curr Alzheimer Res 2021; 18:185-195. [PMID: 34102976 DOI: 10.2174/1567205018666210608114044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/10/2021] [Accepted: 04/18/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study investigated the relationship between neural activities and retinal structures associated with working memory (WM) in older adults with mild cognitive impairment (MCI). METHODS Eleven older adults with MCI and 29 healthy controls (60 to 73 years old) were tested. All participants underwent an event-related potential (ERP) recording while performing the two-back memory task. The Optical coherence tomography angiography (OCT-A) was administered to examine the perfusion and vessel density in the retina. RESULTS Results showed that WM performance in the MCI group was negatively associated with ERP latencies in central parietal regions (CP6 and CP8) (ps< 0.05). The left nasal vessel and perfusion densities were negatively correlated with the latencies in these two central parietal regions and positively related to WM performance only in the MCI group (ps< 0.05). CONCLUSION The findings on WM, central parietal brain activity, and left nasal vessel and perfusion densities in the retina help us gain a better understanding of the neural and retinal underpinnings of WM in relation to MCI.
Collapse
Affiliation(s)
- Mabel N K Wong
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, 11 Yuk Choi Rd, Hung Hom, Hong Kong
| | - Daniel W L Lai
- Faculty of Social Sciences, Hong Kong Baptist University, 224 Waterloo Rd, Kowloon Tong, Hong Kong
| | - Henry H-L Chan
- School of Optometry, The Hong Kong Polytechnic University, 11 Yuk Choi Rd, Hung Hom, Hong Kong
| | - Bess Y-H Lam
- Department of Psychiatry, The University of Hong Kong, Pok Fu Lam, Hong Kong
| |
Collapse
|
28
|
Patel DD, Dhalla AH, Viehland C, Connor TB, Lipinski DM. Development of a Preclinical Laser Speckle Contrast Imaging Instrument for Assessing Systemic and Retinal Vascular Function in Small Rodents. Transl Vis Sci Technol 2021; 10:19. [PMID: 34403474 PMCID: PMC8374978 DOI: 10.1167/tvst.10.9.19] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To develop and test a non-contact, contrast-free, retinal laser speckle contrast imaging (LSCI) instrument for use in small rodents to assess vascular anatomy, quantify hemodynamics, and measure physiological changes in response to retinal vascular dysfunction over a wide field of view (FOV). Methods A custom LSCI instrument capable of wide-field and non-contact imaging in small rodents was constructed. The effect of camera gain, laser power, and exposure duration on speckle contrast variance was standardized before the repeatability of LSCI measurements was determined in vivo. Finally, the ability of LSCI to detect alterations in local and systemic vascular function was evaluated using a laser-induced branch retinal vein occlusion and isoflurane anesthesia model, respectively. Results The LSCI system generates contrast-free maps of retinal blood flow with a 50° FOV at >376 frames per second (fps) and under a short exposure duration (>50 µs) with high reliability (intraclass correlation R = 0.946). LSCI was utilized to characterize retinal vascular anatomy affected by laser injury and longitudinally measure alterations in perfusion and blood flow profile. Under varied doses of isoflurane, LSCI could assess cardiac and systemic vascular function, including heart rate, peripheral resistance, contractility, and pulse propagation. Conclusions We present a LSCI system for detecting anatomical and physiological changes in retinal and systemic vascular health and function in small rodents. Translational Relevance Detecting and quantifying early anatomical and physiological changes in vascular function in animal models of retinal, systemic, and neurodegenerative diseases could strengthen our understanding of disease progression and enable the identification of new prognostic and diagnostic biomarkers for disease management and for assessing treatment efficacies.
Collapse
Affiliation(s)
- Dwani D Patel
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Al-Hafeez Dhalla
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | | | - Thomas B Connor
- Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Daniel M Lipinski
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, WI, USA.,Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, UK
| |
Collapse
|
29
|
Ge YJ, Xu W, Ou YN, Qu Y, Ma YH, Huang YY, Shen XN, Chen SD, Tan L, Zhao QH, Yu JT. Retinal biomarkers in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis. Ageing Res Rev 2021; 69:101361. [PMID: 34000463 DOI: 10.1016/j.arr.2021.101361] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND Retinal changes may reflect the pathophysiological processes in the central nervous system and can be assessed by imaging modalities non-invasively. We aim to localize candidate retinal biomarkers in Alzheimer's disease (AD), mild cognitive impairment (MCI), and preclinical AD. METHODS We systematically searched PubMed, EMBASE, Scopus, and Web of Science from inception to January 2021 for observational studies that investigated retinal imaging and electrophysiological markers in AD, MCI, and preclinical AD. Between-groups standardized mean differences (SMDs) with 95 % confidence intervals were computed using random-effects models. RESULTS Of 19,727 citations identified, 126 articles were eligible for inclusion. Compared with healthy controls, the thickness of peripapillary retinal nerve fiber layer (pRNFL; SMD = -0.723, p < 0.001), total macular (SMD = -0.612, p < 0.001), and subfoveal choroid (SMD = -0.888, p < 0.001) were significantly reduced in patients with AD. Compared with healthy controls, patients with MCI also had lower thickness of pRNFL (SMD = -0.324, p < 0.001), total macular (SMD = -0.302, p < 0.001), and subfoveal choroid (SMD = -0.462, p = 0.020). Other candidate biomarkers included the optic nerve head morphology, retinal amyloid deposition, microvascular morphology and densities, blood flow, and electrophysiological markers. CONCLUSIONS Retinal structural, vascular, and electrophysiological biomarkers hold great potential for the diagnosis, prognosis and risk assessment of AD and MCI. These biomarkers warrant further development in the future, especially in diagnostic test accuracy and longitudinal studies.
Collapse
|
30
|
Past, present and future role of retinal imaging in neurodegenerative disease. Prog Retin Eye Res 2021; 83:100938. [PMID: 33460813 PMCID: PMC8280255 DOI: 10.1016/j.preteyeres.2020.100938] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 02/08/2023]
Abstract
Retinal imaging technology is rapidly advancing and can provide ever-increasing amounts of information about the structure, function and molecular composition of retinal tissue in humans in vivo. Most importantly, this information can be obtained rapidly, non-invasively and in many cases using Food and Drug Administration-approved devices that are commercially available. Technologies such as optical coherence tomography have dramatically changed our understanding of retinal disease and in many cases have significantly improved their clinical management. Since the retina is an extension of the brain and shares a common embryological origin with the central nervous system, there has also been intense interest in leveraging the expanding armamentarium of retinal imaging technology to understand, diagnose and monitor neurological diseases. This is particularly appealing because of the high spatial resolution, relatively low-cost and wide availability of retinal imaging modalities such as fundus photography or OCT compared to brain imaging modalities such as magnetic resonance imaging or positron emission tomography. The purpose of this article is to review and synthesize current research about retinal imaging in neurodegenerative disease by providing examples from the literature and elaborating on limitations, challenges and future directions. We begin by providing a general background of the most relevant retinal imaging modalities to ensure that the reader has a foundation on which to understand the clinical studies that are subsequently discussed. We then review the application and results of retinal imaging methodologies to several prevalent neurodegenerative diseases where extensive work has been done including sporadic late onset Alzheimer's Disease, Parkinson's Disease and Huntington's Disease. We also discuss Autosomal Dominant Alzheimer's Disease and cerebrovascular small vessel disease, where the application of retinal imaging holds promise but data is currently scarce. Although cerebrovascular disease is not generally considered a neurodegenerative process, it is both a confounder and contributor to neurodegenerative disease processes that requires more attention. Finally, we discuss ongoing efforts to overcome the limitations in the field and unmet clinical and scientific needs.
Collapse
|
31
|
Habiba U, Merlin S, Lim JKH, Wong VHY, Nguyen CTO, Morley JW, Bui BV, Tayebi M. Age-Specific Retinal and Cerebral Immunodetection of Amyloid-β Plaques and Oligomers in a Rodent Model of Alzheimer's Disease. J Alzheimers Dis 2021; 76:1135-1150. [PMID: 32597800 DOI: 10.3233/jad-191346] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Amyloid-β soluble oligomers (Aβo) are believed to be the cause of the pathophysiology underlying Alzheimer's disease (AD) and are normally detected some two decades before clinical onset of the disease. Retinal pathology associated with AD pathogenesis has previously been reported, including ganglion cell loss, accumulation of Aβ deposits in the retina, and reduction of nerve fiber layer thickness as well as abnormalities of the microvasculature. OBJECTIVE This study's aim is to better understand the relationship between brain and retinal Aβo deposition and in particular to quantify levels of the toxic Aβo as a function of age in the retina of a rodent model of AD. METHODS Retinas and brain tissue from 5×FAD mice were stained with Congo red, Thioflavin-T (Th-T), and Aβ plaque-specific and Aβo-specific antibodies. RESULTS We show that retinas displayed an age-dependent increase of Th-T-specific amyloid fibrils. Staining with anti-Aβ antibody confirmed the presence of the Aβ plaques in all 5×FAD retinas tested. In contrast, staining with anti-Aβo antibody showed an age-dependent decrease of retinal Aβo. Of note, Aβo was observed mainly in the retinal nuclear layers. Finally, we confirmed the localization of Aβo to neurons, typically accumulating in late endosomes, indicating possible impairment of the endocytic pathway. CONCLUSION Our results demonstrate the presence of intraneuronal Aβo in the retina and its accumulation inversely correlated with retinal Aβ plaque deposition, indicating an age-related conversion in this animal model. These results support the development of an early AD diagnostic test targeting Aβo in the eye.
Collapse
Affiliation(s)
- Umma Habiba
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Sam Merlin
- School of Science & Health, Western Sydney University, Campbelltown, NSW, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - John W Morley
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| |
Collapse
|
32
|
Foveal Avascular Zone and Choroidal Thickness Are Decreased in Subjects with Hard Drusen and without High Genetic Risk of Developing Alzheimer's Disease. Biomedicines 2021; 9:biomedicines9060638. [PMID: 34199664 PMCID: PMC8229973 DOI: 10.3390/biomedicines9060638] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 01/08/2023] Open
Abstract
A family history (FH+) of Alzheimer’s disease (AD) and ɛ4 allele of the ApoE gene are the main genetic risk factors for developing AD, whereas ɛ4 allele plays a protective role in age-related macular degeneration. Ocular vascular changes have been reported in both pathologies. We analyzed the choroidal thickness using optical coherence tomography (OCT) and the foveal avascular zone (FAZ) using OCT-angiography and compared the results with ApoE gene expression, AD FH+, and the presence or absence of hard drusen (HD) in 184 cognitively healthy subjects. Choroidal thickness was statistically significantly different in the (FH−, ɛ4−, HD+) group compared with (i) both the (FH−, ɛ4−, HD−) and the (FH+, ɛ4+, HD+) groups in the superior and inferior points at 1500 μm, and (ii) the (FH+, ɛ4−, HD+) group in the superior point at 1500 μm. There were statistically significant differences in the superficial FAZ between the (FH+, ɛ4−, HD+) group and (i) the (FH+, ɛ4−, HD−) group and (ii) the (FH+, ɛ4+, HD−) group. In conclusion, ocular vascular changes are not yet evident in participants with a genetic risk of developing AD.
Collapse
|
33
|
Jiang H, Wang J, Levin BE, Baumel BS, Camargo CJ, Signorile JF, Rundek T. Retinal Microvascular Alterations as the Biomarkers for Alzheimer Disease: Are We There Yet? J Neuroophthalmol 2021; 41:251-260. [PMID: 33136677 PMCID: PMC8079547 DOI: 10.1097/wno.0000000000001140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Alzheimer disease (AD) is a heterogeneous and multifactorial disorder with an insidious onset and slowly progressive disease course. To date, there are no effective treatments, but biomarkers for early diagnosis and monitoring of disease progression offer a promising first step in developing and testing potential interventions. Cerebral vascular imaging biomarkers to assess the contributions of vascular dysfunction to AD are strongly recommended to be integrated into the current amyloid-β (Aβ) [A], tau [T], and neurodegeneration [(N)]-the "AT(N)" biomarker system for clinical research. However, the methodology is expensive and often requires invasive procedures to document cerebral vascular dysfunction. The retina has been used as a surrogate to study cerebral vascular changes. There is growing interest in the identification of retinal microvascular changes as a safe, easily accessible, low cost, and time-efficient approach to enhancing our understanding of the vascular pathogenesis associated with AD. EVIDENCE ACQUISITION A systemic review of the literature was performed regarding retinal vascular changes in AD and its prodromal stages, focusing on functional and structural changes of large retinal vessels (vessels visible on fundus photographs) and microvasculature (precapillary arterioles, capillary, and postcapillary venules) that are invisible on fundus photographs. RESULTS Static and dynamic retinal microvascular alterations such as retinal arterial wall motion, blood flow rate, and microvascular network density were reported in AD, mild cognitive impairment, and even in the preclinical stages of the disease. The data are somewhat controversial and inconsistent among the articles reviewed and were obtained based on cross-sectional studies that used different patient cohorts, equipment, techniques, and analysis methods. CONCLUSIONS Retinal microvascular alterations exist across the AD spectrum. Further large scale, within-subject longitudinal studies using standardized imaging and analytical methods may advance our knowledge concerning vascular contributions to the pathogenesis of AD.
Collapse
Affiliation(s)
- Hong Jiang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bonnie E. Levin
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bernard S. Baumel
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Christian J. Camargo
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | - Tania Rundek
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
34
|
Biscetti L, Lupidi M, Luchetti E, Eusebi P, Gujar R, Vergaro A, Cagini C, Parnetti L. Novel noninvasive biomarkers of prodromal Alzheimer disease: The role of optical coherence tomography and optical coherence tomography-angiography. Eur J Neurol 2021; 28:2185-2191. [PMID: 33852770 DOI: 10.1111/ene.14871] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE A reduction of retinal thickness and an alteration of retinal perfusion have been found in Alzheimer disease (AD). Nowadays, retinal layers and retinal perfusion can be evaluated by means of noninvasive imaging techniques, namely, optical coherence tomography (OCT) and OCT-angiography (OCT-A). Here, we have compared the retinal thickness and the perfusion index, measured by means of OCT and OCT-A, in patients with mild cognitive impairment due to AD (MCI-AD) and in age- and sex-matched cognitively healthy controls. METHODS Twenty-four MCI-AD patients and 13 control subjects were enrolled. MCI-AD patients underwent lumbar puncture; all of them showed a cerebrospinal fluid (CSF) profile compatible with AD. OCT was used for evaluating retinal volumes and thicknesses, whereas with OCT-A we measured fractal dimension (FD), vascular perfusion density (VPD), and vessel length density (VLD) of superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and choriocapillaris. The comparisons between groups were made after adjustment for age, diabetes, and hypertension. RESULTS A significant reduction of SCP-VLD (p = 0.012), ICP-VPD (p = 0.015), ICP-VLD (p = 0.004), DCP-VPD (p = 0.012), and DCP-VLD (p = 0.009) was found in MCI-AD patients compared to controls. Conversely, FD was higher in MCI-AD than in controls (p = 0.044). CSF Aβ42/total tau negatively correlated with FD (r = -0.51, p = 0.010). CONCLUSIONS OCT-A might have a potential role in detecting new noninvasive biomarkers for early AD detection. Retinal VPD might identify amyloid angiopathy-related chronic injury, and FD could show early vessel recruitment as a compensative mechanism at disease onset. Further studies will be needed to confirm these findings.
Collapse
Affiliation(s)
- Leonardo Biscetti
- Section of Neurology, Laboratory of Clinical Neurochemistry, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Marco Lupidi
- Section of Ophthalmology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy.,Macula Onlus Foundation, Di.N.O.G.Mi., University Eye Clinic, Genoa, Italy.,Odeon Center, Paris, France
| | - Elisa Luchetti
- Section of Neurology, Laboratory of Clinical Neurochemistry, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Paolo Eusebi
- Section of Neurology, Laboratory of Clinical Neurochemistry, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Ramkailash Gujar
- Section of Ophthalmology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Andrea Vergaro
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Carlo Cagini
- Section of Ophthalmology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Lucilla Parnetti
- Section of Neurology, Laboratory of Clinical Neurochemistry, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| |
Collapse
|
35
|
Li X, Fan F, Chen X, Li J, Ning L, Lin K, Chen Z, Qin Z, Yeung AS, Li X, Wang L, So KF. Computer Vision for Brain Disorders Based Primarily on Ocular Responses. Front Neurol 2021; 12:584270. [PMID: 33967931 PMCID: PMC8096911 DOI: 10.3389/fneur.2021.584270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 03/15/2021] [Indexed: 11/18/2022] Open
Abstract
Real-time ocular responses are tightly associated with emotional and cognitive processing within the central nervous system. Patterns seen in saccades, pupillary responses, and spontaneous blinking, as well as retinal microvasculature and morphology visualized via office-based ophthalmic imaging, are potential biomarkers for the screening and evaluation of cognitive and psychiatric disorders. In this review, we outline multiple techniques in which ocular assessments may serve as a non-invasive approach for the early detections of various brain disorders, such as autism spectrum disorder (ASD), Alzheimer's disease (AD), schizophrenia (SZ), and major depressive disorder (MDD). In addition, rapid advances in artificial intelligence (AI) present a growing opportunity to use machine learning-based AI, especially computer vision (CV) with deep-learning neural networks, to shed new light on the field of cognitive neuroscience, which is most likely to lead to novel evaluations and interventions for brain disorders. Hence, we highlight the potential of using AI to evaluate brain disorders based primarily on ocular features.
Collapse
Affiliation(s)
- Xiaotao Li
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States.,BIAI INC., Chelmsford, MA, United States.,BIAI Intelligence Biotech LLC, Shenzhen, China
| | - Fangfang Fan
- Department of Neurology, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Xuejing Chen
- Retina Division, Department of Ophthalmology, Boston University Eye Associates, Boston University, Boston, MA, United States
| | - Juan Li
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.,BIAI INC., Chelmsford, MA, United States.,BIAI Intelligence Biotech LLC, Shenzhen, China
| | - Li Ning
- Center for High Performance Computing, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Kangguang Lin
- Department of Affective Disorders and Academician Workstation of Mood and Brain Sciences, The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, China.,Guangdong-Hong Kong-Macau Institute of Central Nervous System (CNS) Regeneration, Jinan University, Guangzhou, China
| | - Zan Chen
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Zhenyun Qin
- Key Laboratory for Nonlinear Mathematical Models and Methods, School of Mathematical Science, Fudan University, Shanghai, China
| | - Albert S Yeung
- Depression Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Xiaojian Li
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Liping Wang
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Kwok-Fai So
- Guangdong-Hong Kong-Macau Institute of Central Nervous System (CNS) Regeneration, Jinan University, Guangzhou, China.,The State Key Laboratory of Brain and Cognitive Sciences, Department of Ophthalmology, University of Hong Kong, Pok Fu Lam, Hong Kong
| |
Collapse
|
36
|
DeBuc DC, Rege A, Smiddy WE. Use of XyCAM RI for Noninvasive Visualization and Analysis of Retinal Blood Flow Dynamics During Clinical Investigations. Expert Rev Med Devices 2021; 18:225-237. [PMID: 33635742 DOI: 10.1080/17434440.2021.1892486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Ocular blood flow plays a critical role in eye health by nourishing the retinal and ocular tissues with oxygen and nutrients and removal of ocular metabolic waste. Imaging of retinal and optic blood flow may provide insights for early and more specific diagnoses of ocular vascular disorder and facilitate eye-based biomarkers applicable to neurological health assessment and research. AREAS COVERED The ability of the XyCAM RI (Vasoptic Medical Inc., MD, USA) to visualize and to analyze ocular blood flow dynamics XyCAM RI using laser speckle contrast imaging is reviewed and compared with concurrent clinical ophthalmic imaging technologies like optical coherence tomography - angiography (OCT-A), fundus imaging, fluorescein angiography (FA), indocyanine green angiography (ICGA), laser Doppler flowmetry (LDF), and laser speckle flowgraphy (LSFG). EXPERT OPINION XyCAM RI, with its unprecedented imaging capabilities to assess blood flow dynamics provides a powerful tool to ophthalmic researchers and doctors to obtain greater clinical insights into the physiological status of the posterior segment and treatment approaches for various diseases in a very patient-friendly, noninvasive manner, unlike dye-based angiographic techniques such as FA or ICG. XyCAM RI is well suited as a modality that could close the gap between current screening and comprehensive eye exams.
Collapse
Affiliation(s)
- Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | - William E Smiddy
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
37
|
Rifai OM, McGrory S, Robbins CB, Grewal DS, Liu A, Fekrat S, MacGillivray TJ. The application of optical coherence tomography angiography in Alzheimer's disease: A systematic review. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12149. [PMID: 33718582 PMCID: PMC7927164 DOI: 10.1002/dad2.12149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/12/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Discovering non-invasive and easily acquired biomarkers that are conducive to the accurate diagnosis of dementia is an urgent area of ongoing clinical research. One promising approach is retinal imaging, as there is homology between retinal and cerebral vasculature. Recently, optical coherence tomography angiography (OCT-A) has emerged as a promising new technology for imaging the microvasculature of the retina. METHODS A systematic review and meta-analysis was conducted to examine the application of OCT-A in dementia. RESULTS Fourteen studies assessing OCT-A in preclinical Alzheimer's disease (AD), mild cognitive impairment, or AD were included. Exploratory meta-analyses revealed a significant increase in the foveal avascular zone area and a significant decrease in superficial parafoveal and whole vessel density in AD, although there was significant heterogeneity between studies. DISCUSSION Although certain OCT-A metrics may have the potential to serve as biomarkers for AD, the field requires further standardization to allow conclusions to be reached regarding their clinical utility.
Collapse
Affiliation(s)
- Olivia M. Rifai
- Translational Neuroscience PhD ProgrammeUniversity of EdinburghEdinburghUK
- Centre for Clinical Brain SciencesCollege of Medicine and Veterinary MedicineUniversity of EdinburghEdinburghUK
| | - Sarah McGrory
- Centre for Clinical Brain SciencesCollege of Medicine and Veterinary MedicineUniversity of EdinburghEdinburghUK
| | - Cason B. Robbins
- Department of OphthalmologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Dilraj S. Grewal
- Department of OphthalmologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Andy Liu
- Department of NeurologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Sharon Fekrat
- Department of OphthalmologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Thomas J. MacGillivray
- Centre for Clinical Brain SciencesCollege of Medicine and Veterinary MedicineUniversity of EdinburghEdinburghUK
| |
Collapse
|
38
|
Labounkova I, Labounek R, Nestrasil I, Odstrcilik J, Tornow RP, Kolar R. Blind Source Separation of Retinal Pulsatile Patterns in Optic Nerve Head Video-Recordings. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:852-864. [PMID: 33232226 DOI: 10.1109/tmi.2020.3039917] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dynamic optical imaging of retinal hemodynamics is a rapidly evolving technique in vision and eye-disease research. Video-recording, which may be readily accessible and affordable, captures several distinct functional phenomena such as the spontaneous venous pulsations (SVP) of central vein or local arterial blood supply etc. These phenomena display specific dynamic patterns that have been detected using manual or semi-automated methods. We propose a pioneering concept in retina video-imaging using blind source separation (BSS) serving as an automated localizer of distinct areas with temporally synchronized hemodynamics. The feasibility of BSS techniques (such as spatial principal component analysis and spatial independent component analysis) and K-means based post-processing method were successfully tested on the monocular and binocular video-ophthalmoscopic (VO) recordings of optic nerve head (ONH) in healthy subjects. BSSs automatically detected three spatially distinct reproducible areas, i.e. SVP, optic cup pulsations (OCP) that included areas of larger vessels in the nasal part of ONH, and "other" pulsations (OP). The K-means post-processing reduced a spike noise from the patterns' dynamics while high linear dependence between the non-filtered and post-processed signals was preserved. Although the dynamics of all patterns were heart rate related, the morphology analysis demonstrated significant phase shifts between SVP and OCP, and between SVP and OP. In addition, we detected low frequency oscillations that may represent respiratory-induced effects in time-courses of the VO recordings.
Collapse
|
39
|
Wang X, Zhao Q, Tao R, Lu H, Xiao Z, Zheng L, Ding D, Ding S, Ma Y, Lu Z, Xiao Y. Decreased Retinal Vascular Density in Alzheimer's Disease (AD) and Mild Cognitive Impairment (MCI): An Optical Coherence Tomography Angiography (OCTA) Study. Front Aging Neurosci 2021; 12:572484. [PMID: 33519415 PMCID: PMC7843508 DOI: 10.3389/fnagi.2020.572484] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND To explore the retinal vascular density changes in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients using optical coherence tomography angiography (OCTA). METHODS We recruit 62 AD patients, 47 MCI patients, and 49 cognitively healthy controls (HC) in this study. All participants in the study received a comprehensive ophthalmological and neurological evaluation, including global cognitive screening, as well as the Mini-Mental State Examination (MMSE), and completed the following eye examinations: visual acuity (VA), intraocular pressure (IOP), examination with slit-lamp, fundus photography (Version 1.5.0.0, NIDEK CO, LTD) and Optical coherence tomography imaging (software ReVue version 2017.1.0.155, Optovue Inc., Fremont, CA, United States). The visual rating scales for atrophy and white matter lesion in MRI was evaluated for all the patients with AD and MCI. RESULTS In the AD patient group, the superficial vascular density in the superior, inferior and whole retina was 44.64 ± 3.34, 44.65 ± 3.55, and 44.66 ± 3.36, respectively. These values were 44.24 ± 3.15, 43.72 ± 3.16, and 44 ± 3.07, respectively, in the MCI patient group. After multivariate analysis of the generalized linear model, adjustments for the confounding factors of sex, age, hypertension, diabetes and the quality index of OCTA image, the superficial vascular density in the AD and MCI patient groups was significantly lower than that in the HC group (P < 0.05): 46.94 ± 2.04, 46.67 ± 2.26, and 46.82 ± 2.08, respectively. No difference in the area of the FAZ among the three groups was observed (AD group: 0.34 ± 0.11 mm2; MCI group: 0.36 ± 0.12 mm2; control group: 0.33 ± 0.12 mm2, p > 0.05). The ganglion cell complex (GCC) thickness, inner parafovea thickness, and peripapillary retinal nerve fiber layer (p-RNFL) thickness were associated with the superficial vascular density. We found no significant correlation between the global cognition (MMSE scores) or between the Fazekas score and retinal OCT angiogram flow density. CONCLUSION The superficial vascular density in the AD and MCI patient groups was significantly lower than that in the HC group. Our findings suggest the retinal microvascular dysfunction occurred in MCI and AD.
Collapse
Affiliation(s)
- Xi Wang
- Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China
| | - Qianhua Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Rui Tao
- Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China
| | - Huimeng Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhenxu Xiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Li Zheng
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ding Ding
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Saineng Ding
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yichen Ma
- Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhaozeng Lu
- Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yiqin Xiao
- Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
40
|
Vandenabeele M, Veys L, Lemmens S, Hadoux X, Gelders G, Masin L, Serneels L, Theunis J, Saito T, Saido TC, Jayapala M, De Boever P, De Strooper B, Stalmans I, van Wijngaarden P, Moons L, De Groef L. The App NL-G-F mouse retina is a site for preclinical Alzheimer's disease diagnosis and research. Acta Neuropathol Commun 2021; 9:6. [PMID: 33407903 PMCID: PMC7788955 DOI: 10.1186/s40478-020-01102-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/13/2020] [Indexed: 12/13/2022] Open
Abstract
In this study, we report the results of a comprehensive phenotyping of the retina of the AppNL-G-F mouse. We demonstrate that soluble Aβ accumulation is present in the retina of these mice early in life and progresses to Aβ plaque formation by midlife. This rising Aβ burden coincides with local microglia reactivity, astrogliosis, and abnormalities in retinal vein morphology. Electrophysiological recordings revealed signs of neuronal dysfunction yet no overt neurodegeneration was observed and visual performance outcomes were unaffected in the AppNL-G-F mouse. Furthermore, we show that hyperspectral imaging can be used to quantify retinal Aβ, underscoring its potential as a biomarker for AD diagnosis and monitoring. These findings suggest that the AppNL-G-F retina mimics the early, preclinical stages of AD, and, together with retinal imaging techniques, offers unique opportunities for drug discovery and fundamental research into preclinical AD.
Collapse
Affiliation(s)
- Marjan Vandenabeele
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Lien Veys
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Sophie Lemmens
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
- 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
- Ophthalmology, Department of Surgery, University of Melbourne, Parkville, Australia
| | - Géraldine Gelders
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Luca Masin
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Lutgarde Serneels
- Leuven Brain Institute, Leuven, Belgium
- Center for Brain and Disease Research, Flemish Institute for Biotechnology (VIB), Leuven, Belgium
- Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jan Theunis
- Health Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
- Interuniversity Microelectronics Centre (Imec), Leuven, Belgium
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
| | - Murali Jayapala
- Interuniversity Microelectronics Centre (Imec), Leuven, Belgium
| | - Patrick De Boever
- Center for Brain and Disease Research, Flemish Institute for Biotechnology (VIB), Leuven, Belgium
- Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, KU Leuven, Leuven, Belgium
- Center of Environmental Sciences, Hasselt University, Diepenbeek, Belgium
- Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Bart De Strooper
- Leuven Brain Institute, Leuven, Belgium
- Center for Brain and Disease Research, Flemish Institute for Biotechnology (VIB), Leuven, Belgium
- Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Ingeborg Stalmans
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
- Research Group Ophthalmology, Department of Neurosciences, 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
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Lies De Groef
- Neural Circuit Development and Regeneration Research Group, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 61, Box 2464, 3000, Leuven, Belgium.
- Leuven Brain Institute, Leuven, Belgium.
| |
Collapse
|
41
|
Retinal Vein Occlusion and the Risk of Dementia: A Nationwide Cohort Study. Am J Ophthalmol 2021; 221:181-189. [PMID: 32777373 DOI: 10.1016/j.ajo.2020.07.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE Retinal vascular change is associated with changes in the brains of patients with dementia; however, there is limited evidence regarding the relationship between retinal vein occlusion (RVO) and risk of dementia. This study investigated the association between RVO and subsequent risk of dementia using a cohort consisting of the entire Korean population. DESIGN Retrospective cohort study. METHODS This study was based on the data from participants ≥40 years of age who underwent health examinations between 2009 and 2010 provided by the South Korean National Health Insurance Service. The RVO group (n = 46,259) consisted of patients whose initial diagnoses were between 2006 and 2010. The comparison group (3 per RVO patient; n = 138,777) was selected using propensity score matching according to age, sex, and systolic blood pressure. Multivariate Cox proportional hazard regression models were performed. RESULTS During a mean follow-up of 6.6 years, 14,727 cases of dementia developed. From the Kaplan-Meier curves, probabilities of cases for all types of dementia were significantly increased in the RVO group, relative to the comparison group (all log-rank P <.001). After all confounding variables were adjusted, the RVO group exhibited increased risks of subsequent all-cause dementia (hazard ratio [HR]: 1.16; 95% confidence interval [CI]: 1.12-1.21), Alzheimer's disease (HR: 1.15; 95% CI: 1.11-1.20), and vascular dementia (HR: 1.24; 95% CI: 1.12-1.37), relative to the comparison group. The presence of RVO was significantly associated with increased risks of all 3 types of dementia both in hypertensive and nonhypertensive individuals. CONCLUSIONS In this large-scale population-based cohort study, RVO was significantly associated with increased risks of all-cause dementia, Alzheimer's disease, and vascular dementia.
Collapse
|
42
|
Ostrovska SS, Liholetov EО, Pavlova VV, Derkach АK, Shevchenko IF, Adegova LY. RELATIONSHIP BETWEEN ALZHEIMER’S DISEASE, CEREBROVASCULAR AND CARDIOVASCULAR DISEASES (literature review). BULLETIN OF PROBLEMS BIOLOGY AND MEDICINE 2021. [DOI: 10.29254/2077-4214-2021-1-159-302-307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- S. S. Ostrovska
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| | - E. О. Liholetov
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| | - V. V. Pavlova
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| | - А. K. Derkach
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| | - I. F. Shevchenko
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| | - L. Y. Adegova
- Dnipro Medical Institute of Traditional and Alternative Medicine (Dnipro)
| |
Collapse
|
43
|
Dehghani C, Frost S, Jayasena R, Fowler C, Masters CL, Kanagasingam Y, Jiao H, Lim JKH, Chinnery HR, Downie LE. Morphometric Changes to Corneal Dendritic Cells in Individuals With Mild Cognitive Impairment. Front Neurosci 2020; 14:556137. [PMID: 33362451 PMCID: PMC7755610 DOI: 10.3389/fnins.2020.556137] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/09/2020] [Indexed: 11/13/2022] Open
Abstract
Purpose There has been increasing interest in identifying non-invasive, imaging biomarkers for neurodegenerative disorders of the central nervous system (CNS). The aim of this proof-of-concept study was to investigate whether corneal sensory nerve and dendritic cell (DC) parameters, captured using in vivo confocal microscopy (IVCM), are altered in individuals with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods Fifteen participants were recruited from the Australian Imaging Biomarkers and Lifestyle (AIBL) study in Melbourne, VIC, Australia. The cohort consisted of cognitively normal (CN) individuals (n = 5), and those with MCI (n = 5) and AD (n = 5). Participants underwent a slit lamp examination of the anterior segment, followed by corneal imaging using laser-scanning in vivo confocal microscopy (IVCM) of the central and inferior whorl regions. Corneal DC density, field area, perimeter, circularity index, aspect ratio, and roundness were quantified using Image J. Quantitative data were derived for corneal nerve parameters, including nerve fiber length (CNFL), fiber density (CNFD), branch density (CNBD), and diameter. Results Corneal DC field area and perimeter were greater in individuals with MCI, relative to CN controls, in both the central and inferior whorl regions (p < 0.05 for all comparisons). In addition, corneal DCs in the whorl region of MCI eyes had lower circularity and roundness indices and a higher aspect ratio relative to CNs (p < 0.05 for all comparisons). DC density was similar across participant groups in both corneal regions. There was a trend toward lower quantitative parameters for corneal nerve architecture in the AD and MCI groups compared with CN participants, however, the inter-group differences did not reach statistical significance. Central corneal nerve diameters were similar between groups. Conclusion This study is the first to report morphological differences in corneal DCs in humans with MCI. These differences were evident in both the central and mid-peripheral cornea, and in the absence of significant nerve abnormalities or a difference in DC density. These findings justify future large-scale studies to assess the utility of corneal IVCM and DC analysis for identifying early stage pathology in neurodegenerative disorders of the CNS.
Collapse
Affiliation(s)
- Cirous Dehghani
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia.,CSIRO, Australian e-Health Research Centre (AEHRC), Parkville, VIC, Australia.,Discipline of Optometry, University of Canberra, Canberra, ACT, Australia
| | - Shaun Frost
- CSIRO, Australian e-Health Research Centre (AEHRC), Floreat, WA, Australia
| | - Rajiv Jayasena
- CSIRO, Australian e-Health Research Centre (AEHRC), Parkville, VIC, Australia
| | - Christopher Fowler
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Colin L Masters
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | | | - Haihan Jiao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia.,Optometry and Vision Science, College of Nursing and Health Sciences, Flinders University, Adelaide, SA, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
44
|
Chua J, Hu Q, Ke M, Tan B, Hong J, Yao X, Hilal S, Venketasubramanian N, Garhöfer G, Cheung CY, Wong TY, Chen CLH, Schmetterer L. Retinal microvasculature dysfunction is associated with Alzheimer's disease and mild cognitive impairment. ALZHEIMERS RESEARCH & THERAPY 2020; 12:161. [PMID: 33276820 PMCID: PMC7718666 DOI: 10.1186/s13195-020-00724-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/10/2020] [Indexed: 12/20/2022]
Abstract
Background The retina and brain share many neuronal and vasculature characteristics. We investigated the retinal microvasculature in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) using optical coherence tomography angiography (OCTA). Methods In this cross-sectional study, 24 AD participants, 37 MCI participants, and 29 controls were diagnosed according to internationally accepted criteria. OCTA images of the superficial and deep capillary plexus (SCP, DCP) of the retinal microvasculature were obtained using a commercial OCTA system (Zeiss Cirrus HD-5000 with AngioPlex, Carl Zeiss Meditec, Dublin, CA). The main outcome measures were vessel density (VD) and fractal dimension (FD) in the SCP and DCP within a 2.5-mm ring around the fovea which were compared between groups. Perfusion density of large vessels and foveal avascular zone (FAZ) area were additional outcome parameters. Results Age, gender, and race did not differ among groups. However, there was a significant difference in diabetes status (P = 0.039) and systolic blood pressure (P = 0.008) among the groups. After adjusting for confounders, AD participants showed significantly decreased VD in SCP and DCP (P = 0.006 and P = 0.015, respectively) and decreased FD in SCP (P = 0.006), compared to controls. MCI participants showed significantly decreased VD and FD only in SCP (P = 0.006 and P < 0.001, respectively) and not the DCP (P > 0.05) compared with controls. There was no difference in the OCTA variables between AD and MCI (P > 0.05). Perfusion density of large vessels and FAZ area did not differ significantly between groups (P > 0.05). Conclusions and relevance Eyes of patients with AD have significantly reduced macular VD in both plexuses whereas MCI participants only showed reduction in the superficial plexus. Changes in the retinal microvasculature and capillary network may offer a valuable insight on the brain in AD. Supplementary information The online version contains supplementary material available at 10.1186/s13195-020-00724-0.
Collapse
Affiliation(s)
- Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Sha Tin, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore
| | - Qinglan Hu
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore
| | - Mengyuan Ke
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore.,Institute for Health Technologies, Nanyang Technological University, Sha Tin, Singapore
| | - Jimmy Hong
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore
| | - Xinwen Yao
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore.,Institute for Health Technologies, Nanyang Technological University, Sha Tin, Singapore
| | - Saima Hilal
- Memory Aging and Cognition Centre, Departments of Pharmacology and Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Sha Tin, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, Sha Tin, Singapore.,Department of Pharmacology, National University of Singapore, Singapore, Singapore
| | - Narayanaswamy Venketasubramanian
- Memory Aging and Cognition Centre, Departments of Pharmacology and Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Sha Tin, Singapore.,Raffles Neuroscience Centre, Raffles Hospital, Singapore, Singapore
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University Vienna, Vienna, Austria
| | - Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Sha Tin, Singapore
| | - Christopher Li-Hsian Chen
- Memory Aging and Cognition Centre, Departments of Pharmacology and Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Sha Tin, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, 20 College Road, The Academia, Level 6, Discovery Tower, Singapore, 169856, Singapore. .,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Sha Tin, Singapore. .,SERI-NTU Advanced Ocular Engineering (STANCE), Sha Tin, Singapore. .,Institute for Health Technologies, Nanyang Technological University, Sha Tin, Singapore. .,Department of Clinical Pharmacology, Medical University Vienna, Vienna, Austria. .,Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria. .,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland.
| |
Collapse
|
45
|
Cho KA, Rege A, Jing Y, Chaurasia A, Guruprasad A, Arthur E, Cabrera DeBuc D. Portable, non-invasive video imaging of retinal blood flow dynamics. Sci Rep 2020; 10:20236. [PMID: 33214571 PMCID: PMC7677377 DOI: 10.1038/s41598-020-76407-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 07/27/2020] [Indexed: 02/04/2023] Open
Abstract
Retinal blood flow (RBF) information has the potential to offer insight into ophthalmic health and disease that is complementary to traditional anatomical biomarkers as well as to retinal perfusion information provided by fluorescence or optical coherence tomography angiography (OCT-A). The present study was performed to test the functional attributes and performance of the XyCAM RI, a non-invasive imager that obtains and assesses RBF information. The XyCAM RI was installed and used in two different settings to obtain video recordings of the blood flow in the optic nerve head region in eyes of healthy subjects. The mean blood flow velocity index (BFVi) in the optic disc and in each of multiple arterial and venous segments was obtained and shown to reveal a temporal waveform with a peak and trough that correlates with a cardiac cycle as revealed by a reference pulse oximeter (correlation between respective peak-to-peak distances was 0.977). The intra-session repeatability of the XyCAM RI was high with a coefficient of variation (CV) of 1.84 ± 1.13% across both sites. Artery-vein comparisons were made by estimating, in a pair of adjacent arterial and venous segments, various temporal waveform metrics such as pulsatility index, percent time in systole and diastole, and change in vascular blood volume over a cardiac cycle. All arterial metrics were shown to have significant differences with venous metrics (p < 0.001). The XyCAM RI, therefore, by obtaining repeatable blood flow measurements with high temporal resolution, permits the differential assessment of arterial and venous blood flow patterns in the retina that may facilitate research into disease pathophysiology and biomarker development for diagnostics.
Collapse
Affiliation(s)
| | | | - Yici Jing
- Vasoptic Medical, Inc., Baltimore, MD, USA
| | | | | | - Edmund Arthur
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 N.W. 10th Avenue, Room 509, Miami, FL, 33136, USA.
| |
Collapse
|
46
|
Fluid Candidate Biomarkers for Alzheimer's Disease: A Precision Medicine Approach. J Pers Med 2020; 10:jpm10040221. [PMID: 33187336 PMCID: PMC7712586 DOI: 10.3390/jpm10040221] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022] Open
Abstract
A plethora of dynamic pathophysiological mechanisms underpins highly heterogeneous phenotypes in the field of dementia, particularly in Alzheimer's disease (AD). In such a faceted scenario, a biomarker-guided approach, through the implementation of specific fluid biomarkers individually reflecting distinct molecular pathways in the brain, may help establish a proper clinical diagnosis, even in its preclinical stages. Recently, ultrasensitive assays may detect different neurodegenerative mechanisms in blood earlier. ß-amyloid (Aß) peptides, phosphorylated-tau (p-tau), and neurofilament light chain (NFL) measured in blood are gaining momentum as candidate biomarkers for AD. P-tau is currently the more convincing plasma biomarker for the diagnostic workup of AD. The clinical role of plasma Aβ peptides should be better elucidated with further studies that also compare the accuracy of the different ultrasensitive techniques. Blood NFL is promising as a proxy of neurodegeneration process tout court. Protein misfolding amplification assays can accurately detect α-synuclein in cerebrospinal fluid (CSF), thus representing advancement in the pathologic stratification of AD. In CSF, neurogranin and YKL-40 are further candidate biomarkers tracking synaptic disruption and neuroinflammation, which are additional key pathophysiological pathways related to AD genesis. Advanced statistical analysis using clinical scores and biomarker data to bring together individuals with AD from large heterogeneous cohorts into consistent clusters may promote the discovery of pathophysiological causes and detection of tailored treatments.
Collapse
|
47
|
Sarkar B, Siddiqui Z, Kim KK, Nguyen PK, Reyes X, McGill TJ, Kumar VA. Implantable anti-angiogenic scaffolds for treatment of neovascular ocular pathologies. Drug Deliv Transl Res 2020; 10:1191-1202. [PMID: 32232681 PMCID: PMC7483832 DOI: 10.1007/s13346-020-00753-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The retinal physiology can accrue oxidative damage and inflammatory insults due to age and metabolic irregularities. Two notable diseases that involve retinal and choroidal neovascularization are proliferative diabetic retinopathy and wet age-related macular degeneration. Currently, these diseases are mainly treated with anti-VEGF drugs (VEGF = vascular endothelial growth factor), generally on a monthly dosage scheme. We discuss recent developments for the treatment of these diseases, including bioactive tissue-engineered materials, which may reduce frequency of dosage and propose a path forward for improving patient outcomes. Graphical abstract Development of materials for long-term intravitreal delivery for management of posterior segment diseases.
Collapse
Affiliation(s)
- Biplab Sarkar
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA
| | - Zain Siddiqui
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA
| | - Ka Kyung Kim
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA
| | - Peter K Nguyen
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA
| | - Xavier Reyes
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA
| | - Trevor J McGill
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Vivek A Kumar
- Department of Biomedical Engineering, New Jersey Institute of Technology, 138 Warren St. LSEB 316, Newark, NJ, 07102, USA.
- Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
- Department of Restorative Dentistry, Rutgers School of Dental Medicine, Newark, NJ, USA.
| |
Collapse
|
48
|
Asanad S, Mohammed I, Sadun AA, Saeedi OJ. OCTA in neurodegenerative optic neuropathies: emerging biomarkers at the eye-brain interface. Ther Adv Ophthalmol 2020; 12:2515841420950508. [PMID: 32923939 PMCID: PMC7457690 DOI: 10.1177/2515841420950508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/13/2020] [Indexed: 12/22/2022] Open
Abstract
OCTA imaging in optic neuropathies.
Collapse
Affiliation(s)
- Samuel Asanad
- Department of Ophthalmology and Visual Sciences, University of Maryland Eye Associates, University of Maryland Medical Center and University of Maryland School of Medicine, 419 W. Redwood St., Baltimore, MD 21201, USA
| | - Isa Mohammed
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alfredo A Sadun
- Doheny Eye Center, Los Angeles, CA, USA; Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Osamah J Saeedi
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
49
|
Wu SZ, Masurkar AV, Balcer LJ. Afferent and Efferent Visual Markers of Alzheimer's Disease: A Review and Update in Early Stage Disease. Front Aging Neurosci 2020; 12:572337. [PMID: 33061906 PMCID: PMC7518395 DOI: 10.3389/fnagi.2020.572337] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/20/2020] [Indexed: 01/06/2023] Open
Abstract
Vision, which requires extensive neural involvement, is often impaired in Alzheimer's disease (AD). Over the last few decades, accumulating evidence has shown that various visual functions and structures are compromised in Alzheimer's dementia and when measured can detect those with dementia from those with normal aging. These visual changes involve both the afferent and efferent parts of the visual system, which correspond to the sensory and eye movement aspects of vision, respectively. There are fewer, but a growing number of studies, that focus on the detection of predementia stages. Visual biomarkers that detect these stages are paramount in the development of successful disease-modifying therapies by identifying appropriate research participants and in identifying those who would receive future therapies. This review provides a summary and update on common afferent and efferent visual markers of AD with a focus on mild cognitive impairment (MCI) and preclinical disease detection. We further propose future directions in this area. Given the ease of performing visual tests, the accessibility of the eye, and advances in ocular technology, visual measures have the potential to be effective, practical, and non-invasive biomarkers of AD.
Collapse
Affiliation(s)
- Shirley Z. Wu
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, United States
| | - Arjun V. Masurkar
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Laura J. Balcer
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Population Health, New York University Grossman School of Medicine, New York, NY, United States
| |
Collapse
|
50
|
Mirzaei N, Shi H, Oviatt M, Doustar J, Rentsendorj A, Fuchs DT, Sheyn J, Black KL, Koronyo Y, Koronyo-Hamaoui M. Alzheimer's Retinopathy: Seeing Disease in the Eyes. Front Neurosci 2020; 14:921. [PMID: 33041751 PMCID: PMC7523471 DOI: 10.3389/fnins.2020.00921] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/10/2020] [Indexed: 01/18/2023] Open
Abstract
The neurosensory retina emerges as a prominent site of Alzheimer's disease (AD) pathology. As a CNS extension of the brain, the neuro retina is easily accessible for noninvasive, high-resolution imaging. Studies have shown that along with cognitive decline, patients with mild cognitive impairment (MCI) and AD often suffer from visual impairments, abnormal electroretinogram patterns, and circadian rhythm disturbances that can, at least in part, be attributed to retinal damage. Over a decade ago, our group identified the main pathological hallmark of AD, amyloid β-protein (Aβ) plaques, in the retina of patients including early-stage clinical cases. Subsequent histological, biochemical and in vivo retinal imaging studies in animal models and in humans corroborated these findings and further revealed other signs of AD neuropathology in the retina. Among these signs, hyperphosphorylated tau, neuronal degeneration, retinal thinning, vascular abnormalities and gliosis were documented. Further, linear correlations between the severity of retinal and brain Aβ concentrations and plaque pathology were described. More recently, extensive retinal pericyte loss along with vascular platelet-derived growth factor receptor-β deficiency were discovered in postmortem retinas of MCI and AD patients. This progressive loss was closely associated with increased retinal vascular amyloidosis and predicted cerebral amyloid angiopathy scores. These studies brought excitement to the field of retinal exploration in AD. Indeed, many questions still remain open, such as queries related to the temporal progression of AD-related pathology in the retina compared to the brain, the relations between retinal and cerebral changes and whether retinal signs can predict cognitive decline. The extent to which AD affects the retina, including the susceptibility of certain topographical regions and cell types, is currently under intense investigation. Advances in retinal amyloid imaging, hyperspectral imaging, optical coherence tomography, and OCT-angiography encourage the use of such modalities to achieve more accurate, patient- and user-friendly, noninvasive detection and monitoring of AD. In this review, we summarize the current status in the field while addressing the many unknowns regarding Alzheimer's retinopathy.
Collapse
Affiliation(s)
- Nazanin Mirzaei
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Mia Oviatt
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Jonah Doustar
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Altan Rentsendorj
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Keith L. Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| |
Collapse
|