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Cipolla J, Jiang H, Simms AG, Baumel B, Rundek T, Wang J. Impaired Retinal Capillary Function in Patients With Alzheimer Disease. J Neuroophthalmol 2024; 44:30-34. [PMID: 37459384 PMCID: PMC10792098 DOI: 10.1097/wno.0000000000001954] [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] [Indexed: 10/16/2023]
Abstract
BACKGROUND Extensive evidence indicates that vasculopathy, especially the level of microcirculation, contributes to neurodegeneration in Alzheimer disease (AD). However, it is not easy to directly monitor cerebral microcirculation. The retinal microvasculature has been proposed as a surrogate measure to study cerebral vascular changes. Indeed, decreased retinal microvascular network densities were reported in patients with AD. We sought to determine the retinal capillary function (RCF, the efficiency of blood flow transferring in the capillary network) in patients with AD. METHODS Twenty patients (age 60-84 years, mean ± SD: 72.8 ± 7.7 years) with AD and 14 age-matched cognitively normal controls (CN, age 62-81 years, mean ± SD: 68.6 ± 6.7 years.) were recruited. There were no differences in vascular risk factors, including smoking, hypertension, hyperlipidemia, Type 2 diabetes, and cardiovascular disease, between the groups. One eye of each subject in both groups was imaged. Retinal blood flow (RBF) was measured using a retinal function imager, and retinal capillary density (RCD, expressed as fractal dimension Dbox) was measured using optical coherence tomography angiography. RCF was defined as the ratio of RBF to RCD. RESULTS RCF was 1.62 ± 0.56 nl/s/Dbox (mean ± SD) in the AD group, which was significantly lower than that (2.56 ± 0.25 nl/s/Dbox, P < 0.01) in the CN group. The change of RCF in the AD group represented 28% lower than in the CN group. RCF was significantly and positively correlated with RBF in the AD group (r = 0.98, P < 0.05) and in the CN group (r = 0.65, P < 0.05). CONCLUSIONS Our study is the first to demonstrate impaired retinal capillary function in patients with AD. The alteration of RCF was mainly due to decreased retinal blood flow, which is transferred by the capillary network. The RCF may be developed as a biomarker of impaired cerebral microcirculation in patients with AD.
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Affiliation(s)
- Jack Cipolla
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Hong Jiang
- University of Miami Miller School of Medicine, Miami, FL, USA
- 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
- The University of Miami Evelyn F. McKnight Brain Institute, Miami, FL, USA
| | - Ava-Gaye Simms
- University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bernard Baumel
- University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Tatjana Rundek
- University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
- The University of Miami Evelyn F. McKnight Brain Institute, Miami, FL, USA
| | - Jianhua Wang
- University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- The University of Miami Evelyn F. McKnight Brain Institute, Miami, FL, USA
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Dumitrascu OM, Doustar J, Fuchs DT, Koronyo Y, Sherman DS, Miller MS, Johnson KO, Carare RO, Verdooner SR, Lyden PD, Schneider JA, Black KL, Koronyo-Hamaoui M. Distinctive retinal peri-arteriolar versus peri-venular amyloid plaque distribution correlates with the cognitive performance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.580733. [PMID: 38464292 PMCID: PMC10925252 DOI: 10.1101/2024.02.27.580733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Introduction The vascular contribution to Alzheimer's disease (AD) is tightly connected to cognitive performance across the AD continuum. We topographically describe retinal perivascular amyloid plaque (AP) burden in subjects with normal or impaired cognition. Methods Using scanning laser ophthalmoscopy, we quantified retinal peri-arteriolar and peri-venular curcumin-positive APs in the first, secondary and tertiary branches in twenty-eight subjects. Perivascular AP burden among cognitive states was correlated with neuroimaging and cognitive measures. Results Peri-arteriolar exceeded peri-venular AP count (p<0.0001). Secondary branch AP count was significantly higher in cognitively impaired (p<0.01). Secondary small and tertiary peri-venular AP count strongly correlated with clinical dementia rating, hippocampal volumes, and white matter hyperintensity count. Discussion Our topographic analysis indicates greater retinal amyloid accumulation in the retinal peri-arteriolar regions overall, and distal peri-venular regions in cognitively impaired individuals. Larger longitudinal studies are warranted to understand the temporal-spatial relationship between vascular dysfunction and perivascular amyloid deposition in AD. Highlights Retinal peri-arteriolar region exhibits more amyloid compared with peri-venular regions.Secondary retinal vascular branches have significantly higher perivascular amyloid burden in subjects with impaired cognition, consistent across sexes.Cognitively impaired individuals have significantly greater retinal peri-venular amyloid deposits in the distal small branches, that correlate with CDR and hippocampal volumes.
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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.
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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
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Shen Z, Zhang S, Yu W, Yue M, Hong C. Optical Coherence Tomography Angiography: Revolutionizing Clinical Diagnostics and Treatment in Central Nervous System Disease. Aging Dis 2024:AD.2024.0112. [PMID: 38300645 DOI: 10.14336/ad.2024.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/12/2024] [Indexed: 02/02/2024] Open
Abstract
Optical coherence tomography angiography (OCTA), as a new generation of non-invasive and efficient fundus imaging technology, can provide non-invasive assessment of vascular lesions in the retina and choroid. In terms of anatomy and development, the retina is referred to as an extension of the central nervous system (CNS). CNS diseases are closely related to changes in fundus structure and blood vessels, and direct visualization of fundus structure and blood vessels provides an effective "window" for CNS research. This has important practical significance for identifying the characteristic changes of various CNS diseases on OCTA in the future, and plays a key role in promoting early screening, diagnosis, and monitoring of disease progression in CNS diseases. This article reviews relevant fundus studies by comparing and summarizing the unique advantages and existing limitations of OCTA in various CNS disease patients, in order to demonstrate the clinical significance of OCTA in the diagnosis and treatment of CNS diseases.
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Affiliation(s)
- Zeqi Shen
- Postgraduate training base Alliance of Wenzhou Medical University (Affiliated People's Hospital), Hangzhou, Zhejiang, China
| | - Sheng Zhang
- Center for Rehabilitation Medicine, Department of Neurology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Weitao Yu
- The Second School of Clinical Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Mengmeng Yue
- Postgraduate training base Alliance of Wenzhou Medical University (Affiliated People's Hospital), Hangzhou, Zhejiang, China
| | - Chaoyang Hong
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
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Sheriff S, Shen T, Saks D, Schultz A, Francis H, Wen W, Jiang J, Mirzaei M, Gupta V, Fiatarone Singh M, Sachdev PS, Graham SL, Gupta V. The Association of APOE ε4 Allele with Retinal Layer Thickness and Microvasculature in Older Adults: Optic Nerve Decline and Cognitive Change Study. J Clin Med 2023; 12:6219. [PMID: 37834863 PMCID: PMC10573915 DOI: 10.3390/jcm12196219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
PURPOSE To investigate the relationship between the apolipoprotein E (APOE) ε4 allele and retinal structural and vascular characteristics in older adult participants from several research studies. We also studied the relationship between these structural and vascular characteristics with multifocal visual evoked potential (mfVEP) indices, neuropsychological parameters and MRI brain volumes in these participants. METHODS In this study, 109 participants with a mean (SD) age of 67.1 (9.0) years were recruited. Participants were classified as APOE ε4 carriers or non-carriers based on the presence or absence of the ε4 allele. Baseline measurements included peripapillary retinal nerve fibre layer optical coherence tomography (RNFL OCT), and OCT-angiography (OCT-A) for evaluation of the retinal layer thickness and vessel density (VD) parameters. A multifocal visual evoked potential (mfVEP) test, including amplitude and latency, was used to assess the visual pathway function. Finally, cognitive function was evaluated using a battery of neuropsychological tests. OCT-A images were analysed in ImageJ to quantify VD in the superficial and deep vascular plexus and the size of the foveal avascular zone (FAZ). The relationship between carriers of APOE ε4 allele and these ocular parameters was analysed using generalised estimating equation (GEE) models and data adjusted for age, sex and inter-eye differences as within-subject variables (p < 0.05). RESULTS Twenty-four participants were APOE ε4 carriers. Temporal RNFL thickness was decreased in APOE ε4 carriers (p < 0.01). Vessel density between carriers and non-carriers was not significantly different at either the superficial or deep level. The FAZ area was significantly smaller in ε4 carriers in both superficial (p < 0.01) and deep layers (p < 0.003). CONCLUSIONS Retinal abnormalities were present in participants with increased genetic risk of dementia due to presence of the ε4 allele. These findings provide preliminary evidence for their potential role in the diagnosis of dementia.
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Affiliation(s)
- Samran Sheriff
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Ting Shen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People’s Hospital), School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Danit Saks
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Angela Schultz
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Heather Francis
- School of Psychological Sciences, Macquarie University, Sydney, NSW 2019, Australia
- Neurology Department, Royal North Shore Hospital, Sydney, NSW 2065, Australia
| | - Wei Wen
- Centre for Healthy Brain Ageing, University of New South Wales, Sydney, NSW 2052, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Jiyang Jiang
- Centre for Healthy Brain Ageing, University of New South Wales, Sydney, NSW 2052, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Mehdi Mirzaei
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Melbourne, VIC 3125, Australia
| | - Maria Fiatarone Singh
- Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA 02131, USA
| | - Perminder S. Sachdev
- Centre for Healthy Brain Ageing, University of New South Wales, Sydney, NSW 2052, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Stuart L. Graham
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Vivek Gupta
- Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
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Jiang H, Signorile JF, Simms AG, Wang J. Improvement of Retinal Capillary Function After High-Speed Circuit Resistance Training in Healthy Older Adults. J Neuroophthalmol 2023; 43:180-184. [PMID: 35921279 DOI: 10.1097/wno.0000000000001679] [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] [Indexed: 11/25/2022]
Abstract
BACKGROUND To determine the retinal capillary function (RCF, the efficiency of blood flow transferring in the capillary network) and its relation to cognitive function in healthy older people without known cognitive impairment following an 8-week high-speed circuit resistance training program (HSCT). METHODS Eleven subjects in the HSCT group and 7 age-matched nontraining controls (CON) were recruited. The HSCT group trained 3 times per week for 8 weeks, whereas CON performed no formal training. One eye of each subject from both groups was imaged at baseline and 8-week follow-up. Retinal blood flow (RBF) was measured using a retinal function imager, and retinal capillary density (RCD, expressed as fractal dimension Dbox) was measured using optical coherence tomography angiography. RCF was defined as the ratio of RBF to RCD. Cognitive function was assessed during both visits using the NIH Toolbox Fluid Cognition Battery. RESULTS RCF was 2.07 ± 0.64 nL⋅s -1 ·Dbox -1 (mean ± SD) at baseline, and significantly increased to 2.59 ± 0.54 nL⋅s -1 ·Dbox -1 after training ( P = 0.0003) in the HSCT group, reflecting an increase of 25%. The changes of RBF were not related to the changes of RCD in the HSCT group (r = -0.18, P = 0.59). There was no significant change of RCF in the CON group ( P = 0.58). In the HSCT group, the Pattern Comparison Processing Speed Test and Fluid Cognition Composite Score were significantly increased after HSCT ( P = 0.01). Furthermore, the changes in Flanker Inhibitory Control and Attention Test (FLNK) were positively correlated to increases in RCF (r = 0.77, P = 0.005). CONCLUSIONS This is the first prospective study to demonstrate that the increased RCF after HSCT was related to improved cognition in cognitively normal older adults.
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Affiliation(s)
- Hong Jiang
- Department of Ophthalmology (HJ, JW, A-GS), Bascom Palmer Eye Institute, Department of Neurology (HJ), University of Miami Miller School of Medicine, Miami, Florida; and Department of Kinesiology and Sports Sciences (JFS), University of Miami, Miami, Florida
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Retinal Neurodegeneration Measured With Optical Coherence Tomography and Neuroimaging in Alzheimer Disease: A Systematic Review. J Neuroophthalmol 2023; 43:116-125. [PMID: 36255105 DOI: 10.1097/wno.0000000000001673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Optical coherence tomography (OCT) has enabled several retinal alterations to be detected in patients with Alzheimer disease (AD), alterations that could be potential biomarkers. However, the relationship between the retina and other biomarkers of AD has been underresearched. We gathered and analyzed the literature about the relationship between retinal and cerebral alterations detected via neuroimaging in patients with AD, mild cognitive impairment (MCI), and preclinical AD. METHODS This systematic review followed the PRISMA Statement guidelines through the 27 items on its checklist. We searched in PubMed, BVS, Scopus, and the Cochrane Library, using the keywords: Alzheimer's disease, optical coherence tomography, white matter, cortex, atrophy, cortical thickness, neuroimaging, magnetic resonance imaging, and positron emission tomography. We included articles that studied the retina in relation to neuroimaging in patients with AD, MCI, and preclinical AD. We excluded studies without OCT, without neuroimaging, clinical cases, opinion articles, systematic reviews, and animal studies. RESULTS Of a total of 35 articles found, 23 were finally included. Although mixed results were found, most of these corroborate the relationship between retinal and brain disorders. CONCLUSIONS More rigorous research is needed in the field, including homogenized, longitudinal, and prolonged follow-up studies, as well as studies that include all stages of AD. This will enable better understanding of the retina and its implications in AD, leading to the discovery of retinal biomarkers that reflect brain alterations in AD patients in an accessible and noninvasive manner.
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Moon S, Jeon S, Seo SK, Kim DE, Jung NY, Kim SJ, Lee MJ, Lee J, Kim EJ. Comparison of Retinal Structural and Neurovascular Changes between Patients with and without Amyloid Pathology. J Clin Med 2023; 12:jcm12041310. [PMID: 36835845 PMCID: PMC9964845 DOI: 10.3390/jcm12041310] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 02/10/2023] Open
Abstract
To evaluate whether an impaired anterior visual pathway (retinal structures with microvasculature) is associated with underlying beta-amyloid (Aβ) pathologies in patients with Alzheimer's disease dementia (ADD) and mild cognitive impairment (MCI), we compared retinal structural and vascular factors in each subgroup with positive or negative amyloid biomarkers. Twenty-seven patients with dementia, thirty-five with MCI, and nine with cognitively unimpaired (CU) controls were consecutively recruited. All participants were divided into positive Aβ (A+) or negative Aβ (A-) pathology based on amyloid positron emission tomography or cerebrospinal fluid Aβ. The retinal circumpapillary retinal nerve fiber layer thickness (cpRNFLT), macular ganglion cell/inner plexiform layer thickness (mGC/IPLT), and microcirculation of the macular superficial capillary plexus were measured using optical coherence tomography (OCT) and OCT angiography. One eye of each participant was included in the analysis. Retinal structural and vascular factors significantly decreased in the following order: dementia < MCI < CU controls. The A+ group had significantly lower microcirculation in the para- and peri-foveal temporal regions than did the A-. However, the structural and vascular parameters did not differ between the A+ and A- with dementia. The cpRNFLT was unexpectedly greater in the A+ than in the A- with MCI. mGC/IPLT was lower in the A+ CU than in the A- CU. Our findings suggest that retinal structural changes may occur in the preclinical and early stages of dementia but are not highly specific to AD pathophysiology. In contrast, decreased temporal macula microcirculation may be used as a biomarker for the underlying Aβ pathology.
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Affiliation(s)
- Sangwoo Moon
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
| | - Sumin Jeon
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
| | - Sook Kyeong Seo
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
| | - Da Eun Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
| | - Na-Yeon Jung
- Department of Neurology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan 50612, Republic of Korea
| | - Seung Joo Kim
- Department of Neurology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea
| | - Myung Jun Lee
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
| | - Jiwoong Lee
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
- Correspondence: (J.L.); (E.-J.K.)
| | - Eun-Joo Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan 49241, Republic of Korea
- Correspondence: (J.L.); (E.-J.K.)
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Mroczkowska S, Shokr H, Benavente-Pérez A, Negi A, Bentham P, Gherghel D. Retinal Microvascular Dysfunction Occurs Early and Similarly in Mild Alzheimer's Disease and Primary-Open Angle Glaucoma Patients. J Clin Med 2022; 11:jcm11226702. [PMID: 36431179 PMCID: PMC9717733 DOI: 10.3390/jcm11226702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022] Open
Abstract
Purpose: To assess the similarities and differences in retinal microvascular function between mild Alzheimer’s disease (AD) patients, early-stage primary open angle glaucoma (POAG) patients and healthy controls. Methods: Retinal vessel reactivity to flickering light was assessed in 10 AD, 19 POAG and 20 healthy age matched control patients by means of dynamic retinal vessel analysis (DVA, IMEDOS, GmbH, Jena, Germany) according to an established protocol. All patients additionally underwent BP measurements and blood analysis for glucose and lipid metabolism markers. Results: AD and POAG patients demonstrated comparable alterations in retinal artery reactivity, in the form of an increased arterial reaction time (RT) to flicker light on the final flicker cycle (p = 0.009), which was not replicated by healthy controls (p > 0.05). Furthermore, the sequential changes in RT on progressing from flicker one to flicker three were found to differ between healthy controls and the two disease groups (p = 0.001). Conclusion: AD and POAG patients demonstrate comparable signs of vascular dysfunction in their retinal arteries at the early stages of their disease process. This provides support for the concept of a common underlying vascular aetiology in these two neurodegenerative diseases.
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Affiliation(s)
- Stephanie Mroczkowska
- Vascular Research Laboratory, Ophthalmic Research Group, College Health and Life Sciences, Aston University, Birmingham B4 7ET, UK
- Eye and Vision Research Group, School of Health Professions, Plymouth University, Plymouth PL4 8AA, UK
- Correspondence: (S.M.); (D.G.); Tel.: +44-0121-204-3000 (D.G.)
| | - Hala Shokr
- Vascular Research Laboratory, Ophthalmic Research Group, College Health and Life Sciences, Aston University, Birmingham B4 7ET, UK
- Pharmacy Division, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Alexandra Benavente-Pérez
- Vascular Research Laboratory, Ophthalmic Research Group, College Health and Life Sciences, Aston University, Birmingham B4 7ET, UK
| | - Anil Negi
- Medical Innovation Development and Research Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 1NT, UK
| | - Peter Bentham
- Medical Innovation Development and Research Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 1NT, UK
| | - Doina Gherghel
- Vascular Research Laboratory, Ophthalmic Research Group, College Health and Life Sciences, Aston University, Birmingham B4 7ET, UK
- Division of Cardiovascular Sciences, University of Manchester, Manchester M13 9PL, UK
- Correspondence: (S.M.); (D.G.); Tel.: +44-0121-204-3000 (D.G.)
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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.
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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
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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: 7] [Impact Index Per Article: 3.5] [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.
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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
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Yeh TC, Kuo CT, Chou YB. Retinal Microvascular Changes in Mild Cognitive Impairment and Alzheimer's Disease: A Systematic Review, Meta-Analysis, and Meta-Regression. Front Aging Neurosci 2022; 14:860759. [PMID: 35572135 PMCID: PMC9096234 DOI: 10.3389/fnagi.2022.860759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/14/2022] [Indexed: 01/03/2023] Open
Abstract
Background The remarkable increase in prevalence and significant morbidity of neurodegenerative diseases pose a tremendous burden for the health care system. Changes in retinal microvasculature metrics associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI) may provide opportunities for early diagnosis and intervention. However, the role of retinal vascular biomarkers remains controversial. We aim to perform a systematic review, meta-analysis and meta-regression to evaluate the comprehensive retinal microvasculature changes in patients with AD and MCI. Methods We conducted a literature search on PubMed, MEDLINE, and EMBASE to identify studies published before May 2021 which assessed the measurements of optical coherence tomography angiography (OCTA) between AD, MCI with healthy control eyes, including foveal avascular zone (FAZ), vessel density (VD) of peripapillary, superficial and deep capillary plexus, and choroidal thickness using a random-effect model. We also performed meta-regression and subgroup analysis and assessed heterogeneity and publication bias to evaluate potential sources of bias. Results Compared with control eyes, VD of superficial capillary plexus was significantly lower in AD [standardized mean difference (SMD): −0.48; 95% CI (−0.70 to −0.27); p = 0.04] and MCI eyes [SMD: −0.42; 95% CI (−0.81 to −0.03); p = 0.03], as well as reduced VD of deep capillary plexus [SMD: −1.19; 95% CI (−2.00 to −0.38]; p < 0.001], [SMD: −0.53; 95% CI (−0.85 to −0.22); p < 0.001]. FAZ was significantly enlarged in AD eyes [SMD: 0.54; 95% CI (0.09 to 0.99); p = 0.02]. The meta-regression analysis showed that the OCTA machine type and macular scan size significantly influenced the variation of VD and FAZ between AD and control eyes (p < 0.05). Conclusion Our results highlight the potential of OCTA as a biomarker to detect early microvasculature deficits in AD and MCI. Notably, the macular scan size and different OCTA machine type could explain the heterogeneity observed in literatures. This information might be useful for future longitudinal study design to evaluate the role of OCTA in monitoring disease progression and treatment efficacy.
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Affiliation(s)
- Tsai-Chu Yeh
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chun-Tung Kuo
- Institute of Health Behaviors and Community Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Bai Chou
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- *Correspondence: Yu-Bai Chou
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13
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Colin E, Plyer A, Golzio M, Meyer N, Favre G, Orlik X. Imaging of the skin microvascularization using spatially depolarized dynamic speckle. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210355GR. [PMID: 35478040 PMCID: PMC9043838 DOI: 10.1117/1.jbo.27.4.046003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 04/05/2022] [Indexed: 05/29/2023]
Abstract
SIGNIFICANCE We propose a technique devoted to real-time high-resolution imaging of skin microvascularization. AIM The process utilizes the temporal variation of the spatially depolarized optical speckle field generated by moving red blood cells when illuminated with fully polarized coherent light. APPROACH Polarimetric filtering prevents the contribution of surface scattering from reaching the camera and thus favors the detection of multiscattered photons from the deeper layers of the skin. RESULTS Full-field images reveal the microvasculature with a spatial resolution of 80 μm. The acquisition speed allows for real-time applications. CONCLUSIONS We demonstrate the ability of this method to determine in 1 s a stable and reliable microvascular activity, enabling numerous clinical applications that require quantitative measurements.
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Affiliation(s)
- Elise Colin
- Paris Saclay University, DTIS, ONERA, Palaiseau, France
- ITAE Medical Research, Pechabou, France
| | - Aurélien Plyer
- Paris Saclay University, DTIS, ONERA, Palaiseau, France
- ITAE Medical Research, Pechabou, France
| | | | | | - Gilles Favre
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, CNRS UMR5071, Université Toulouse 3, Toulouse, France
- Institut Universitaire du Cancer de Toulouse-Oncopole, Institut Claudius Regaud, Toulouse, France
| | - Xavier Orlik
- ITAE Medical Research, Pechabou, France
- Toulouse University, ONERA/DOTA, Toulouse, France
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14
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Dumitrascu OM, Rosenberry R, Sherman DS, Khansari MM, Sheyn J, Torbati T, Sherzai A, Sherzai D, Johnson KO, Czeszynski AD, Verdooner S, Black KL, Frautschy S, Lyden PD, Shi Y, Cheng S, Koronyo Y, Koronyo-Hamaoui M. Retinal Venular Tortuosity Jointly with Retinal Amyloid Burden Correlates with Verbal Memory Loss: A Pilot Study. Cells 2021; 10:cells10112926. [PMID: 34831149 PMCID: PMC8616417 DOI: 10.3390/cells10112926] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/21/2021] [Accepted: 10/25/2021] [Indexed: 12/11/2022] Open
Abstract
Introduction: Retinal imaging is a non-invasive tool to study both retinal vasculature and neurodegeneration. In this exploratory retinal curcumin-fluorescence imaging (RFI) study, we sought to determine whether retinal vascular features combined with retinal amyloid burden correlate with the neurocognitive status. Methods: We used quantitative RFI in a cohort of patients with cognitive impairment to automatically compute retinal amyloid burden. Retinal blood vessels were segmented, and the vessel tortuosity index (VTI), inflection index, and branching angle were quantified. We assessed the correlations between retinal vascular and amyloid parameters, and cognitive domain Z-scores using linear regression models. Results: Thirty-four subjects were enrolled and twenty-nine (55% female, mean age 64 ± 6 years) were included in the combined retinal amyloid and vascular analysis. Eleven subjects had normal cognition and 18 had impaired cognition. Retinal VTI was discriminated among cognitive scores. The combined proximal mid-periphery amyloid count and venous VTI index exhibited significant differences between cognitively impaired and cognitively normal subjects (0.49 ± 1.1 vs. 0.91 ± 1.4, p = 0.006), and correlated with both the Wechsler Memory Scale-IV and SF-36 mental component score Z-scores (p < 0.05). Conclusion: This pilot study showed that retinal venular VTI combined with the proximal mid-periphery amyloid count could predict verbal memory loss. Future research is needed to finesse the clinical application of this retinal imaging-based technology.
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Affiliation(s)
- Oana M. Dumitrascu
- Department of Neurology, Mayo Clinic, Scottsdale, AZ 85251, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
| | - Ryan Rosenberry
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Dale S. Sherman
- Department of Neuropsychology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Maziyar M. Khansari
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Julia Sheyn
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Tania Torbati
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Ayesha Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Dean Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Kenneth O. Johnson
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Alan D. Czeszynski
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Steven Verdooner
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Keith L. Black
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Sally Frautschy
- Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA;
| | - Patrick D. Lyden
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Yonggang Shi
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Susan Cheng
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Yosef Koronyo
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
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15
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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: 55] [Impact Index Per Article: 18.3] [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.
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16
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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.
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17
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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.
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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
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18
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Riemann S, Kolibabka M, Busch S, Lin J, Hoffmann S, Gretz N, Feng Y, Wohlfart P, Hammes HP. Microglial Activation Is Associated With Vasoprotection in a Rat Model of Inflammatory Retinal Vasoregression. Front Physiol 2021; 12:660164. [PMID: 33981252 PMCID: PMC8107726 DOI: 10.3389/fphys.2021.660164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/16/2021] [Indexed: 02/02/2023] Open
Abstract
Vascular dysfunction and vasoregression are hallmarks of a variety of inflammatory central nervous system disorders and inflammation-related retinal diseases like diabetic retinopathy. Activation of microglia and the humoral innate immune system are contributing factors. Anti-inflammatory approaches have been proposed as therapies for neurovascular diseases, which include the modulation of microglial activation. The present study aimed at investigating the effects of microglial activation by clodronate-coated liposomes on vasoregression in a model of retinal degeneration. Clodronate treatment over 5 weeks led to an increase in activated CD74+ microglia and completely prevented acellular capillaries and pericyte loss. Gene expression analyses indicated that vasoprotection was due to the induction of vasoprotective factors such as Egr1, Stat3, and Ahr while expression of pro-inflammatory genes remained unchanged. We concluded that activated microglia led to a shift toward induction of pleiotropic protective pathways supporting vasoprotection in neurovascular retinal diseases.
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Affiliation(s)
- Sarah Riemann
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Matthias Kolibabka
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stephanie Busch
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jihong Lin
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sigrid Hoffmann
- Medical Research Center, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Norbert Gretz
- Medical Research Center, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Yuxi Feng
- Experimental Pharmacology, European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Paulus Wohlfart
- Sanofi Aventis Deutschland GmbH, TA Diabetes R&D, Frankfurt, Germany
| | - Hans-Peter Hammes
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Guerraty M, Bhargava A, Senarathna J, Mendelson AA, Pathak AP. Advances in translational imaging of the microcirculation. Microcirculation 2021; 28:e12683. [PMID: 33524206 PMCID: PMC8647298 DOI: 10.1111/micc.12683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 12/21/2022]
Abstract
The past few decades have seen an explosion in the development and use of methods for imaging the human microcirculation during health and disease. The confluence of innovative imaging technologies, affordable computing power, and economies of scale have ushered in a new era of "translational" imaging that permit us to peer into blood vessels of various organs in the human body. These imaging techniques include near-infrared spectroscopy (NIRS), positron emission tomography (PET), and magnetic resonance imaging (MRI) that are sensitive to microvascular-derived signals, as well as computed tomography (CT), optical imaging, and ultrasound (US) imaging that are capable of directly acquiring images at, or close to microvascular spatial resolution. Collectively, these imaging modalities enable us to characterize the morphological and functional changes in a tissue's microcirculation that are known to accompany the initiation and progression of numerous pathologies. Although there have been significant advances for imaging the microcirculation in preclinical models, this review focuses on developments in the assessment of the microcirculation in patients with optical imaging, NIRS, PET, US, MRI, and CT, to name a few. The goal of this review is to serve as a springboard for exploring the burgeoning role of translational imaging technologies for interrogating the structural and functional status of the microcirculation in humans, and highlight the breadth of current clinical applications. Making the human microcirculation "visible" in vivo to clinicians and researchers alike will facilitate bench-to-bedside discoveries and enhance the diagnosis and management of disease.
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Affiliation(s)
- Marie Guerraty
- Division of Cardiovascular Medicine, Department of
Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA,
USA
| | - Akanksha Bhargava
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Janaka Senarathna
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Asher A. Mendelson
- Department of Medicine, Section of Critical Care, Rady
Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Arvind P. Pathak
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, The Johns Hopkins
University School of Medicine, Baltimore, MD, USA
- Department of Electrical Engineering, Johns Hopkins
University, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, The Johns
Hopkins University School of Medicine, Baltimore, MD, USA
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20
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Zhang J, Strand K, Totillo M, Chen Q, Signorile JF, Jiang H, Wang J. Improvement of retinal tissue perfusion after circuit resistance training in healthy older adults. Exp Gerontol 2021; 146:111210. [PMID: 33385483 DOI: 10.1016/j.exger.2020.111210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/15/2020] [Accepted: 12/10/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE To determine the retinal tissue perfusion (RTP) and its relation to cognitive function in healthy older people after an 8-week high-speed circuit resistance training program (HSCT). METHODS Eleven subjects in the HSCT group and seven age-matched non-training controls (CON) were recruited. The HSCT group trained 3 times per week for 8 weeks, while CON performed no formal training. One eye of each subject in both groups was imaged at baseline and at an 8-week follow-up, using a Retinal Function Imager to measure retinal blood flow (RBF). Retinal tissue perfusion (RTP) was calculated as RBF divided by the corresponding tissue volume. Cognitive function was assessed during both visits using the NIH Toolbox Fluid Cognition Battery. RESULTS RTP was 2.99 ± 0.91 nl·s-1·mm-3 (mean ± SD) at baseline and significantly increased to 3.77 ± 0.86 nl·s-1·mm-3 after training (P < 0.001) in the HSCT group, reflecting an increase of 26%. In the HSCT group, the Pattern Comparison Processing Speed Test (PAT) and Fluid Cognition Composite Score (FCS) were significantly increased after HSCT (P = 0.01). Furthermore, the changes in Flanker Inhibitory Control and Attention Test (FLNK) were positively correlated to increases in RTP (r = 0.80, P = 0.003). CONCLUSIONS This is the first prospective study to demonstrate that the increased RTP after HSCT was related to improved cognition in cognitively-normal elders, indicating RTP could be an imaging marker for monitoring cognitive changes due to physical activity in the elderly.
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Affiliation(s)
- Juan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Keri Strand
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - Matthew Totillo
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - Qi Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joseph F Signorile
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - 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.
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21
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Singer MB, Ringman JM, Chu Z, Zhou X, Jiang X, Shahidzadeh A, Wang RK, Kashani AH. Abnormal retinal capillary blood flow in autosomal dominant Alzheimer's disease. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12162. [PMID: 33728371 PMCID: PMC7931411 DOI: 10.1002/dad2.12162] [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: 10/09/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 02/03/2023]
Abstract
INTRODUCTION This study characterizes retinal capillary blood flow in subjects with autosomal dominant Alzheimer's disease (ADAD)-causing mutations. METHODS Carriers of PSEN1 or APP mutations were prospectively recruited and split into early-stage (ES) and late-stage (LS) groups. Controls were normal subjects and non-carriers from the at-risk group. Capillary blood flow was quantified using an optical coherence tomography angiography-based measure of erythrocyte flux through capillary segments. Statistical analyses were adjusted for correlation between two eyes of the same subject. RESULTS ES carriers had significantly greater capillary blood flow than controls and LS carriers. ES and LS carriers had significantly greater capillary blood flow heterogeneity than controls. There was no difference between capillary blood flow of LS carriers and controls. DISCUSSION ES ADAD carriers demonstrate increased retinal capillary blood flow and flow heterogeneity compared to controls. These findings support the hypothesis that increased perfusion is a pathophysiologic feature of presymptomatic stages of ADAD.
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Affiliation(s)
- Maxwell B. Singer
- Department of OphthalmologyUSC Roski Eye InstituteKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
| | - John M. Ringman
- Department of NeurologyKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Zhongdi Chu
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
| | - Xiao Zhou
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
| | - Xuejuan Jiang
- Department of OphthalmologyUSC Roski Eye InstituteKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Anoush Shahidzadeh
- Department of OphthalmologyUSC Roski Eye InstituteKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Ruikang K. Wang
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
- Department of OphthalmologyUniversity of WashingtonSeattleWashingtonUSA
| | - Amir H. Kashani
- Department of OphthalmologyUSC Roski Eye InstituteKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
- Department of NeurologyKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
- USC Ginsburg Institute for Biomedical TherapeuticsKeck School of Medicine of the University of Southern CaliforniaLos AngelesCaliforniaUSA
- Department of Biomedical EngineeringUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
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22
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Abstract
PURPOSE OF REVIEW The retina is growingly recognized as a window into cerebrovascular and systemic vascular conditions. The utility of noninvasive retinal vessel biomarkers in cerebrovascular risk assessment has expanded due to advances in retinal imaging techniques and machine learning-based digital analysis. The purpose of this review is to underscore the latest evidence linking retinal vascular abnormalities with stroke and vascular-related cognitive disorders; to highlight modern developments in retinal vascular imaging modalities and software-based vasculopathy quantification. RECENT FINDINGS Longitudinal studies undertaken for extended periods indicate that retinal vascular changes can predict cerebrovascular disorders (CVD). Cerebrovascular ties to dementia provoked recent explorations of retinal vessel imaging tools for conceivable early cognitive decline detection. Innovative biomedical engineering technologies and advanced dynamic and functional retinal vascular imaging methods have recently been added to the armamentarium, allowing an unbiased and comprehensive analysis of the retinal vasculature. Improved artificial intelligence-based deep learning algorithms have boosted the application of retinal imaging as a clinical and research tool to screen, risk stratify, and monitor with precision CVD and vascular cognitive impairment. SUMMARY Mounting evidence supports the use of quantitative retinal vessel analysis in predicting CVD, from clinical stroke to neuroimaging markers of stroke and neurodegeneration.
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23
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Song A, Johnson N, Ayala A, Thompson AC. Optical Coherence Tomography in Patients with Alzheimer's Disease: What Can It Tell Us? Eye Brain 2021; 13:1-20. [PMID: 33447120 PMCID: PMC7802785 DOI: 10.2147/eb.s235238] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/09/2020] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Although Alzheimer's disease (AD) is a leading cause of dementia worldwide, its clinical diagnosis remains a challenge. Optical coherence tomography (OCT) and OCT with angiography (OCTA) are non-invasive ophthalmic imaging tools with the potential to detect retinal structural and microvascular changes in patients with AD, which may serve as biomarkers for the disease. In this systematic review, we evaluate whether certain OCT and OCTA parameters are significantly associated with AD and mild cognitive impairment (MCI). METHODS PubMed database was searched using a combination of MeSH terms to identify studies for review. Studies were organized by participant diagnostic groups, type of imaging modality, and OCT/OCTA parameters of interest. Participant demographic data was also collected and baseline descriptive statistics were calculated for the included studies. RESULTS Seventy-one studies were included for review, representing a total of 6757 patients (2350 AD, 793 MCI, 2902 healthy controls (HC), and 841 others with a range of other neurodegenerative diagnoses). The mean baseline ages were 72.78±3.69, 71.52±2.88, 70.55±3.85 years for AD, MCI and HC groups, respectively. The majority of studies noted significant structural and functional decline in AD patients when compared to HC. Although analysis of MCI groups yielded more mixed results, a similar pattern of decline was often noted amongst patients with MCI relative to HC. OCT and OCTA measurements were also shown to correlate with established measures of AD such as neuropsychological testing or neuroimaging. CONCLUSION OCT and OCTA show great potential as non-invasive technologies for the diagnosis of AD. However, further research is needed to determine whether there are AD-specific patterns of structural or microvascular change in the retina and optic nerve that distinguish AD from other neurodegenerative diseases. Development of sensitive and specific OCT/OCTA parameters will be necessary before they can be used to detect AD in clinical settings.
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Affiliation(s)
- Ailin Song
- Duke University School of Medicine, Durham, NC, USA
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24
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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.
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25
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Courtie E, Veenith T, Logan A, Denniston AK, Blanch RJ. Retinal blood flow in critical illness and systemic disease: a review. Ann Intensive Care 2020; 10:152. [PMID: 33184724 PMCID: PMC7661622 DOI: 10.1186/s13613-020-00768-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/23/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Assessment and maintenance of end-organ perfusion are key to resuscitation in critical illness, although there are limited direct methods or proxy measures to assess cerebral perfusion. Novel non-invasive methods of monitoring microcirculation in critically ill patients offer the potential for real-time updates to improve patient outcomes. MAIN BODY Parallel mechanisms autoregulate retinal and cerebral microcirculation to maintain blood flow to meet metabolic demands across a range of perfusion pressures. Cerebral blood flow (CBF) is reduced and autoregulation impaired in sepsis, but current methods to image CBF do not reproducibly assess the microcirculation. Peripheral microcirculatory blood flow may be imaged in sublingual and conjunctival mucosa and is impaired in sepsis. Retinal microcirculation can be directly imaged by optical coherence tomography angiography (OCTA) during perfusion-deficit states such as sepsis, and other systemic haemodynamic disturbances such as acute coronary syndrome, and systemic inflammatory conditions such as inflammatory bowel disease. CONCLUSION Monitoring microcirculatory flow offers the potential to enhance monitoring in the care of critically ill patients, and imaging retinal blood flow during critical illness offers a potential biomarker for cerebral microcirculatory perfusion.
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Affiliation(s)
- E Courtie
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- NIHR Surgical Reconstruction and Microbiology Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - T Veenith
- Critical Care Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - A Logan
- Axolotl Consulting Ltd, Droitwich, WR9 0JS, Worcestershire, UK
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7HL, UK
| | - A K Denniston
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
- Centre for Rare Diseases, Institute of Translational Medicine, Birmingham Health Partners, Birmingham, UK
| | - R J Blanch
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- NIHR Surgical Reconstruction and Microbiology Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, UK.
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Fang M, Strand K, Zhang J, Totillo M, Chen Q, Signorile JF, Jiang H, Wang J. Characterization of retinal microvasculature and its relations to cognitive function in older people after circuit resistance training. Exp Gerontol 2020; 142:111114. [PMID: 33132156 DOI: 10.1016/j.exger.2020.111114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/29/2020] [Accepted: 10/08/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To characterize the changes of retinal microvascular density and their relations to cognitive function in the healthy older people without known cognitive impairment after an 8-week high-speed circuit resistance training program (HSCT). METHODS Twenty cognitively normal older people were recruited and randomly assigned to either the HSCT group or control group (CON). Twelve subjects (age 70.8 ± 5.8 yrs) in the HSCT group trained three times per week for 8 weeks. Eight subjects in the CON group (age 71.8 ± 4.8 yrs) did not perform formal training. Both eyes of each subject were imaged using optical coherence tomography angiography (OCTA) at baseline and at 8-week follow-up. The densities of the retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP) were measured. In addition, their cognitive functions were tested using the NIH toolbox. RESULTS There were significant increases in pattern comparison processing speed (PAT, P = 0.02) and fluid composite score (FCS, P = 0.005) at the follow-up in the HSCT group. Although the vessel densities did not differ between visits in either group, the variation (i.e., change) in retinal vessel density of SVP was negatively related to the changes of FCS (r = -0.54, P = 0.007) and the List Sorting Working Memory test (r = -0.43, P = 0.039) in the HSCT group. CONCLUSIONS This is the first study to reveal that the individual response of the SVD was related to the improvement in the cognition in cognitively normal older people after HSCT.
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Affiliation(s)
- Min Fang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Keri Strand
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - Juan Zhang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Matthew Totillo
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - Qi Chen
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Joseph F Signorile
- Department of Kinesiology and Sports Sciences, University of Miami, FL, USA
| | - 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
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Mejia-Vergara AJ, Restrepo-Jimenez P, Pelak VS. Optical Coherence Tomography in Mild Cognitive Impairment: A Systematic Review and Meta-Analysis. Front Neurol 2020; 11:578698. [PMID: 33178120 PMCID: PMC7596384 DOI: 10.3389/fneur.2020.578698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/09/2020] [Indexed: 01/17/2023] Open
Abstract
Purpose: The use of optical coherence tomography (OCT) of the retina to detect inner retinal degeneration is being investigated as a potential biomarker for mild cognitive impairment (MCI) and Alzheimer's disease (AD), and an overwhelming body of evidence indicates that discovery of disease-modifying treatments for AD should be aimed at the pre-dementia clinical stage of AD, i.e., MCI. We aimed to perform a systematic review and meta-analysis on retinal OCT in MCI. Methods: We performed a systematic review of the English literature in three databases (PubMed, Embase, and Latindex) for studies that measured retinal thickness using OCT in people with MCI and healthy controls, age 50 or older, between 1 January 2000 and 31 July 2019. Only cohort and case-control studies were reviewed, and independent extraction of quality data and established objective data was performed. We calculated the effect size for studies in the review that met the following criteria: (1) a statistically significant difference between MCI subjects and normal controls for several OCT variables, (2) use of spectral domain OCT, and (3) use of APOSTEL recommendations for OCT reporting. Weighted Hedges' g statistic was used to calculate the pooled effect size for four variables: ganglion cell layer-inner plexiform layer (GCL-IPL) complex thickness in micrometers (μm), circumpapillary retinal nerve fiber layer (pRNFL) thickness in μm, macular thickness in μm, and macular volume in μm3. For variables with high heterogeneity, a multivariate meta-regression was performed. We followed the PRISMA guidelines for systematic reviews. Results: Fifteen articles met the inclusion criteria. A total of 58.9% of MCI patients had statistically significant thinning of the pRNFL compared with normal subjects, while 61.6% of all MCI patients who had macular volume measured had a statistically significant reduction in volume compared with controls, and 50.0% of the macular GCL-IPL complexes measured demonstrated significant thinning in MCI compared with normal controls. Meta-analysis demonstrated a large effect size for decreased macular thickness in MCI subjects compared with normal controls, but there was a substantial heterogeneity for macular thickness results. The other variables did not demonstrate a significant difference and also had substantial heterogeneity. Meta-regression analysis did not reveal an explanation for the heterogeneity. Conclusions: A better understanding of the cause of retina degeneration and longitudinal, standardized studies are needed to determine if optical coherence tomography can be used as a biomarker for mild cognitive impairment due to Alzheimer's disease.
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Affiliation(s)
- Alvaro J Mejia-Vergara
- Department of Neuro-Ophthalmology, Stein and Doheny Eye Institutes, University of California, Los Angeles, Pasadena, CA, United States.,Ophthalmology Department, San Ignacio University Hospital, Pontificia Universidad Javeriana School of Medicine, Bogotá, Colombia
| | - Paula Restrepo-Jimenez
- Ophthalmology Department, San Ignacio University Hospital, Pontificia Universidad Javeriana School of Medicine, Bogotá, Colombia
| | - Victoria S Pelak
- Departments of Neurology and Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
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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.
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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
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29
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Optical coherence tomography in mild cognitive impairment - Systematic review and meta-analysis. Clin Neurol Neurosurg 2020; 196:106036. [PMID: 32623211 DOI: 10.1016/j.clineuro.2020.106036] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/23/2022]
Abstract
Thinning of retinal layers, measured using optical coherence tomography (OCT), is associated with some neurodegenerative disorders such as established Alzheimer's disease and multiple sclerosis. The evidence for retinal layer thinning in both mild cognitive impairment (MCI), a precursor of dementia, and delirium, a potential pre-clinical stage of neurodegenerative disorder, is unclear. We performed a systematic review of the associations, in older people, between retinal layer thickness changes (measured using OCT) and delirium or MCI compared to controls (Protocol registration ID (Prospero) CRD42019122165). We did not identify any relevant studies on delirium. This report is therefore a review of retinal nerve layer changes in mild cognitive impairment. Databases were searched using predetermined keywords such as mild cognitive impairment, retinal nerve fibre layer and delirium. Where there were sufficient data, meta-analyses were performed. Twenty-six relevant studies were identified on retinal layer thickness in people with MCI compared to controls. There was significant heterogeneity in the studies for all retinal layers investigated (retinal nerve fibre layer (RNFL), ganglion cell inner plexiform layer (GCIP), foveal thickness and macular volume). Analysis of 17 studies of mean RNFL thickness in MCI (n = 622) compared to controls (n = 1154), irrespective of the type of OCT device, demonstrated a significant thinning in MCI (SMD: - 0·42 and 95 % confidence interval: - 0·68 to - 0·16). This difference was non-significant when studies using only spectral-domain devices were analysed. Subgroup analysis of studies using spectral-domain devices in amnestic MCI diagnosed using comparable criteria, showed statistically significant thinning of RNFL in amnestic MCI (p = 0·02). Meta-analysis of foveal thickness did not show a significant difference between MCI and controls. In conclusion, there is some evidence of an association between retinal nerve fibre layer thinning and MCI. We found no data on the association between RNFL and delirium.
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Lin Y, Jiang H, Liu Y, Rosa Gameiro G, Gregori G, Dong C, Rundek T, Wang J. Age-Related Alterations in Retinal Tissue Perfusion and Volumetric Vessel Density. Invest Ophthalmol Vis Sci 2019; 60:685-693. [PMID: 30786280 PMCID: PMC6383727 DOI: 10.1167/iovs.18-25864] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose To determine age-related alterations in the retinal tissue perfusion (RTP) and volumetric vessel density (VVD) in healthy subjects. Methods Total 148 healthy subjects (age 18 to 83 years) were enrolled and divided into four groups (G1, <35 years; G2, 35 ∼ 49 years; G3, 50 ∼ 64 years; and G4, ≥65 years). The RTP and VVD were measured at the macula. The RTP was calculated as the blood flow supplying the macular area (ϕ 2.5 mm) divided by the perfused tissue volume of the inner retina from the inner limiting membrane to the outer plexiform layer. The VVD of the macula (ϕ 2.5 mm) was calculated as the vessel density divided by the corresponding tissue volume. Results The RTP and VVD of the retinal vascular network and deep vascular plexus (DVP) reached a peak in G2. Compared to G2, G4 had significantly lower RTP and VVD of DVP (P < 0.05). After 35 years old, age was negatively related to the RTP (r = −0.26, P = 0.02) and VVD of the DVP (r = −0.47, P < 0.001). However, age was positively related to VVD of the superficial vascular plexus (SVP; r = 0.24, P = 0.04) in subjects aged more than 35 years. The RTP was correlated to VVD measurements (r = 0.23–0.37, P < 0.01). Conclusions This is the first study to reveal the age-related alterations in the RTP and VVD during normal aging in a healthy population. Decreased RTP and VVD in the DVP along with increased VVD in the SVP may represent a characteristic pattern of normal aging in the healthy population.
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Affiliation(s)
- Ying Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.,Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Hong Jiang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.,Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Yi Liu
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.,Department of Ophthalmology, Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Giovana Rosa Gameiro
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Giovanni Gregori
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Chuanhui Dong
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Tatjana Rundek
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Jianhua Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
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Liu Y, Delgado S, Jiang H, Lin Y, Hernandez J, Deng Y, Gameiro GR, Wang J. Retinal Tissue Perfusion in Patients with Multiple Sclerosis. Curr Eye Res 2019; 44:1091-1097. [PMID: 31046490 DOI: 10.1080/02713683.2019.1612444] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Purpose: The goal of this work was to determine whether the retinal tissue perfusion (RTP) is impaired in patients with multiple sclerosis (MS). Methods: Seventy-four patients [66 relapsing-remitting MS (RRMS) and 8 clinically isolated syndrome (CIS)] and 74 age- and gender-matched healthy controls were recruited. RTP was calculated as the retinal blood flow (measured using retinal function imager) supplying the macular area divided by the corresponding tissue volume of the inner retina from the inner limiting membrane to the outer plexiform layer, as measured by ultrahigh-resolution optical coherence tomography. Results: The RTP in the MS group was 2.37 ± 0.59 nl/s/mm3 (mean ± standard deviation), which was significantly lower than the control group (4.06 ± 0.89 nl/s/mm3, P < .001), reflecting a decrease of 42%. The blood flow volume was 2.50 ± 0.50 nl/s in MS, which was 45% lower than in the control group (4.56 ± 0.91 nl/s, P < .001). In addition, the tissue volume of the inner retina was significantly lower than in the control group (P < .05). The RTP in patients with MS was significantly correlated with the retinal blood flow volume (r = 0.84, P < .001) and retinal tissue volume (r = -0.56, P < .001). However, the retinal blood flow in patients with MS was not related to the tissue volume (r = -0.06, P = .59). Conclusions: Impaired retinal tissue perfusion occurred in patients with MS, which could be developed as a possible biomarker in monitoring disease progression in MS.
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Affiliation(s)
- Yi Liu
- Department of Ophthalmology, Third Affiliated Hospital of Nanjing University of Chinese Medicine , Nanjing , China.,Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Silvia Delgado
- MS Center of Excellence, Department of Neurology, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Hong Jiang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA.,MS Center of Excellence, Department of Neurology, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Ying Lin
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , Guangdong , China
| | - Jeffrey Hernandez
- MS Center of Excellence, Department of Neurology, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Yuqing Deng
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , Guangdong , China
| | - Giovana Rosa Gameiro
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Jianhua Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
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Shi C, Jiang H, Gameiro GR, Wang J. Microcirculation in the conjunctiva and retina in healthy subjects. EYE AND VISION 2019; 6:11. [PMID: 30993144 PMCID: PMC6451216 DOI: 10.1186/s40662-019-0136-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/18/2019] [Indexed: 01/15/2023]
Abstract
Background The aim was to determine the relationship between bulbar conjunctival microcirculation and retinal microcirculation in a healthy population. Method A functional slit-lamp biomicroscope (FSLB) was used to measure blood flow velocity (BFV) and blood flow rate (BFR) in the conjunctiva while a retinal function imager (RFI) was used to measure macular BFV and BFR in the retina. One eye of each subject of 58 self-reported healthy subjects was imaged in the same session on the same day. Results The mean BFV in the venules of the conjunctiva was 0.49 ± 0.13 mm/s, which was significantly slower than that in the retinal arterioles (3.71 ± 0.78 mm/s, P < 0.001) and retinal venules (2.98 ± 0.58 mm/s, P < 0.001). The BFR in the conjunctiva (0.09 nl/s) was also significantly lower than that in the retina (arterioles = 0.81 nl/s, venules = 0.68 nl/s, all P < 0.001). The BFVs and BFRs were not related between the conjunctiva and retina (r ranged from − 0.17 to − 0.05, all P > 0.05). Conclusion The microcirculation in the retina appeared to be different from that in the conjunctiva.
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Affiliation(s)
- Ce Shi
- 1School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China.,2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Hong Jiang
- 2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Giovana Rosa Gameiro
- 2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Jianhua Wang
- 2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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Zhang YS, Zhou N, Knoll BM, Samra S, Ward MR, Weintraub S, Fawzi AA. Parafoveal vessel loss and correlation between peripapillary vessel density and cognitive performance in amnestic mild cognitive impairment and early Alzheimer's Disease on optical coherence tomography angiography. PLoS One 2019; 14:e0214685. [PMID: 30939178 PMCID: PMC6445433 DOI: 10.1371/journal.pone.0214685] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/18/2019] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Patients with Alzheimer's Disease (AD) exhibit decreased retinal blood flow and vessel density (VD). However, it is not known whether these changes are also present in individuals with early AD (eAD) or amnestic type mild cognitive impairment (aMCI), an enriched pre-AD population with a higher risk for progressing to dementia. We performed a prospective case-control clinical study to investigate whether optical coherence tomography angiography (OCTA) parameters in the macula and disc are altered in those with aMCI and eAD. METHODS This is a single center study of 32 participants. Individuals with aMCI/eAD (n = 16) were 1:1 matched to cognitively normal controls (n = 16). We evaluated OCTA images of the parafoveal superficial capillary plexus (SCP) and two vascular layers in the peripapillary region, the radial peripapillary capillary (RPC) and superficial vascular complex (SVC). Outcome vascular and structural parameters included VD, vessel length density (VLD), adjusted flow index (AFI) and structural retinal nerve fiber layer (RNFL) thickness. We compared these parameters between the two groups and examined the correlation between OCTA parameters and cognitive performance on the Montreal Cognitive Assessment (MoCA). RESULTS Cognitively impaired participants demonstrated statistically significant decrease in parafoveal SCP VD and AFI as compared to controls, but no statistically significant difference in peripapillary parameters. Furthermore, we found a significant positive correlation between MoCA scores for the entire study cohort and both the parafoveal SCP VD and peripapillary RPC VLD. CONCLUSION OCTA shows significant decline in parafoveal flow and VD in individuals with early cognitive impairment related to AD, suggesting that these parameters could have potential utility as early disease biomarkers. In contrast, the presence of larger vascular channels in the peripapillary region may have obscured subtle capillary changes in that region. Overall, the correlation between vascular OCTA parameters and cognitive performance supports further OCTA studies in this population.
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Affiliation(s)
- Yi Stephanie Zhang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Nina Zhou
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Brianna Marie Knoll
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Sahej Samra
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Mallory R. Ward
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Sandra Weintraub
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
- Department of Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
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Qu D, Lin Y, Jiang H, Shao Y, Shi Y, Airen S, Gregori G, Wang J. Retinal nerve fiber layer (RNFL) integrity and its relations to retinal microvasculature and microcirculation in myopic eyes. EYE AND VISION 2018; 5:25. [PMID: 30349842 PMCID: PMC6190551 DOI: 10.1186/s40662-018-0120-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/26/2018] [Indexed: 11/10/2022]
Abstract
Background The aim was to determine retinal nerve fiber layer function and its relations to retinal microvasculature and microcirculation in patients with myopia. Method Polarization-sensitive optical coherence tomography (PS-OCT) was used to measure phase retardation per unit depth (PR/UD, proportional to the birefringence) of the retinal nerve fiber layer (RNFL). Optical coherence tomography angiography (OCTA) was used to measure macular vessel density analyzed using fractal analysis. In addition, a retinal function imager (RFI) was used to measure macular blood flow velocities in arterioles and venules. Twenty-two patients with moderate myopia (MM, refraction > 3 and < 6 diopters), seventeen patients with high myopia (HM, ≥ 6 D) and 29 healthy control subjects (HC, ≤ 3.00 D) were recruited. One eye of each patient was imaged. Results Although the average PR/UD of the RNFL in the HM group did not reach a significant level, the birefringence of the inferior quadrant was significantly lower (P < 0.05) in the HM group compared to the HC group. Significant thinning of the average RNFL and focal thinning of RFNL in temporal, superior and inferior quadrants in the HM group were found, compared to the HC group (P < 0.05). There were no significant differences of retinal blood flow velocities in arterioles and venules among groups (P > 0.05). The macular vessel density in both superficial and deep vascular plexuses was significantly lower in the HM group than in the other two groups (P < 0.05) as well as in the MM group than in the HC group (P < 0.05). The average PR/UD and PR/UD in the inferior quadrant were not related to refraction, axial length, blood flow velocities and macular vessel densities (r ranged from − 0.09 to 0.19, P > 0.05). Conclusions The impairment of the retinal nerve fiber birefringence in the HM group may be one of the independent features in high myopic eyes, which appeared not to relate to macular microvascular density and blood flow velocity.
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Affiliation(s)
- Dongyi Qu
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA
| | - Ying Lin
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA.,2State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong China
| | - Hong Jiang
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA.,3Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
| | - Yi Shao
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA
| | - Yingying Shi
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA
| | - Shriya Airen
- 4College of Arts and Sciences, University of Miami, Miami, FL USA
| | - Giovanni Gregori
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA
| | - Jianhua Wang
- 1Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA.,5Department of Ophthalmology Bascom Palmer Eye Institute, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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Dumitrascu OM, Qureshi TA. Retinal Vascular Imaging in Vascular Cognitive Impairment: Current and Future Perspectives. J Exp Neurosci 2018; 12:1179069518801291. [PMID: 30262988 PMCID: PMC6149015 DOI: 10.1177/1179069518801291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Vascular cognitive disorders are heterogeneous and increasingly recognized
entities with intricate correlation to neurodegenerative conditions. Retinal
vascular analysis is a noninvasive approach to study cerebrovascular pathology,
with promise to assist particularly during early disease phases. In this
article, we have systematically summarized the current understanding, potential
applications, and inevitable limitations of retinal vascular imaging in patients
with vascular cognitive impairment. In addition, future directions in the field
with support from automated technology using deep learning methods and their
existing challenges are emphasized.
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Affiliation(s)
- Oana M Dumitrascu
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Touseef A Qureshi
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Gameiro GR, Jiang H, Liu Y, Deng Y, Sun X, Nascentes B, Baumel B, Rundek T, Wang J. Retinal tissue hypoperfusion in patients with clinical Alzheimer's disease. EYE AND VISION 2018; 5:21. [PMID: 30140712 PMCID: PMC6097197 DOI: 10.1186/s40662-018-0115-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/02/2018] [Indexed: 12/19/2022]
Abstract
Background It remains unknow whether retinal tissue perfusion occurs in patients with Alzheimer’s disease. The goal was to determine retinal tissue perfusion in patients with clinical Alzheimer’s disease (CAD). Methods Twenty-four CAD patients and 19 cognitively normal (CN) age-matched controls were recruited. A retinal function imager (RFI, Optical Imaging Ltd., Rehovot, Israel) was used to measure the retinal blood flow supplying the macular area of a diameter of 2.5 mm centered on the fovea. Blood flow volumes of arterioles (entering the macular region) and venules (exiting the macular region) of the supplied area were calculated. Macular blood flow was calculated as the average of arteriolar and venular flow volumes. Custom ultra-high-resolution optical coherence tomography (UHR–OCT) was used to calculate macular tissue volume. Automated segmentation software (Orion, Voxeleron LLC, Pleasanton, CA) was used to segment six intra-retinal layers in the 2.5 mm (diameter) area centered on the fovea. The inner retina (containing vessel network), including retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL) and outer plexiform layer (OPL), was segmented and tissue volume was calculated. Perfusion was calculated as the flow divided by the tissue volume. Results The tissue perfusion in CAD patients was 2.58 ± 0.79 nl/s/mm3 (mean ± standard deviation) and was significantly lower than in CN subjects (3.62 ± 0.44 nl/s/mm3, P < 0.01), reflecting a decrease of 29%. The flow volume was 2.82 ± 0.92 nl/s in CAD patients, which was 31% lower than in CN subjects (4.09 ± 0.46 nl/s, P < 0.01). GCIPL tissue volume was 0.47 ± 0.04 mm3 in CAD patients and 6% lower than CN subjects (0.50 ± 0.05 mm3, P < 0.05). No other significant alterations were found in the intra-retinal layers between CAD and CN participants. Conclusions This study is the first to show decreased retinal tissue perfusion that may be indicative of diminished tissue metabolic activity in patients with clinical Alzheimer’s disease.
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Affiliation(s)
- Giovana Rosa Gameiro
- 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Hong Jiang
- 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,2Evelyn F. McKnight Brain Institute, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
| | - Yi Liu
- 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,3Department of Ophthalmology, Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Yuqing Deng
- 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,4State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong China
| | - Xiaoyan Sun
- 2Evelyn F. McKnight Brain Institute, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
| | - Bernardo Nascentes
- 5School of Nursing and Health Studies, University of Miami, Miami, FL USA
| | - Bernard Baumel
- 2Evelyn F. McKnight Brain Institute, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
| | - Tatjana Rundek
- 2Evelyn F. McKnight Brain Institute, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
| | - Jianhua Wang
- 1Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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Wang GH, Wang LH, Wang C, Qin LH. Spore powder of Ganoderma lucidum for the treatment of Alzheimer disease: A pilot study. Medicine (Baltimore) 2018; 97:e0636. [PMID: 29742702 PMCID: PMC5959386 DOI: 10.1097/md.0000000000010636] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/11/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND This study explored the feasible efficacy and safety of the Spore Powder of Ganoderma Lucidum (SPGL) for treating patients with Alzheimer disease (AD). METHODS Forty-two eligible patients with AD were recruited. These patients were randomly allocated to an intervention group and a control group equally. The patients in the intervention group underwent SPGL, whereas the subjects in the control received placebo. All patients were treated for a total of 6 weeks. The primary outcome was measured by Alzheimer's disease Assessment Scale-Cognitive (ADAS-cog). The secondary outcomes were measured by the World Health Organization Quality of Life questionnaire (WHOQOL-BREF) and Neuropsychiatric Index (NPI). The adverse events were also recorded during the treatment period. RESULTS At the end of the treatment, GLSP did not show more encouraging outcomes in symptoms improvement, measured by the ADAS-cog (P = .31), and NPI (P = .79); and quality of life enhancement, measured by the WHOQOL-BREF (physical, P = .62; psychological, P = .69; social relationships, P = .75; environment, P = .82; overall quality of life, P = .74), compared with the control group. In addition, all adverse events were mild, and no significant differences were found between 2 groups. CONCLUSION The results of this study did not find the promising efficacy of SPGL for the treatment of AD after 6-week treatment. It may be because of the relative short-term of intervention. Future clinical trials with larger sample size and longer treatment period are urgently needed.
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