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Liu WYS, Narasimhalu K, Woon FP, Allen JC, De Silva DA. Association of intracranial large artery disease with long-term prognosis after ischaemic stroke. Singapore Med J 2024:00077293-990000000-00139. [PMID: 39229734 DOI: 10.4103/singaporemedj.smj-2023-063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 10/28/2023] [Indexed: 09/05/2024]
Abstract
INTRODUCTION Intracranial large artery disease (ICLAD) is a common cause of ischaemic stroke and is associated with the risk of recurrent vascular events in the short term. We compared the incidence of various long-term vascular outcomes between ischaemic stroke patients with and without ICLAD. METHODS This was a longitudinal observational study of acute ischaemic stroke patients who were followed up serially for recurrent stroke, myocardial infarction or vascular death up to a median of 86 months. Transcranial colour-coded Doppler was used in the diagnosis of ICLAD. RESULTS Among the 581 ischaemic stroke patients studied (median age 63 ± 11 years, male 71%), 354 (60.9%) had ICLAD. In regression analyses adjusting for covariates, patients with ICLAD were more likely to have long-term composite vascular outcomes (hazard ratio [HR] 1.44, 95% confidence interval [CI] 1.02-2.03, P = 0.041), myocardial infarction (HR 2.89, 95% CI 1.71-4.91, P < 0.001) and vascular death (HR 3.52, 95% CI 1.67-7.52, P = 0.001) but not recurrent stroke (HR 1.10, 95% CI 0.72-1.70, P = 0.652), at a median of 86 months as compared to patients without ICLAD. CONCLUSION Our findings of poor prognostic impact of ICLAD on long-term recurrent vascular events after ischaemic stroke provide evidence for the need of specific, emphasised screening and secondary prevention, especially for coronary artery disease in this high-risk group.
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Affiliation(s)
| | - Kaavya Narasimhalu
- Department of Neurology, National Neuroscience Institute (Singapore General Hospital Campus), Singapore
| | - Fung Peng Woon
- Department of Neurology, Singapore General Hospital, Singapore
| | - John Carson Allen
- Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | - Deidre Anne De Silva
- Department of Neurology, National Neuroscience Institute (Singapore General Hospital Campus), Singapore
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Shareef MAH, Narasimhalu K, Saffari SE, Woon FP, De Silva DA. Recurrent vascular events partially explain association between diabetes and poor prognosis in young ischemic stroke patients. J Neurol Sci 2024; 457:122881. [PMID: 38219383 DOI: 10.1016/j.jns.2024.122881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 01/16/2024]
Abstract
BACKGROUND AND AIMS Stroke is the second leading cause of death and third leading cause of disability worldwide. There is an increasing incidence of stroke among the young. In this study, we aimed to identify factors associated with poor long-term prognosis in young stroke patients. METHODS In this longitudinal observational study, we recruited 147 young ischemic stroke patients within one week of ischemic stroke and followed them up for functional outcome (modified Rankin score (mRS)), recurrent vascular events, and recurrent hospitalisation. Poor function was labelled as mRS score of 3 and above. We performed univariate and multivariable logistic regression analyses to determine factors associated with poor long term functional outcome. RESULTS At a median follow-up of 7-years, 32 (22%) of the 147 patients had poor functional outcome. In multivariable analyses, diabetes mellitus (OR = 9.01, CI 3.15 to 26.92), was the only independent predictor of poor function. In analyses stratified by diabetic status, recurrent vascular events (OR = 4.47, CI 1.40 to 14.28) were associated with poor functional outcome within young diabetic patients but not in non-diabetic patients. CONCLUSIONS Our findings suggest that diabetes mellitus affects long-term functional outcome in young ischemic stroke and that its effect is mediated partly by recurrent vascular events. DATA ACCESS STATEMENT Data obtained from Multi-Centre Retinal study (MCRS), Singapore site. Data cannot be made publicly available due to potentially identifiable research participant information.
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Affiliation(s)
| | - Kaavya Narasimhalu
- Duke-NUS Medical School, Singapore; National Neuroscience Institute (Singapore General Hospital Campus), Department of Neurology, Singapore.
| | | | - Fung Peng Woon
- Singapore General Hospital, Department of Neurology, Singapore
| | - Deidre Anne De Silva
- Duke-NUS Medical School, Singapore; National Neuroscience Institute (Singapore General Hospital Campus), Department of Neurology, Singapore
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Qu Y, Zhuo Y, Lee J, Huang X, Yang Z, Yu H, Zhang J, Yuan W, Wu J, Owens D, Zee B. Ischemic and haemorrhagic stroke risk estimation using a machine-learning-based retinal image analysis. Front Neurol 2022; 13:916966. [PMID: 36071896 PMCID: PMC9441897 DOI: 10.3389/fneur.2022.916966] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Background Stroke is the second leading cause of death worldwide, causing a considerable disease burden. Ischemic stroke is more frequent, but haemorrhagic stroke is responsible for more deaths. The clinical management and treatment are different, and it is advantageous to classify their risk as early as possible for disease prevention. Furthermore, retinal characteristics have been associated with stroke and can be used for stroke risk estimation. This study investigated machine learning approaches to retinal images for risk estimation and classification of ischemic and haemorrhagic stroke. Study design A case-control study was conducted in the Shenzhen Traditional Chinese Medicine Hospital. According to the computerized tomography scan (CT) or magnetic resonance imaging (MRI) results, stroke patients were classified as either ischemic or hemorrhage stroke. In addition, a control group was formed using non-stroke patients from the hospital and healthy individuals from the community. Baseline demographic and medical information was collected from participants' hospital medical records. Retinal images of both eyes of each participant were taken within 2 weeks of admission. Classification models using a machine-learning approach were developed. A 10-fold cross-validation method was used to validate the results. Results 711 patients were included, with 145 ischemic stroke patients, 86 haemorrhagic stroke patients, and 480 controls. Based on 10-fold cross-validation, the ischemic stroke risk estimation has a sensitivity and a specificity of 91.0% and 94.8%, respectively. The area under the ROC curve for ischemic stroke is 0.929 (95% CI 0.900 to 0.958). The haemorrhagic stroke risk estimation has a sensitivity and a specificity of 93.0% and 97.1%, respectively. The area under the ROC curve is 0.951 (95% CI 0.918 to 0.983). Conclusion A fast and fully automatic method can be used for stroke subtype risk assessment and classification based on fundus photographs alone.
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Affiliation(s)
- Yimin Qu
- Centre for Clinical Research and Biostatistics, Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Clinical Trials and Biostatistics Lab, CUHK Shenzhen Research Institute, Shenzhen, China
- School of Population Medicine and Public Health, Chinese Academy of Medical Science (CAMS) and Peking Union Medical College (PUMC), Beijing, China
| | - Yuanyuan Zhuo
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Jack Lee
- Centre for Clinical Research and Biostatistics, Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Clinical Trials and Biostatistics Lab, CUHK Shenzhen Research Institute, Shenzhen, China
| | - Xingxian Huang
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Zhuoxin Yang
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Haibo Yu
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Jinwen Zhang
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Weiqu Yuan
- Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Jiaman Wu
- Affiliated Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Shenzhen, China
| | | | - Benny Zee
- Centre for Clinical Research and Biostatistics, Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Clinical Trials and Biostatistics Lab, CUHK Shenzhen Research Institute, Shenzhen, China
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De Silva DA, Narasimhalu K, Huang IW, Woon FP, Allen JC, Wong MC. Long term Post-Stroke Functional Outcomes: a comparison of diabetics and non-diabetics. Cerebrovasc Dis Extra 2021; 12:7-13. [PMID: 34915467 PMCID: PMC8958600 DOI: 10.1159/000521442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/18/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Diabetes mellitus (DM) is known to influence outcomes in the short-term following stroke. However, the impact of DM on long-term functional outcomes after stroke is unclear. We compared functional outcomes periodically over 7 years between diabetic and non-diabetic ischemic stroke patients and investigated the impact of DM on the long-term trajectory of post-stroke functional outcomes. We also studied the influence of age on the diabetes-functional outcome association. METHODS This is a longitudinal observational cohort study of 802 acute ischemic stroke patients admitted to the Singapore General Hospital from 2005 to 2007. Functional outcomes were assessed using the modified Rankin Scale (mRS) with poor functional outcome defined as mRS≥3. Follow-up data was determined at 6 months and at median follow-up durations of 29 and 86 months. RESULTS Among the 802 ischemic stroke patients studied (mean age 64 ± 12 years, male 63%), 42% had DM. In regression analyses adjusting for covariates, diabetic patients were more likely to have poor functional outcomes at 6 months (OR=2.12, 95% CI: 1.23-3.67) and at median follow-up durations of 29 months (OR=1.96, 95% CI: 1.37-2.81) and 86 months (OR=2.27, 95% CI: 1.58-3.25). In addition, age modulated the effect of DM, with younger stroke patients (≤65 years) more likely to have long term poor functional outcome at the 29-month (p=0.0179) and 86-month (p=0.0144) time points. CONCLUSIONS DM was associated with poor functional outcomes following ischemic stroke in the long term with the effect remaining consistent throughout the 7-year follow-up period. Age modified the effect of DM in the long term, with an observed increase in risk in the ≤65 age group but not in the >65 age group.
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Affiliation(s)
- Deidre Anne De Silva
- National Neuroscience Institute, Department of Neurology, Singapore General Hospital Campus, Singapore, Singapore
| | - Kaavya Narasimhalu
- National Neuroscience Institute, Department of Neurology, Singapore General Hospital Campus, Singapore, Singapore
| | - Ian Wang Huang
- Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Fung Peng Woon
- Department of Neurology, Singapore General Hospital, Singapore, Singapore
| | - John Carson Allen
- Centre for Quantitative Medicine, Duke-National University of Singapore Medical School, Singapore, Singapore
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Ballerini L, McGrory S, Valdés Hernández MDC, Lovreglio R, Pellegrini E, MacGillivray T, Muñoz Maniega S, Henderson R, Taylor A, Bastin ME, Doubal F, Trucco E, Deary IJ, Wardlaw J. Quantitative measurements of enlarged perivascular spaces in the brain are associated with retinal microvascular parameters in older community-dwelling subjects. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2020; 1:100002. [PMID: 33458712 PMCID: PMC7792660 DOI: 10.1016/j.cccb.2020.100002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/05/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Perivascular Spaces (PVS) become increasingly visible with advancing age on brain MRI, yet their relationship to morphological changes in the underlying microvessels remains poorly understood. Retinal and cerebral microvessels share morphological and physiological properties. We compared computationally-derived PVS morphologies with retinal vessel morphologies in older people. METHODS We analysed data from community-dwelling individuals who underwent multimodal brain MRI and retinal fundus camera imaging at mean age 72.55 years (SD=0.71). We assessed centrum semiovale PVS computationally to determine PVS total volume and count, and mean per-subject individual PVS length, width and size. We analysed retinal images using the VAMPIRE software suite, obtaining the Central Retinal Artery and Vein Equivalents (CRVE and CRAE), Arteriole-to-Venule ratio (AVR), and fractal dimension (FD) of both eyes. We investigated associations using general linear models, adjusted for age, gender, and major vascular risk factors. RESULTS In 381 subjects with all measures, increasing total PVS volume and count were associated with decreased CRAE in the left eye (volume β=-0.170, count β=-0.184, p<0.001). No associations of PVS with CRVE were found. The PVS total volume, individual width and size increased with decreasing FD of the arterioles (a) and venules (v) of the left eye (total volume: FDa β=-0.137, FDv β=-0.139, p<0.01; width: FDa β=-0.144, FDv β=-0.158, p<0.01; size: FDa β=-0.157, FDv β=-0.162, p<0.01). CONCLUSIONS Increase in PVS number and size visible on MRI reflect arteriolar narrowing and lower retinal arteriole and venule branching complexity, both markers of impaired microvascular health. Computationally-derived PVS metrics may be an early indicator of failing vascular health and should be tested in longitudinal studies.
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Affiliation(s)
- Lucia Ballerini
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Sarah McGrory
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Maria del C. Valdés Hernández
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | | | - Enrico Pellegrini
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Tom MacGillivray
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Susana Muñoz Maniega
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Ross Henderson
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Adele Taylor
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Mark E. Bastin
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Fergus Doubal
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Emanuele Trucco
- VAMPIRE Project, Computing (SSEN), University of Dundee, Dundee, UK
| | - Ian J. Deary
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Joanna Wardlaw
- Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, and VAMPIRE Project, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
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Hasan T, Khare S, Jain S, Gupta P, Sharma S. Retinal vasculature – An imaging based morphological study. J ANAT SOC INDIA 2013. [DOI: 10.1016/j.jasi.2013.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Unnikrishnan P, Aliahmad B, Kawasaki R, Kumar D. Adaptive colour transformation of retinal images for stroke prediction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:7384-7. [PMID: 24111451 DOI: 10.1109/embc.2013.6611264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Identifying lesions in the retinal vasculature using Retinal imaging is most often done on the green channel. However, the effect of colour and single channel analysis on feature extraction has not yet been studied. In this paper an adaptive colour transformation has been investigated and validated on retinal images associated with 10-year stroke prediction, using principle component analysis (PCA). Histogram analysis indicated that while each colour channel image had a uni-modal distribution, the second component of the PCA had a bimodal distribution, and showed significantly improved separation between the retinal vasculature and the background. The experiments showed that using adaptive colour transformation, the sensitivity and specificity were both higher (AUC 0.73) compared with when single green channel was used (AUC 0.63) for the same database and image features.
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9
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Liu YP, Kuznetsova T, Jin Y, Thijs L, Asayama K, Gu YM, Bochud M, Verhamme P, Struijker-Boudier HAJ, Staessen JA. Heritability of the retinal microcirculation in Flemish families. Am J Hypertens 2013; 26:392-9. [PMID: 23382490 DOI: 10.1093/ajh/hps064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Few population studies have described the heritability and intrafamilial concordance of the retinal microvessels, or the genetic or environmental correlations of the phenotypes of these vessels. METHODS We randomly selected 413 participants from 70 families (mean age, 51.5 years; 50.1% women) from a Flemish population. We postprocessed retinal images using IVAN software to generate the central retinal arteriole equivalent (CRAE), central retinal venule equivalent (CRVE), and arteriole-to-venule-ratio (AVR) from these images. We used SAGE version 6.2 and SAS version 9.2 to compute multivariate-adjusted estimates of heritability and intrafamilial correlations of the CRAE, CRVE, and AVR of the retinal microvessels in the images. RESULTS Sex, age, mean arterial pressure, and smoking explained up to 12.7% of the variance of the phenotypes of the retinal microvessels of the study participants. With adjustments applied for these covariates, the heritability estimates of CRAE, CRVE, and AVR were 0.213 (P = 0.044), 0.339 (P = 0.010), and 0.272 (P = 0.004), respectively. The parent-offspring correlations for CRAE, CRVE, and AVR were 0.118 (NS), 0.225 (P < 0.01), and 0.215 (P < 0.05), respectively. The corresponding values were 0.222 (P < 0.05), 0.213 (P < 0.05), and 0.390 (P < 0.001) for sib-sib correlations, respectively. The genetic and environmental correlations between CRAE and CRVE were 0.360 and 0.545 (P < 0.001 for both). CONCLUSION Our study showed moderate heritability for CRAE, CRVE, and AVR, and a significant genetic correlation of CRAE with CRVE in the Flemish population of our study. These findings suggest that genetic factors influence the diameter of the retinal microvessels, and that CRAE and CRVE share some genetic determinants.
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Affiliation(s)
- Yan-Ping Liu
- Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
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Yeo HJ, Lee JH, Lee HJ, Byun KS, Im HJ, Kim MJ. Microvascular Findings in Patients with Rheumatoid Arthritis - Assessed, Using Fundus Photography and Fluorescein Angiography. JOURNAL OF RHEUMATIC DISEASES 2013. [DOI: 10.4078/jrd.2013.20.4.231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hyun Jung Yeo
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
| | - Ji Hyun Lee
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
| | - Hong Jik Lee
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
| | - Ki Sup Byun
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
| | - Ho Joon Im
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
| | - Min Jung Kim
- Division of Rheumatology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea
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Liew G, Baker ML, Wong TY, Hand PJ, Wang JJ, Mitchell P, De Silva DA, Wong MC, Rochtchina E, Lindley RI, Wardlaw JM, Hankey GJ. Differing Associations of White Matter Lesions and Lacunar Infarction with Retinal Microvascular Signs. Int J Stroke 2012; 9:921-5. [DOI: 10.1111/j.1747-4949.2012.00865.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 02/09/2012] [Indexed: 12/01/2022]
Abstract
Background White matter lesions (WML) and lacunar infarcts (LI) are believed to have microvascular etiologies but the exact microvascular changes occurring in each is unclear. Aim Using the retina as a proxy, we assessed retinal microvascular changes in WML and LI. Methods We prospectively recruited 1211 acute stroke patients. Four subgroups were identified from neuroimaging: WML alone, LI alone, both WML and LI, neither WML nor LI. Masked retinal photographs identified retinopathy and retinal arteriolar wall signs and measured retinal vascular caliber. Results Compared with 448 controls with neither WML nor LI, 384 patients with only WML were more likely to have retinopathy [odds ratio (OR) 1·5, 95% confidence interval (CI) 1·1 to 2·1] and enhanced arteriolar light reflex (OR 1·6, 95% CI 1·1 to 2·3); 200 patients with only LI were more likely to have arteriolar narrowing (OR 1·6, 95% CI 1·1 to 2·3) and enhanced arteriolar light reflex (OR 1·6, 95% CI 1·0 to 2·4); and 179 patients with both WML and LI were more likely to have arteriovenous nicking (OR 1·7, 95% CI 1·1 to 2·6), enhanced arteriolar light reflex (OR 2·0, 95% CI 1·3 to 3·2) and wider venules (OR 2·3, 95% CI 1·4 to 3·6). All analyses were adjusted for age, gender, study site and cardiovascular risk factors. Conclusion Both WML and LI were associated with retinal microvascular signs, supporting a microvascular etiology. Differing patterns of association suggest different mechanisms may predominate, e.g. greater endothelial permeability in WML, and ischemia associated with arteriolar wall disease in LI.
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Affiliation(s)
- Gerald Liew
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Sydney, Australia
| | - Michelle L. Baker
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia
| | - Tien Y. Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia
- Singapore Eye Research Institute, National University of Singapore, Singapore
| | - Peter J. Hand
- Department of Neurology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Jie Jin Wang
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Sydney, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia
| | - Paul Mitchell
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia
| | - Deidre A. De Silva
- Singapore General Hospital Campus, National Neuroscience Institute, Singapore
| | | | - Elena Rochtchina
- Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Sydney, Australia
| | - Richard I. Lindley
- Discipline of Medicine, Sydney Medical School – Westmead, Westmead Hospital, University of Sydney, Sydney, Australia
| | - Joanna M. Wardlaw
- SINAPSE Collaboration, Division of Clinical Neurosciences, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Graeme J. Hankey
- Royal Perth Hospital, University of Western Australia, Perth, Australia Received: 29 December 2011; Accepted 9 February 2012; Published online 18 September 2012
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De Silva DA, Woon FP, Manzano JJF, Liu EY, Chang HM, Chen C, Wang JJ, Mitchell P, Kingwell BA, Cameron JD, Lindley RI, Wong TY, Wong MC. The relationship between aortic stiffness and changes in retinal microvessels among Asian ischemic stroke patients. J Hum Hypertens 2011; 26:716-22. [PMID: 21975690 DOI: 10.1038/jhh.2011.88] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Large-artery stiffness is a risk factor for stroke, including cerebral small-vessel disease. Retinal microvascular changes are thought to mirror those in cerebral microvessels. We investigated the relationship between aortic stiffness and retinal microvascular changes in Asian ischemic stroke patients. We studied 145 acute ischemic stroke patients in Singapore who had aortic stiffness measurements using carotid-femoral pulse wave velocity (cPWV). Retinal photographs were assessed for retinal microvessel caliber and qualitative signs of focal arteriolar narrowing, arteriovenous nicking and enhanced arteriolar light reflex. Aortic stiffening was associated with retinal arteriolar changes. Retinal arteriolar caliber decreased with increasing cPWV (r=-0.207, P=0.014). After adjusting for age, gender, hypertension, diabetes, mean arterial pressure and small-vessel stroke subtype, patients within the highest cPWV quartile were more likely to have generalized retinal arteriolar narrowing defined as lowest caliber tertile (odds ratio (OR) 6.84, 95% confidence interval (CI) 1.45-32.30), focal arteriolar narrowing (OR 13.85, CI 1.82-105.67), arteriovenous nicking (OR 5.08, CI 1.12-23.00) and enhanced arteriolar light reflex (OR 3.83, CI 0.89-16.48), compared with those within the lowest quartile. In ischemic stroke patients, aortic stiffening is associated with retinal arteriolar luminal narrowing as well as features of retinal arteriolosclerosis.
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Affiliation(s)
- D A De Silva
- Singapore General Hospital Campus, National Neuroscience Institute, Singapore.
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13
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Wang JJ, Baker ML, Hand PJ, Hankey GJ, Lindley RI, Rochtchina E, Wong TY, Liew G, Mitchell P. Transient Ischemic Attack and Acute Ischemic Stroke. Stroke 2011; 42:404-8. [DOI: 10.1161/strokeaha.110.598599] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Jie Jin Wang
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Michelle L. Baker
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Peter J. Hand
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Graeme J. Hankey
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Richard I. Lindley
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Elena Rochtchina
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Tien Y. Wong
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Gerald Liew
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
| | - Paul Mitchell
- From the Centre for Eye Research Australia (J.J.W., M.L.B., T.Y.W.), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., E.R., G.L., P.M.), Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Royal Perth Hospital (G.J.H.), University of Western Australia, Western
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14
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Baker ML, Wang JJ, Liew G, Hand PJ, De Silva DA, Lindley RI, Mitchell P, Wong MC, Rochtchina E, Wong TY, Wardlaw JM, Hankey GJ. Differential Associations of Cortical and Subcortical Cerebral Atrophy With Retinal Vascular Signs in Patients With Acute Stroke. Stroke 2010; 41:2143-50. [DOI: 10.1161/strokeaha.110.594317] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michelle L. Baker
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Jie Jin Wang
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Gerald Liew
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Peter J. Hand
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Deidre A. De Silva
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Richard I. Lindley
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Paul Mitchell
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Meng-Cheong Wong
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Elena Rochtchina
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Tien Y. Wong
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Joanna M. Wardlaw
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
| | - Graeme J. Hankey
- From the Centre for Eye Research Australia (M.L.B., J.J.W., T.Y.W.), University of Melbourne, Melbourne, Australia; the Centre for Vision Research (J.J.W., G.L., P.M., E.R.), Westmead Millennium Institute, University of Sydney, Sydney, Australia; the Department of Neurology (P.J.H.), Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Singapore General Hospital Campus (D.D.S.), National Neuroscience Institute, Singapore; the Discipline of Medicine (R.I.L.), Sydney Medical
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Cheung N, Liew G, Lindley RI, Liu EY, Wang JJ, Hand P, Baker M, Mitchell P, Wong TY. Retinal fractals and acute lacunar stroke. Ann Neurol 2010; 68:107-11. [PMID: 20582985 DOI: 10.1002/ana.22011] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49-12.17 and OR, 1.85; 95% CI, 1.20-2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke.
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Affiliation(s)
- Ning Cheung
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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Retinal Microvascular Signs May Provide Clues to the Underlying Vasculopathy in Patients With Deep Intracerebral Hemorrhage. Stroke 2010; 41:618-23. [DOI: 10.1161/strokeaha.109.569764] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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McGeechan K, Liew G, Macaskill P, Irwig L, Klein R, Klein BEK, Wang JJ, Mitchell P, Vingerling JR, de Jong PTVM, Witteman JCM, Breteler MMB, Shaw J, Zimmet P, Wong TY. Prediction of incident stroke events based on retinal vessel caliber: a systematic review and individual-participant meta-analysis. Am J Epidemiol 2009; 170:1323-32. [PMID: 19884126 DOI: 10.1093/aje/kwp306] [Citation(s) in RCA: 241] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The caliber of the retinal vessels has been shown to be associated with stroke events. However, the consistency and magnitude of association, and the changes in predicted risk independent of traditional risk factors, are unclear. To determine the association between retinal vessel caliber and the risk of stroke events, the investigators combined individual data from 20,798 people, who were free of stroke at baseline, in 6 cohort studies identified from a search of the Medline (National Library of Medicine, Bethesda, Maryland) and EMBASE (Elsevier B.V., Amsterdam, the Netherlands) databases. During follow-up of 5-12 years, 945 (4.5%) incident stroke events were recorded. Wider retinal venular caliber predicted stroke (pooled hazard ratio = 1.15, 95% confidence interval: 1.05, 1.25 per 20-micron increase in caliber), but the caliber of retinal arterioles was not associated with stroke (pooled hazard ratio = 1.00, 95% confidence interval: 0.92, 1.08). There was weak evidence of heterogeneity in the hazard ratio for retinal venular caliber, which may be attributable to differences in follow-up strategies across studies. Inclusion of retinal venular caliber in prediction models containing traditional stroke risk factors reassigned 10.1% of people at intermediate risk into different, mostly lower, risk categories.
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Affiliation(s)
- Kevin McGeechan
- Singapore Eye Research Institute, National University of Singapore, 11 Third Hospital Avenue, Singapore 168751, Singapore
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De Silva DA, Liew G, Wong MC, Chang HM, Chen C, Wang JJ, Baker ML, Hand PJ, Rochtchina E, Liu EY, Mitchell P, Lindley RI, Wong TY. Retinal vascular caliber and extracranial carotid disease in patients with acute ischemic stroke: the Multi-Centre Retinal Stroke (MCRS) study. Stroke 2009; 40:3695-9. [PMID: 19815829 DOI: 10.1161/strokeaha.109.559435] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Previous studies show that both retinal vascular caliber and carotid disease predict incident stroke in the general population, but the exact relationship between these 2 microvascular and macrovascular structural risk factors is unclear. We studied the relationship between retinal vascular caliber and carotid disease in patients presenting with acute ischemic stroke. METHODS We conducted a cross-sectional study of patients with acute ischemic stroke recruited from 3 centers (Melbourne, Sydney, Singapore). The caliber of retinal arterioles and venules was measured from digital retinal photographs. Severe extracranial carotid disease was defined as stenosis >or=75% or occlusion determined by carotid Doppler using North American Symptomatic Carotid Endarterectomy Trial-based criteria. RESULTS Among the 1029 patients with acute stroke studied, 7% of the population had severe extracranial carotid disease. Retinal venular caliber was associated with ipsilateral severe carotid disease (P<0.001 in multivariate models). Patients with wider retinal venular caliber were more likely to have severe ipsilateral carotid disease (multivariable-adjusted OR, 3.81; 95% CI, 1.80 to 8.07, comparing the largest and smallest venular caliber quartiles). The retinal venular caliber-carotid disease association remained significant in patients with large artery stroke. CONCLUSIONS In patients with acute stroke, retinal venular widening was strongly associated with ipsilateral severe extracranial carotid disease. Our findings suggest concomitant retinal and cerebral microvascular disease may be present in patients with carotid stenosis or occlusion disease. The pathogenesis of stroke due to carotid disease may thus be partially mediated by microvascular disease.
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Affiliation(s)
- Deidre A De Silva
- Singapore General Hospital Campus, National Neuroscience Institute, Singapore.
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Aly Z, Taj F, Kamal AK. Evaluating ischemic stroke subtypes: does the retinal microvasculature hold clues to what lies beneath? Stroke 2009; 40:e400; author reply e401. [PMID: 19342604 DOI: 10.1161/strokeaha.109.549600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Retinal vascular signs and cerebrovascular disease - a response. Clin Exp Ophthalmol 2009. [DOI: 10.1111/j.1442-9071.2009.02013.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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