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Szilágyi A, Takács B, Szekeres R, Tarjányi V, Nagy D, Priksz D, Bombicz M, Kiss R, Szabó AM, Lehoczki A, Gesztelyi R, Juhász B, Szilvássy Z, Varga B. Effects of voluntary and forced physical exercise on the retinal health of aging Wistar rats. GeroScience 2024; 46:4707-4728. [PMID: 38795184 PMCID: PMC11336036 DOI: 10.1007/s11357-024-01208-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/13/2024] [Indexed: 05/27/2024] Open
Abstract
Aging is accompanied by an increased prevalence of degenerative conditions, including those affecting ocular health, which significantly impact quality of life and increase the burden on healthcare systems. Among these, retinal aging is of particular concern due to its direct link to vision impairment, a leading cause of disability in the elderly. Vision loss in the aging population is associated with heightened risks of cognitive decline, social isolation, and morbidity. This study addresses the critical gap in our understanding of modifiable lifestyle factors, such as physical exercise, that may mitigate retinal aging and its related pathologies. We investigated the effects of different exercise regimens-voluntary (recreational-type) and forced (high-intensity)-on the retinal health of aging Wistar rats (18-month-old), serving as a model for studying the translational potential of exercise interventions in humans. Male Wistar rats were divided into four groups: a young control (3-month-old) for baseline comparison, an aged sedentary control, an aged group engaging in voluntary exercise via a running wheel in their cage, and an aged group subjected to forced exercise on a treadmill for six sessions of 20 min each per week. After a 6-month experimental period, we assessed retinal function via electroretinography (ERG), measured retinal thickness histologically, and analyzed protein expression changes relevant to oxidative stress, inflammation, and anti-aging mechanisms. Our findings reveal that voluntary exercise positively impacts retinal function and morphology, reducing oxidative stress and inflammation markers while enhancing anti-aging protein expression. In contrast, forced exercise showed diminished benefits. These insights underscore the importance of exercise intensity and preference in preserving retinal health during aging. The study highlights the potential of recreational physical activity as a non-invasive strategy to counteract retinal aging, advocating for further research into exercise regimens as preventative therapies for age-related ocular degenerations.
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Affiliation(s)
- Anna Szilágyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Barbara Takács
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Réka Szekeres
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Vera Tarjányi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Dávid Nagy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Dániel Priksz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Mariann Bombicz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Rita Kiss
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Adrienn Mónika Szabó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Andrea Lehoczki
- Departments of Hematology and Stem Cell Transplantation, South Pest Central Hospital, National Institute of Hematology and Infectious Diseases, Saint Ladislaus Campus, Budapest, Hungary
- Department of Public Health, Semmelweis University, Budapest, Hungary
- Doctoral College, Health Sciences Program, Semmelweis University, Budapest, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Zoltán Szilvássy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Balázs Varga
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary.
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Andrade DDM, Oliveira JBV, Lacordia MHFA, Laterza MC, Martinez DG. Low Ocular Perfusion Pressure Values at Rest and during Resistance Exercise in Offspring of Glaucoma Patients. J Curr Ophthalmol 2023; 35:320-325. [PMID: 39281407 PMCID: PMC11392303 DOI: 10.4103/joco.joco_207_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/24/2023] [Accepted: 11/25/2023] [Indexed: 09/18/2024] Open
Abstract
Purpose To compare the ocular perfusion pressure (OPP) response during physical exercise in individuals with and without a family history (FH+, FH-) of glaucoma. Methods Thirty-four subjects, divided into FH+ and FH- groups, realized 3 min at rest, 3 min of isometric handgrip exercise at 30% of maximal voluntary contraction, followed by 3 min of recovery. Blood pressure (Dixtal® automatic device) and intraocular pressure (Goldmann applanation tonometer) were measured during rest, exercise, and recovery. The mean OPP (mOPP) was calculated. Results In the FH+ group (17 subjects), baseline mOPP values were significantly lower than in the FH- group (17 subjects) (right eye: P < 0.001, left eye: P < 0.001, respectively). During exercise, both the FH+ and FH- groups showed a similar increase in mOPP in both eyes (right eye: FH+: 38 ± 4 mmHg vs. 51 ± 7 mmHg, FH-: 48 ± 5 mmHg vs. 57 ± 9 mmHg, P < 0.001; left eye: FH+: 39 ± 3 mmHg vs. 51 ± 7 mmHg; FH-: 46 ± 5 mmHg vs. 58 ± 8 mmHg, P < 0.001, respectively). However, the FH+ group maintained significantly lower mOPP values compared to the FH- group in the right and left eyes (group effect: P = 0.002, P = 0.002, respectively). The percentage of increase in mOPP in the FH+ group was greater compared to the FH- group during exercise (right eye: 34.1% ± 15.9% vs. 22.1% ± 13.2%, respectively; P = 0.025; left eye: 33.2% ± 17.7% vs. 22.4% ± 13.7%, respectively, P = 0.056). Conclusions mOPP increased during physical exercise in both groups, but the FH+ group had lower absolute values. In addition, the FH+ group appears to demonstrate a higher percentage increase in mOPP compared to the FH- group.
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Affiliation(s)
- Diana de Medeiros Andrade
- Cardiovascular Research Unit and Exercise Physiology, Federal University of Juiz de Fora, Minas Gerais, Brazil
| | | | | | - Mateus Camaroti Laterza
- Cardiovascular Research Unit and Exercise Physiology, Federal University of Juiz de Fora, Minas Gerais, Brazil
| | - Daniel Godoy Martinez
- Cardiovascular Research Unit and Exercise Physiology, Federal University of Juiz de Fora, Minas Gerais, Brazil
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Zhu X, Zhu J, Wang Y, Chu Z, Wang RK, Xu Y, Lu L, Zou H. A moderate dosage of coffee causes acute retinal capillary perfusion decrease in healthy young individuals. BMC Ophthalmol 2022; 22:460. [PMID: 36451130 PMCID: PMC9710088 DOI: 10.1186/s12886-022-02638-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/17/2022] [Indexed: 12/05/2022] Open
Abstract
AIM Caffeinated beverages are very popular across populations and cultures, but quantitative evidence of the acute effects of moderate coffee doses on retinal perfusion is sparse and contradicting. Thus, the aim of this randomized, cross-over and parallel-group design study was to investigate whether moderate consumption of coffee alters macular retinal capillary perfusion in young healthy individuals. METHODS Twenty-seven young healthy individuals were recruited for this study. Acute changes in retinal microvasculature were assessed using spectral-domain optical coherence tomography angiography (SD-OCTA) at baseline, 0.5 h, and 2 h after intake of coffee, or water. Meanwhile, cerebral blood flow (CBF) and retina-choroid blood flow were evaluated in a parallel-group design (4 participants each in coffee or water group) using magnetic resonance imaging (MRI) with pseudo-continuous arterial spin labeling sequences. RESULTS Two hours after coffee intake, blood caffeine concentration increased from 0 to 5.05 ± 1.36 µg/mL. Coffee caused a significant decrease in retinal vessel diameter index (VDI) (19.05 ± 0.24 versus [vs] 19.13 ± 0.26; p < 0.001) and CBF in the frontal lobe (77.47 ± 15.21 mL/100 mL/min vs. 84.13 ± 15.55 mL/100 mL/min; p < 0.05) 2 h after intake. However, it significantly increased retina-choroid blood flow after 0.5 and 2 h (163.18 ± 61.07 mL/100 mL/min vs. 132.68 ± 70.47 mL/100 mL/min, p < 0.001, and 161.21 ± 47.95 vs. 132.68 ± 70.47; p < 0.001, respectively). CONCLUSION This is the first study to demonstrate the acute effects of daily dose coffee consumption on retinal capillary perfusion using SD-OCTA combinate with blood flow MRI. The findings imply that although moderate coffee intake caused a significant increase in retina-choroid blood flow, there was a significant acute decrease both in macular retinal capillary perfusion and CBF.
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Affiliation(s)
- Xiaofeng Zhu
- grid.452752.30000 0004 8501 948XDepartment of Preventive Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, No. 380 Kangding Road, 200040 Shanghai, China ,grid.412478.c0000 0004 1760 4628 Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Road, 200080 Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Jiong Zhu
- grid.16821.3c0000 0004 0368 8293Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yongyi Wang
- Department of Medical Administration, Huizhou First Hospital, Guangdong, China
| | - Zhongdi Chu
- grid.34477.330000000122986657Departments of Bioengineering and Ophthalmology, University of Washington, Seattle, WA USA
| | - Ruikang K. Wang
- grid.34477.330000000122986657Departments of Bioengineering and Ophthalmology, University of Washington, Seattle, WA USA
| | - Yi Xu
- grid.452752.30000 0004 8501 948XDepartment of Preventive Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, No. 380 Kangding Road, 200040 Shanghai, China ,grid.412478.c0000 0004 1760 4628 Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Road, 200080 Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Lina Lu
- grid.452752.30000 0004 8501 948XDepartment of Preventive Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, No. 380 Kangding Road, 200040 Shanghai, China ,grid.412478.c0000 0004 1760 4628 Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Road, 200080 Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Haidong Zou
- grid.452752.30000 0004 8501 948XDepartment of Preventive Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center, Shanghai Eye Hospital, No. 380 Kangding Road, 200040 Shanghai, China ,grid.412478.c0000 0004 1760 4628 Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Road, 200080 Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
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The Effect of Diet and Lifestyle on the Course of Diabetic Retinopathy-A Review of the Literature. Nutrients 2022; 14:nu14061252. [PMID: 35334909 PMCID: PMC8955064 DOI: 10.3390/nu14061252] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/23/2022] Open
Abstract
Diabetes is a major social problem. As shown by epidemiological studies, the world incidence of diabetes is increasing and so is the number of people suffering from its complications. Therefore, it is important to determine possible preventive tools. In the prevention of diabetic retinopathy, it is essential to control glycemia, lipid profile and blood pressure. This can be done not only by pharmacological treatment, but first of all by promoting a healthy lifestyle, changing dietary habits and increasing physical activity. In our work, we present a review of the literature to show that physical exercise and an adequate diet can significantly reduce the risk of diabetes and diabetic retinopathy.
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Hou Y, Song S, Sun J, Wang H, Wang Y, Wang Z, Li J, Li H. Non-invasive Diagnosis and Prognosis Values of 3D Pseudocontinuous Arterial Spin Labeling and Optical Coherence Tomography Angiography in Proliferative Diabetic Retinopathy. Front Med (Lausanne) 2021; 8:682708. [PMID: 34150814 PMCID: PMC8211895 DOI: 10.3389/fmed.2021.682708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/12/2021] [Indexed: 11/27/2022] Open
Abstract
Background: 3D Pseudocontinuous Arterial Spin Labeling (3D-PCASL) MRI and optical coherence tomography angiography (OCTA) have been applied to detect ocular blood flow (BF). We aim to characterize the ocular BF in diabetic retinopathy (DR) using 3D-PCASL and OCTA, to discuss the relationship between ocular and cerebral BF, and to evaluate their potential utility to assess the severity of DR. Methods: A total of 66 participants (132 eyes) were included. Seventy-two eyes were classified in the proliferative diabetic retinopathy (PDR) group, and 60 were in the non-proliferative diabetic retinopathy NPDR group. Ocular and cerebral BF values were detected by 3D-PCASL using a 3.0T MRI scanner with two post-labeling delays (PLDs). Vessel density (VD)/perfusion density (PD) of the macular or peripapillary area were detected by OCTA. Parameters and clinical characteristics were compared between the PDR and NPDR eyes utilizing two-sample t-tests and chi-square tests. Spearman's rank correlation analysis, logistic regression analysis, and receiver operating characteristic curves (ROC) analyses were performed to evaluate the factors' role in DR severity. Results: The perfusions of the retinal/choroidal plexus (RCP), optic nerve head (ONH)/optic nerve (ON), and VD/PD of macular/peripapillary area in the PDR group were significantly lower compared to the NPDR group (p < 0.05). They were protective factors for PDR [ORs = 0.842 for RCP (1.5 s PLD), 0.910 for ONH (1.5 s PLD), 0.905 for ON (both 1.5 and 2.5 s PLD), 0.707 for macular VD, 0.652 for peripapillary VD, p < 0.05, respectively]. Ocular BF had a positive correlation with BF of the occipital lobe (OL) and temporal lobe (TL) in the cerebrum. The BF of RCP (lower than 7.825 mL/min/100 g at 1.5 s PLD) indicated PDR [areas under the curve (AUCs) = 0.682, 95% CI: 0.588–0.777, sensitivity: 70.7% specificity: 63.9%]. The AUC of RCP (PLD = 1.5 s) BF combined with peripapillary VD was 0.841 (95% CI: 0.588–0.777, sensitivity: 75.9% specificity: 82.9%). Conclusions: 3D-pcASL and OCTA may be effective non-invasive methods to measure ocular blood flow in DR patients and assess the severity of DR.
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Affiliation(s)
- Yanli Hou
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Shuai Song
- Deparment of Thoracic Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jiao Sun
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Huihui Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yanling Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zhenchang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Hongyang Li
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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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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Sousa DC, Leal I, Moreira S, do Vale S, Silva-Herdade AS, Aguiar P, Dionísio P, Abegão Pinto L, Castanho MARB, Marques-Neves C. Retinal Vascular Reactivity in Type 1 Diabetes Patients Without Retinopathy Using Optical Coherence Tomography Angiography. Invest Ophthalmol Vis Sci 2021; 61:49. [PMID: 32574352 PMCID: PMC7415313 DOI: 10.1167/iovs.61.6.49] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy. Methods Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated. Results In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F1,23 = 15.69, P < 0.001 and F1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F1,23 = 27.37, P < 0.0001 and F1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F1,23 = 11.04, P < 0.01). Conclusions Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.
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Bongers-Karmaoui MN, Jaddoe VWV, Roest AAW, Gaillard R. The Cardiovascular Stress Response as Early Life Marker of Cardiovascular Health: Applications in Population-Based Pediatric Studies-A Narrative Review. Pediatr Cardiol 2020; 41:1739-1755. [PMID: 32879997 PMCID: PMC7695663 DOI: 10.1007/s00246-020-02436-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023]
Abstract
Stress inducement by physical exercise requires major cardiovascular adaptations in both adults and children to maintain an adequate perfusion of the body. As physical exercise causes a stress situation for the cardiovascular system, cardiovascular exercise stress tests are widely used in clinical practice to reveal subtle cardiovascular pathology in adult and childhood populations with cardiac and cardiovascular diseases. Recently, evidence from small studies suggests that the cardiovascular stress response can also be used within research settings to provide novel insights on subtle differences in cardiovascular health in non-diseased adults and children, as even among healthy populations an abnormal response to physical exercise is associated with an increased risk of cardiovascular diseases. This narrative review is specifically focused on the possibilities of using the cardiovascular stress response to exercise combined with advanced imaging techniques in pediatric population-based studies focused on the early origins of cardiovascular diseases. We discuss the physiology of the cardiovascular stress response to exercise, the type of physical exercise used to induce the cardiovascular stress response in combination with advanced imaging techniques, the obtained measurements with advanced imaging techniques during the cardiovascular exercise stress test and their associations with cardiovascular health outcomes. Finally, we discuss the potential for cardiovascular exercise stress tests to use in pediatric population-based studies focused on the early origins of cardiovascular diseases.
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Affiliation(s)
- Meddy N Bongers-Karmaoui
- The Generation R Study Group, Erasmus MC, University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - Vincent W V Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - Arno A W Roest
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Romy Gaillard
- The Generation R Study Group, Erasmus MC, University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
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Wang H, Sun J, Li J, Li H, Wang Y, Wang Z. Ocular Blood Flow Measurements in Diabetic Retinopathy Using 3D Pseudocontinuous Arterial Spin Labeling. J Magn Reson Imaging 2020; 53:791-798. [PMID: 33140547 DOI: 10.1002/jmri.27398] [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: 08/03/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Distinguishing between the two broad categories of diabetic retinopathy (DR), nonproliferative DR (NPDR) and proliferative DR (PDR), is significant, as the therapeutic strategies for each are completely different. PURPOSE To characterize the ocular blood flow (OBF) of DR patients and evaluate the potential utility of OBF values in categorizing DR. STUDY TYPE Prospective. SUBJECTS A total of 41 DR patients (82 eyes) were recruited in our study. Group 1 comprised 48 eyes with NPDR, and Group 2 comprised 34 eyes with PDR. FIELD STRENGTH/SEQUENCE 3D pseudocontinuous arterial spin labeling (3D-pcASL) with two postlabeling delays (PLDs) was acquired at 3.0T MR. ASSESSMENT OBF values were independently obtained by two doctors from the OBF map. STATISTICAL TESTS OBF values and clinical characteristics were compared between the groups using two-sample t-tests and chi-square tests. Receiver operating characteristic (ROC) curves were obtained, and the area under the curve (AUC) was calculated. The consistency of OBF values reported by the two doctors was evaluated using the intraclass correlation coefficient (ICC). RESULTS OBF values at PLDs of 1.5 seconds and 2.5 seconds were significantly lower in Group 2 than in Group 1 (P < 0.05 for both PLDs). The OBF values of Group 2 showed a greater increase than those of Group 1 from PLD 1.5 to 2.5 seconds. The AUC of OBF at the 1.5 seconds PLD was 0.90, with a cutoff of 7.73 mL/min/100 g, and the AUC of the OBF at the 2.5 seconds PLD was 0.75, with a cutoff of 8.44 mL/min/100 g. The ICC between the two observers was 0.844 for the OBF at 1.5 seconds PLD and 0.872 for the OBF at 2.5 seconds PLD. DATA CONCLUSION PDR can be differentiated from NPDR by the value of OBF as measured by 3D-pcASL. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Huihui Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jiao Sun
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Hongyang Li
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yanling Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zhenchang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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Ren C, Liu W, Li J, Cao Y, Xu J, Lu P. Physical activity and risk of diabetic retinopathy: a systematic review and meta-analysis. Acta Diabetol 2019; 56:823-837. [PMID: 30900027 DOI: 10.1007/s00592-019-01319-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/05/2019] [Indexed: 01/28/2023]
Abstract
AIMS Diabetic retinopathy (DR) is an important microvascular complication of diabetes mellitus (DM) and a leading cause of visual impairment and blindness among people of working age. Physical activity (PA) or exercise is critical and beneficial for DM patients, whereas studies evaluating the relationship between PA and DR have yielded inconsistent and inconclusive results. The American Diabetes Association's "Standards of Medical Care in Diabetes" has also pointed out the indeterminate roles of PA in DR prevention. The purpose of this systematic review and meta-analysis was to explore the association between PA and DR risk. METHODS Medline (accessed by PubMed), EmBase, and Cochrane Library were systematically searched for studies up to June 2018, and the reference lists of the published articles were searched manually. The association between PA and DR risk was assessed using random-effect meta-analysis. RESULTS Twenty-two studies were included in this meta-analysis. PA was found to have a protective association with DR [risk ratio (RR) = 0.94, 95% confidence interval (95% CI) 0.90-0.98, p = 0.005] in diabetic patients, and the impact was more pronounced on vision-threatening DR (RR = 0.89, 95% CI 0.80-0.98, p = 0.02). Sedentary behavior could increase the risk of DR (RR = 1.18, 95% CI 1.01-1.37, p = 0.04). Moderate-intensity PA was likely to have a slight protective effect (RR = 0.76, 95% CI 0.58-1.00, p = 0.05). CONCLUSION PA is associated with lower DR risk, and more studies should focus on the causality between them.
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Affiliation(s)
- Chi Ren
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Weiming Liu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Jianqing Li
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Yihong Cao
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Jiayi Xu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China
| | - Peirong Lu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, People's Republic of China.
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11
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Sousa DC, Leal I, Moreira S, do Vale S, Silva-Herdade AS, Aguiar P, Dionísio P, Abegão Pinto L, Castanho MARB, Marques-Neves C. A Protocol to Evaluate Retinal Vascular Response Using Optical Coherence Tomography Angiography. Front Neurosci 2019; 13:566. [PMID: 31249500 PMCID: PMC6582622 DOI: 10.3389/fnins.2019.00566] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/17/2019] [Indexed: 12/26/2022] Open
Abstract
Introduction Optical coherence tomography angiography (OCT-A) is a novel diagnostic tool with increasing applications in ophthalmology clinics that provides non-invasive high-resolution imaging of the retinal microvasculature. Our aim is to report in detail an experimental protocol for analyzing both vasodilatory and vasoconstriction retinal vascular responses with the available OCT-A technology. Methods A commercial OCT-A device was used (AngioVue®, Optovue, CA, United States), and all examinations were performed by an experienced technician using the standard protocol for macular examination. Two standardized tests were applied: (i) the hypoxia challenge test (HCT) and (ii) the handgrip test, in order to induce a vasodilatory and vasoconstriction response, respectively. OCT-A was performed at baseline conditions and during the stress test. Macular parafoveal vessel density of the superficial and deep plexuses was assessed from the en face angiograms. Statistical analysis was performed using STATA v14.1 and p < 0.05 was considered for statistical significance. Results Twenty-four eyes of 24 healthy subjects (10 male) were studied. Mean age was 31.8 ± 8.2 years (range, 18–57 years). Mean parafoveal vessel density in the superficial plexus increased from 54.7 ± 2.6 in baseline conditions to 56.0 ± 2.0 in hypoxia (p < 0.01). Mean parafoveal vessel density in the deep plexuses also increased, from 60.4 ± 2.2 at baseline to 61.5 ± 2.1 during hypoxia (p < 0.01). The OCT-A during the handgrip test revealed a decrease in vessel density in both superficial (55.5 ± 2.6 to 53.7 ± 2.9, p < 0.001) and deep (60.2 ± 1.8 to 56.7 ± 2.8, p < 0.001) parafoveal plexuses. Discussion In this work, we detail a simple, non-invasive, safe, and non-costly protocol to assess a central nervous system vascular response (i.e., the retinal circulation) using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditions—mild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.
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Affiliation(s)
- David Cordeiro Sousa
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Manchester Royal Eye Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Inês Leal
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Susana Moreira
- Respiratory Medicine Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Sónia do Vale
- Endocrinology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Endocrinology Department, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana S Silva-Herdade
- Instituto de Bioquímica, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Patrício Aguiar
- Medicine I Department, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Clinica Universitária de Medicina I, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Patrícia Dionísio
- Respiratory Medicine Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Luís Abegão Pinto
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel A R B Castanho
- Instituto de Bioquímica, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Carlos Marques-Neves
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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12
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Li HY, Hong X, Huang M, So KF. Voluntary running delays primary degeneration in rat retinas after partial optic nerve transection. Neural Regen Res 2019; 14:728-734. [PMID: 30632515 PMCID: PMC6352605 DOI: 10.4103/1673-5374.247481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Running is believed to be beneficial for human health. Many studies have focused on the neuroprotective effects of voluntary running on animal models. There were both primary and secondary degeneration in neurodegenerative diseases, including glaucoma. However, whether running can delay primary or secondary degeneration or both of them was not clear. Partial optic nerve transection model is a valuable glaucoma model for studying both primary and secondary degeneration because it can separate primary (mainly in the superior retina) from secondary (mainly in the inferior retina) degeneration. Therefore, we compared the survival of retinal ganglion cells between Sprague-Dawley rat runners and non-runners both in the superior and inferior retinas. Excitotoxicity, oxidative stress, and apoptosis are involved in the degeneration of retinal ganglion cells in glaucoma. So we also used western immunoblotting to compare the expression of some proteins involved in apoptosis (phospho-c-Jun N-terminal kinases, p-JNKs), oxidative stress (manganese superoxide dismutase, MnSOD) and excitotoxicity (glutamine synthetase) between runners and non-runners after partial optic nerve transection. Results showed that voluntary running delayed the death of retinal ganglion cells vulnerable to primary degeneration but not those to secondary degeneration. In addition, voluntary running decreased the expression of glutamine synthetase, but not the expression of p-JNKs and MnSOD in the superior retina after partial optic nerve transection. These results illustrated that primary degeneration of retinal ganglion cells might be mainly related with excitotoxicity rather than oxidative stress; and the voluntary running could down-regulate excitotoxicity to delay the primary degeneration of retinal ganglion cells after partial optic nerve transection.
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Affiliation(s)
- Hong-Ying Li
- Department of Anatomy, School of Medicine; Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, Guangdong Province, China
| | - Xi Hong
- Department of Anatomy, School of Medicine, Jinan University, Guangzhou, Guangdong Province, China
| | - Mi Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China
| | - Kwok-Fai So
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province; Department of Ophthalmology and State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China
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13
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Khanal S, Turnbull PRK, Vaghefi E, Phillips JR. Repeatability of Arterial Spin Labeling MRI in Measuring Blood Perfusion in the Human Eye. J Magn Reson Imaging 2018; 49:966-974. [PMID: 30252997 DOI: 10.1002/jmri.26323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/16/2018] [Accepted: 08/17/2018] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Quantifying blood perfusion in ocular tissues is challenging, partly because the majority of the blood is carried by the choroid, which is difficult to visualize because it is located between the retina and sclera. PURPOSE/HYPOTHESIS To evaluate the intra- and interday repeatability of MRI measures of chorio-retinal blood perfusion. STUDY TYPE Prospective, cross-sectional, observational study. POPULATION Twenty young healthy adults (six male, age: 25 ± 5 years) scanned twice within a single session repeated at the same time of day on 2 days. FIELD STRENGTH/SEQUENCE Arterial spin labeling (ASL) MRI at 3.0T using pseudocontinuous ASL (PCASL) labeling scheme and a 3D turbo-gradient-spin-echo (TGSE) acquisition, including axial T2 -weighted structural images using a 2D turbo-spin-echo (TSE) sequence. ASSESSMENTS Region-of-interest analysis for assessment of chorio-retinal blood perfusion. STATISTICAL TESTS Intra- and interday repeatability of measures analyzed using intraclass correlation coefficients (ICC), Pearson's correlation analysis, paired t-tests, and Bland-Altman plots. RESULTS The mean chorio-retinal perfusion was 77.86 (standard deviation [SD] = 29.80) ml/100ml/min. Perfusion measurements correlated strongly within a single session (r = 0.95, 95% confidence interval [CI] [0.880-0.980], P < 0.001) and between the two sessions based on a single run (r = 0.80 [0.582-0.913], P < 0.001), and two runs (r = 0.80 [0.479-0.918], P < 0.001). There were mean differences of 2.69 [16.85 to -22.23] ml/100ml/min for intraday measures, -7.44 [27.45 to -42.32] ml/100ml/min for single-run interday measures, and 5.73 [28.71 to -40.17] ml/100ml/min for two-run interday measures, but none were significant (all P > 0.05). DATA CONCLUSION Quantitative ASL-MRI measurements of chorio-retinal blood perfusion showed high intra- and interday repeatability. The ASL-MRI technique provides reliable measures of chorio-retinal perfusion in vivo. LEVEL OF EVIDENCE 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;49:966-974.
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Affiliation(s)
- Safal Khanal
- School of Optometry and Vision Science, University of Auckland, New Zealand
| | | | - Ehsan Vaghefi
- School of Optometry and Vision Science, University of Auckland, New Zealand
| | - John R Phillips
- School of Optometry and Vision Science, University of Auckland, New Zealand.,Department of Optometry, Asia University, Taichung, Taiwan
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14
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Zhu MM, Lai JSM, Choy BNK, Shum JWH, Lo ACY, Ng ALK, Chan JCH, So KF. Physical exercise and glaucoma: a review on the roles of physical exercise on intraocular pressure control, ocular blood flow regulation, neuroprotection and glaucoma-related mental health. Acta Ophthalmol 2018; 96:e676-e691. [PMID: 29338126 DOI: 10.1111/aos.13661] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 11/06/2017] [Indexed: 12/13/2022]
Abstract
The benefits of physical exercise on health and well-being have been studied in a wide range of systemic and ocular diseases, including glaucoma, a progressive optic neuropathy characterized by accelerated apoptosis of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and insufficient ocular perfusion have been postulated to be the two main theories in glaucoma development and progression. The effects of exercise in these two aspects have been demonstrated by numerous researches. A review in 2009 focusing on these two theories concluded that exercise results in transient IOP reduction but an inconsistent elevation in ocular perfusion. However, the majority of the studies had been conducted in healthy subjects. Over the past decade, technological advancement has brought forth new and more detailed evidence regarding the effects of exercise. Moreover, the neuroprotective effect of exercise by upregulation of neurotrophin and enhancement of mitochondrial function has been a focus of interest. Apart from visual impairment, the mental health issues in patients with glaucoma, which include anxiety and depression, should also be addressed. In this review, we mainly focus on publications from the recent years, so as to provide a comprehensive review on the impact of physical exercise on IOP, ocular perfusion, neuroprotection and mental health in patients with glaucoma.
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Affiliation(s)
- Ming Ming Zhu
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Jimmy Shiu Ming Lai
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Bonnie Nga Kwan Choy
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Jennifer Wei Huen Shum
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Alex Lap Ki Ng
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Jonathan Cheuk Hung Chan
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
| | - Kwok Fai So
- Department of Ophthalmology; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
- School of Biomedical Sciences; LKS Faculty of Medicine; The University of Hong Kong; Hong Kong SAR China
- State Key Laboratory of Brain and Cognitive Sciences; The University of Hong Kong; Hong Kong SAR China
- GHM Institute of CNS Regeneration; Ministry of Education CNS Regeneration Collaborative Joint Laboratory; Jinan University; Guangzhou China
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15
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Fanea L. Reference 3 T MRI parameters of the normal human eye. Phys Med 2018; 47:50-57. [DOI: 10.1016/j.ejmp.2018.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 11/30/2017] [Accepted: 02/09/2018] [Indexed: 12/16/2022] Open
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16
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Paul K, Huelnhagen T, Oberacker E, Wenz D, Kuehne A, Waiczies H, Schmitter S, Stachs O, Niendorf T. Multiband diffusion-weighted MRI of the eye and orbit free of geometric distortions using a RARE-EPI hybrid. NMR IN BIOMEDICINE 2018; 31:e3872. [PMID: 29315932 DOI: 10.1002/nbm.3872] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/19/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Abstract
Diffusion-weighted imaging (DWI) provides information on tissue microstructure. Single-shot echo planar imaging (EPI) is the most common technique for DWI applications in the brain, but is prone to geometric distortions and signal voids. Rapid acquisition with relaxation enhancement [RARE, also known as fast spin echo (FSE)] imaging presents a valuable alternative to DWI with high anatomical accuracy. This work proposes a multi-shot diffusion-weighted RARE-EPI hybrid pulse sequence, combining the anatomical integrity of RARE with the imaging speed and radiofrequency (RF) power deposition advantage of EPI. The anatomical integrity of RARE-EPI was demonstrated and quantified by center of gravity analysis for both morphological images and diffusion-weighted acquisitions in phantom and in vivo experiments at 3.0 T and 7.0 T. The results indicate that half of the RARE echoes in the echo train can be replaced by EPI echoes whilst maintaining anatomical accuracy. The reduced RF power deposition of RARE-EPI enabled multiband RF pulses facilitating simultaneous multi-slice imaging. This study shows that diffusion-weighted RARE-EPI has the capability to acquire high fidelity, distortion-free images of the eye and the orbit. It is shown that RARE-EPI maintains the immunity to B0 inhomogeneities reported for RARE imaging. This benefit can be exploited for the assessment of ocular masses and pathological changes of the eye and the orbit.
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Affiliation(s)
- Katharina Paul
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Till Huelnhagen
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Eva Oberacker
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Daniel Wenz
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | | | | | - Sebastian Schmitter
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
| | - Oliver Stachs
- Department of Ophthalmology, University of Rostock, Rostock, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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17
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ASSESSMENT OF RETINAL BLOOD FLOW IN DIABETIC RETINOPATHY USING DOPPLER FOURIER-DOMAIN OPTICAL COHERENCE TOMOGRAPHY. Retina 2018; 37:2001-2007. [PMID: 28098726 DOI: 10.1097/iae.0000000000001479] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate retinal blood flow measurements in normal eyes and eyes with varying levels of diabetic retinopathy (DR) using Doppler Fourier-domain optical coherence tomography (FD-OCT). METHODS Twenty-two eyes of 19 subjects, 10 with severe nonproliferative DR (NPDR) and 12 with proliferative DR (PDR), were compared with 44 eyes of 40 healthy control subjects. All eyes were scanned by RTvue FD-OCT. Color disk photographs and cube/volume scans of the optic nerve head were obtained. Doppler OCT scans and accessory imaging data were imported into Doppler OCT of Retinal Circulation grading software to calculate TRBF and vascular parameters (e.g., venous and arterial cross-sectional area). Measurements were compared between cases and controls using independent t-tests. RESULTS Mean TRBF was 44.98 ± 9.80 (range: 30.18-64.58) µL/minute for normal eyes, 35.80 ± 10.48 (range: 20.69-49.56) µL/minute for eyes with severe NPDR, and 34.79 ± 10.61 (range: 16.77-48.9) µL/minute for eyes with PDR. Mean TRBF was significantly lower in eyes with severe NPDR (P = 0.01) and PDR (P = 0.003) than in normal eyes. CONCLUSION Total retinal blood flow was significantly lower in eyes with severe NPDR and PDR compared with normal eyes. Retinal blood flow determined by Doppler OCT may be a useful parameter for evaluating patients with DR.
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18
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Vaghefi E, Kauv K, Pan W, Squirrell D. Application of Arterial Spin Labelling in Detecting Retinal Ischemia. Case Rep Ophthalmol 2017; 8:545-557. [PMID: 29422857 PMCID: PMC5803724 DOI: 10.1159/000485316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/15/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose Here, we have tried to quantify the chorioretinal blood perfusion in patients who are clinically identified to be suffering from retinal ischemia using arterial spin labelling (ASL) MRI. Method Four participants, diagnosed with retinal ischemia based on their structural OCT and angiography test, were then scanned using anatomical MRI as well as ASL. We optimized MR parameters to maximize resolution and target fixation, blinking, and breathing ques to minimize motion artifacts. Results Participants had a maximum of ∼50 mL/100 mL/min of blood perfusion, which is below the normal values of ∼200 mL/100 mL/min. It also appeared that thinning of the choroid contributes more to the measured decreased chorioretinal perfusion, compared to slowed arterial filling time. Conclusion Decreased chorioretinal perfusion is a multifactorial event and has been implicated in several posterior eye pathologies. Based on our current results, it seems that ischemia of the eye could be due to anatomy (tissue volume) and/or functionality (arterial flow).
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Affiliation(s)
- Ehsan Vaghefi
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Kevin Kauv
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Wilson Pan
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - David Squirrell
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand.,Auckland District Health Board Ophthalmology Services, Auckland, New Zealand
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19
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Jensen BH, Bram T, Kappelgaard P, Arvidsson H, Loskutova E, Munch IC, Larsen M. Visual function and retinal vessel diameters during hyperthermia in man. Acta Ophthalmol 2017; 95:690-696. [PMID: 28000983 DOI: 10.1111/aos.13361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/07/2016] [Indexed: 11/29/2022]
Abstract
PURPOSE To assess the effect of elevated core body temperature on temporal and spatial contrast sensitivity and retinal vessel diameters. METHODS The study included 13 healthy volunteers aged 20-37 years. Core body temperature elevation (target +1.1°C) was induced by wrapping the participants in cling film, tinfoil and warming blankets. Subsequent cooling was achieved by undressing. Flicker sensitivity (critical flicker fusion frequency) was chosen to assess temporal resolution, while the Freiburg Vision Test was used to determine spatial contrast sensitivity at 1.5 cycles per degree. Scanning laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p < 0.01), a 10.6-mmHg mean reduction in diastolic blood pressure (p < 0.01), a mean increase in pulse rate of 36.3 bpm (p < 0.0001), a 2.66% improvement in flicker sensitivity (CI95 1.37-3.94, p < 0.001), a 2.80% increase in retinal artery diameters (CI95 1.09-4.51, p < 0.01) and a 2.95% increase in retinal vein diameters (CI95 0.96-4.94, p < 0.01). There was no detectable effect of temperature on spatial contrast sensitivity. All ocular test parameters returned to baseline levels after cooling. CONCLUSION Increased core body temperature was accompanied by improved temporal visual resolution and retinal trunk vessel dilation. The results suggest that hyperthermia is associated with enhanced retinal function and increased retinal metabolism.
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Affiliation(s)
- Bettina Hagström Jensen
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | - Thue Bram
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | - Per Kappelgaard
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | | | - Ekaterina Loskutova
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
- Department of Chemical and Life Sciences; Waterford Institute of Technology; MPRG: Macular Pigment Research Group; Waterford Ireland
| | - Inger Christine Munch
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Roskilde Hospital; Roskilde Denmark
| | - Michael Larsen
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
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20
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Guevara-Torres A, Joseph A, Schallek JB. Label free measurement of retinal blood cell flux, velocity, hematocrit and capillary width in the living mouse eye. BIOMEDICAL OPTICS EXPRESS 2016; 7:4228-4249. [PMID: 27867728 PMCID: PMC5102544 DOI: 10.1364/boe.7.004228] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 05/02/2023]
Abstract
Measuring blood cell dynamics within the capillaries of the living eye provides crucial information regarding the health of the microvascular network. To date, the study of single blood cell movement in this network has been obscured by optical aberrations, hindered by weak optical contrast, and often required injection of exogenous fluorescent dyes to perform measurements. Here we present a new strategy to non-invasively image single blood cells in the living mouse eye without contrast agents. Eye aberrations were corrected with an adaptive optics camera coupled with a fast, 15 kHz scanned beam orthogonal to a capillary of interest. Blood cells were imaged as they flowed past a near infrared imaging beam to which the eye is relatively insensitive. Optical contrast of cells was optimized using differential scatter of blood cells in the split-detector imaging configuration. Combined, these strategies provide label-free, non-invasive imaging of blood cells in the retina as they travel in single file in capillaries, enabling determination of cell flux, morphology, class, velocity, and rheology at the single cell level.
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Affiliation(s)
- A. Guevara-Torres
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- The Institute of Optics, University of Rochester, Rochester, NY 14620, USA
| | - A. Joseph
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- The Institute of Optics, University of Rochester, Rochester, NY 14620, USA
| | - J. B. Schallek
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
- Department of Neuroscience, University of Rochester, Rochester, NY 14642, USA
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Merkle CW, Leahy C, Srinivasan VJ. Dynamic contrast optical coherence tomography images transit time and quantifies microvascular plasma volume and flow in the retina and choriocapillaris. BIOMEDICAL OPTICS EXPRESS 2016; 7:4289-4312. [PMID: 27867732 PMCID: PMC5102529 DOI: 10.1364/boe.7.004289] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/19/2016] [Accepted: 09/16/2016] [Indexed: 05/18/2023]
Abstract
Despite the prevalence of optical imaging techniques to measure hemodynamics in large retinal vessels, quantitative measurements of retinal capillary and choroidal hemodynamics have traditionally been challenging. Here, a new imaging technique called dynamic contrast optical coherence tomography (DyC-OCT) is applied in the rat eye to study microvascular blood flow in individual retinal and choroidal layers in vivo. DyC-OCT is based on imaging the transit of an intravascular tracer dynamically as it passes through the field-of-view. Hemodynamic parameters can be determined through quantitative analysis of tracer kinetics. In addition to enabling depth-resolved transit time, volume, and flow measurements, the injected tracer also enhances OCT angiograms and enables clear visualization of the choriocapillaris, particularly when combined with a post-processing method for vessel enhancement. DyC-OCT complements conventional OCT angiography through quantification of tracer dynamics, similar to fluorescence angiography, but with the important added benefit of laminar resolution.
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Affiliation(s)
- Conrad W. Merkle
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Conor Leahy
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, California, USA
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Application of Arterial Spin Labelling in the Assessment of Ocular Tissues. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6240504. [PMID: 27066501 PMCID: PMC4811053 DOI: 10.1155/2016/6240504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/07/2016] [Indexed: 11/17/2022]
Abstract
Arterial spin labelling (ASL) is a noninvasive magnetic resonance imaging (MRI) modality, capable of measuring blood perfusion without the use of a contrast agent. While ASL implementation for imaging the brain and monitoring cerebral blood flow has been reviewed in depth, the technique is yet to be widely used for ocular tissue imaging. The human retina is a very thin but highly stratified structure and it is also situated close to the surface of the body which is not ideal for MR imaging. Hence, the application of MR imaging and ASL in particular has been very challenging for ocular tissues and retina. That is despite the fact that almost all of retinal pathologies are accompanied by blood perfusion irregularities. In this review article, we have focused on the technical aspects of the ASL and their implications for its optimum adaptation for retinal blood perfusion monitoring. Retinal blood perfusion has been assessed through qualitative or invasive quantitative methods but the prospect of imaging flow using ASL would increase monitoring and assessment of retinal pathologies. The review provides details of ASL application in human ocular blood flow assessment.
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Clinical evaluation of ultra-high-field MRI for three-dimensional visualisation of tumour size in uveal melanoma patients, with direct relevance to treatment planning. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:571-7. [PMID: 26915081 PMCID: PMC4891368 DOI: 10.1007/s10334-016-0529-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/14/2016] [Accepted: 01/18/2016] [Indexed: 11/01/2022]
Abstract
OBJECTIVES To assess the tumour dimensions in uveal melanoma patients using 7-T ocular MRI and compare these values with conventional ultrasound imaging to provide improved information for treatment options. MATERIALS AND METHODS Ten uveal melanoma patients were examined on a 7-T MRI system using a custom-built eye coil and dedicated 3D scan sequences to minimise eye-motion-induced image artefacts. The maximum tumour prominence was estimated from the three-dimensional images and compared with the standard clinical evaluation from 2D ultrasound images. RESULTS The MRI protocols resulted in high-resolution motion-free images of the eye in which the tumour and surrounding tissues could clearly be discriminated. For eight of the ten patients the MR images showed a slightly different value of tumour prominence (average 1.0 mm difference) compared to the ultrasound measurements, which can be attributed to the oblique cuts through the tumour made by the ultrasound. For two of these patients the more accurate results from the MR images changed the treatment plan, with the smaller tumour dimensions making them eligible for eye-preserving therapy. CONCLUSION High-field ocular MRI can yield a more accurate measurement of the tumour dimensions than conventional ultrasound, which can result in significant changes in the prescribed treatment.
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Diffusion-Sensitized Ophthalmic Magnetic Resonance Imaging Free of Geometric Distortion at 3.0 and 7.0 T. Invest Radiol 2015; 50:309-21. [DOI: 10.1097/rli.0000000000000129] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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25
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Srinivas S, Tan O, Wu S, Nittala MG, Huang D, Varma R, Sadda SR. Measurement of retinal blood flow in normal Chinese-American subjects by Doppler Fourier-domain optical coherence tomography. Invest Ophthalmol Vis Sci 2015; 56:1569-74. [PMID: 25670487 PMCID: PMC4351651 DOI: 10.1167/iovs.14-15038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-automated analysis of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans. METHODS Two hundred sixty-six normal, healthy Chinese-American participants (266 eyes) were enrolled from The Chinese American Eye Study. All participants underwent complete ophthalmic examination, including best-corrected visual acuity, indirect ophthalmoscopy, and Doppler FD-OCT imaging, using the circumpapillary double circular scan protocol. Total retinal blood flow and other vascular parameters (e.g., venous and arterial cross-sectional area and their velocities) were calculated by using Doppler OCT of Retinal Circulation software. Associations between TRBF and other clinical parameters were assessed by using bivariate correlations and linear regression. RESULTS The mean age of study participants was 57.40 ± 5.60 (range, 50-82) years. The mean TRBF was 49.34 ± 10.08 (range, 27.17-78.08, 95% confidence interval: 25.98-69.10) μL/min. The mean venous area was 0.0548 (±0.0084) mm(2). Superior retinal hemispheric blood flow (25.50 ± 6.62 μL/min) was slightly greater than inferior retinal hemispheric blood flow (23.84 ± 7.19 μL/min, P = 0.008). The mean flow velocity was 15.16 ± 3.12 mm/s. There was a weak but significant negative correlation between TRBF and age (r = -0.15, P = 0.012). No significant correlation was found between TRBF and axial length (r = 0.11, P = 0.08). Retinal blood flow was not significantly correlated with any other clinical parameters, including body mass index, systolic blood pressure, diastolic blood pressure, and intraocular pressure. CONCLUSIONS Normal Doppler OCT-derived total retinal blood values in a Chinese-American population showed considerable variability, some of which was explained by age. These observations should help design future studies evaluating TRBF in populations with eye disease.
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Affiliation(s)
- Sowmya Srinivas
- Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Shuang Wu
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | | | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Rohit Varma
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - SriniVas R. Sadda
- Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States
,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
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Ophthalmic Magnetic Resonance Imaging at 7 T Using a 6-Channel Transceiver Radiofrequency Coil Array in Healthy Subjects and Patients With Intraocular Masses. Invest Radiol 2014; 49:260-70. [DOI: 10.1097/rli.0000000000000049] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Duong TQ. Magnetic resonance imaging of the retina: from mice to men. Magn Reson Med 2014; 71:1526-30. [PMID: 23716429 PMCID: PMC3783549 DOI: 10.1002/mrm.24797] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/25/2013] [Accepted: 04/15/2013] [Indexed: 11/09/2022]
Abstract
This mini-review provides an overview of magnetic resonance imaging (MRI) applications to study rodent, cat, non-human primate, and human retinas. These techniques include T(1) - and T(2) -weighted anatomical, diffusion, blood flow, blood volume, blood-oxygenation level dependent, manganese-enhanced, physiological, and functional MRI. Applications to study the retinas in diabetic retinopathy, glaucoma, and retinal degeneration are also reviewed. MRI offers some unique advantages compared with existing imaging techniques and has the potential to further our understanding of physiology and function in healthy and diseased retinas.
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Affiliation(s)
- Timothy Q Duong
- South Texas Veterans Health Care System, Research Imaging Institute, Department of Ophthalmology, University of Texas Health Science Center, San Antonio, Texas, USA
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Emeterio Nateras OS, Harrison JM, Muir ER, Zhang Y, Peng Q, Chalfin S, Gutierrez JE, Johnson DA, Kiel JW, Duong TQ. Choroidal blood flow decreases with age: an MRI study. Curr Eye Res 2014; 39:1059-67. [PMID: 24655028 DOI: 10.3109/02713683.2014.892997] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans. METHODS The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24-68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects. RESULTS The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9 μm and 38 ± 11 μm within individual fixation periods, and 50 ± 34 μm and 48 ± 19 μm across different fixation periods. The absolute displacements were 67 ± 31 μm and 81 ± 26 μm. ChBF was negatively correlated with age (R = -0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03). CONCLUSIONS The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.
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Ultrahigh field magnetic resonance and colour Doppler real-time fusion imaging of the orbit – a hybrid tool for assessment of choroidal melanoma. Eur Radiol 2014; 24:1112-7. [DOI: 10.1007/s00330-014-3101-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/10/2014] [Accepted: 01/16/2014] [Indexed: 11/27/2022]
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Park SH, Wang DJJ, Duong TQ. Balanced steady state free precession for arterial spin labeling MRI: Initial experience for blood flow mapping in human brain, retina, and kidney. Magn Reson Imaging 2013; 31:1044-50. [PMID: 23664680 DOI: 10.1016/j.mri.2013.03.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 03/26/2013] [Accepted: 03/26/2013] [Indexed: 11/26/2022]
Abstract
We implemented pseudo-continuous ASL (pCASL) with 2D and 3D balanced steady state free precession (bSSFP) readout for mapping blood flow in the human brain, retina, and kidney, free of distortion and signal dropout, which are typically observed in the most commonly used echo-planar imaging acquisition. High resolution functional brain imaging in the human visual cortex was feasible with 3D bSSFP pCASL. Blood flow of the human retina could be imaged with pCASL and bSSFP in conjunction with a phase cycling approach to suppress the banding artifacts associated with bSSFP. Furthermore, bSSFP based pCASL enabled us to map renal blood flow within a single breath hold. Control and test-retest experiments suggested that the measured blood flow values in retina and kidney were reliable. Because there is no specific imaging tool for mapping human retina blood flow and the standard contrast agent technique for mapping renal blood flow can cause problems for patients with kidney dysfunction, bSSFP based pCASL may provide a useful tool for the diagnosis of retinal and renal diseases and can complement existing imaging techniques.
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Affiliation(s)
- Sung-Hong Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
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31
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Li G, Shih YYI, Kiel JW, De La Garza BH, Du F, Duong TQ. MRI study of cerebral, retinal and choroidal blood flow responses to acute hypertension. Exp Eye Res 2013; 112:118-24. [PMID: 23623996 DOI: 10.1016/j.exer.2013.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/03/2013] [Accepted: 04/05/2013] [Indexed: 11/17/2022]
Abstract
Blood flow (BF) in many tissues is stable during significant fluctuations in systemic arterial blood pressure or perfusion pressure under normal conditions. The regulatory mechanisms responsible for this non-passive BF behavior include both local and neural control mechanisms. This study evaluated cerebral BF (CBF), retinal BF (RBF) and choroidal BF (ChBF) responses to acute blood pressure increases in rats using magnetic resonance imaging (MRI). A transient increase in blood pressure inside the MRI scanner was achieved by mechanically inflating a balloon catheter to occlude the descending aorta near the diaphragm. We verified the rat model of mechanical occlusion and MRI approach by first measuring blood-flow regulatory responses to changing BP in the brain under normoxia and hypercapnia where the phenomenon is well documented. Retinal and choroidal blood-flow responses to transient increased arterial pressure were then investigated. In response to an acute increase in blood pressure, RBF exhibited autoregulatory behavior and ChBF exhibited baroregulation similar to that seen in the cerebral circulation. This approach may prove useful to investigate retinal and choroidal vascular dysregulation in rat models of retinal diseases with suspected vascular etiology.
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Affiliation(s)
- Guang Li
- Research Imaging Institute, University of Texas Health Science Center, USA
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Zhang Y, Harrison JM, Nateras OSE, Chalfin S, Duong TQ. Decreased retinal-choroidal blood flow in retinitis pigmentosa as measured by MRI. Doc Ophthalmol 2013; 126:187-97. [PMID: 23408312 DOI: 10.1007/s10633-013-9374-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 01/28/2013] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate retinal and choroidal blood flow (BF) using high-resolution magnetic resonance imaging (MRI) as well as visual function measured by the electroretinogram (ERG) in patients with retinitis pigmentosa (RP). METHODS MRI studies were performed in 6 RP patients (29-67 years) and 5 healthy volunteers (29-64 years) on a 3-Tesla scanner with a custom-made surface coil. Quantitative BF was measured using the pseudo-continuous arterial spin-labeling technique at 0.5 × 0.8 × 6.0 mm. Full-field ERGs of all patients were recorded. Amplitudes and implicit times of standard ERGs were analyzed. RESULTS Basal BF in the posterior retinal-choroid was 142 ± 16 ml/100ml/min (or 1.14 ± 0.13 μl/mm(2)/min) in the control group and was 70 ±19 ml/100ml/min (or 0.56 ± 0.15 μl/mm(2)/min) in the RP group. Retinal-choroidal BF was significantly reduced by 52 ± 8 % in RP patients compared to controls (P<0.05). ERG a- and b-wave amplitudes of RP patients were reduced, and b-wave implicit times were delayed. There were statistically significant correlations between a-wave amplitude and BF value (r=0.9, P<0.05) but not between b-wave amplitude and BF value (r =0.7, P=0.2). CONCLUSIONS This study demonstrates a novel non-invasive MRI approach to measure quantitative retinal and choroidal BF in RP patients. We found that retinal-choroidal BF was markedly reduced and significantly correlated with reduced amplitudes of the a-wave of the standard combined ERG.
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Affiliation(s)
- Yi Zhang
- Research Imaging Institute, University of Texas Health Science Center, 8403 Floyd Curl Dr, San Antonio, TX 78229, USA
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Fanea L, Fagan AJ. Review: magnetic resonance imaging techniques in ophthalmology. Mol Vis 2012; 18:2538-60. [PMID: 23112569 PMCID: PMC3482169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 10/10/2012] [Indexed: 11/19/2022] Open
Abstract
Imaging the eye with magnetic resonance imaging (MRI) has proved difficult due to the eye's propensity to move involuntarily over typical imaging timescales, obscuring the fine structure in the eye due to the resulting motion artifacts. However, advances in MRI technology help to mitigate such drawbacks, enabling the acquisition of high spatiotemporal resolution images with a variety of contrast mechanisms. This review aims to classify the MRI techniques used to date in clinical and preclinical ophthalmologic studies, describing the qualitative and quantitative information that may be extracted and how this may inform on ocular pathophysiology.
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Affiliation(s)
- Laura Fanea
- Department of Biomedical Physics, Physics Faculty, Babes-Bolyai University, Cluj-Napoca, Romania,Department of Radiology, Cluj County Emergency Hospital, Cluj-Napoca, Romania
| | - Andrew J. Fagan
- Centre for Advanced Medical Imaging, St. James’s Hospital Dublin / University of Dublin Trinity College, Ireland
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