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Sinclair SH, Schwartz S. Diabetic retinopathy: New concepts of screening, monitoring, and interventions. Surv Ophthalmol 2024; 69:882-892. [PMID: 38964559 DOI: 10.1016/j.survophthal.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/30/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
The science of diabetes care has progressed to provide a better understanding of the oxidative and inflammatory lesions and pathophysiology of the neurovascular unit within the retina (and brain) that occur early in diabetes, even prediabetes. Screening for retinal structural abnormalities, has traditionally been performed by fundus examination or color fundus photography; however, these imaging techniques detect the disease only when there are sufficient lesions, predominantly hemorrhagic, that are recognized to occur late in the disease process after significant neuronal apoptosis and atrophy, as well as microvascular occlusion with alterations in vision. Thus, interventions have been primarily oriented toward the later-detected stages, and clinical trials, while demonstrating a slowing of the disease progression, demonstrate minimal visual improvement and modest reduction in the continued loss over prolonged periods. Similarly, vision measurement utilizing charts detects only problems of visual function late, as the process begins most often parafoveally with increasing number and progressive expansion, including into the fovea. While visual acuity has long been used to define endpoints of visual function for such trials, current methods reviewed herein are found to be imprecise. We review improved methods of testing visual function and newer imaging techniques with the recommendation that these must be utilized to discover and evaluate the injury earlier in the disease process, even in the prediabetic state. This would allow earlier therapy with ocular as well as systemic pharmacologic treatments that lower the and neuro-inflammatory processes within eye and brain. This also may include newer, micropulsed laser therapy that, if applied during the earlier cascade, should result in improved and often normalized retinal function without the adverse treatment effects of standard photocoagulation therapy.
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Affiliation(s)
| | - Stan Schwartz
- University of Pennsylvania Affiliate, Main Line Health System, USA
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2
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Zhang Z, Deng C, Paulus YM. Advances in Structural and Functional Retinal Imaging and Biomarkers for Early Detection of Diabetic Retinopathy. Biomedicines 2024; 12:1405. [PMID: 39061979 PMCID: PMC11274328 DOI: 10.3390/biomedicines12071405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/27/2024] [Accepted: 06/10/2024] [Indexed: 07/28/2024] Open
Abstract
Diabetic retinopathy (DR), a vision-threatening microvascular complication of diabetes mellitus (DM), is a leading cause of blindness worldwide that requires early detection and intervention. However, diagnosing DR early remains challenging due to the subtle nature of initial pathological changes. This review explores developments in multimodal imaging and functional tests for early DR detection. Where conventional color fundus photography is limited in the field of view and resolution, advanced quantitative analysis of retinal vessel traits such as retinal microvascular caliber, tortuosity, and fractal dimension (FD) can provide additional prognostic value. Optical coherence tomography (OCT) has also emerged as a reliable structural imaging tool for assessing retinal and choroidal neurodegenerative changes, which show potential as early DR biomarkers. Optical coherence tomography angiography (OCTA) enables the evaluation of vascular perfusion and the contours of the foveal avascular zone (FAZ), providing valuable insights into early retinal and choroidal vascular changes. Functional tests, including multifocal electroretinography (mfERG), visual evoked potential (VEP), multifocal pupillographic objective perimetry (mfPOP), microperimetry, and contrast sensitivity (CS), offer complementary data on early functional deficits in DR. More importantly, combining structural and functional imaging data may facilitate earlier detection of DR and targeted management strategies based on disease progression. Artificial intelligence (AI) techniques show promise for automated lesion detection, risk stratification, and biomarker discovery from various imaging data. Additionally, hematological parameters, such as neutrophil-lymphocyte ratio (NLR) and neutrophil extracellular traps (NETs), may be useful in predicting DR risk and progression. Although current methods can detect early DR, there is still a need for further research and development of reliable, cost-effective methods for large-scale screening and monitoring of individuals with DM.
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Affiliation(s)
- Zhengwei Zhang
- Department of Ophthalmology, Jiangnan University Medical Center, Wuxi 214002, China;
- Department of Ophthalmology, Wuxi No.2 People’s Hospital, Wuxi Clinical College, Nantong University, Wuxi 214002, China
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA;
| | - Callie Deng
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA;
| | - Yannis M. Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA;
- Department of Biomedical Engineering, University of Michigan, 1000 Wall Street, Ann Arbor, MI 48105, USA
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3
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Khalil MAM, Sadagah NM, Tan J, Syed FO, Chong VH, Al-Qurashi SH. Pros and cons of live kidney donation in prediabetics: A critical review and way forward. World J Transplant 2024; 14:89822. [PMID: 38576756 PMCID: PMC10989475 DOI: 10.5500/wjt.v14.i1.89822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/11/2023] [Accepted: 01/16/2024] [Indexed: 03/15/2024] Open
Abstract
There is shortage of organs, including kidneys, worldwide. Along with deceased kidney transplantation, there is a significant rise in live kidney donation. The prevalence of prediabetes (PD), including impaired fasting glucose and impaired glucose tolerance, is on the rise across the globe. Transplant teams frequently come across prediabetic kidney donors for evaluation. Prediabetics are at risk of diabetes, chronic kidney disease, cardiovascular events, stroke, neuropathy, retinopathy, dementia, depression and nonalcoholic liver disease along with increased risk of all-cause mortality. Unfortunately, most of the studies done in prediabetic kidney donors are retrospective in nature and have a short follow up period. There is lack of prospective long-term studies to know about the real risk of complications after donation. Furthermore, there are variations in recommendations from various guidelines across the globe for donations in prediabetics, leading to more confusion among clinicians. This increases the responsibility of transplant teams to take appropriate decisions in the best interest of both donors and recipients. This review focuses on pathophysiological changes of PD in kidneys, potential complications of PD, other risk factors for development of type 2 diabetes, a review of guidelines for kidney donation, the potential role of diabetes risk score and calculator in kidney donors and the way forward for the evaluation and selection of prediabetic kidney donors.
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Affiliation(s)
- Muhammad Abdul Mabood Khalil
- Center of Renal Diseases and Transplantation, King Fahad Armed Forces Hospital Jeddah, Jeddah 23311, Saudi Arabia
| | - Nihal Mohammed Sadagah
- Center of Renal Diseases and Transplantation, King Fahad Armed Forces Hospital Jeddah, Jeddah 23311, Saudi Arabia
| | - Jackson Tan
- Department of Nephrology, RIPAS Hospital Brunei Darussalam, Brunei Muara BA1710, Brunei Darussalam
| | - Furrukh Omair Syed
- Center of Renal Diseases and Transplantation, King Fahad Armed Forces Hospital Jeddah, Jeddah 23311, Saudi Arabia
| | - Vui Heng Chong
- Division of Gastroenterology and Hepatology, Department of Medicine, Raja Isteri Pengiran Anak Saleha Hospital, Bandar Seri Begawan BA1710, Brunei Darussalam
| | - Salem H Al-Qurashi
- Center of Renal Diseases and Transplantation, King Fahad Armed Forces Hospital Jeddah, Jeddah 23311, Saudi Arabia
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4
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Erb C, Erb C, Kazakov A, Umetalieva M, Weisser B. Influence of Diabetes Mellitus on Glaucoma-Relevant Examination Results in Primary Open-Angle Glaucoma. Klin Monbl Augenheilkd 2024; 241:177-185. [PMID: 37643738 DOI: 10.1055/a-2105-0756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Primary open-angle glaucoma (POAG) is no longer considered an isolated eye pressure-dependent optic neuropathy, but a neurodegenerative disease in which oxidative stress and neuroinflammation are prominent. These processes may be exacerbated by additional systemic diseases. The most common are arterial hypertension, dyslipidemia, and diabetes mellitus. Using diabetes mellitus as an example, it will be shown how far-reaching the influence of such a systemic disease can be on both the functional and the structural diagnostic methods for POAG. This knowledge is essential, since these interferences can lead to misinterpretations of POAG, which can also affect therapeutic decisions.
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Affiliation(s)
- Carl Erb
- Augenklinik am Wittenbergplatz, Berlin, Deutschland
| | | | - Avaz Kazakov
- Department of External Relations and Development, Salymbekov University, Bishkek, Kyrgyzstan
| | - Maana Umetalieva
- Medical Faculty of Medicine, Salymbekov University, Bishkek, Kyrgyzstan
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Ghannam N, Alahmed S, Aldahash R, Aljohani N, Alshammary A, Amir A, Kamal A, Khader S, Salah M, Shalabi H, Abdallah A, Elboghdady A. Addressing the Continuum of Dysglycaemia and Vascular Complications in Prediabetes and Type 2 Diabetes: Need for Early and Intensive Treatment. Diabetes Metab Syndr Obes 2023; 16:105-115. [PMID: 36760588 PMCID: PMC9844108 DOI: 10.2147/dmso.s396621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/23/2022] [Indexed: 01/18/2023] Open
Abstract
The onset of type 2 diabetes increases the risk of vascular complications and death. We know now that that this risk begins long before the diabetes diagnosis. Prediabetes and type 2 diabetes are not separate entities in practice and exist within a continuum of dysglycaemia and vascular risk that increases in severity over time. This excess risk requires early intervention with lifestyle therapy supported with pharmacologic antidiabetic therapy, intensified promptly where necessary throughout the duration of the diabetes continuum. Metformin is an evidence-based treatment for preventing prediabetes and improves cardiovascular outcomes in people with type 2 diabetes from diagnosis onwards. Newer agents (SGLT2 inhibitors and GLP-1 agonists) are appropriate for people presenting with type 2 diabetes and significant cardiovascular comorbidity. Additional therapies should be used without delay to achieve patients' individualised HbA1c goals and to minimise cardiovascular risk.
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Affiliation(s)
- Nadia Ghannam
- Ghannam Clinic, Jeddah, Saudi Arabia
- Correspondence: Nadia Ghannam, Ghannam Clinic, King Abdulaziz Road, Jeddah, 21411, Saudi Arabia, Email
| | | | - Raed Aldahash
- Ministry of National Guard (Health Affairs) and King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | | | - Afaf Alshammary
- Ministry of National Guard (Health Affairs), King Abdulaziz Medical City, Riyadh and King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Ashraf Amir
- Family Medicine International Medical Center, Jeddah, Saudi Arabia
| | | | - Said Khader
- Dr. Sulaiman Al Habib Medical Group, Riyadh, Saudi Arabia
| | - Mohammed Salah
- Cairo University, Cairo, Egypt and GNP Hospital, Jeddah, Saudi Arabia
| | - Hani Shalabi
- University of Jeddah, Jeddah, Saudi Arabia
- Dr. Soliman Fakeeh Hospital, Jeddah, Saudi Arabia
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Hommer N, Kallab M, Schlatter A, Janku P, Werkmeister RM, Howorka K, Schmidl D, Schmetterer L, Garhöfer G. Neuro-vascular coupling and heart rate variability in patients with type II diabetes at different stages of diabetic retinopathy. Front Med (Lausanne) 2022; 9:1025853. [PMID: 36438055 PMCID: PMC9684184 DOI: 10.3389/fmed.2022.1025853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022] Open
Abstract
Aims/Hypothesis There is evidence that diabetes is accompanied by a break-down of functional hyperemia, an intrinsic mechanism of neural tissues to adapt blood flow to changing metabolic demands. However, to what extent functional hyperemia is altered in different stages of diabetic retinopathy (DR) in patients with type II diabetes is largely unknown. The current study set out to investigate flicker-induced retinal blood flow changes in patients with type II diabetes at different stages of DR. Materials and methods A total of 76 subjects were included in the present parallel-group study, of which 56 had diabetes with either no DR or different stages of non-proliferative DR (n = 29 no DR, 12 mild DR, 15 moderate to severe DR). In addition, 20 healthy subjects were included as controls. Retinal blood flow was assessed before and during visual stimulation using a combined measurement of retinal vessel calibers and blood velocity by the means of Doppler optical coherence tomography (OCT). To measure systemic autonomic nervous system function, heart rate variability (HRV) was assessed using a short-term orthostatic challenge test. Results In healthy controls, retinal blood flow increased by 40.4 ± 27.2% during flicker stimulation. Flicker responses in patients with DR were significantly decreased depending on the stage of the disease (no DR 37.7 ± 26.0%, mild DR 26.2 ± 28.2%, moderate to severe DR 22.3 ± 13.9%; p = 0.035, ANOVA). When assessing systemic autonomous neural function using HRV, normalized low frequency (LF) spectral power showed a significantly different response to the orthostatic maneuver in diabetic patients compared to healthy controls (p < 0.001). Conclusion/Interpretation Our study indicates that flicker induced hyperemia is reduced in patients with DR compared to healthy subjects. Further, this impairment is more pronounced with increasing severity of DR. Further studies are needed to elucidate mechanisms behind the reduced hyperemic response in patients with type II diabetes. Clinical trial registration [https://clinicaltrials.gov/], identifier [NCT03 552562].
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Affiliation(s)
- Nikolaus Hommer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martin Kallab
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Andreas Schlatter
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Hanusch Hospital, Karl Landsteiner Institute, Vienna, Austria
- Hanusch Hospital, Vienna Institute for Research in Ocular Surgery, Vienna, Austria
| | - Patrick Janku
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - René M. Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Kinga Howorka
- Metabolic Competence Center, Medical University of Vienna, Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
- Institute of Clinical and Experimental Ophthalmology, Basel, Switzerland
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- *Correspondence: Gerhard Garhöfer,
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Gottwald-Hostalek U, Gwilt M. Vascular complications in prediabetes and type 2 diabetes: a continuous process arising from a common pathology. Curr Med Res Opin 2022; 38:1841-1851. [PMID: 35833523 DOI: 10.1080/03007995.2022.2101805] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The term, "prediabetes", describes a state of hyperglycaemia that is intermediate between true normoglycaemia and the diagnostic cut-offs for indices of glycaemia that are used to diagnose type 2 diabetes. The presence of prediabetes markedly increases the risk of developing type 2 diabetes. Numerous randomized, controlled evaluations of various agents have demonstrated significant prevention or delay of the onset of type 2 diabetes in subjects with prediabetes. Intensive lifestyle interventions and metformin have been studied most widely, with the lifestyle intervention being more effective in the majority of subjects. The application of therapeutic interventions at the time of prediabetes to preserve long-term outcomes has been controversial, however, due to a lack of evidence relating to the pathogenic effects of prediabetes and the effectiveness of interventions to produce a long-term clinical benefit. Recent studies have confirmed that prediabetes, however defined, is associated with a significantly increased risk of macrovascular and microvascular complications essentially identical to those of diabetes, and also with subclinical derangements of the function of microvasculature and neurons that likely signify increased risk of compilations in future. Normoglycaemia, prediabetes and type 2 diabetes appear to be part of a continuum of increased risk of adverse outcomes. Long-term (25-30 years) post-trial follow up of two major diabetes prevention trials have shown that short-term interventions to prevent diabetes lead to long-term reductions in the risk of complications. These findings support the concept of therapeutic intervention to preserve long-term health in people with prediabetes before type 2 diabetes becomes established.
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White NH, Pan Q, Knowler WC, Schroeder EB, Dabelea D, Chew EY, Blodi B, Goldberg RB, Pi-Sunyer X, Darwin C, Schlögl M, Nathan DM. Risk Factors for the Development of Retinopathy in Prediabetes and Type 2 Diabetes: The Diabetes Prevention Program Experience. Diabetes Care 2022; 45:2653-2661. [PMID: 36098658 PMCID: PMC9679265 DOI: 10.2337/dc22-0860] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/14/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine glycemic and nonglycemic risk factors that contribute to the presence of diabetic retinopathy (DR) before and after the onset of type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS During the Diabetes Prevention Program (DPP) and DPP Outcome Study (DPPOS), we performed fundus photography over time in adults at high risk for developing T2D, including after they developed diabetes. Fundus photographs were graded using the Early Treatment Diabetic Retinopathy Study (ETDRS) grading system, with DR defined as typical lesions of DR (microaneurysms, exudates, hemorrhage, or worse) in either eye. RESULTS By DPPOS year 16 (∼20 years after random assignment into DPP), 24% of 1,614 participants who had developed T2D and 14% of 885 who remained without diabetes had DR. In univariate analyses, using results from across the entire duration of follow-up, American Indian race was associated with less frequent DR compared with non-Hispanic White (NHW) race, and higher HbA1c, fasting and 2-h plasma glucose levels during an oral glucose tolerance test, weight, and history of hypertension, dyslipidemia, and smoking, but not treatment group assignment, were associated with more frequent DR. On multivariate analysis, American Indian race was associated with less DR compared with NHW (odds ratio [OR] 0.36, 95% CI 0.20-0.66), and average HbA1c was associated with more DR (OR 1.92, 95% CI 1.46-1.74 per SD [0.7%] increase in HbA1c). CONCLUSIONS DR may occur in adults with prediabetes and early in the course of T2D. HbA1c was an important risk factor for the development of DR across the entire glycemic range from prediabetes to T2D.
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Affiliation(s)
- Neil H. White
- Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Qing Pan
- The Biostatistics Center, Milken Institute School of Public Health, George Washington University, Rockville, MD
| | - William C. Knowler
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
| | | | - Dana Dabelea
- Colorado School of Public Health, Anschutz Medical Campus, Aurora, CO
| | - Emily Y. Chew
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Barbara Blodi
- Wisconsin Reading Center, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Ronald B. Goldberg
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
| | | | - Christine Darwin
- Department of Medicine/Endocrinology Diabetes, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Mathias Schlögl
- University Clinic for Acute Geriatric Care, City Hospital Waid Zurich, Zurich, Switzerland
| | - David M. Nathan
- Diabetes Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA
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Sinclair SH, Miller E, Talekar KS, Schwartz SS. Diabetes mellitus associated neurovascular lesions in the retina and brain: A review. FRONTIERS IN OPHTHALMOLOGY 2022; 2:1012804. [PMID: 38983558 PMCID: PMC11182219 DOI: 10.3389/fopht.2022.1012804] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/14/2022] [Indexed: 07/11/2024]
Abstract
Diabetes mellitus (DM) is now recognized as a system-wide, autoimmune, inflammatory, microvascular disorder, which, in the retina and brain results in severe multifocal injury now recognized as a leading cause, world-wide, of progressive vision loss and dementia. To address this problem, resulting primarily from variations in glycemia in the prediabetic and overt diabetic states, it must be realized that, although some of the injury processes associated with diabetes may be system wide, there are varying responses, effector, and repair mechanisms that differ from organ to organ or within varying cell structures. Specifically, within the retina, and similarly within the brain cortex, lesions occur of the "neurovascular unit", comprised of focal microvascular occlusions, inflammatory endothelial and pericyte injury, with small vessel leakage resulting in injury to astrocytes, Müller cells, and microglia, all of which occur with progressive neuronal apoptosis. Such lesions are now recognized to occur before the first microaneurysms are visible to imaging by fundus cameras or before they result in detectable symptoms or signs recognizable to the patient or clinician. Treatments, therefore, which currently are not initiated within the retina until edema develops or there is progression of vascular lesions that define the current staging of retinopathy, and in the brain only after severe signs of cognitive failure. Treatments, therefore are applied relatively late with some reduction in progressive cellular injury but with resultant minimal vision or cognitive improvement. This review article will summarize the multiple inflammatory and remediation processes currently understood to occur in patients with diabetes as well as pre-diabetes and summarize as well the current limitations of methods for assessing the structural and functional alterations within the retina and brain. The goal is to attempt to define future screening, monitoring, and treatment directions that hopefully will prevent progressive injury as well as enable improved repair and attendant function.
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Affiliation(s)
- Stephen H Sinclair
- Pennsylvania College of Optometry, Salus University, Philadelphia, PA, United States
| | - Elan Miller
- Division of Vascular Neurology, Vickie & Jack Farber Institute for Institute for Neuroscience, Sidney Kimmel Medical College (SKMC) Thomas Jefferson University, Philadelphia, PA, United States
| | - Kiran S Talekar
- Department of Radiology, Section of Neuroradiology and ENT Radiology, Clinical Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging at Thomas Jefferson University Hospital and The Jefferson Integrated Magnetic Resonance Imaging Center (JIMRIC) Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - Stanley S Schwartz
- Department of Endocrinology and Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Main Line Health System, Philadelphia, PA, United States
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ENGİN S, AKKAN T, DAĞDEVİREN M, ŞENGEZER T, ALTAY M. Are disease-related symptoms important to predicting developing diabetes from prediabetes? Turk J Med Sci 2022; 52:1093-1102. [PMID: 36326390 PMCID: PMC10388077 DOI: 10.55730/1300-0144.5412] [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: 10/17/2021] [Revised: 08/10/2022] [Accepted: 04/10/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND There are not many studies conducted to detect and recognize the symptoms during the prediabetes period. In our study, we aimed to determine the symptoms that can be seen in prediabetes and diabetes and their prevalence and to determine the similarities and differences between the two groups. METHODS Individuals who were diagnosed with prediabetes or diabetes, over the age of 18, literate, and accepted to collaborate were included in our study. The "Diabetes Symptoms Checklist Scale" was used by interviewing 321 participants, 161 prediabetic and 160 diabetic, face-to-face. RESULTS It has been found that the most common symptom in both the prediabetes and the diabetes group is "fatigue" (88.2% prediabetes, 89.4% diabetes). The symptoms seen in the dimensions of neurology and hyperglycemia are more common in individuals with diabetes than in individuals with prediabetes [neurology score: 1.85 ± 0.84 vs. 1.66 ± 0.64 (p = 0.02), respectively; hyperglycemia score: 2.39 ± 0.94 vs. 2.08 ± 0.83 (p = 0.002), respectively]. It was observed that the symptom burden increased in all subdimensions with the long duration of illness, being a female, not working, having a family history, and not doing exercise, and high fasting blood glucose and high HbA1c values. The level of education, family history, accompanying hyperlipidemia, neurology, and hyperglycemia symptoms are associated with diabetes; and it has been determined that cardiology symptoms are associated with prediabetes. DISCUSSION Especially; during the follow-up of patients with prediabetes who have a low education level and diabetic family history and concomitant hyperlipidemia, there may be an increase in neurological and hyperglycemic symptoms at the point of development of type 2 diabetes. In this respect, we recommend that these factors, which we found to be predictive of diabetes compared to prediabetes, should be questioned more carefully during patient visits.
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Affiliation(s)
- Sibel ENGİN
- Department of Family Medicine, Keçiören Health Administration and Research Center, University of Health Sciences, Ankara,
Turkey
| | - Tolga AKKAN
- Department of Endocrinology and Metabolism, Keçiören Health Administration and Research Center, University of Health Sciences, Ankara,
Turkey
| | - Murat DAĞDEVİREN
- Department of Endocrinology and Metabolism, Keçiören Health Administration and Research Center, University of Health Sciences, Ankara,
Turkey
| | - Tijen ŞENGEZER
- Department of Family Medicine, Keçiören Health Administration and Research Center, University of Health Sciences, Ankara,
Turkey
| | - Mustafa ALTAY
- Department of Endocrinology and Metabolism, Keçiören Health Administration and Research Center, University of Health Sciences, Ankara,
Turkey
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11
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Hanssen H, Streese L, Vilser W. Retinal vessel diameters and function in cardiovascular risk and disease. Prog Retin Eye Res 2022; 91:101095. [PMID: 35760749 DOI: 10.1016/j.preteyeres.2022.101095] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 12/13/2022]
Abstract
In the last two decades evidence has gradually accumulated suggesting that the eye may be a unique window for cardiovascular risk stratification based on the assessment of subclinical damage of retinal microvascular structure and function. This can be facilitated by non-invasive analysis of static retinal vessel diameters and dynamic recording of flicker light-induced and endothelial function-related dilation of both retinal arterioles and venules. Recent new findings have made retinal microvascular biomarkers strong candidates for clinical implementation as reliable risk predictors. Beyond a review of the current evidence and state of research, the article aims to discuss the methodological benefits and pitfalls and to identify research gaps and future directions. Above all, the potential use for screening and treatment monitoring of cardiovascular disease risk are highlighted. The article provides fundamental comprehension of retinal vessel imaging by explaining anatomical and physiological essentials of the retinal microcirculation leading to a detailed description of the methodological approach. This allows for better understanding of the underlying retinal microvascular pathology associated with the prevalence and development of cardiovascular disease. A body of new evidence is presented on the clinical validity and predictive value of retinal vessel diameters and function for incidence cardiovascular disease and outcome. Findings in children indicate the potential for utility in childhood cardiovascular disease prevention, and the efficacy of exercise interventions highlight the treatment sensitivity of retinal microvascular biomarkers. Finally, coming from the availability of normative data, solutions for diagnostic challenges are discussed and conceptual steps towards clinical implementation are put into perspective.
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Affiliation(s)
- Henner Hanssen
- Department of Sport, Exercise and Health, Preventive Sports Medicine and Systems Physiology, Medical Faculty, University of Basel, Switzerland.
| | - Lukas Streese
- Department of Sport, Exercise and Health, Preventive Sports Medicine and Systems Physiology, Medical Faculty, University of Basel, Switzerland
| | - Walthard Vilser
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany; Neonatology and Pediatric Intensive Care Unit, Department of Pediatrics, Jena University Hospital, Jena, Germany
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Lal A, Dave N, Barry MA, Sood A, Mitchell P, Thiagalingam A. A stronger association of diabetes mellitus with impaired hyperaemia using a novel ECG-gated device compared with peripheral arterial tonometry. Int Ophthalmol 2022; 42:2855-2869. [PMID: 35672599 PMCID: PMC9420096 DOI: 10.1007/s10792-022-02276-8] [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: 08/14/2021] [Accepted: 03/12/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE Impaired digital reactive hyperaemia and flicker-stimulated retinal vascular response are commonly reported risk markers of cardiovascular disease. This is the first study to determine the correlation of these risk markers with diabetes mellitus by comparing our novel flicker-modulated ECG-gated fundoscope with the EndoPAT2000 system. METHODS In total, 119 controls and 120 participants with diabetes mellitus partook in this cross-sectional study. The EndoPAT2000 system assessed digital reactive hyperaemia under fasting conditions. A mydriatic ECG-gated fundoscope with a novel flicker module acquired digital retinal images of the left eye before, during and after flicker stimulation. An inhouse semi-automated software measured retinal vessel diameters using a validated protocol with two observers repeating measurements in a subset of 10 controls and 10 participants with diabetes mellitus. Intra- and inter-observer reliability analyses occurred by the interclass correlation coefficient. A receiver operating characteristic curve established associations of variables with diabetes mellitus. RESULTS Diabetes mellitus was more strongly associated with flicker-stimulated retinal arteriolar calibre change from baseline (AUC 0.81, 95% CI 0.75-0.87, p < 0.0001) than reactive hyperaemia index. Median flicker-stimulated arteriolar calibre change from baseline (controls: 2.74%, IQR 1.07 vs diabetes mellitus: 1.64%, IQR 1.25, p < 0.0001) and reactive hyperaemia index (controls: 1.87, IQR 0.81 vs diabetes mellitus: 1.60, IQR 0.81, p = 0.003) were lower in diabetes mellitus than controls. Intra- and inter-observer reliability coefficients were high from 0.87 to 0.93. CONCLUSIONS Impaired flicker-stimulated retinal arteriolar calibre change from baseline is more highly correlated with diabetes mellitus in this study than a reduced reactive hyperaemia index.
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Affiliation(s)
- Anchal Lal
- Department of Cardiology, Westmead Hospital, Sydney, NSW, Australia, 2145. .,Sydney Medical School (Westmead Clinical School), The University of Sydney, Sydney, NSW, Australia, 2145. .,Centre for Vision Research, Westmead Institute for Medical Research, Sydney, NSW, Australia, 2145. .,Department of Cardiology, Room 2082, Level 2, Clinical Sciences Corridor, Westmead Hospital, Cnr Darcy and Hawkesbury Roads, Westmead, Sydney, NSW, Australia, 2145.
| | - Neha Dave
- School of Medicine and Public Health, The University of Newcastle, Callaghan, NSW, Australia, 2308
| | | | - Annika Sood
- Department of Cardiology, Westmead Hospital, Sydney, NSW, Australia, 2145
| | - Paul Mitchell
- Sydney Medical School (Westmead Clinical School), The University of Sydney, Sydney, NSW, Australia, 2145.,Centre for Vision Research, Westmead Institute for Medical Research, Sydney, NSW, Australia, 2145
| | - Aravinda Thiagalingam
- Department of Cardiology, Westmead Hospital, Sydney, NSW, Australia, 2145.,Sydney Medical School (Westmead Clinical School), The University of Sydney, Sydney, NSW, Australia, 2145
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13
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Dierschke SK, Dennis MD. Retinal Protein O-GlcNAcylation and the Ocular Renin-angiotensin System: Signaling Cross-roads in Diabetic Retinopathy. Curr Diabetes Rev 2022; 18:e011121190177. [PMID: 33430751 PMCID: PMC8272735 DOI: 10.2174/1573399817999210111205933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/14/2020] [Accepted: 11/16/2020] [Indexed: 01/23/2023]
Abstract
It is well established that diabetes and its associated hyperglycemia negatively impact retinal function, yet we know little about the role played by augmented flux through the Hexosamine Biosynthetic Pathway (HBP). This offshoot of the glycolytic pathway produces UDP-Nacetyl- glucosamine, which serves as the substrate for post-translational O-linked modification of proteins in a process referred to as O-GlcNAcylation. HBP flux and subsequent protein O-GlcNAcylation serve as nutrient sensors, enabling cells to integrate metabolic information to appropriately modulate fundamental cellular processes including gene expression. Here we summarize the impact of diabetes on retinal physiology, highlighting recent studies that explore the role of O-GlcNAcylation- induced variation in mRNA translation in retinal dysfunction and the pathogenesis of Diabetic Retinopathy (DR). Augmented O-GlcNAcylation results in wide variation in the selection of mRNAs for translation, in part, due to O-GlcNAcylation of the translational repressor 4E-BP1. Recent studies demonstrate that 4E-BP1 plays a critical role in regulating O-GlcNAcylation-induced changes in the translation of the mRNAs encoding Vascular Endothelial Growth Factor (VEGF), a number of important mitochondrial proteins, and CD40, a key costimulatory molecule involved in diabetes-induced retinal inflammation. Remarkably, 4E-BP1/2 ablation delays the onset of diabetes- induced visual dysfunction in mice. Thus, pharmacological interventions to prevent the impact of O-GlcNAcylation on 4E-BP1 may represent promising therapeutics to address the development and progression of DR. In this regard, we discuss the potential interplay between retinal O-GlcNAcylation and the ocular renin-angiotensin system as a potential therapeutic target of future interventions.
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Affiliation(s)
- Sadie K. Dierschke
- Department of Cellular and Molecular Physiology, Penn State College of Medicine
| | - Michael D. Dennis
- Department of Cellular and Molecular Physiology, Penn State College of Medicine
- Department of Ophthalmology, Penn State College of Medicine
- Address correspondence to this author at the Department of Cellular and Molecular Physiology, H166, Penn State College of Medicine, 500 University Drive Hershey, PA 17033; Tel: (717)531-0003 Ext-282596; Fax: (717)531-7667;
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14
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Mills SA, Jobling AI, Dixon MA, Bui BV, Vessey KA, Phipps JA, Greferath U, Venables G, Wong VHY, Wong CHY, He Z, Hui F, Young JC, Tonc J, Ivanova E, Sagdullaev BT, Fletcher EL. Fractalkine-induced microglial vasoregulation occurs within the retina and is altered early in diabetic retinopathy. Proc Natl Acad Sci U S A 2021; 118:e2112561118. [PMID: 34903661 PMCID: PMC8713803 DOI: 10.1073/pnas.2112561118] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2021] [Indexed: 01/19/2023] Open
Abstract
Local blood flow control within the central nervous system (CNS) is critical to proper function and is dependent on coordination between neurons, glia, and blood vessels. Macroglia, such as astrocytes and Müller cells, contribute to this neurovascular unit within the brain and retina, respectively. This study explored the role of microglia, the innate immune cell of the CNS, in retinal vasoregulation, and highlights changes during early diabetes. Structurally, microglia were found to contact retinal capillaries and neuronal synapses. In the brain and retinal explants, the addition of fractalkine, the sole ligand for monocyte receptor Cx3cr1, resulted in capillary constriction at regions of microglial contact. This vascular regulation was dependent on microglial Cx3cr1 involvement, since genetic and pharmacological inhibition of Cx3cr1 abolished fractalkine-induced constriction. Analysis of the microglial transcriptome identified several vasoactive genes, including angiotensinogen, a constituent of the renin-angiotensin system (RAS). Subsequent functional analysis showed that RAS blockade via candesartan abolished microglial-induced capillary constriction. Microglial regulation was explored in a rat streptozotocin (STZ) model of diabetic retinopathy. Retinal blood flow was reduced after 4 wk due to reduced capillary diameter and this was coincident with increased microglial association. Functional assessment showed loss of microglial-capillary response in STZ-treated animals and transcriptome analysis showed evidence of RAS pathway dysregulation in microglia. While candesartan treatment reversed capillary constriction in STZ-treated animals, blood flow remained decreased likely due to dilation of larger vessels. This work shows microglia actively participate in the neurovascular unit, with aberrant microglial-vascular function possibly contributing to the early vascular compromise during diabetic retinopathy.
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Affiliation(s)
- Samuel A Mills
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Andrew I Jobling
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Michael A Dixon
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Kirstan A Vessey
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Joanna A Phipps
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Ursula Greferath
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Gene Venables
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Connie H Y Wong
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University, Clayton, 3800 VIC, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Flora Hui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010 VIC, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, 3002 VIC, Australia
| | - James C Young
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Josh Tonc
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia
| | - Elena Ivanova
- Burke Neurological Institute, Weill Cornell Medical College, White Plains, NY 10605
| | - Botir T Sagdullaev
- Burke Neurological Institute, Weill Cornell Medical College, White Plains, NY 10605
| | - Erica L Fletcher
- Department of Anatomy and Physiology, University of Melbourne, Parkville, 3010 VIC, Australia;
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15
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Xu H, Zong Y, Yu J, Jiang C, Zhu H, Sun X. Retinal Microvascular Reactivity in Chronic Cigarette Smokers and Non-smokers: An Observational Cross-Sectional Study. Front Med (Lausanne) 2021; 8:782010. [PMID: 34988096 PMCID: PMC8720846 DOI: 10.3389/fmed.2021.782010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/29/2021] [Indexed: 11/16/2022] Open
Abstract
Purpose: To evaluate the changes in the retinal microvasculature and its reactivity in chronic cigarette smokers. Methods: Thirty-four male chronic cigarette smokers and 18 male non-smokers were enrolled. Optical coherence tomography angiography was used to measure the perfused retinal vessel densities (PVDs) of the peripapillary and parafoveal areas at baseline and during phase IV of the Valsalva maneuver (VM-IV). Systemic blood pressure and intraocular pressure were also measured. Results: The baseline PVD in the peripapillary area of the smokers was significantly lower than the non-smokers (59.56 ± 2.26% vs. 61.67 ± 3.58%, respectively; P = 0.005). However, there was no significant difference in the foveal avascular zone or parafoveal PVD between the two groups. During VM-IV, the peripapillary PVD of the smokers decreased by 1.13 ± 3.50%, which was significantly less than that of the non-smokers (−3.83 ± 4.26%, P < 0.05). Similarly, the parafoveal PVD of the smokers decreased by 5.49 ± 9.70%, which was significantly less than the percentage change of the non-smokers (−13.01 ± 8.39%, P < 0.05). There was no significant difference in the percentage change in systemic blood pressure parameters between the two groups. Conclusion: The retinal microvasculature and its reactivity were impaired in chronic smokers compared with non-smokers. The extent of impairment differed among different regions of the fundus.
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Affiliation(s)
- Huan Xu
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China
- Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China
| | - Yuan Zong
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China
- Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China
| | - Jian Yu
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China
- Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China
| | - Chunhui Jiang
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China
- Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China
- *Correspondence: Chunhui Jiang
| | - Haohao Zhu
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
- Haohao Zhu
| | - Xinghuai Sun
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China
- Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China
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16
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Zhang YS, Mucollari I, Kwan CC, Dingillo G, Amar J, Schwartz GW, Fawzi AA. Reversed Neurovascular Coupling on Optical Coherence Tomography Angiography Is the Earliest Detectable Abnormality before Clinical Diabetic Retinopathy. J Clin Med 2020; 9:jcm9113523. [PMID: 33142724 PMCID: PMC7692675 DOI: 10.3390/jcm9113523] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Diabetic retinopathy (DR) has traditionally been viewed as either a microvasculopathy or a neuropathy, though neurovascular coupling deficits have also been reported and could potentially be the earliest derangement in DR. To better understand neurovascular coupling in the diabetic retina, we investigated retinal hemodynamics by optical coherence tomography angiography (OCTA) in individuals with diabetes mellitus (DM) but without DR (DM no DR) and mild non-proliferative DR (mild NPDR) compared to healthy eyes. Using an experimental design to monitor the capillary responses during transition from dark adaptation to light, we examined 19 healthy, 14 DM no DR and 11 mild NPDR individuals. We found that the only structural vascular abnormality in the DM no DR group was increased superficial capillary plexus (SCP) vessel density (VD) compared to healthy eyes, while mild NPDR eyes showed significant vessel loss in the SCP at baseline. There was no significant difference in inner retinal thickness between the groups. During dark adaptation, the deep capillary plexus (DCP) VD was lower in mild NPDR individuals compared to the other two groups, which may leave the photoreceptors more susceptible to ischemia in the dark. When transitioning from dark to ambient light, both diabetic groups showed a qualitative reversal of VD trends in the SCP and middle capillary plexus (MCP), with significantly decreased SCP at 5 min and increased MCP VD at 50 s compared to healthy eyes, which may impede metabolic supply to the inner retina during light adaptation. Mild NPDR eyes also demonstrated DCP dilation at 50 s and 5 min and decreased adjusted flow index at 5 min in light. Our results show altered neurovascular responses in all three macular vascular plexuses in diabetic subjects in the absence of structural neuronal changes on high resolution imaging, suggesting that neurovascular uncoupling may be a key mechanism in the early pathogenesis of DR, well before the clinical appearance of vascular or neuronal loss.
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Affiliation(s)
- Yi Stephanie Zhang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
| | - Ilda Mucollari
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
| | - Changyow C. Kwan
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
| | - Gianna Dingillo
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
| | - Jaspreet Amar
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
| | - Gregory W. Schwartz
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (Y.S.Z.); (I.M.); (C.C.K.); (G.D.); (J.A.); (G.W.S.)
- Correspondence:
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17
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Wentzel A, Malan L, von Känel R, Smith W, Malan NT. Heart rate variability, the dynamic nature of the retinal microvasculature and cardiac stress: providing insight into the brain-retina-heart link: the SABPA study. Eye (Lond) 2020; 34:835-846. [PMID: 31278382 PMCID: PMC7182573 DOI: 10.1038/s41433-019-0515-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/15/2019] [Accepted: 06/14/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND AIMS Decreased heart-rate-variability (HRV) indicates increased sympathetic nervous system (SNS) activity and modulation with a shift in the sympatho-vagal balance towards SNS predominance. Increased SNS activity may precede volume-loading hypertension, contribute to increases in cardiac troponin T (cTnT), endothelial dysfunction and small vessel disease. Therefore, we investigated the retinal vasculature, HRV during flicker-light-induced-provocation (FLIP) and systemic cTnT, a marker of cardiac stress, to provide further evidence in support of the brain-retina-heart link. METHODS Cross-sectional observations were obtained from a bi-ethnic cohort (N = 264), aged 23-68 years. Fasting serum samples for cTnT were obtained. Retinal vascular calibres were quantified from mydriatic eye fundus images and dynamic retinal vessel calibre responses were determined during FLIP. Time-and frequency domain parameters of HRV were calculated during FLIP for each participant. RESULTS Africans had wider venules and attenuated time domain parameters during FLIP. In Africans, inverse associations emerged between arteriolar dilation and both cTnT and root-mean squared of the standard deviations of successive RR-intervals (rMSSD) (p = 0.030), and between arteriolar constriction and both low-frequency expressed in normalised units (LFnu) (p = 0.003) and high-frequency expressed in normalised units (p = 0.021). Wider venules inversely associated with standard deviation of the NN intervals (SDNN) as well as LFnu (p = 0.009) in Africans. An opposite profile was observed in Caucasians with both time-and frequency domain parameters of HRV in relation to retinal vessel structure and function. CONCLUSION FLIP elicited increased SNS activity and modulation in this bi-ethnic cohort. In Africans, decreased HRV during FLIP accompanied arteriolar and venular responses and elevated systemic levels of cTnT, implying that the SNS exerted a significant effect on the smooth muscle tone of the retinal vasculature. Disrupted retinal autoregulation may imply general autonomic nervous system dysfunction; exemplifying central control by the brain on all systemic regulatory functions, across different vascular beds.
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Affiliation(s)
- Annemarie Wentzel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Leoné Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
| | - Roland von Känel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
- Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
- South African Medical Research Council, Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Nicolaas T Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
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Abstract
PURPOSE OF REVIEW To introduce recent advances in the understanding of diabetic retinopathy and to summarize current and emerging strategies to treat this common and complex cause of vision loss. RECENT FINDINGS Advances in retinal imaging and functional analysis indicate that retinal vascular and neural pathologies exist long before the development of clinically visible retinopathy. Such diagnostics could facilitate risk stratification and selective early intervention in high-risk patients. Antagonists of the vascular endothelial growth factor pathway effectively reduce vision loss in diabetes and promote regression of disease severity. Promising new strategies to treat diabetic retinopathy involve novel systemic diabetes therapy and ocular therapies that antagonize angiogenic growth factor signaling, improve blood-retina barrier function and neurovascular coupling, modulate neuroretinal metabolism, or provide neuroprotection. Long considered a pure microvasculopathy, diabetic retinopathy in fact affects the neural and vascular retina as well as neurovascular communication. Emerging therapies include those that target neuroretinal dysfunction in addition to those modulating vascular biology.
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Affiliation(s)
- Avinash Honasoge
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave. 8096, St. Louis, MO, 63108, USA
| | - Eric Nudleman
- Shiley Eye Institute, University of California, San Diego, La Jolla, CA, USA
| | - Morton Smith
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave. 8096, St. Louis, MO, 63108, USA
| | - Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave. 8096, St. Louis, MO, 63108, USA.
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Baier JM, Funck KL, Petersen L, Vernstrøm L, Knudsen ST, Bek T, Poulsen PL, Laugesen E. Retinal vessel reactivity is not attenuated in patients with type 2 diabetes compared with matched controls and is associated with peripheral endothelial function in controls. J Diabetes Complications 2019; 33:641-647. [PMID: 31270030 DOI: 10.1016/j.jdiacomp.2019.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND AIMS Attenuated retinal vasoreactivity in patients with type 2 diabetes preceding diabetic retinopathy development has been proposed to reflect local endothelial dysfunction. Whether retinal vessel reactivity is associated with peripheral endothelial dysfunction and large artery stiffness in patients with type 2 diabetes remains to be elucidated. METHODS Twenty patients with type 2 diabetes without retinopathy and 20 sex- and age matched controls (diabetes duration: 9.9 years (range 6.0;12.4), 40% male, age: 66.5 ± 7.3 (diabetes) and 65.2 ± 7.6 years (controls)) were included. Endothelial function was assessed using EndoPAT. Arterial stiffness was assessed by carotid-femoral pulse wave velocity using the SphygmoCor. Retinal blood supply regulation was examined by retinal arteriolar diameter change during 1) isometric exercise (hand-weight lifting), 2) exposure to flickering lights, and 3) a combined stimulus of 1) + 2) using the Dynamic Vessel Analyzer. RESULTS No significant differences were observed in retinal vessel reactivity in T2DM patients compared to controls. Endothelial function was associated with mean arteriolar diameter change during only the combination intervention, (Beta = 0.033 [0.0013;0.064], p = 0.042) in the overall population of patients and controls. When groups were analyzed separately, the associations was statistically significant only in controls. However, formal test for interaction was not statistically significant, p = 0.40. No association was observed between pulse wave velocity and retinal arteriolar %-diameter change in patients or controls. CONCLUSION Peripheral endothelial function was associated with retinal arteriolar diameter change in the combined sample. The association seemed to be driven primarily by the controls. Our findings indicate that peripheral endothelial function is reflective of endothelial function in the retina mainly in subjects without T2DM, whereas an association in T2DM without retinopathy was not observed. Further studies are needed in T2DM patients with more advanced retinopathy.
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Affiliation(s)
- Jonathan Mathias Baier
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
| | - Kristian Løkke Funck
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
| | - Line Petersen
- Department of Ophthalmology, Aarhus University Hospital, DK-8200, Denmark.
| | - Liv Vernstrøm
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
| | - Søren T Knudsen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, DK-8200, Denmark.
| | - Per Løgstrup Poulsen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
| | - Esben Laugesen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, DK-8200, Denmark.
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Aramo C, Oyom AP, Okello E, Acam V, Okiria JC, Mwambi B, Oyet C. Assessing the prevalence and risk factors of pre-diabetes among the community of Iganga municipality, Uganda: a cross sectional study. BMC Res Notes 2019; 12:553. [PMID: 31470894 PMCID: PMC6717370 DOI: 10.1186/s13104-019-4589-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/21/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE The prevalence of pre-diabetes is increasing globally with more than 470 million people projected to develop pre-diabetes by 2030. In Africa, the average prevalence of pre-diabetes was estimated at 7.3% in 2015 and affected individual will develop type 2 diabetes mellitus within few decades. The aim of the study was to determine the prevalence of pre-diabetes and associated risk factors among residents of Iganga municipality. A cross-sectional study was conducted among males and females aged 13-60 years. District health office provided updated household list from which sampling of the villages was performed based on probability proportionate to population. Consented participants were prepared for the study, allowing fasting for 8 to 10 h before blood collection the next morning. Individuals with impaired fasting glucose, were subjected to OGTT. RESULTS 130 participants were enrolled, of which 98 were women. The mean age of the participants was 35 years. The prevalence of pre-diabetes was 3.8%. The proportion of impaired glucose tolerance was higher in current smokers (p = 0.01), obese participants (p = 0.002) and hypertensive participants (p < 0.001). Prevalence of pre-diabetes is high in this community and is associated with current smoking, hypertension and high BMI.
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Affiliation(s)
- Christine Aramo
- Clarke International University, P O Box 7782, Kampala, Uganda
| | | | - Emmanuel Okello
- Clarke International University, P O Box 7782, Kampala, Uganda
| | - Victoria Acam
- Clarke International University, P O Box 7782, Kampala, Uganda
| | | | - Bashir Mwambi
- Clarke International University, P O Box 7782, Kampala, Uganda
| | - Caesar Oyet
- Clarke International University, P O Box 7782, Kampala, Uganda
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Consumption of a high fat diet promotes protein O-GlcNAcylation in mouse retina via NR4A1-dependent GFAT2 expression. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3568-3576. [PMID: 30254013 DOI: 10.1016/j.bbadis.2018.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/29/2018] [Accepted: 09/08/2018] [Indexed: 01/30/2023]
Abstract
The incidence of type 2 diabetes, the most common cause of diabetic retinopathy (DR), is rapidly on the rise in developed countries due to overconsumption of calorie rich diets. Using an animal model of diet-induced obesity/pre-diabetes, we evaluated the impact of a diet high in saturated fat (HFD) on O-GlcNAcylation of retinal proteins, as dysregulated O-GlcNAcylation contributes to diabetic complications and evidence supports a role in DR. Protein O-GlcNAcylation was increased in the retina of mice fed a HFD as compared to littermates receiving control chow. Similarly, O-GlcNAcylation was elevated in retinal Müller cells in culture exposed to the saturated fatty acid palmitate or the ceramide analog Cer6. One potential mechanism responsible for elevated O-GlcNAcylation is increased flux through the hexosamine biosynthetic pathway (HBP). Indeed, inhibition of the pathway's rate-limiting enzyme glutamine-fructose-6-phosphate amidotransferase (GFAT) prevented Cer6-induced O-GlcNAcylation. Importantly, expression of the mRNA encoding GFAT2, but not GFAT1 was elevated in both the retina of mice fed a HFD and in retinal cells in culture exposed to palmitate or Cer6. Notably, expression of nuclear receptor subfamily 4 group A member 1 (NR4A1) was increased in the retina of mice fed a HFD and NR4A1 expression was sufficient to promote GFAT2 mRNA expression and O-GlcNAcylation in retinal cells in culture. Whereas palmitate or Cer6 addition to culture medium enhanced NR4A1 and GFAT2 expression, chemical inhibition of NR4A1 transactivation repressed Cer6-induced GFAT2 mRNA expression. Overall, the results support a model wherein HFD increases retinal protein O-GlcNAcylation by promoting NR4A1-dependent GFAT2 expression.
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22
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Kurt MM, Çekiç O, Akpolat Ç, Elçioglu M. EFFECTS OF INTRAVITREAL RANIBIZUMAB AND BEVACIZUMAB ON THE RETINAL VESSEL SIZE IN DIABETIC MACULAR EDEMA. Retina 2018; 38:1120-1126. [PMID: 28520638 DOI: 10.1097/iae.0000000000001682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE The goal of this study was to assess the effects of a single injection of intravitreal ranibizumab (RAN) or bevacizumab (BEV) on the retinal vessel size in eyes with diabetic macular edema. MATERIALS AND METHODS In total, 32 patients were enrolled in the RAN group, and 30 patients were included in BEV group. Each of these groups was also subdivided into two others groups: a study group and a control group. The study groups were composed of the injected eyes, whereas the noninjected fellow eyes served as the control groups. The patients underwent complete ophthalmic examinations, including optical coherence tomography and fundus fluorescein angiography, and the primary outcome measures included the central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio. RESULTS In the RAN study group (n = 32), the preinjection mean central retinal artery equivalent (175.42 μm) decreased to 169.01 μm after 1 week, and to 167.47 μm after 1 month (P < 0.001), whereas the baseline central retinal vein equivalent (235.29 μm) decreased initially to 219.90 μm after 1 week, and to 218.36 μm after 1 month (P < 0.001). In the BEV study group (n = 30), the preinjection central retinal artery equivalent (150.21 μm) decreased to 146.25 μm after 1 week, and to 145.89 μm after 1 month (P < 0.001); whereas the baseline central retinal vein equivalent (211.87 μm) decreased initially to 204.59 μm after 1 week and was 205.24 μm after 1 month (P < 0.001). The preinjection artery-to-vein ratio values changed significantly (P = 0.001) after 1 week and after 1 month in the RAN group, but no significant alteration in the artery-to-vein ratio was observed in the BEV group (P = 0.433). In both the RAN (n = 32) and BEV (n = 30) control groups, none of the 3 parameters changed throughout the study period, when compared with the baseline. CONCLUSION The results of this study showed that both RAN and BEV injections significantly constricted the retinal blood vessel diameters.
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Affiliation(s)
- Muhammed Mustafa Kurt
- Department of Ophthalmology, Okmeydani Training and Research Hospital, Istanbul, Turkey
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23
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Brannick B, Wynn A, Dagogo-Jack S. Prediabetes as a toxic environment for the initiation of microvascular and macrovascular complications. Exp Biol Med (Maywood) 2017; 241:1323-31. [PMID: 27302176 DOI: 10.1177/1535370216654227] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. Evidence is increasingly demonstrating that prediabetes is a toxic state, in addition to being a harbinger of future development of diabetes mellitus. This minireview discusses the pathophysiology and clinical significance of prediabetes, and approach to its management, in the context of the worldwide diabetes epidemic. The pathophysiologic defects underlying prediabetes include insulin resistance, β cell dysfunction, increased lipolysis, inflammation, suboptimal incretin effect, and possibly hepatic glucose overproduction. Recent studies have revealed that the long-term complications of diabetes may manifest in some people with prediabetes; these complications include classical microvascular and macrovascular disorders, and our discussion explores the role of glycemia in their development. Finally, landmark intervention studies in prediabetes, including lifestyle modification and pharmacologic treatment, are reviewed.
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Affiliation(s)
- Ben Brannick
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, Tennessee, TN 38163, USA
| | - Anne Wynn
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, Tennessee, TN 38163, USA
| | - Samuel Dagogo-Jack
- Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, Tennessee, TN 38163, USA
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24
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Heitmar R, Lip GYH, Ryder RE, Blann AD. Retinal vessel diameters and reactivity in diabetes mellitus and/or cardiovascular disease. Cardiovasc Diabetol 2017; 16:56. [PMID: 28446234 PMCID: PMC5406879 DOI: 10.1186/s12933-017-0534-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/11/2017] [Indexed: 12/27/2022] Open
Abstract
Background Retinal vessel calibre and vascular dilation/constriction in response to flicker light provocation may provide a measure distinguishing patients suffering from diabetes mellitus and/or cardiovascular disease. Methods One hundred and sixteen age and sex matched patients with diabetes mellitus (DM), cardiovascular disease (CVD) and both DM and CVD (DM + CVD) underwent systemic and intraocular pressure measurements. Retinal vessel calibres were assessed using a validated computer-based program to compute central retinal artery and vein equivalents (CRVE) from monochromatic retinal images. Vessel dilation and constriction responses to flicker light provocation were assessed by continuous retinal vessel diameter recordings. Plasma endothelial markers von Willebrand factor (vWf) and soluble E selectin (sEsel) were measured by ELISA. Results Retinal vessel calibres were comparable across groups but CRVE correlated significantly with disease duration in DM patients (r = 0.57, p < 0.001). Patients suffering DM only exhibited reduced arterial vasomotion at rest and reduced arterial constriction following flicker light induced vessel dilation compared to patients with CVD and those suffering both CVD + DM (p = 0.030). Patients suffering from CVD + DM exhibited significant differences between each flicker cycle in regards to arterial maximum constriction (p = 0.006) and time needed to reach arterial maximum dilation (p = 0.004), whereas the other two groups did not show such inconsistencies between individual flicker cycles. vWf was raised in CVD + DM compared to the other two groups (p ≤ 0.02), whilst sEsel was raised in CVD + DM compared to DM alone (p = 0.044). Conclusions Dynamic retinal vascular calibres as obtained by continuous diameter measurements using flicker light provocation can reveal subtle differences between groups suffering from CVD with and without DM. This difference in reaction pattern and lack of arterial constriction in DM may provide a suitable marker to monitor progression.
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Affiliation(s)
- R Heitmar
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
| | - G Y H Lip
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.,Institute for Cardiovascular Sciences, University of Birmingham, City Hospital, Birmingham, B18 7QH, UK
| | - R E Ryder
- Department of Diabetes and Endocrinology, City Hospital, Birmingham, B18 7QH, UK
| | - A D Blann
- Institute for Cardiovascular Sciences, University of Birmingham, City Hospital, Birmingham, B18 7QH, UK
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25
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Yazgan S, Arpaci D, Celik HU, Dogan M, Isık I. Macular Choroidal Thickness May Be the Earliest Determiner to Detect the Onset of Diabetic Retinopathy in Patients with Prediabetes: A Prospective and Comparative Study. Curr Eye Res 2017; 42:1039-1047. [PMID: 28121176 DOI: 10.1080/02713683.2016.1264606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE To evaluate the macular and peripapillary choroidal thickness and retinal volume in prediabetes. MATERIAL AND METHODS This prospective comparative study included 53 patients with prediabetes and 53 age- and sex-matched healthy subjects. Only right eyes were selected. Choroidal thicknesses (CT) and retinal volume were measured by optical coherence tomography. Macular CT was measured at the seven points including macular center, 1, 2, and 3 mm distances along the temporal and nasal scans. Peripapillary CT was measured at the eight points of the optic disk area. Systemic and laboratory findings of the subjects were also recorded. RESULTS There were no significant differences in blood pressures, ocular findings including intraocular pressure, visual acuity, and refractive powers, and macular volumes between the two groups (p > 0.005). Macular and peripapillary CT at all measuring points, body mass index (BMI), fasting blood glucose (FBG), hemoglobinA1C, and lipid profile were significantly higher in prediabetic patients (p < 0.05). There was a significant positive correlation between all points of macular choroidal thicknesses with BMI, FBG, and hemoglobin A1C (p < 0.05). CONCLUSION Prediabetic factors including impaired FBG, increased hemoglobinA1C, and BMI are independent risk factors for increase in choroidal thickness. Increased macular choroidal thickness may be the earliest determiner to detect the onset of diabetic retinopathy in prediabetes.
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Affiliation(s)
- Serpil Yazgan
- a Department of Ophthalmology , Bülent Ecevit University , Zonguldak , Turkey
| | - Dilek Arpaci
- b Department of Internal Medicine, Division of Endocrinology , Bülent Ecevit University , Zonguldak , Turkey
| | - Haci Ugur Celik
- c Department of Ophthalmology , Medeniyet University , Istanbul , Turkey
| | - Mustafa Dogan
- d Department of Ophthalmology , Afyon Kocatepe University , Afyon , Turkey
| | - Irem Isık
- a Department of Ophthalmology , Bülent Ecevit University , Zonguldak , Turkey
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26
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Bettermann K, Slocomb J, Shivkumar V, Quillen D, Gardner TW, Lott ME. Impaired Retinal Vasoreactivity: An Early Marker of Stroke Risk in Diabetes. J Neuroimaging 2016; 27:78-84. [PMID: 27892636 DOI: 10.1111/jon.12412] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/25/2016] [Accepted: 10/30/2016] [Indexed: 12/01/2022] Open
Abstract
Diabetes is a common cause of small vessel disease leading to stroke and vascular dementia. While the function and structure of large cerebral vessels can be easily studied, the brain's microvasculature remains difficult to assess. Previous studies have demonstrated that structural changes in the retinal vessel architecture predict stroke risk, but these changes occur at late disease stages. Our goal was to examine whether retinal vascular status can predict cerebral small vessel dysfunction during early stages of diabetes. Retinal vasoreactivity and cerebral vascular function were measured in 78 subjects (19 healthy controls, 22 subjects with prediabetes, and 37 with type-2 diabetes) using a new noninvasive retinal imaging device (Dynamic Vessel Analyzer) and transcranial Doppler studies, respectively. Cerebral blood vessel responsiveness worsened with disease progression of diabetes. Similarly, retinal vascular reactivity was significantly attenuated in subjects with prediabetes and diabetes compared to healthy controls. Subjects with prediabetes and diabetes with impaired cerebral vasoreactivity showed mainly attenuation of the retinal venous flicker response. This is the first study to explore the relationship between retinal and cerebral vascular function in diabetes. Impairment of venous retinal responsiveness may be one of the earliest markers of vascular dysfunction in diabetes possibly indicating subsequent risk of stroke and vascular dementia.
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Affiliation(s)
| | - Julia Slocomb
- Department of Biology, Johns Hopkins University, Baltimore, MD
| | | | - David Quillen
- Penn State Hershey Medical Center, Department of Ophthalmology, Hershey, PA
| | | | - Mary E Lott
- Penn State Hershey Medical Center, Heart and Vascular Institute, Hershey, PA
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27
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Prediabetes and Type 2 Diabetes Are Associated With Generalized Microvascular Dysfunction. Circulation 2016; 134:1339-1352. [DOI: 10.1161/circulationaha.116.023446] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/29/2016] [Indexed: 11/16/2022]
Abstract
Background:
Type 2 diabetes (T2DM) is associated with an increased risk of cardiovascular disease. This can be partly explained by large-artery dysfunction, which already occurs in prediabetes (“ticking clock hypothesis”). Whether a similar phenomenon also applies to microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction is already present in prediabetes and is more severe in T2DM. To do so, we investigated the associations of prediabetes, T2DM, and measures of hyperglycemia with microvascular function measured as flicker light-induced retinal arteriolar dilation and heat-induced skin hyperemia.
Methods:
In the Maastricht Study, a T2DM-enriched population-based cohort study (n=2213, 51% men, aged [mean±standard deviation] 59.7±8.2 years), we determined flicker light-induced retinal arteriolar %-dilation (Dynamic Vessel Analyzer), heat-induced skin %-hyperemia (laser-Doppler flowmetry), and glucose metabolism status (oral glucose tolerance test; normal glucose metabolism [n=1269], prediabetes [n=335], or T2DM [n=609]). Differences were assessed with multivariable regression analyses adjusted for age, sex, body mass index, smoking, physical activity, systolic blood pressure, lipid profile, retinopathy, estimated glomerular filtration rate, (micro)albuminuria, the use of lipid-modifying and blood pressure-lowering medication, and prior cardiovascular disease.
Results:
Retinal arteriolar %-dilation was (mean±standard deviation) 3.4±2.8 in normal glucose metabolism, 3.0±2.7 in prediabetes, and 2.3±2.6 in T2DM. Adjusted analyses showed a lower arteriolar %-dilation in prediabetes (B=–0.20, 95% confidence interval –0.56 to 0.15) with further deterioration in T2DM (B=–0.61 [–0.97 to –0.25]) versus normal glucose metabolism (
P
for trend=0.001). Skin %-hyperemia was (mean±standard deviation) 1235±810 in normal glucose metabolism, 1109±748 in prediabetes, and 937±683 in T2DM. Adjusted analyses showed a lower %-hyperemia in prediabetes (B=–46 [–163 to 72]) with further deterioration in T2DM (B=–184 [–297 to –71]) versus normal glucose metabolism (
P
for trend=0.001). In addition, higher glycohemoglobin A1c and fasting plasma glucose were associated with lower retinal arteriolar %-dilation and skin %-hyperemia in fully adjusted models (for glycohemoglobin A1c, standardized B=–0.10 [–0.15 to –0.05],
P
<0.001 and standardized B=–0.13 [–0.19 to –0.07],
P
<0.001, respectively; for fasting plasma glucose, standardized B=–0.09 [–0.15 to –0.04],
P
<0.001 and standardized B=–0.10 [–0.15 to –0.04],
P
=0.002, respectively).
Conclusion:
Prediabetes, T2DM, and measures of hyperglycemia are independently associated with impaired microvascular function in the retina and skin. These findings support the concept that microvascular dysfunction precedes and thus may contribute to T2DM-associated cardiovascular disease and other complications, which may in part have a microvascular origin such as impaired cognition and heart failure.
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Selvarajah D, Hughes T, Reeves J, Boland E, Marques J, Gandhi R, Griffiths PD, Tesfaye S, Wilkinson ID. A preliminary study of brain macrovascular reactivity in impaired glucose tolerance and type-2 diabetes: Quantitative internal carotid artery blood flow using magnetic resonance phase contrast angiography. Diab Vasc Dis Res 2016; 13:367-72. [PMID: 27190084 DOI: 10.1177/1479164116644404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE The aims of this study were (1) to examine cerebrovascular autoregulation in subjects with impaired glucose tolerance and type 2 diabetes and (2) to clarify whether cardiovascular autonomic nerve function is associated with abnormal cerebrovascular autoregulation. RESEARCH DESIGN AND METHODS Totally, 46 subjects were recruited (12 = impaired glucose tolerance, 17 = type 2 diabetes and 17 = healthy volunteers). Arterial blood flow was assessed within the internal carotid artery at baseline and 20 min after intravenous pharmacological stress (1 g acetazolamide), using quantitative magnetic resonance phase-contrast angiography. Internal carotid artery vascular reactivity and pulsatility index was determined. All subjects underwent baroreceptor reflex sensitivity assessment. RESULTS Subjects with impaired glucose tolerance and type 2 diabetes had significantly lower internal carotid artery vascular reactivity [40.2%(19.8) and 41.5%(18.7)], respectively, compared with healthy volunteers [57.0%(14.2); analysis of variance, p = 0.02]. There was no significant difference in internal carotid artery vascular reactivity between type 2 diabetes and impaired glucose tolerance groups (p = 0.84). There was a significant positive correlation between baroreceptor reflex sensitivity (low frequency:high frequency) with cardiac rhythm variability (ρ = 0.47, p = 0.04) and PI (ρ = 0.46, p = 0.04). CONCLUSION We have demonstrated significant cerebrovascular haemodynamic abnormalities in subjects with type 2 diabetes and impaired glucose tolerance. This was associated with greater sympathovagal imbalance. This may provide an important mechanistic explanation for increased risk of cerebrovascular disease in diabetes. It also highlights that these abnormalities may already be present in prediabetes.
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Affiliation(s)
- Dinesh Selvarajah
- Department of Human Metabolism, The University of Sheffield, Sheffield, UK
| | - Timothy Hughes
- Academic Unit of Radiology, The University of Sheffield, Sheffield, UK
| | - Josie Reeves
- Academic Unit of Radiology, The University of Sheffield, Sheffield, UK
| | - Elaine Boland
- Academic Unit of Radiology, The University of Sheffield, Sheffield, UK
| | - Jefferson Marques
- Academic Unit of Diabetes and Endocrinology, Royal Hallamshire Hospital, Sheffield, UK
| | - Rajiv Gandhi
- Academic Unit of Diabetes and Endocrinology, Royal Hallamshire Hospital, Sheffield, UK
| | - Paul D Griffiths
- Academic Unit of Radiology, The University of Sheffield, Sheffield, UK
| | - Solomon Tesfaye
- Academic Unit of Diabetes and Endocrinology, Royal Hallamshire Hospital, Sheffield, UK
| | - Iain D Wilkinson
- Academic Unit of Radiology, The University of Sheffield, Sheffield, UK
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Heitmar R, Varma C, De P, Lau YC, Blann AD. The relationship of systemic markers of renal function and vascular function with retinal blood vessel responses. Graefes Arch Clin Exp Ophthalmol 2016; 254:2257-2265. [PMID: 27436082 PMCID: PMC5080305 DOI: 10.1007/s00417-016-3432-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/09/2016] [Accepted: 06/27/2016] [Indexed: 01/18/2023] Open
Abstract
PURPOSE To test the hypothesis of a significant relationship between systemic markers of renal and vascular function (processes linked to cardiovascular disease and its development) and retinal microvascular function in diabetes and/or cardiovascular disease. METHODS Ocular microcirculatory function was measured in 116 patients with diabetes and/or cardiovascular disease using static and continuous retinal vessel responses to three cycles of flickering light. Endothelial function was evaluated by von Willebrand factor (vWf), endothelial microparticles and soluble E selectin, renal function by serum creatinine, creatinine clearance and estimated glomerular filtration rate (eGFR). HbA1c was used as a control index. RESULTS Central retinal vein equivalence and venous maximum dilation to flicker were linked to HbA1c (both p < 0.05). Arterial reaction time was linked to serum creatinine (p = 0.036) and eGFR (p = 0.039); venous reaction time was linked to creatinine clearance (p = 0.018). Creatinine clearance and eGFR were linked to arterial maximum dilatation (p < 0.001 and p = 0.003, respectively) and the dilatation amplitude (p = 0.038 and p = 0.048, respectively) responses in the third flicker cycle. Of venous responses to the first flicker cycle, HbA1c was linked to the maximum dilation response (p = 0.004) and dilatation amplitude (p = 0.017), vWf was linked to the maximum constriction response (p = 0.016), and creatinine clearance to the baseline diameter fluctuation (p = 0.029). In the second flicker cycle, dilatation amplitude was linked to serum creatinine (p = 0.022). CONCLUSIONS Several retinal blood vessel responses to flickering light are linked to glycaemia and renal function, but only one index is linked to endothelial function. Renal function must be considered when interpreting retinal vessel responses.
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Affiliation(s)
- R Heitmar
- Aston University, School of Life and Health Sciences, Aston Triangle, B4 7ET, Birmingham, UK
| | - C Varma
- Department of Cardiology, City Hospital, Birmingham, B18 7QH, UK
| | - P De
- Department of Diabetes and Endocrinology, City Hospital, Birmingham, B18 7QH, UK
| | - Y C Lau
- University of Birmingham Institute for Cardiovascular Sciences, City Hospital, Birmingham, B18 7QH, UK
| | - A D Blann
- University of Birmingham Institute for Cardiovascular Sciences, City Hospital, Birmingham, B18 7QH, UK.
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Dong Y, Lin L, Yan H, Fu Y, Zong Y, Yuan Y, Huang X, Li Y, He H, Gao Q. Shifts in retinal vessel diameter and oxygen saturation in Chinese type 2 diabetes mellitus patients. BMC Ophthalmol 2016; 16:43. [PMID: 27095023 PMCID: PMC4837630 DOI: 10.1186/s12886-016-0217-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 04/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study was to analyze the shifts in retinal vessel diameter and oxygen saturation in diabetic patients with and without diabetic retinopathy (DR), as well as to assess the association between diabetes duration and either vessel diameter or oxygen saturation. METHODS In total, 99 Type 2 DM patients were recruited for the study and were divided into three groups: DM with non-obvious retinopathy (DM, n = 29), non-proliferative diabetic retinopathy (NPDR, n = 40), and proliferative diabetic retinopathy (PDR, n = 30). In addition, 78 age-matched healthy individuals were chosen as the control. The diameter and oxygen saturation of the retinal vessels were analyzed using a noninvasive retinal oximeter, and then compared between the three groups and the normal control. Association analysis was applied to analyze the possible influencing factors, including the diameter and oxygen saturation of retinal vessels, on best corrected visual acuity BCVA, as well as the relationship between diabetes duration and the oximetry values. RESULTS All of the diabetic patients showed thinner arterioles, wider venules, and a smaller arteriolar-to-venular ratio (AVR) than the healthy individuals. The AVR results from the controls through to the PDR group were 0.81 ± 0.07, 0.78 ± 0.07, 0.76 ± 0.07 and 0.67 ± 0.07, respectively. Both the NPDR and PDR groups showed significantly smaller AVR than the control. All of the diabetic patients exhibited higher retinal vessel oxygen saturation than the healthy individuals. Among all of the oximetry values, AVR exhibited the most significant correlation with best corrected visual acuity (BCVA) (β = 1.533, P < 0.0001). An increased diabetes duration was associated with decreased arteriolar diameter (slope = -0.082 pixels/year, r (2) = 0.085, P = 0.004) and AVR (slope = -0.009/year, r (2) = 0.349, P < 0.001), and with increased venular diameter (slope = 0.104 pixels/year, r (2) = -0.109, P = 0.001). CONCLUSIONS In this Chinese population with type 2 DM, the thinner arterioles and wider venules point to microvascular dysfunction in DR. The increased oxygen saturation of the retinal vessels suggests that retinal oxygen metabolism is affected in diabetic retinopathy.
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Affiliation(s)
- Yanmin Dong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Leilei Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Hong Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Yue Fu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Yao Zong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Yongguang Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Xia Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Yujie Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Huining He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China
| | - Qianying Gao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54S Xianlie Road, Guangzhou, 510060, China.
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Abstract
PURPOSE OF REVIEW The risk of vision loss from diabetic retinopathy has fallen dramatically over the past 3 decades with improvements in diabetes and blood pressure treatments, and with advances in laser surgery and intraocular drug delivery. Nevertheless, diabetes continues to be a major cause of blindness. This study summarizes the state of the art in diabetic retinopathy research and provides a perspective on opportunities for future investigations. RECENT FINDINGS New insights into the pathophysiology of diabetes and diabetic retinopathy will improve metabolic control. Structure-function analyses are revealing new details of diabetic retinopathy. Intraocular drug therapy provides improved visual outcomes. Together these steps will yield better means to detect and quantify vision loss, and to develop patient-specific treatments to preserve vision for persons with diabetes. SUMMARY Retinopathy is one of the most successfully treated complications of diabetes and will continue to be an important area of research for patients and their families.
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Affiliation(s)
- Thomas W Gardne
- Department of Ophthalmology and Visual Sciences, WK Kellogg Eye Center, University of Michigan Medical School, 1000 Wall Street, Ann Arbor, MI 48105, 734-232-8283,
| | - Emily Y. Chew
- National Eye Institute, Building 10-CRC, Room 3-2531, 10 Center Drive, Bethesda, MD 20892-1204, 301-496-6583,
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32
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Petersen L, Bek T. Preserved Pressure Autoregulation but Disturbed Cyclo-Oxygenase and Nitric Oxide Effects on Retinal Arterioles during Acute Hypoxia in Diabetic Patients without Retinopathy. Ophthalmologica 2016; 235:114-20. [PMID: 26741496 DOI: 10.1159/000443147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/03/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Acute hypoxia induces retinal vasodilatation, which depends on cyclooxygenase (COX) products and nitric oxide (NO) in vitro. However, it is unknown whether these mechanisms are active in diabetic patients and may contribute to the development of diabetic retinopathy. METHODS The Dynamic Vessel Analyzer was used to study the diameter regulation in retinal vessels during hypoxia in type 1 diabetic patients without retinopathy. The influence of NO and COX synthesis inhibition on the diameter of larger retinal vessels was studied during hypoxia, during isometric exercise and during flicker stimulation. RESULTS Increased arterial blood pressure during L-NMMA infusion and isometric exercise were paralleled by constriction of the retinal arterioles suggesting normal pressure autoregulation. Hypoxia significantly reduced the diameter responses during isometric exercise and during flicker stimulation as compared to normal persons. CONCLUSION The findings support that changes in metabolic autoregulation develop before changes in pressure autoregulation in diabetic patients.
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Affiliation(s)
- Line Petersen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
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Klefter ON, Vilsbøll T, Knop FK, Larsen M. Retinal vascular and structural dynamics during acute hyperglycaemia. Acta Ophthalmol 2015; 93:697-705. [PMID: 26146858 DOI: 10.1111/aos.12797] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 06/01/2015] [Indexed: 12/24/2022]
Abstract
PURPOSE To compare retinal vascular dynamics during acute hyperglycaemia in patients with type 2 diabetes and healthy volunteers. METHODS Twenty-one patients with type 2 diabetes and 27 healthy controls were examined with fundus photographic measurement of retinal vessel diameters, retinal oximetry, macular perfusion velocities and optical coherence tomographic measurement of subfoveal choroidal thickness every 30 min during a 3-hr 75 g oral glucose tolerance test (OGTT). Patients paused antidiabetic therapy for 1 week prior to the OGTT. RESULTS Plasma glucose (PG) and fluctuations in PG were larger in patients with diabetes (p < 0.0001). PG increased significantly 30 min after ingestion of glucose (p < 0.0001 in both groups). With a delay of 0-120 min, the PG increase was followed by increased retinal arterial oxygen saturations and arteriovenous oxygen saturation differences, narrowed retinal veins and increased arteriovenous diameter ratios. No effect of age, gender or diabetes status was observed. Choroidal thickness was transiently reduced in controls and unchanged in patients with diabetes (p = 0.021). Macular perfusion velocities increased after 150 min in patients with diabetes but not in controls (arterial p = 0.059; venous p = 0.16). Higher age and diabetes tended to be associated with higher retinal arterial oxygen saturation. CONCLUSION The transition from fasting to acute hyperglycaemia is followed, with a delay of up to 2 hr, by retinal vascular changes, notably increased oxygen extraction, suggesting an effect of secondary metabolic changes. Retinal responses were similar in patients with type 2 diabetes and controls despite differences in glucose levels. It is necessary to standardize measurement conditions in studies of retinal physiology.
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Affiliation(s)
- Oliver N. Klefter
- Department of Ophthalmology; Glostrup Hospital; University of Copenhagen; Glostrup Denmark
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research; Gentofte Hospital; University of Copenhagen; Hellerup Denmark
| | - Filip K. Knop
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
- Center for Diabetes Research; Gentofte Hospital; University of Copenhagen; Hellerup Denmark
| | - Michael Larsen
- Department of Ophthalmology; Glostrup Hospital; University of Copenhagen; Glostrup Denmark
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
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Reimann M, Vilser W, Gruber M, Bornstein SR, Ziemssen T. Insulin is a key determinant of elevated retinal arteriolar flicker response in insulin-resistant individuals. Diabetologia 2015; 58:2154-60. [PMID: 26003327 DOI: 10.1007/s00125-015-3639-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Insulin may link metabolic disorders to retinal microvascular pathology. The aim of the present study was to investigate the impact of early insulin resistance on retinal microcirculation. METHODS Retinal diameter responses to flicker-light stimulation were investigated in 81 clinically healthy participants (32 ± 6 years [mean ± SD], 59% women) who were recruited according to their BMI. All participants underwent an OGTT and euglycaemic-hyperinsulinaemic clamp (40 mU/m(2) · min(-1) insulin dose). After stratification by low and high insulin sensitivity based on a clamp-derived glucose disposal rate of ≤ or >4.9 mg/kg body mass, respectively, baseline retinal diameters and their relative changes to flicker stimulation were compared while controlling for mean arterial pressure, BMI and sex. RESULTS The arterial vasodilator response at the end of flicker stimulation (p = 0.044) and the area under the arterial reaction curve during flicker stimulation (p = 0.015) were significantly higher in individuals with low vs high insulin sensitivity. Vasodilatory responses of retinal veins to flicker stimulation and baseline retinal diameters did not differ between insulin-sensitive and insulin-resistant participants (p > 0.05). In a stepwise linear regression analysis, fasting insulin remained the only predictor of the arterial vasodilator response to flicker-light (p < 0.01). Waist circumference also contributed, although to a lesser extent, to the arterial vasodilator response (p = 0.023). CONCLUSIONS/INTERPRETATION Insulin sensitivity is an important determinant of retinal microvascular function. We propose that the elevated arterial flicker response in insulin-resistant states is a result of higher circulating insulin levels.
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Affiliation(s)
- Manja Reimann
- Autonomic and Neuroendocrinological Laboratory Dresden, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany,
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Ilievski V, Cho Y, Katwala P, Rodriguez H, Tulowiecka M, Kurian D, Leoni L, Christman JW, Unterman TG, Watanabe K. TLR4 Expression by Liver Resident Cells Mediates the Development of Glucose Intolerance and Insulin Resistance in Experimental Periodontitis. PLoS One 2015; 10:e0136502. [PMID: 26317345 PMCID: PMC4552742 DOI: 10.1371/journal.pone.0136502] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 08/05/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Results from epidemiological studies indicate a close association between periodontitis and type 2 diabetes mellitus. However, the mechanism linking periodontitis to glucose intolerance (GI) and insulin resistance (IR) is unknown. We therefore tested the hypothesis that periodontitis induces the development of GI/IR through a liver Toll-like receptor 4 (TLR4) dependent mechanism. METHODS TLR4 chimeric mice were developed by bone marrow transplantation using green fluorescent protein expressing TLR4WT mouse (GFPWT) as donor and TLR4 WT or TLR4-/- as recipient mice (GFPWT:WT and GFPWT:KO chimeras respectively). These chimeras were subjected to experimental chronic periodontitis induced by repeated applications of LPS to the gingival sulci for 18 weeks. The levels of GI/IR were monitored and plasma cytokines and LPS were determined at 18 weeks when differences in glucose tolerance were most apparent. Cytokine gene expression was measured in liver tissue by qPCR. RESULTS Alveolar bone loss was significantly greater in GFPWT:WT chimeras treated with LPS compared with chimeras treated with PBS or GFPWT:KO chimeras. However, the degree of gingival inflammation was similar between GFPWT:WT and GFPWT:KO mice with LPS application. Severe GI/IR occurred in GFPWT:WT chimeras but not in the GFPWT:KO chimeras that were subjected to 18 weeks of LPS. Serum LPS was detected only in animals to which LPS was applied and the level was similar in GFPWT:WT and GFPWT:KO mice at the 18 week time point. Surprisingly, there was no significant difference in the plasma levels of IL1β, IL6 and TNFα at 18 weeks in spite of the severe GI/IR in the GFPWT:WT chimeras with LPS application. Also, no difference in the expression of TNFα or IL6 mRNA was detected in the liver of GFPWT:WT vs GFPWT:KO mice. In contrast, liver IL1β expression was significantly greater in GFPWT:WT chimeras compared to GFPWT:KO chimeras treated with LPS. CONCLUSION We observed that GFPWT:WT, but not GFPWT:KO chimeras, treated with LPS developed GI/IR despite similar degrees of gingival inflammation, circulating cytokine levels, and LPS concentrations. We conclude that LPS from periodontitis sites has a pivotal role in triggering the development of GI/IR through a mechanism that involves TLR4 expression by resident macrophages/Kupffer cells in the liver.
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Affiliation(s)
- Vladimir Ilievski
- Department of Periodontics, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yale Cho
- Undergraduate Program, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Priya Katwala
- Undergraduate Program, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Heriberto Rodriguez
- Undergraduate Program, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Margaret Tulowiecka
- Undergraduate Program, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - David Kurian
- Undergraduate Program, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Lara Leoni
- Department of Radiology, University of Chicago, Chicago, Illinois, United States of America
| | - John W. Christman
- Department of Internal Medicine, Section of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Terry G. Unterman
- Departments of Medicine and Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, and Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Keiko Watanabe
- Department of Periodontics, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Diabetic retinopathy: recent advances towards understanding neurodegeneration and vision loss. SCIENCE CHINA-LIFE SCIENCES 2015; 58:541-9. [DOI: 10.1007/s11427-015-4856-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 02/02/2015] [Indexed: 12/22/2022]
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Cheung CY, Ikram MK, Klein R, Wong TY. The clinical implications of recent studies on the structure and function of the retinal microvasculature in diabetes. Diabetologia 2015; 58:871-85. [PMID: 25669631 DOI: 10.1007/s00125-015-3511-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/12/2015] [Indexed: 12/26/2022]
Abstract
The retinal blood vessels provide the opportunity to study early structural and functional changes in the microvasculature prior to clinically significant microvascular and macrovascular complications of diabetes. Advances in digital retinal photography and computerised assessment of the retinal vasculature have provided more objective and precise measurements of retinal vascular changes. Clinic- and population-based studies have reported that these quantitatively measured retinal vascular changes (e.g. retinal arteriolar narrowing and venular widening) are associated with preclinical structural changes in other microvascular systems (e.g. infarct in the cerebral microcirculation), as well as diabetes and diabetic complications, suggesting that they are markers of early microvascular dysfunction. In addition, there are new retinal imaging techniques to further assess alterations in retinal vascular function (e.g. flicker-induced vasodilatory response, blood flow and oxygen saturation) in diabetes and complications that result from the effects of chronic hyperglycaemia, inflammation and endothelial dysfunction. In this review, we summarise the latest findings on the relationships between quantitatively measured structural and functional retinal vascular changes with diabetes and diabetic complications. We also discuss clinical implications and future research to evaluate whether detection of retinal vascular changes has additional value beyond that achieved with methods currently used to stratify the risk of diabetes and its complications.
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Affiliation(s)
- Carol Yimlui Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, 11 Third Hospital Avenue, Singapore, 168751, Republic of Singapore
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Schuster AKG, Fischer JE, Vossmerbaeumer C, Vossmerbaeumer U. Optical coherence tomography-based retinal vessel analysis for the evaluation of hypertensive vasculopathy. Acta Ophthalmol 2015; 93:e148-53. [PMID: 25113436 DOI: 10.1111/aos.12509] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 06/15/2014] [Indexed: 01/18/2023]
Abstract
PURPOSE Evaluation of retinal vessels in cardiovascular disease traditionally relies upon funduscopy, but more recently digital photo analysis has expanded the spectrum. As spectral domain optical coherence tomography (OCT) allows an in-vivo assessment of retinal tissue and its vessels on a histological scale, our study aimed at using this tool for the analysis of the retinal vasculature. METHODS Circumferential peripapillary OCT scans (3DOCT-2000; Topcon Inc., Tokyo, Japan), with centration on the optic nerve head, were taken from 20 eyes (20 participants) with normal blood pressure and 20 eyes (20 participants) with arterial hypertension above 120 mmHg (mean blood pressure). The diameter of all vessels intersecting the scan line was measured in the OCT and used to calculate central vessel equivalents, and the A/V ratios were calculated. Bland-Altman analysis was performed to evaluate reliability. Correlation coefficients were determined for reliability of the method as well as with the individual mean arterial blood pressures. RESULTS Forty eyes (40 participants) were included in the study. Mean arterial blood pressure was 96±4 mmHg in the control group and 132±7 mmHg in the hypertonic group. Mean A/V ratio as determined from OCT scans was 0.82±0.13 (normotonic) versus 0.62±0.11 (hypertonic). A Pearson's correlation coefficient of 0.67 (p<0.001) was determined between A/V ratio and blood pressure. CONCLUSIONS Our results highlight the feasibility of retinal vessel measurements in spectral domain OCT. A relation between mean arterial blood pressure and OCT-based A/V ratio was established. Further research will elucidate influencing factors and provide a broader basis for therapeutic approaches.
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Affiliation(s)
- Alexander Karl-Georg Schuster
- Medical Faculty Mannheim; Mannheim Institute of Public Health, Social and Preventive Medicine; Heidelberg University; Mannheim Germany
| | - Joachim Ernst Fischer
- Medical Faculty Mannheim; Mannheim Institute of Public Health, Social and Preventive Medicine; Heidelberg University; Mannheim Germany
| | | | - Urs Vossmerbaeumer
- Medical Faculty Mannheim; Mannheim Institute of Public Health, Social and Preventive Medicine; Heidelberg University; Mannheim Germany
- Department of Ophthalmology; University of Mainz; Mainz Germany
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Liew G, Sim DA, Keane PA, Tan AG, Mitchell P, Wang JJ, Wong TY, Fruttiger M, Tufail A, Egan CA. Diabetic macular ischaemia is associated with narrower retinal arterioles in patients with type 2 diabetes. Acta Ophthalmol 2015; 93:e45-51. [PMID: 25613127 DOI: 10.1111/aos.12519] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/03/2014] [Indexed: 11/30/2022]
Abstract
PURPOSE Diabetic macular ischaemia (DMI) is an important cause of visual loss in patients with diabetes, but its relationship to the larger retinal vessels is unknown. We examined whether retinal vessel calibre is related to DMI. METHODS Clinic-based case-control study of patients with type 2 diabetes. The presence and severity of DMI was assessed using Early Treatment Diabetic Retinopathy Study (ETDRS) protocols from fundus fluorescein angiographic (FFA) images. Custom software was used to quantify the greatest linear dimension and area of the foveal avascular zone (FAZ). Retinal vessel calibre was measured using a semi-automated software on fundus fluorescein images. RESULTS Of 53 patients examined, 18 (34%), 18 (34%) and 17 (32%) had no/mild, moderate and severe DMI, respectively. Persons with moderate or severe DMI had narrower mean retinal arteriolar calibre than persons with no/mild DMI (140.6 μm 95% confidence interval (CI) 134.7, 146.4 versus 150.7 μm, 95% CI 142.5, 158, p = 0.04). The association remained after multivariate adjustment for age, gender, previous panretinal photocoagulation, neovascularization at the disc and elsewhere and diabetic retinopathy severity. Increased FAZ size was also associated with narrower arteriolar calibre. Retinal venular calibre and arteriole to venule ratio (AVR) were not associated with DMI. CONCLUSIONS Retinal arteriolar narrowing was associated with moderate-to-severe macular ischaemia in eyes with diabetic retinopathy. This suggests that larger vessels other than capillaries may also be associated with DMI.
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Affiliation(s)
- Gerald Liew
- Moorfields Eye Hospital NHS Foundation Trust; London UK
- Center for Vision Research; Westmead Millenium Institute; University of Sydney; Sydney NSW Australia
| | - Dawn A. Sim
- Moorfields Eye Hospital NHS Foundation Trust; London UK
- Institute of Ophthalmology; University College London; London UK
| | - Pearse A. Keane
- Moorfields Eye Hospital NHS Foundation Trust; London UK
- Institute of Ophthalmology; University College London; London UK
| | - Ava G. Tan
- Center for Vision Research; Westmead Millenium Institute; University of Sydney; Sydney NSW Australia
| | - Paul Mitchell
- Center for Vision Research; Westmead Millenium Institute; University of Sydney; Sydney NSW Australia
| | - Jie Jin Wang
- Center for Vision Research; Westmead Millenium Institute; University of Sydney; Sydney NSW Australia
| | - Tien Y. Wong
- Singapore National Eye Center; Singapore Eye Research Institute; Yong Loo Lin School of Medicine; National University of Singapore; Singapore City Singapore
| | - Marcus Fruttiger
- Institute of Ophthalmology; University College London; London UK
| | - Adnan Tufail
- Moorfields Eye Hospital NHS Foundation Trust; London UK
- Institute of Ophthalmology; University College London; London UK
| | - Catherine A. Egan
- Moorfields Eye Hospital NHS Foundation Trust; London UK
- Institute of Ophthalmology; University College London; London UK
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J MS, Schallenberg M, Kramer S, Anastassiou G, Steuhl KP, Vilser W, Kremmer S. Trabeculectomy Improves Vessel Response Measured by Dynamic Vessel Analysis (DVA) in Glaucoma Patients. Open Ophthalmol J 2014; 8:75-81. [PMID: 25352934 PMCID: PMC4209500 DOI: 10.2174/1874364101408010075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To determine the effects of surgical IOP reduction (trabeculectomy) on retinal blood flow parameters in glaucoma patients using Dynamic Vessel Analysis (DVA). METHODS 26 eyes of 26 patients with progressive primary open-angle glaucoma (POAG) despite maximal topical therapy were examined before and after trabeculectomy. The responses of the retinal vessels to flickering light provocation were measured with DVA the day before surgery and 4 to 6 weeks after trabeculectomy. Between 3 and 4 weeks before surgery all local therapies were stopped and a systemic therapy with acetazolamide and conservative free topic steroidal eye drops was started. RESULTS In 19 patients (73%), an inadequate response to the flicker stimulation was measured preoperatively. In these patients, the maximum dilation of arteries and veins was reduced significantly as compared to healthy eyes. In this group, the maximum dilation of the arteries following the flicker provocation improved from 1.4% before to 3.8% following trabeculectomy (p<0.01). In retinal veins, this parameter increased from 3.1% to 4.6% (p<0.05). In the 7 patients whose arterial and venous reactions to flickering light provocation preoperatively did not differ from healthy eyes, there was no significant change after surgery. The initial baseline values of arteries and veins (MU) did not deviate significantly in both groups. CONCLUSION POAG patients with progressive disease and impaired vascular regulation profit from IOP lowering trabeculectomy concerning vascular reactivity and dilative reserve, indicating a possible improvement of retinal perfusion following effective IOP control. Future studies with long-term follow-up must determine the clinical importance of these findings for the treatment of glaucoma patients.
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Affiliation(s)
- Michael Selbach J
- Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Maurice Schallenberg
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Sebastian Kramer
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Gerasimos Anastassiou
- Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Klaus-Peter Steuhl
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Walthard Vilser
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Gustav-Kirchhoff-Str.2, Germany
- Imedos Systems UG, Jena, Am Naßtal 4, Germany
| | - Stephan Kremmer
- Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany
- Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
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Abcouwer SF, Gardner TW. Diabetic retinopathy: loss of neuroretinal adaptation to the diabetic metabolic environment. Ann N Y Acad Sci 2014; 1311:174-90. [PMID: 24673341 DOI: 10.1111/nyas.12412] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy (DR) impairs vision of patients with type 1 and type 2 diabetes, associated with vascular dysfunction and occlusion, retinal edema, hemorrhage, and inappropriate growth of new blood vessels. The recent success of biologic treatments targeting vascular endothelial growth factor (VEGF) demonstrates that treating the vascular aspects in the later stages of the disease can preserve vision in many patients. It would also be highly desirable to prevent the onset of the disease or arrest its progression at a stage preceding the appearance of overt microvascular pathologies. The progression of DR is not necessarily linear but may follow a series of steps that evolve over the course of multiple years. Abundant data suggest that diabetes affects the entire neurovascular unit of the retina, with an early loss of neurovascular coupling, gradual neurodegeneration, gliosis, and neuroinflammation occurring before observable vascular pathologies. In this article, we consider the pathology of DR from the point of view that diabetes causes measurable dysfunctions in the complex integral network of cell types that produce and maintain human vision.
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Affiliation(s)
- Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan
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