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Arias-Alvarez M, Tomas-Grasa C, Sopeña-Pinilla M, Orduna-Hospital E, Fernandez-Espinosa G, Bielsa-Alonso S, Acha-Perez J, Rodriguez-Mena D, Pinilla I. Electrophysiological findings in long-term type 1 diabetes patients without diabetic retinopathy using different ERG recording systems. Sci Rep 2024; 14:3520. [PMID: 38347052 PMCID: PMC10861544 DOI: 10.1038/s41598-024-54099-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/08/2024] [Indexed: 02/15/2024] Open
Abstract
To assess full-field electroretinogram findings in long-term type 1 diabetes patients without diabetic retinopathy. Prospective study including 46 eyes of 23 patients with type 1 diabetes and 46 age-matched healthy eyes evaluated by the RETI-port/scan21 and the portable system RETeval following ISCEV guidelines. The average duration of diabetes was 28.88 ± 8.04 years. In scotopic conditions, using the RETI-port/scan21, diabetic patients showed an increase in b-wave implicit time (IT) (p = 0.017) with the lowest stimuli; a diminished b-wave amplitude (p = 0.005) in the mixed response, an increased IT (p = 0.004) with the high-intensity stimuli and an OP2 increased IT (p = 0.008) and decreased amplitude (p = 0.002). Under photopic conditions, b-wave amplitude was lower (p < 0.001) and 30-Hz flicker response was diminished (p = 0.021). Using the RETeval, in scotopic conditions, diabetic patients showed a reduction in the rod b-wave amplitude (p = 0.009), an increase in a-wave IT with the 280 Td.s stimulus (p = 0.005). OP2 had an increased IT and diminished amplitude (p = 0.003 and p = 0.002 respectively). 16 Td.s flicker showed an increased IT (p = 0.008) and diminished amplitude (p = 0.048). Despite variations in values between both systems, nearly all results displayed positive correlations. Long-term type 1 diabetes patients without diabetic retinopathy exhibit alterations in scotopic conditions, as evidenced by both conventional and portable electroretinogram devices. These findings suggest a modified retinal function, particularly in rod-driven pathways, even in the absence of vascular signs.
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Affiliation(s)
- Marta Arias-Alvarez
- Department of Neurophysiology, Lozano Blesa University Hospital, 50009, Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragon), 50009, Zaragoza, Spain
| | - Cristina Tomas-Grasa
- Department of Internal Medicine, Lozano Blesa University Hospital, 50009, Zaragoza, Spain
| | - Maria Sopeña-Pinilla
- Aragon Institute for Health Research (IIS Aragon), 50009, Zaragoza, Spain
- Department of Ophthalmology, Miguel Servet University Hospital, 50009, Zaragoza, Spain
| | - Elvira Orduna-Hospital
- Aragon Institute for Health Research (IIS Aragon), 50009, Zaragoza, Spain
- Department of Applied Physics, University of Zaragoza, 50009, Zaragoza, Spain
| | | | | | - Javier Acha-Perez
- Aragon Institute for Health Research (IIS Aragon), 50009, Zaragoza, Spain
- Department of Endocrinology, Miguel Servet University Hospital, 50009, Zaragoza, Spain
| | - Diego Rodriguez-Mena
- Department of Neurophysiology, Lozano Blesa University Hospital, 50009, Zaragoza, Spain
| | - Isabel Pinilla
- Aragon Institute for Health Research (IIS Aragon), 50009, Zaragoza, Spain.
- Department of Surgery, University of Zaragoza, 50009, Zaragoza, Spain.
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009, Zaragoza, Spain.
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Tănasie CA, Dan AO, Ică OM, Mercuț MF, Mitroi G, Taisescu CI, Sfredel V, Corbeanu RI, Mocanu CL, Danielescu C. Retinal Functional Impairment in Diabetic Retinopathy. Biomedicines 2023; 12:44. [PMID: 38255151 PMCID: PMC10813090 DOI: 10.3390/biomedicines12010044] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a neurodegenerative disease of the retina. The aim of our study was to analyze latency changes in a full-field electroretinogram (ERG) in patients with type 2 diabetes. MATERIAL This prospective study included 15 diabetic patients without DR, 16 diabetic patients with non-proliferative DR, 14 patients with pre-proliferative DR, 15 patients with proliferative DR, and 14 age-matched controls. All the participants underwent ophthalmologic examination and full-field ERGs. The ERGs were recorded with the Metrovision MonPackOne system. The latencies were analyzed for "a"- and "b"-waves in the dark-adapted (DA) 0.01 ERG, DA 3.0 ERG, DA oscillatory potentials, light-adapted (LA) 3.0 ERG, and 30 Hz flicker ERG. RESULTS The delayed responses of healthy subjects compared to diabetic patients without DR were the DA oscillatory potentials (25.45 ± 1.04 ms vs. 26.15 ± 0.96 ms, p = 0.027). When comparing diabetic patients without DR and with non-proliferative DR, we did not obtain statistically significant delays. Significant delays in the DA 0.01 "b"-wave (61.91 ± 5.52 ms vs. 66.36 ± 8.12 ms, p = 0.029), DA 3.0 "b"-wave (41.01 ± 2.50 ms vs. 44.16 ± 3.78 ms, p = 0.035), and LA 3.0 "a"-wave (16.21 ± 0.91 ms vs. 16.99 ± 1.16 ms, p = 0.045) were found between non-proliferative DR and pre-proliferative DR. When comparing the groups of patients with pre-proliferative DR and proliferative DR, the LA 3.0 ERG "b"-wave (32. 63 ± 2.53 ms vs. 36.19 ± 3.21 ms, p < 0.0001), LA 30 Hz flicker ERG "a"-wave (19.56 ± 3.59 vs. 21.75 ± 4.74 ms, p= 0.025), and "b"-wave (32.23 ± 4.02 vs. 36.68 ± 3.48 ms, p = 0.017) were delayed. CONCLUSIONS the electrophysiological findings from our study indicate that there is a substantial dysfunction of the neural retina in all stages of DR.
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Affiliation(s)
- Cornelia Andreea Tănasie
- Department of Physiology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.A.T.); (C.-I.T.); (V.S.); (R.I.C.)
| | - Alexandra Oltea Dan
- Department of Physiology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.A.T.); (C.-I.T.); (V.S.); (R.I.C.)
| | - Oana Maria Ică
- Department of Dermatology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Maria Filoftea Mercuț
- Department of Ophthalmology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (M.F.M.); (C.L.M.)
| | - George Mitroi
- Department of Urology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania;
| | - Citto-Iulian Taisescu
- Department of Physiology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.A.T.); (C.-I.T.); (V.S.); (R.I.C.)
| | - Veronica Sfredel
- Department of Physiology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.A.T.); (C.-I.T.); (V.S.); (R.I.C.)
| | - Ramona Ingrid Corbeanu
- Department of Physiology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (C.A.T.); (C.-I.T.); (V.S.); (R.I.C.)
| | - Carmen Luminița Mocanu
- Department of Ophthalmology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (M.F.M.); (C.L.M.)
| | - Ciprian Danielescu
- Department of Ophthalmology, University of Medicine and Pharmacy “Grigore T. Popa”, 700111 Iasi, Romania;
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Amorim M, Martins B, Fernandes R. Immune Fingerprint in Diabetes: Ocular Surface and Retinal Inflammation. Int J Mol Sci 2023; 24:9821. [PMID: 37372968 DOI: 10.3390/ijms24129821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 05/29/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Diabetes is a prevalent global health issue associated with significant morbidity and mortality. Diabetic retinopathy (DR) is a well-known inflammatory, neurovascular complication of diabetes and a leading cause of preventable blindness in developed countries among working-age adults. However, the ocular surface components of diabetic eyes are also at risk of damage due to uncontrolled diabetes, which is often overlooked. Inflammatory changes in the corneas of diabetic patients indicate that inflammation plays a significant role in diabetic complications, much like in DR. The eye's immune privilege restricts immune and inflammatory responses, and the cornea and retina have a complex network of innate immune cells that maintain immune homeostasis. Nevertheless, low-grade inflammation in diabetes contributes to immune dysregulation. This article aims to provide an overview and discussion of how diabetes affects the ocular immune system's main components, immune-competent cells, and inflammatory mediators. By understanding these effects, potential interventions and treatments may be developed to improve the ocular health of diabetic patients.
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Affiliation(s)
- Madania Amorim
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Beatriz Martins
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
| | - Rosa Fernandes
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
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Starr CR, Gorbatyuk MS. Posttranslational modifications of proteins in diseased retina. Front Cell Neurosci 2023; 17:1150220. [PMID: 37066080 PMCID: PMC10097899 DOI: 10.3389/fncel.2023.1150220] [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: 01/23/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Posttranslational modifications (PTMs) are known to constitute a key step in protein biosynthesis and in the regulation of protein functions. Recent breakthroughs in protein purification strategies and current proteome technologies make it possible to identify the proteomics of healthy and diseased retinas. Despite these advantages, the research field identifying sets of posttranslationally modified proteins (PTMomes) related to diseased retinas is significantly lagging, despite knowledge of the major retina PTMome being critical to drug development. In this review, we highlight current updates regarding the PTMomes in three retinal degenerative diseases-namely, diabetic retinopathy (DR), glaucoma, and retinitis pigmentosa (RP). A literature search reveals the necessity to expedite investigations into essential PTMomes in the diseased retina and validate their physiological roles. This knowledge would accelerate the development of treatments for retinal degenerative disorders and the prevention of blindness in affected populations.
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Affiliation(s)
| | - Marina S. Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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Jia Y, Lin Q, Xiao Y, Zhou X, Zou H, Yang C. Are we overlooking the neurodegeneration in the early stage of Type 1 Diabetes Mellitus without Visual Impairment or Diabetic Retinopathy: is it probably occurred before retinal vasculature dysfunction? Curr Eye Res 2022; 48:433-440. [PMID: 36420789 DOI: 10.1080/02713683.2022.2152056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Using electrophysiology (ERG) to investigate the early alterations of retinal function in diabetic children and adolescents without diabetic retinopathy (DR) or visual impairment (VI). METHODS We recorded and compared the data of full-field flicker ERGs between 59 normal subjects and 60 children and adolescents with type 1 diabetes mellitus (T1DM) from the Children's Hospital of Fudan University in Shanghai. RESULTS In both groups, patients with diabetes and healthy controls were matched for age, gender, weight, height, BMI, intraocular pressure (IOP), and best-corrected visual acuity (BCVA). Among the parameters of the outcomes of ERG, the implicit time in eyes in DM patients was significantly prolonged compared to normal eyes (p = .008, 16 Td-s; p = .000, 32 Td-s). In the case group, we found significantly positive correlation between implicit time and BMI (p < .05), as well as implicit time and axial length (AL). CONCLUSIONS The study reveals that the dysfunction of retina in DM children can be detected with ERGs. It also shows that hyperglycemia has an impact on the occurrence of neurodegeneration in the early stage of DM.
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Affiliation(s)
- Yan Jia
- Department of Ophthalmology, Children’s Hospital of Fudan University, Shanghai, China
| | - Qiurong Lin
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, Shanghai, China
| | - Ying Xiao
- Department of Ophthalmology, Children’s Hospital of Fudan University, Shanghai, China
| | - Xiaohong Zhou
- Department of Ophthalmology, Children’s Hospital of Fudan University, Shanghai, China
| | - Haidong Zou
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, Shanghai, China
| | - Chenhao Yang
- Department of Ophthalmology, Children’s Hospital of Fudan University, Shanghai, China
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Pandurangan K, Sachidanandam R, Sen P. Structural and functional changes among diabetics with no diabetic retinopathy and mild non-proliferative diabetic retinopathy using swept-source optical coherence tomography angiography and photopic negative response. Doc Ophthalmol 2022; 145:113-125. [PMID: 35902440 DOI: 10.1007/s10633-022-09891-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 07/08/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE To assess the structural and functional changes among diabetics with no diabetic retinopathy (NDR) and mild non-proliferative diabetic retinopathy (NPDR) using swept-source optical coherence tomography angiography (SSOCTA) and photopic negative response (PhNR) and to find the earliest changes. METHODS This was a prospective, cross-sectional, case-control study. Participants with minimum 5 years of diabetes mellitus (DM) were recruited and classified as NDR and mild NPDR based on fundus findings. Age-matched normals with nil ocular pathology were considered as controls. SSOCTA scan acquisition (6*6 mm angiography), followed by full field photopic electroretinography (FFERG) and red on blue PhNR (R/B PhNR) were done with complete pupillary dilatation. RESULTS A total of 88 participants were included with 35 controls, 39 NDR and 14 mild NPDR subjects. Vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of mild NPDR were significantly reduced compared to the controls (17.12 ± 2.65 mm-1 vs. 18.75 ± 0.90 mm-1, p = 0.025 and 7.96 ± 3.92 mm-1 vs. 11.83 ± 3.05 mm-1, p = 0.001 respectively). None of the parameters of controls had significant difference compared to NDR group (p > 0.05). The amplitudes of white on white (W/W) a-wave, W/W b-wave, red on blue (R/B) PhNR baseline to trough (BT) and R/B PhNR peak to trough in controls were significantly high compared to NDR and mild NPDR. Amplitude of R/B PhNR BT had the maximum area under the curve of 75.9% with a sensitivity and specificity of 94.3and 77.4%, respectively. CONCLUSION A significant decrease in functional changes as measured by ERG especially PhNR, is seen even among the NDR group compared to controls unlike SSOCTA parameters that measures very early vascular structural changes. PhNR is a sensitive test to identify early preclinical changes in DR when microvascular structural changes as determined by SSOCTA are normal.
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Affiliation(s)
| | - Ramya Sachidanandam
- Elite School of Optometry, Unit of Medical Research Foundation, Chennai, India
| | - Parveen Sen
- Department of Vitreo-Retinal Services, Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Medical Research Foundation, 18 College Road, Nungambakkam, Chennai, 600 006, India.
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Association of inner retinal reflectivity with qualitative and quantitative changes in retinal layers over time in diabetic eyes without retinopathy. Eye (Lond) 2022; 36:1253-1260. [PMID: 34117378 PMCID: PMC9151723 DOI: 10.1038/s41433-021-01607-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 05/05/2021] [Accepted: 05/13/2021] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE To assess the course of neurodegeneration based on retinal layer thickness and integrity analysis in diabetic patients without retinopathy and to evaluate its association with inner retinal reflectivity. METHODS This retrospective case-control study included 80 eyes of 80 patients with DM without retinopathy and 40 eyes of 40 healthy subjects with a follow-up of ≥1 year. SD-OCT was used for assessment of retinal reflectivity and macular layer thicknesses. Optical intensity ratios (OIRs) were defined as the mean OCT reflectivity of ganglion cell and inner nuclear layer to the mean reflectivity of RPE. RESULTS After Bonferroni correction, thinning in pericentral, superior and nasal sectors in total retina, superior ganglion cell, pericentral and nasal inner plexiform, and superior inner retinal layers, as well as thickening in inferior and pericentral outer plexiform layer remained significant in the study group (p < 0.0125). Ganglion cell layer OIR significantly correlated with the changes in superior retina (r = 0.278, p = 0.013), central inner retina (r = 0.247, p = 0.027), and pericentral retinal thickness (r = 0.240, p = 0.032), and no eyes had disruption of retinal layers in the study group initially or finally. CONCLUSION Ganglion cell layer reflectivity significantly correlated with the amount of pericentral retinal thinning during the time course in the diabetic group, which was more prominent in the inner retinal layers.
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Liu L, Zuo Z. Excessive dietary salt promotes neuroinflammation to worsen retinopathy in mice with streptozotocin-induced diabetes. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166426. [PMID: 35533904 DOI: 10.1016/j.bbadis.2022.166426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Diabetic retinopathy (DR) includes vascular and neural tissue injury. Persistent low-grade inflammation may contribute to DR. Increased salt intake has been shown to promote autoimmunity in the brain. This study determined the role of salt intake in DR development. METHODS Eight-week-old C57BL/6 J male mice received streptozotocin to induce diabetes. Diabetic or non-diabetic mice were fed a diet containing normal, low and high amounts of salt. The retinal function, structure and inflammatory response were determined 8 weeks after the establishment of diabetes. Interleukin (IL)-1β or a NLR family pyrin domain containing 3 (NLRP3) inhibitor was injected intravitreally and the retinal changes were evaluated. RESULTS A high salt diet worsened the functional and structural damage of retinal cells and increased IL-1β in the retina of diabetic mice. IL-1β injection impaired the function of photoreceptors and retinal structure in the diabetic mice. Blocking NLRP3 inhibited IL-1β increase in the mouse bone marrow macrophages cultured in high sodium medium. NLRP3 inhibition attenuated retinal injury of diabetic mice on high salt diet. A low-salt diet also triggered inflammation and cell damage in the retina of diabetic mice but at a lower grade than those induced by high salt diet. A low or high salt diet for 8 weeks did not induce inflammation or cell injury in the retina of mice without diabetes. CONCLUSION These results indicate that high salt intake has deleterious effects in DR development through NLRP3 inflammasome activation and the subsequent production of IL-1β. Limiting salt intake may not attenuate DR development.
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Affiliation(s)
- Lei Liu
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, United States of America; Department of Ophthalmology, The First Hospital of Jilin University, Changchun 130021, China.
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, United States of America.
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Multifocal pupillographic objective perimetry for assessment of early diabetic retinopathy and generalised diabetes-related tissue injury in persons with type 1 diabetes. BMC Ophthalmol 2022; 22:166. [PMID: 35418088 PMCID: PMC9008936 DOI: 10.1186/s12886-022-02382-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/28/2022] [Indexed: 12/01/2022] Open
Abstract
Background To examine the potential utility of five multifocal pupillographic objective perimetry (mfPOP) protocols, in the assessment of early diabetic retinopathy (DR) and generalised diabetes-related tissue injury in subjects with type 1 diabetes (T1D). Methods Twenty-five T1D subjects (age 41.8 ± 12.1 (SD) years, 13 male) with either no DR (n = 13) or non-proliferative DR (n = 12), and 23 age and gender-matched control subjects (age 39.7 ± 12.9 years, 9 male) were examined by mfPOP using five different stimulus methods differing in visual field eccentricity (central 30° and 60°), and colour (blue, yellow or green test-stimuli presented on, respectively, a blue, yellow or red background), each assessing 44 test-locations per eye. In the T1D subjects, we assessed 16 metabolic status and diabetes complications variables. These were summarised as three principal component analysis (PCA) factors. DR severity was assessed using Early Treatment of Diabetic Retinopathy Study (ETDRS) scores. Area under the curve (AUC) from receiver operator characteristic analyses quantified the diagnostic power of mfPOP response sensitivity and delay deviations for differentiating: (i) T1D subjects from control subjects, (ii) T1D subjects according to three levels of the identified PCA-factors from control subjects, and (iii) TID subjects with from those without non-proliferative DR. Results The two largest PCA-factors describing the T1D subjects were associated with metabolic variables (e.g. body mass index, HbA1c), and tissue-injury variables (e.g. serum creatinine, vibration perception). Linear models showed that mfPOP per-region response delays were more strongly associated than sensitivities with the metabolic PCA-factor and ETDRS scores. Combined mfPOP amplitude and delay measures produced AUCs of 90.4 ± 8.9% (mean ± SE) for discriminating T1D subjects with DR from control subjects, and T1D subjects with DR from those without of 85.9 ± 8.8%. The yellow and green stimuli performed better than blue on most measures. Conclusions/interpretation In T1D subjects, mfPOP testing was able to identify localised visual field functional abnormalities (retinal/neural reflex) in the absence or presence of mild DR. mfPOP responses were also associated with T1D metabolic status, but less so with early stages of non-ophthalmic diabetes complications.
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Qin X, Zou H. The role of lipopolysaccharides in diabetic retinopathy. BMC Ophthalmol 2022; 22:86. [PMID: 35193549 PMCID: PMC8862382 DOI: 10.1186/s12886-022-02296-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 02/03/2022] [Indexed: 11/29/2022] Open
Abstract
Diabetes mellitus (DM) is a complex metabolic syndrome characterized by hyperglycemia. Diabetic retinopathy (DR) is the most common complication of DM and the leading cause of blindness in the working-age population of the Western world. Lipopolysaccharides (LPS) is an essential ingredient of the outer membrane of gram-negative bacteria, which induces systemic inflammatory responses and cellular apoptotic changes in the host. High-level serum LPS has been found in diabetic patients at the advanced stages, which is mainly due to gut leakage and dysbiosis. In this light, increasing evidence points to a strong correlation between systemic LPS challenge and the progression of DR. Although the underlying molecular mechanisms have not been fully elucidated yet, LPS-related pathobiological events in the retina may contribute to the exacerbation of vasculopathy and neurodegeneration in DR. In this review, we focus on the involvement of LPS in the progression of DR, with emphasis on the blood-retina barrier dysfunction and dysregulated glial activation. Eventually, we summarize the recent advances in the therapeutic strategies for antagonising LPS activity, which may be introduced to DR treatment with promising clinical value.
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Affiliation(s)
- Xinran Qin
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, Shanghai, China. .,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China. .,National Clinical Research Center for Eye Diseases, Shanghai, China. .,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.
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McAnany JJ, Persidina OS, Park JC. Clinical electroretinography in diabetic retinopathy: a review. Surv Ophthalmol 2021; 67:712-722. [PMID: 34487740 DOI: 10.1016/j.survophthal.2021.08.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 11/30/2022]
Abstract
The electroretinogram (ERG) is a noninvasive, objective technique to evaluate retinal function that has become increasingly important in the study of diabetic retinopathy. We summarize the principles and rationale of the ERG, present findings from recent clinical studies that have used the full-field ERG, multifocal ERG, and pattern ERG to evaluate neural dysfunction in patients with diabetes, and weigh the strengths and limitations of the technique as it applies to clinical studies and management of patients with diabetic retinopathy. Taken together, ERG studies have provided convincing evidence for dysfunction of the neural retina in patients with diabetes, including those who have no clinically-apparent retinal vascular abnormalities. Recent full-field ERG findings have pointed to the intriguing possibility that photoreceptor function is abnormal in early-stage disease. Pattern ERG data, in conjunction with recently developed photopic negative response analyses, indicate inner retina dysfunction. In addition, multifocal ERG studies have shown spatially localized neural abnormalities that can predict the location of future microaneurysms. Given the insights provided by the ERG, it is likely to play a growing role in understanding the natural history of neural dysfunction in diabetes, as well as providing an attractive outcome measure for future clinical trials that target neural preservation in diabetic retinopathy.
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Affiliation(s)
- J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA; Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA.
| | - Oksana S Persidina
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
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12
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Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
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Role of Oral Antioxidant Supplementation in the Current Management of Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22084020. [PMID: 33924714 PMCID: PMC8069935 DOI: 10.3390/ijms22084020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 12/13/2022] Open
Abstract
Oxidative stress has been postulated as an underlying pathophysiologic mechanism of diabetic retinopathy (DR), the main cause of avoidable blindness in working-aged people. This review addressed the current daily clinical practice of DR and the role of antioxidants in this practice. A systematic review of the studies on antioxidant supplementation in DR patients was presented. Fifteen studies accomplished the inclusion criteria. The analysis of these studies concluded that antioxidant supplementation has a IIB level of recommendation in adult Type 1 and Type 2 diabetes mellitus subjects without retinopathy or mild-to-moderate nonproliferative DR without diabetic macular oedema as a complementary therapy together with standard medical care.
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14
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Reduction of Glut1 in the Neural Retina But Not the RPE Alleviates Polyol Accumulation and Normalizes Early Characteristics of Diabetic Retinopathy. J Neurosci 2021; 41:3275-3299. [PMID: 33622781 DOI: 10.1523/jneurosci.2010-20.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 12/16/2020] [Accepted: 02/11/2021] [Indexed: 01/04/2023] Open
Abstract
Hyperglycemia is a key determinant for development of diabetic retinopathy (DR). Inadequate glycemic control exacerbates retinopathy, while normalization of glucose levels delays its progression. In hyperglycemia, hexokinase is saturated and excess glucose is metabolized to sorbitol by aldose reductase via the polyol pathway. Therapies to reduce retinal polyol accumulation for the prevention of DR have been elusive because of low sorbitol dehydrogenase levels in the retina and inadequate inhibition of aldose reductase. Using systemic and conditional genetic inactivation, we targeted the primary facilitative glucose transporter in the retina, Glut1, as a preventative therapeutic in diabetic male and female mice. Unlike WT diabetics, diabetic Glut1 +/- mice did not display elevated Glut1 levels in the retina. Furthermore, diabetic Glut1 +/- mice exhibited ameliorated ERG defects, inflammation, and oxidative stress, which was correlated with a significant reduction in retinal sorbitol accumulation. Retinal pigment epithelium-specific reduction of Glut1 did not prevent an increase in retinal sorbitol content or early hallmarks of DR. However, like diabetic Glut1 +/- mice, reduction of Glut1 specifically in the retina mitigated polyol accumulation and diminished retinal dysfunction and the elevation of markers for oxidative stress and inflammation associated with diabetes. These results suggest that modulation of retinal polyol accumulation via Glut1 in photoreceptors can circumvent the difficulties in regulating systemic glucose metabolism and be exploited to prevent DR.SIGNIFICANCE STATEMENT Diabetic retinopathy affects one-third of diabetic patients and is the primary cause of vision loss in adults 20-74 years of age. While anti-VEGF and photocoagulation treatments for the late-stage vision threatening complications can prevent vision loss, a significant proportion of patients do not respond to anti-VEGF therapies, and mechanisms to stop progression of early-stage symptoms remain elusive. Glut1 is the primary facilitative glucose transporter for the retina. We determined that a moderate reduction in Glut1 levels, specifically in the retina, but not the retinal pigment epithelium, was sufficient to prevent retinal polyol accumulation and the earliest functional defects to be identified in the diabetic retina. Our study defines modulation of Glut1 in retinal neurons as a targetable molecule for prevention of diabetic retinopathy.
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Pan WW, Gardner TW, Harder JL. Integrative Biology of Diabetic Retinal Disease: Lessons from Diabetic Kidney Disease. J Clin Med 2021; 10:1254. [PMID: 33803590 PMCID: PMC8003049 DOI: 10.3390/jcm10061254] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/09/2021] [Accepted: 03/12/2021] [Indexed: 01/13/2023] Open
Abstract
Diabetic retinal disease (DRD) remains the most common cause of vision loss in adults of working age. Progress on the development of new therapies for DRD has been limited by the complexity of the human eye, which constrains the utility of traditional research techniques, including animal and tissue culture models-a problem shared by those in the field of kidney disease research. By contrast, significant progress in the study of diabetic kidney disease (DKD) has resulted from the successful employment of systems biology approaches. Systems biology is widely used to comprehensively understand complex human diseases through the unbiased integration of genetic, environmental, and phenotypic aspects of the disease with the functional and structural manifestations of the disease. The application of a systems biology approach to DRD may help to clarify the molecular basis of the disease and its progression. Acquiring this type of information might enable the development of personalized treatment approaches, with the goal of discovering new therapies targeted to an individual's specific DRD pathophysiology and phenotype. Furthermore, recent efforts have revealed shared and distinct pathways and molecular targets of DRD and DKD, highlighting the complex pathophysiology of these diseases and raising the possibility of therapeutics beneficial to both organs. The objective of this review is to survey the current understanding of DRD pathophysiology and to demonstrate the investigative approaches currently applied to DKD that could promote a more thorough understanding of the structure, function, and progression of DRD.
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Affiliation(s)
- Warren W. Pan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, MI 48105, USA; (W.W.P.); (T.W.G.)
| | - Thomas W. Gardner
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, MI 48105, USA; (W.W.P.); (T.W.G.)
- Department of Internal Medicine (Metabolism, Endocrinology and Diabetes), University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jennifer L. Harder
- Department of Internal Medicine (Nephrology), University of Michigan Medical School, Ann Arbor, MI 48109, USA
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16
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The innate immune system in diabetic retinopathy. Prog Retin Eye Res 2021; 84:100940. [PMID: 33429059 DOI: 10.1016/j.preteyeres.2021.100940] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.
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Gorbatyuk OS, Pitale PM, Saltykova IV, Dorofeeva IB, Zhylkibayev AA, Athar M, Fuchs PA, Samuels BC, Gorbatyuk MS. A Novel Tree Shrew Model of Diabetic Retinopathy. Front Endocrinol (Lausanne) 2021; 12:799711. [PMID: 35046899 PMCID: PMC8762304 DOI: 10.3389/fendo.2021.799711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/10/2021] [Indexed: 01/03/2023] Open
Abstract
Existing animal models with rod-dominant retinas have shown that hyperglycemia injures neurons, but it is not yet clearly understood how blue cone photoreceptors and retinal ganglion cells (RGCs) deteriorate in patients because of compromised insulin tolerance. In contrast, northern tree shrews (Tupaia Belangeri), one of the closest living relatives of primates, have a cone-dominant retina with short wave sensitivity (SWS) and long wave sensitivity (LWS) cones. Therefore, we injected animals with a single streptozotocin dose (175 mg/kg i.p.) to investigate whether sustained hyperglycemia models the features of human diabetic retinopathy (DR). We used the photopic electroretinogram (ERG) to measure the amplitudes of A and B waves and the photopic negative responses (PhNR) to evaluate cone and RGC function. Retinal flat mounts were prepared for immunohistochemical analysis to count the numbers of neurons with antibodies against cone opsins and RGC specific BRN3a proteins. The levels of the proteins TRIB3, ISR-1, and p-AKT/p-mTOR were measured with western blot. The results demonstrated that tree shrews manifested sustained hyperglycemia leading to a slight but significant loss of SWS cones (12%) and RGCs (20%) 16 weeks after streptozotocin injection. The loss of BRN3a-positive RGCs was also reflected by a 30% decline in BRN3a protein expression. These were accompanied by reduced ERG amplitudes and PhNRs. Importantly, the diabetic retinas demonstrated increased expression of TRIB3 and level of p-AKT/p-mTOR axis but reduced level of IRS-1 protein. Therefore, a new non-primate model of DR with SWS cone and RGC dysfunction lays the foundation to better understand retinal pathophysiology at the molecular level and opens an avenue for improving the research on the treatment of human eye diseases.
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Affiliation(s)
- Oleg S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Priyamvada M Pitale
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Irina V Saltykova
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Iuliia B Dorofeeva
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Assylbek A Zhylkibayev
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mohammad Athar
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Preston A Fuchs
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Marina S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
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Deng X, Li Z, Zeng P, Wang J, Liang J, Lan Y. A Diagnostic Model for Screening Diabetic Retinopathy Using the Hand-Held Electroretinogram Device RETeval. Front Endocrinol (Lausanne) 2021; 12:632457. [PMID: 33912134 PMCID: PMC8074966 DOI: 10.3389/fendo.2021.632457] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/11/2021] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To construct a proper model to screen for diabetic retinopathy (DR) with the RETeval. METHOD This was a cross-sectional study. Two hundred thirty-two diabetic patients and seventy controls were recruited. The DR risk assessment protocol was performed to obtain subjects' DR risk score using the RETeval. Afterwards, the receiver operating characteristic (ROC) curve was used to determine the best cutoff for diagnosing DR. Random forest and decision tree models were constructed. RESULTS With increasing DR severity, the DR score gradually increased. When the DR score was used to diagnose DR, the ROC curve had an area under the curve of 0.881 (95% confidence interval: 0.836-0.927, P < 0.001), with a best cutoff value of 22.95, a sensitivity of 74.3% (95 CI: 66.0%~82.6%), and a specificity of 90.6% (95 CI: 83.7% ~94.8%). The top four risk factors selected by the random forest were used to construct the decision tree for diagnosing DR, which had a sensitivity of 93.3% (95% CI: 86.3%~97.0%) and a specificity of 80.3% (95% CI: 72.1% ~86.6%). CONCLUSIONS The DR risk assessment protocol combined with the decision tree model was innovatively used to evaluate the risk of DR, improving the sensitivity of diagnosis, which makes this method more suitable than the current protocol for DR screening.
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Affiliation(s)
- Xiaowen Deng
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zijing Li
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Peng Zeng
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jing Wang
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jiaqi Liang
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yuqing Lan
- Department of Ophthalmology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Yuqing Lan,
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Wroblewski JJ, McChancy C, Pickel K, Buterbaugh H, Wieland T, Gonzalez A. Reproducibility of Fixed-luminance and Multi-luminance Flicker Electroretinography in Patients With Diabetic Retinopathy Using an Office-based Testing Paradigm. J Diabetes Sci Technol 2020; 14:1095-1103. [PMID: 31640411 PMCID: PMC7645135 DOI: 10.1177/1932296819882719] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND We evaluated the reproducibility of office-based flicker electroretinography (ERG) in patients with nonproliferative diabetic retinopathy (NPDR). METHODS An observational study was conducted in which ultra-widefield fluorescein angiography (UWF-FA) was performed on 20 patients with mild-to-moderate NPDR; images were graded by the Fundus Photography Reading Center (Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA). Fixed- and multi-luminance flicker ERG was repeated four times (greater than or equal to seven days apart). Recording consistency was assessed using intra-class correlation coefficients (ICCs), coefficients of variation, and Pearson correlations. RESULTS 82.5% and 17.5% of eyes had mild and moderate NPDR using UWF-FA; 90% of the angiograms were given a high confidence grade. Fixed-luminance phase values were highly reproducible (ICC: 0.949; P < .001). There was a significant negative correlation between fixed-luminance phase and log-corrected ischemic index values (-0.426; P = .015). CONCLUSIONS Office-based, fixed-luminance phase values are highly reproducible and negatively correlate with retinal ischemia in NPDR, suggesting that global retinal dysfunction may be reliably quantified early in patients with diabetes.
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Affiliation(s)
- John J. Wroblewski
- Cumberland Valley Retina Consultants, Hagerstown, MD, USA
- John J. Wroblewski, MD, Cumberland Valley Retina Consultants, 1150 Opal Court, Hagerstown, MD 21740, USA.
| | | | | | | | - Tyler Wieland
- Cumberland Valley Retina Consultants, Hagerstown, MD, USA
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20
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Karson N, Smith J, Jones M, Datta A, Richdale K, Harrison WW. Functional retinal outcomes in patients with prediabetes and type 2 diabetes. Ophthalmic Physiol Opt 2020; 40:770-777. [PMID: 32955730 PMCID: PMC7606818 DOI: 10.1111/opo.12733] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/25/2020] [Indexed: 02/04/2023]
Abstract
PURPOSE Type 2 diabetes (T2DM) is a leading cause of visual impairment. Its precursor, prediabetes (preDM), is growing in numbers every year. While it is well known that T2DM causes changes in retinal function early in the disease process, it is likely that some of these changes emerge during the preDM stage. This study evaluates retinal function measures in patients with preDM to determine if there are differences in colour vision, contrast sensitivity (CS), and multifocal electroretinogram (mfERG) measures present before T2DM is diagnosed. METHODS The L'Anthony desaturated D-15 test, Mars Chart CS test, and mfERG were administered on the right eye of 43 participants; 15 controls (HbA1c ≤ 5.6%), 17 with preDM (HbA1c 5.7%-6.4%), and 11 with T2DM (either physician diagnosed or with untreated HbA1c ≥ 6.5%). HbA1c values were measured at the time of the other tests. Colour vision confusion scores (CVCS) were calculated from the D-15 using the method developed by Torok. Multivariate regression (which controlled for age differences) was used to evaluate the relationship of HbA1c and functional measures. Kruskal-Wallis tests were also used to evaluate differences between groups with post-hoc analysis. RESULTS CVCSs were significantly different between the three groups (p = 0.009). There was an association between higher CVCS and higher HbA1c values across all groups as well as specifically within the preDM group when controlling for age (R2 = 0.29, p = 0.01 and R2 = 0.39, p = 0.02 respectively). Multivariate regression of all of the functional tests together and HbA1c found only colour vision remained significant, indicating that the functional examination metrics may provide redundant data, with similar changes in prediabetes where colour vision may be the strongest indicator early in the process. CONCLUSIONS Patients with prediabetes have functional changes that can be measured in the retina before the diagnosis of diabetes, with the L'Anthony D-15 colour vision test providing the strongest association with glucose dysregulation in this population. This has important implications for follow up and screening for diabetes within optometric practices. Further studies are needed to follow these patients over time to see how and when these metrics change.
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Affiliation(s)
- Nicole Karson
- University of Houston College of Optometry, Houston, USA
| | | | - Morgan Jones
- University of Houston College of Optometry, Houston, USA
| | - Ananya Datta
- University of Houston College of Optometry, Houston, USA
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21
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Silverstein SM, Demmin DL, Schallek JB, Fradkin SI. Measures of Retinal Structure and Function as Biomarkers in Neurology and Psychiatry. Biomark Neuropsychiatry 2020. [DOI: 10.1016/j.bionps.2020.100018] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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22
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Silverstein SM, Fradkin SI, Demmin DL. Schizophrenia and the retina: Towards a 2020 perspective. Schizophr Res 2020; 219:84-94. [PMID: 31708400 PMCID: PMC7202990 DOI: 10.1016/j.schres.2019.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 09/28/2019] [Accepted: 09/30/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Differences between people with schizophrenia and psychiatrically healthy controls have been consistently demonstrated on measures of retinal function such as electroretinography (ERG), and measures of retinal structure such as optical coherence tomography (OCT). Since our 2015 review of this literature, multiple new studies have been published using these techniques. At the same time, the accumulation of data has highlighted the "fault lines" in these fields, suggesting methodological considerations that need greater attention in future studies. METHODS We reviewed studies of ERG and OCT in schizophrenia, as well as data from studies whose findings are relevant to interpreting these papers, such as those on effects of the following on ERG and OCT data: comorbid medical conditions that are over-represented in schizophrenia, smoking, antipsychotic medication, substance abuse, sex and gender, obesity, attention, motivation, and influences of brain activity on retinal function. RESULTS Recent ERG and OCT studies continue to support the hypothesis of retinal structural and functional abnormalities in schizophrenia, and suggest that these are relevant to understanding broader aspects of pathophysiology, neurodevelopment, and neurodegeneration in this disorder. However, there are differences in findings which suggest that the effects of multiple variables on ERG and OCT data need further clarification. CONCLUSIONS The retina, as the only component of the CNS that can be imaged directly in live humans, has potential to clarify important aspects of schizophrenia. With greater attention to specific methodological issues, the true potential of ERG and OCT as biomarkers for important clinical phenomena in schizophrenia should become apparent.
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Affiliation(s)
- Steven M Silverstein
- Rutgers University Behavioral Health Care, United States; Rutgers University, Robert Wood Johnson Medical School, Departments of Psychiatry and Ophthalmology, United States.
| | | | - Docia L Demmin
- Rutgers University, Department of Psychology, United States.
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23
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Dumpala S, Zele AJ, Feigl B. Outer Retinal Structure and Function Deficits Contribute to Circadian Disruption in Patients With Type 2 Diabetes. Invest Ophthalmol Vis Sci 2019; 60:1870-1878. [PMID: 31042793 DOI: 10.1167/iovs.18-26297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Light transmitted by retinal photoreceptors provides the input for circadian photoentrainment. In diabetes, there is a high prevalence of circadian and sleep disruption but the underlying causes are not well understood. Patients with diabetes can exhibit dysfunctional photoreceptors but their role in circadian health is not known. Here we quantify photoreceptor function and contributions to circadian health and sleep in patients with diabetes without diabetic retinopathy and healthy controls. Methods Rod, cone, and melanopsin function was derived using chromatic pupillometry in 47 participants including 23 patients with type 2 diabetes and 24 age-matched healthy controls after an ophthalmic examination including retinal thickness assessment using optical coherence tomography. Circadian health was determined using dim light melatonin onset (DLMO) and sleep questionnaires; light exposure was measured using actigraphy. Results Compared with the control group, the patients with diabetes had a significantly earlier DLMO (1 hour) (P = 0.008), higher subjective sleep scores (P < 0.05), a reduction in pupil constriction amplitude for red stimuli (P = 0.039) and for the early postillumination pupil response (PIPR) for blue (P = 0.024) stimuli. There were no between-group differences in the light exposure pattern, activity levels, and intrinsic melanopsin-mediated PIPR amplitude (P > 0.05). A significant correlation was evident between outer retinal thickness and DLMO (r = -0.65, P = 0.03) and the pupil constriction amplitude (r = 0.63, P = 0.03); patients with thinner retina had earlier DLMO and lower pupil amplitudes. Conclusions We infer that the observed changes in circadian function in patients with no diabetic retinopathy are due to structural and functional outer retinal rod photoreceptor deficits at early stage of diabetic eye disease.
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Affiliation(s)
- Sunila Dumpala
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Optometry and Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - Andrew J Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Optometry and Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,Queensland Eye Institute, Brisbane, Australia
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Bahr HI, Abdelghany AA, Galhom RA, Barakat BM, Arafa ESA, Fawzy MS. Duloxetine protects against experimental diabetic retinopathy in mice through retinal GFAP downregulation and modulation of neurotrophic factors. Exp Eye Res 2019; 186:107742. [PMID: 31344388 DOI: 10.1016/j.exer.2019.107742] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 12/23/2022]
Abstract
Diabetic retinopathy (DR) is recognized as one of the leading causes of blindness worldwide. Searching and validation for a novel therapeutic strategy to prevent its progress are promising. This work aimed to assess the retinal protective effects of duloxetine (DLX) in Alloxan-induced diabetic mice model. Animals were equally and randomly divided to four groups (eight mice per group); group 1: is the control group, 2: diabetic group, 3&4: diabetic and after 9 weeks received DLX for 4 weeks (15 mg/kg and 30 mg/kg), respectively. Quantitative real-time PCR (qPCR) analysis revealed nerve growth factor (NGF), inducible nitric oxide synthase (iNOS) and transforming growth factor beta (TGF-β) genes upregulation in the diabetic group compared to controls. Also, increased retinal malondialdehyde (MDA) and the decline of reduced glutathione (GSH) levels were observed. The morphometric analysis of diabetic retina revealed a significant reduction in total retinal thickness compared to control. Diabetic retinal immunostaining and Western blot analyses displayed glial fibrillary acidic protein (GFAP) and vascular endothelial cell growth factor (VEGF) proteins expression upregulation as well as glucose transporter-1 (GLUT-1) downregulation comparing to controls. However, DLX-treated groups showed downregulated NGF, iNOS, and TGF-β that was more obviously seen in the DLX-30 mg/kg group than DLX-15 mg/kg group. Furthermore, these groups showed amelioration of the oxidative markers; MDA and GSH, retaining the total retinal thickness nearly to control, GFAP and VEGF downregulation, and GLUT-1 upregulation compared to diabetic group. Taken together, it could be summarized that duloxetine can attenuate DR via the anti-inflammatory and the anti-oxidative properties as well as modulating the angiogenic and the neurotrophic factors expressions. This could hopefully pave the road to be included in the novel list of the therapeutic regimen for DR after validation in the clinic.
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Affiliation(s)
- Hoda I Bahr
- Department of Biochemistry, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Ahmed A Abdelghany
- Department of Ophthalmology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Rania A Galhom
- Department of Human Anatomy and Embryology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Bassant M Barakat
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt; Department of Clinical Pharmacy, College of Clinical Pharmacy, Al-Baha University, Al-Baha, Saudi Arabia.
| | - El-Shaimaa A Arafa
- Department of Clinical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman, 346, United Arab Emirates; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, 62514, Egypt.
| | - Manal S Fawzy
- Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia; Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
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Allen RS, Feola A, Motz CT, Ottensmeyer AL, Chesler KC, Dunn R, Thulé PM, Pardue MT. Retinal Deficits Precede Cognitive and Motor Deficits in a Rat Model of Type II Diabetes. Invest Ophthalmol Vis Sci 2019; 60:123-133. [PMID: 30640976 DOI: 10.1167/iovs.18-25110] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the temporal appearance of retinal, cognitive, and motor deficits in Goto-Kakizaki (GK) rats, a spontaneously occurring, polygenic model of type II diabetes. GK rats develop impaired insulin secretion at 2 weeks and fasting hyperglycemia at 4 weeks. Methods In male and female GK rats and Wistar controls, glucose tolerance test (hyperglycemia) and electroretinogram (ERG, retinal function) were performed at 4 and 8 weeks of age. Spectral domain-optical coherence tomography (retinal structure) was assessed at 6 weeks. Spatial alternation (cognitive function) and number of entries (exploratory behavior) were assessed via Y-maze at 4, 5, 6, 7, and 8 weeks. Rotarod (motor function) was performed at 4, 6, and 8 weeks. Results By 4 weeks, the GK rats exhibited significant glucose intolerance (P < 0.001) and retinal deficits, including delays in ERG implicit times (flicker, P < 0.01; oscillatory potentials, P < 0.001). In addition, the GK rats showed greater ERG amplitudes (P < 0.001) and thinner retinas (P < 0.001). At 7 weeks, the GK rats showed deficits in cognitive function (P < 0.001) and exploratory behavior (P < 0.01). However, no motor function deficits were observed by 8 weeks. Interestingly, the male GK rats showed greater hyperglycemia (P < 0.05), but the female rats showed greater ERG delays (P < 0.001). Conclusions In GK rats, retinal function deficits developed prior to cognitive or motor deficits. Future studies will investigate common mechanistic links, long-term functional and vascular changes, and whether early retinal deficits can predict cognitive dysfunction or late-stage retinal disease.
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Affiliation(s)
- Rachael S Allen
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Andrew Feola
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Cara T Motz
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States
| | - Amy L Ottensmeyer
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Kyle C Chesler
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Ryan Dunn
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Peter M Thulé
- Section Endocrinology & Metabolism, Atlanta VA Health Care System & Emory University School of Medicine, Decatur, Georgia, United States
| | - Machelle T Pardue
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
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Lim RR, Grant DG, Olver TD, Padilla J, Czajkowski AM, Schnurbusch TR, Mohan RR, Hainsworth DP, Walters EM, Chaurasia SS. Young Ossabaw Pigs Fed a Western Diet Exhibit Early Signs of Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2019; 59:2325-2338. [PMID: 29847637 PMCID: PMC5937800 DOI: 10.1167/iovs.17-23616] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Purpose Recent clinical data suggest an increasing prevalence of obesity and type 2 diabetes in adolescents, placing them at high risk of developing diabetic retinopathy during adult working years. The present study was designed to characterize the early retinal and microvascular alterations in young Ossabaw pigs fed a Western diet, described as a model of metabolic syndrome genetically predisposed to type 2 diabetes. Methods Four-month-old Ossabaw miniature pigs were divided into two groups, lean and diet-induced obesity. Obese pigs were fed a Western diet with high-fat/high-fructose corn syrup/high-choleric content for 10 weeks. Blood and retina were collected for biochemical profiling, trypsin digest, flatmounts, Fluoro-Jade C staining, electron microscopy, quantitative PCR, immunohistochemistry, and Western blots. Results Young Ossabaw pigs had elevated fasting blood glucose after feeding on a Western diet for 10 weeks. Their retina showed disrupted cellular architecture across neural layers, with numerous large vacuoles seen in cell bodies of the inner nuclear layer. Microvessels in the obese animals exhibited thickened basement membrane, along with pericyte ghosts and acellular capillaries. The pericyte to endothelial ratio decreased significantly. Retina flatmounts from obese pigs displayed reduced capillary density, numerous terminal capillary loops, and string vessels, which stained collagen IV but not isolectin IB4. Quantitative PCR and Western blots showed significantly high levels of basement membrane proteins collagen IV and fibronectin in obese pigs. Conclusions This is the first study to describe the ultrastructural neuronal and vascular changes in the retina of young Ossabaw pigs fed a Western diet, simulating early signs of diabetic retinopathy pathogenesis.
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Affiliation(s)
- Rayne R Lim
- Ocular Immunology and Angiogenesis Lab, Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, Missouri, United States.,Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States.,Harry S. Truman Memorial Veteran Hospital, Columbia, Missouri, United States
| | - DeAna G Grant
- Electron Microscopy Core, University of Missouri, Columbia, Missouri, United States
| | - T Dylan Olver
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States
| | - Jaume Padilla
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States.,Child Health, University of Missouri, Columbia, Missouri, United States
| | - Alana M Czajkowski
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, United States
| | - Teagan R Schnurbusch
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, United States
| | - Rajiv R Mohan
- Ocular Immunology and Angiogenesis Lab, Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, Missouri, United States.,Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States.,Harry S. Truman Memorial Veteran Hospital, Columbia, Missouri, United States.,Mason Eye Institute, University of Missouri, Columbia, Missouri, United States
| | - Dean P Hainsworth
- Mason Eye Institute, University of Missouri, Columbia, Missouri, United States
| | - Eric M Walters
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, United States
| | - Shyam S Chaurasia
- Ocular Immunology and Angiogenesis Lab, Department of Veterinary Medicine & Surgery, University of Missouri, Columbia, Missouri, United States.,Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States.,Harry S. Truman Memorial Veteran Hospital, Columbia, Missouri, United States
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Role of a mydriasis-free, full-field flicker ERG device in the detection of diabetic retinopathy. Doc Ophthalmol 2018; 137:131-141. [PMID: 30334119 DOI: 10.1007/s10633-018-9656-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/02/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To determine if the RETeval system can be used for the screening of diabetic retinopathy (DR) to provide early diagnosis. METHODS The subjects were 42 diabetic patients selectively recruited by examination of their medical records to have varying severities of DR. The severity of DR was classified into four groups according to the International Clinical Diabetic Retinopathy Disease Severity Scale. Full-field electroretinograms (ERG) without mydriasis were obtained by the DR assessment protocol of the RETeval system. Macular retinal nerve fiber layer (RNFL) thickness was measured by optical coherence tomography. We compared the DR assessment protocol results and the macular RNFL thickness among four groups. Moreover, an analysis was conducted on whether there was any correlation among the DR assessment protocol results, duration of diabetes mellitus, and RNFL thickness individually for each group of patients. RESULTS The mean ages and mean duration of diabetes mellitus of the four groups were similar. The DR assessment protocol results in the moderate-severe nonproliferative DR, and proliferative DR groups were significantly higher than those in the other groups (p < 0.001). The mean macular RNFL thickness was similar in all groups. No significant correlation was found between the DR assessment protocol results and duration of DM and the RNFL thickness. CONCLUSIONS Our results suggest that the RETeval full-field ERG system can be used as an adjunctive tool for the mass screening of DR, while macular RNFL thickness would not be useful.
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The Role of Microglia in Diabetic Retinopathy: Inflammation, Microvasculature Defects and Neurodegeneration. Int J Mol Sci 2018; 19:ijms19010110. [PMID: 29301251 PMCID: PMC5796059 DOI: 10.3390/ijms19010110] [Citation(s) in RCA: 240] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/23/2017] [Accepted: 12/25/2017] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy is a common complication of diabetes mellitus, which appears in one third of all diabetic patients and is a prominent cause of vision loss. First discovered as a microvascular disease, intensive research in the field identified inflammation and neurodegeneration to be part of diabetic retinopathy. Microglia, the resident monocytes of the retina, are activated due to a complex interplay between the different cell types of the retina and diverse pathological pathways. The trigger for developing diabetic retinopathy is diabetes-induced hyperglycemia, accompanied by leukostasis and vascular leakages. Transcriptional changes in activated microglia, mediated via the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) and extracellular signal–regulated kinase (ERK) signaling pathways, results in release of various pro-inflammatory mediators, including cytokines, chemokines, caspases and glutamate. Activated microglia additionally increased proliferation and migration. Among other consequences, these changes in microglia severely affected retinal neurons, causing increased apoptosis and subsequent thinning of the nerve fiber layer, resulting in visual loss. New potential therapeutics need to interfere with these diabetic complications even before changes in the retina are diagnosed, to prevent neuronal apoptosis and blindness in patients.
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Zorrilla-Zubilete MA, Yeste A, Quintana FJ, Toiber D, Mostoslavsky R, Silberman DM. Epigenetic control of early neurodegenerative events in diabetic retinopathy by the histone deacetylase SIRT6. J Neurochem 2017; 144:128-138. [DOI: 10.1111/jnc.14243] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 10/06/2017] [Accepted: 10/09/2017] [Indexed: 01/03/2023]
Affiliation(s)
- María A. Zorrilla-Zubilete
- Centro de Estudios Farmacológicos y Botánicos (CEFYBO-CONICET); 1ª Cátedra de Farmacología; Facultad de Medicina; UBA; Buenos Aires Argentina
| | - Ada Yeste
- Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts USA
| | - Francisco J. Quintana
- Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts USA
- Broad Institute of MIT and Harvard; Cambridge Massachusetts USA
| | - Debra Toiber
- Department of Life Sciences; The Zlotowski Center for Neuroscience; Ben-Gurion University of the Negev; Beer-Sheva Israel
| | - Raul Mostoslavsky
- The Massachusetts General Hospital Cancer Center; Harvard Medical School; Boston Massachusetts USA
- Broad Institute of MIT and Harvard; Cambridge Massachusetts USA
| | - Dafne M. Silberman
- Centro de Estudios Farmacológicos y Botánicos (CEFYBO-CONICET); 1ª Cátedra de Farmacología; Facultad de Medicina; UBA; Buenos Aires Argentina
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Tyrberg M, Nyström L, Arnqvist HJ, Bolinder J, Gudbjörnsdottir S, Landin-Olsson M, Eriksson JW, Svensson MK. Overweight, hyperglycemia and tobacco use are modifiable risk factors for onset of retinopathy 9 and 17years after the diagnosis of diabetes - A retrospective observational nation-wide cohort study. Diabetes Res Clin Pract 2017; 133:21-29. [PMID: 28888147 DOI: 10.1016/j.diabres.2017.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/24/2017] [Accepted: 08/14/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND The aims of this study were to estimate the risk for diabetic retinopathy (DR) and to identify risk factors. We investigated a nationwide population-based cohort with diabetes diagnosed at age 15-34years. PATIENTS AND METHODS Of 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) 444 (56%) patients with retinal photos available for classification of retinopathy participated in a follow-up study 15-19 (median 17) years after diagnosis. Mean age was 42.3±5.7years, BMI 26.1±4.1kg/m2, 62% were male and 91% had type 1 diabetes. A sub-study was performed in 367 patients with retinal photos from both the 9 and 17year follow up and the risk for development of retinopathy between 9 and 17years of follow up was calculated. RESULTS After median 17years 324/444 (73%, 67% of T1D and 71% of T2D), had developed any DR but only 5.4% proliferative DR. Male sex increased the risk of developing retinopathy (OR 1.9, 95% CI 1.2-2.9). In the sub-study obesity (OR 1.2, 95% CI 1.04-1.4), hyperglycemia (OR 2.5, 95% CI 1.6-3.8) and tobacco use (OR 2.9, 95% CI 1.1-7.3) predicted onset of retinopathy between 9 and 17years after diagnosis of diabetes. CONCLUSION The number of patients with severe retinopathy after 17years of diabetes disease was small. The risk of developing retinopathy with onset between 9 and 17years after diagnosis of diabetes was strongly associated to modifiable risk factors such as glycemic control, obesity and tobacco use.
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Affiliation(s)
- M Tyrberg
- Department of Ophthalmology, Helsingborg Hospital, Lund University, Helsingborg, Sweden
| | - L Nyström
- Department of Public Health and Clinical Medicine, Epidemiology, Umeå University, Umeå, Sweden
| | - H J Arnqvist
- Department of Endocrinology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - J Bolinder
- Department of Endocrinology, Metabolism, and Diabetes, Karolinska University Hospital Huddinge, Karolinska Institutet, Sweden
| | - S Gudbjörnsdottir
- Department of Medicine, Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden
| | - M Landin-Olsson
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - J W Eriksson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - M K Svensson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
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Moschos MM, Dettoraki M, Tsatsos M, Kitsos G, Kalogeropoulos C. Effect of carotenoids dietary supplementation on macular function in diabetic patients. EYE AND VISION 2017; 4:23. [PMID: 29046877 PMCID: PMC5641400 DOI: 10.1186/s40662-017-0088-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/29/2017] [Indexed: 01/25/2023]
Abstract
Background Diabetic retinopathy is a major cause of visual impairment and blindness among working-age people worldwide. The aim of our study was to investigate the effects of a carotenoid supplementation on retinal thickness and macular function of patients with diabetes using optical coherence tomography (OCT) and multifocal electroretinography (mfERG). Methods A retrospective study of one hundred and twenty eyes of sixty patients age between 40 and 60 years with non-insulin dependent type 2 diabetes mellitus without diabetic retinopathy who underwent OCT and mfERG and took vitamin supplements for a period of two years. Patients received a carotenoid supplement containing lutein (10 mg), zeaxanthin (2 mg) and meso-zeaxanthin (10 mg) once a day for two years. The thickness of the fovea was evaluated using OCT and the macular function was tested by mfERG. Results OCT showed an increase in the central foveal thickness and mfERG revealed increased retinal response density within the central 13° surrounding the fovea (rings 1 to 3) at two years after the onset of carotenoids supplement intake. Conclusion The use of carotenoid supplements may be of benefit for improving visual function of type 2 diabetes patients. However, further study is needed to assess the treatment’s long-term efficacy.
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Affiliation(s)
- Marilita M Moschos
- First Department of Ophthalmology, Medical School, National and Kapodistrian University of Athens, 6 Ikarias street, Ekali, 14578 Athens, Greece
| | - Maria Dettoraki
- First Department of Ophthalmology, Medical School, National and Kapodistrian University of Athens, 6 Ikarias street, Ekali, 14578 Athens, Greece
| | - Michael Tsatsos
- Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - George Kitsos
- Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece
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Sawides L, Sapoznik KA, de Castro A, Walker BR, Gast TJ, Elsner AE, Burns SA. Alterations to the Foveal Cone Mosaic of Diabetic Patients. Invest Ophthalmol Vis Sci 2017; 58:3395-3403. [PMID: 28687853 PMCID: PMC5501497 DOI: 10.1167/iovs.17-21793] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Purpose We measured localized changes occurring in the foveal cone photoreceptors and related defects in the cone mosaic to alterations in the nearby retinal vasculature. Methods The central 4° of the retina of 54 diabetic (53.7 ± 12.5 years) and 85 control (35.8 ± 15.2 years) participants were imaged with the Indiana adaptive optics scanning laser ophthalmoscope. Foveal cones and overlying retinal capillaries were imaged and infrared scanning laser ophthalmoscopy (IR SLO) images and optical coherence tomography (OCT) B-scans were obtained. Follow-up imaging sessions were performed with intervals from 4 to 50 months for 22 of the 54 diabetic participants. Results The foveal cone mosaics of 49 of 54 diabetic participants were of sufficient quality to assess the absence or presence of small localized defects in the cone mosaic. In 13 of these 49 diabetic participants we found localized defects, visualized as sharp-edged areas of cones with diminished reflectivity. These small, localized areas ranged in size from 10 × 10 μm to 75 × 30 μm. Of these 13 participants with cone defects, 11 were imaged over periods from 4 to 50 months and the defects remained relatively stable. These dark regions were not shadows of overlying retinal vessels, but all participants with these localized defects had alterations in the juxtafoveal capillary network. Conclusions The foveal cone mosaic can show localized areas of dark cones that persist over time, that apparently correspond to either missing or nonreflecting cones, and may be related to local retinal ischemia.
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Affiliation(s)
- Lucie Sawides
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Kaitlyn A Sapoznik
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Alberto de Castro
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Brittany R Walker
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Thomas J Gast
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Ann E Elsner
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Stephen A Burns
- School of Optometry, Indiana University, Bloomington, Indiana, United States
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Al-Otaibi H, Al-Otaibi MD, Khandekar R, Souru C, Al-Abdullah AA, Al-Dhibi H, Stone DU, Kozak I. Validity, Usefulness and Cost of RET eval System for Diabetic Retinopathy Screening. Transl Vis Sci Technol 2017; 6:3. [PMID: 28516001 PMCID: PMC5433802 DOI: 10.1167/tvst.6.3.3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/07/2017] [Indexed: 12/15/2022] Open
Abstract
Purpose We studied the validity, usefulness, and relative cost to detect diabetic retinopathy (DR) and sight-threatening DR (STDR) by using a hand-held electrophysiologic tool compared to digital fundus photography. Method Patients with diabetes attending the screening unit of King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia were evaluated by “RETeval”, Amsler grid, and digital dilated fundus photography. Fundus images were evaluated by a retina specialist to determine grade of DR. The sensitivity and specificity of STDR and DR screening compared to photography were calculated, as well as “RETeval” combined with Amsler grid testing. The area under the curve (AUC) of “RETeval” screening outcome was calculated. Result We analyzed data of 400 diabetic patients. The prevalence of DR of any grade was 48.8% (95% confidence interval [CI], 43.9–53.7) while the prevalence of STDR was 27% (95% CI, 22.6–31.4). The outcome of RETeval test was “fail” (based on 20 μV or more amplitude of electrophysiologic spikes) in 351 (87.8%; 95% CI, 84.5–91.0) eyes. The sensitivity of the device was 95.4% and the specificity was 17.5%. Thus, the sensitivity of sequential testing with RETeval and Amsler grid test was 30.1% and the specificity was 80.1%. The AUCs for STDR and DR in general were 76.6% and 50.6%, respectively. Conclusions “RETeval” is a rapid screening device with excellent sensitivity for detecting STDR. It has potential as a first level screening tool to detect patients who require further evaluation. Translational Relevance Retinal function, such as electrophysiology, can be used as a new concept for screening for DR.
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Affiliation(s)
- Humoud Al-Otaibi
- King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | | | | | - Ches Souru
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | | | | | - Donald U Stone
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,The Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Igor Kozak
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Moorfields Eye Hospital Centre, Abu Dhabi, UAE
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Iwona BS. Growth Factors in the Pathogenesis of Retinal Neurodegeneration in Diabetes Mellitus. Curr Neuropharmacol 2017; 14:792-804. [PMID: 27528260 PMCID: PMC5333593 DOI: 10.2174/1570159x14666160813182009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/12/2015] [Accepted: 01/06/2015] [Indexed: 12/13/2022] Open
Abstract
Neurodegeneration is an initial process in the development of diabetic retinopathy (DR). High quantities of glutamate, oxidative stress, induction of the renin-angiotensin system (RAS) and elevated levels of RAGE are crucial elements in the retinal neurodegeneration caused by diabetes mellitus. At least, there is emerging proof to indicate that the equilibrium between the neurotoxic and neuroprotective components will affect the state of the retinal neurons. Somatostatin (SST), pigment epithelium-derived factor (PEDF), and erythropoietin (Epo) are endogenous neuroprotective peptides that are decreased in the eye of diabetic persons and play an essential role in retinal homeostasis. On the other hand, insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) are pivotal proteins which participate in the development of new capillaries and finally cause damage to the retinal neurons. During recent years, our knowledge about the function of growth factors in the pathogenesis of retinal neurodegeneration has increased. However, intensive investigations are needed to clarify the basic processes that contribute to retinal neurodegeneration and its association with damage to the capillary blood vessels. The objective of this review article is to show new insights on the role of neurotransmitters and growth factors in the pathogenesis of diabetic retinopathy. The information contained in this manuscript may provide the basis for novel strategies based on the factors of neurodegeneration to diagnose, prevent and treat DR in its earliest phases.
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Affiliation(s)
- Ben-Skowronek Iwona
- Department Pediatric Endocrinology and Diabetology, Medical University of Lublin, ul. Prof. A. Gebali 6, 20-093 Lublin, Poland
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Maa AY, Feuer WJ, Davis CQ, Pillow EK, Brown TD, Caywood RM, Chasan JE, Fransen SR. A novel device for accurate and efficient testing for vision-threatening diabetic retinopathy. J Diabetes Complications 2016; 30:524-32. [PMID: 26803474 PMCID: PMC4853922 DOI: 10.1016/j.jdiacomp.2015.12.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/30/2015] [Accepted: 12/01/2015] [Indexed: 10/22/2022]
Abstract
AIMS To evaluate the performance of the RETeval device, a handheld instrument using flicker electroretinography (ERG) and pupillography on undilated subjects with diabetes, to detect vision-threatening diabetic retinopathy (VTDR). METHODS Performance was measured using a cross-sectional, single armed, non-interventional, multi-site study with Early Treatment Diabetic Retinopathy Study 7-standard field, stereo, color fundus photography as the gold standard. The 468 subjects were randomized to a calibration phase (80%), whose ERG and pupillary waveforms were used to formulate an equation correlating with the presence of VTDR, and a validation phase (20%), used to independently validate that equation. The primary outcome was the prevalence-corrected area under the receiver operating characteristic (ROC) curve for the detection of VTDR. RESULTS The area under the ROC curve was 0.86 for VTDR. With a sensitivity of 83%, the specificity was 78% and the negative predictive value was 99%. The average testing time was 2.3 min. CONCLUSIONS With a VTDR prevalence similar to that in the U.S., the RETeval device will identify about 75% of the population as not having VTDR with 99% accuracy. The device is simple to use, does not require pupil dilation, and has a short testing time.
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Affiliation(s)
- April Y Maa
- Atlanta VA Medical Center, Ophthalmology, 1670 Clairmont Road MC 112E, Decatur, GA, 30033, USA; Emory University School of Medicine, Emory Eye Center, Comprehensive Ophthalmology, 1365B Clifton Road NE, Atlanta, GA, 30322, USA.
| | - William J Feuer
- University of Miami Miller School of Medicine, Biostatistics, Dominion Tower, Box C210, 1400 NW 10th Avenue, Suite 506, Miami, FL, 33136, USA; Bascom Palmer Eye Institute, 900 NW 17th Street, Miami, FL, 33136, USA.
| | - C Quentin Davis
- LKC Technologies, Inc., 2 Professional Drive, Suite 222, Gaithersburg, MD, 20879, USA.
| | - Ensa K Pillow
- Oklahoma City VA Medical Center, Ophthalmology, 921 NE 13th Street, Oklahoma City, OK 73104, USA; University of Oklahoma College of Medicine, Ophthalmology, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA; Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA.
| | - Tara D Brown
- Oklahoma City VA Medical Center, Ophthalmology, 921 NE 13th Street, Oklahoma City, OK 73104, USA.
| | - Rachel M Caywood
- Oklahoma City VA Medical Center, Ophthalmology, 921 NE 13th Street, Oklahoma City, OK 73104, USA.
| | - Joel E Chasan
- Emory University School of Medicine, Emory Eye Center, Comprehensive Ophthalmology, 1365B Clifton Road NE, Atlanta, GA, 30322, USA.
| | - Stephen R Fransen
- University of Oklahoma College of Medicine, Ophthalmology, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA; Dean McGee Eye Institute, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA; Inoveon Corporation, 800 Research Parkway, Suite 370, Oklahoma City, OK, 73104, USA.
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Hernández C, Dal Monte M, Simó R, Casini G. Neuroprotection as a Therapeutic Target for Diabetic Retinopathy. J Diabetes Res 2016; 2016:9508541. [PMID: 27123463 PMCID: PMC4830713 DOI: 10.1155/2016/9508541] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/29/2016] [Accepted: 03/16/2016] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy (DR) is a multifactorial progressive disease of the retina and a leading cause of vision loss. DR has long been regarded as a vascular disorder, although neuronal death and visual impairment appear before vascular lesions, suggesting an important role played by neurodegeneration in DR and the appropriateness of neuroprotective strategies. Upregulation of vascular endothelial growth factor (VEGF), the main target of current therapies, is likely to be one of the first responses to retinal hyperglycemic stress and VEGF may represent an important survival factor in early phases of DR. Of central importance for clinical trials is the detection of retinal neurodegeneration in the clinical setting, and spectral domain optical coherence tomography seems the most indicated technique. Many substances have been tested in animal studies for their neuroprotective properties and for possible use in humans. Perhaps, the most intriguing perspective is the use of endogenous neuroprotective substances or nutraceuticals. Together, the data point to the central role of neurodegeneration in the pathogenesis of DR and indicate neuroprotection as an effective strategy for treating this disease. However, clinical trials to determine not only the effectiveness and safety but also the compliance of a noninvasive route of drug administration are needed.
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Affiliation(s)
- Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
- *Cristina Hernández: and
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Via San Zeno 31, 56127 Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Giovanni Casini
- Department of Biology, University of Pisa, Via San Zeno 31, 56127 Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
- *Giovanni Casini:
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Yu Y, Chen H, Su SB. Neuroinflammatory responses in diabetic retinopathy. J Neuroinflammation 2015; 12:141. [PMID: 26245868 PMCID: PMC4527131 DOI: 10.1186/s12974-015-0368-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/27/2015] [Indexed: 01/14/2023] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes and has been recognized as a vascular dysfunction leading to blindness in working-age adults. It becomes increasingly clear that neural cells in retina play an important role in the pathogenesis of DR. Neural retina located at the back of the eye is part of the brain and a representative of the central nervous system. The neurosensory deficits seen in DR are related to inflammation and occur prior to the clinically identifiable vascular complications. The neural deficits are associated with abnormal reactions of retina glial cells and neurons in response to hyperglycemia. Improper activation of the innate immune system may also be an important contributor to the pathophysiology of DR. Therefore, DR manifests characteristics of both vasculopathy and chronic neuroinflammatory diseases. In this article, we attempt to provide an overview of the current understanding of inflammation in neural retina abnormalities in diabetes. Inhibition of neuroinflammation may represent a novel therapeutic strategy to the prevention of the progression of DR.
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Affiliation(s)
- Ying Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 S Xianlie Road, Guangzhou, 510060, China.
| | - Hui Chen
- Eye Institute, Affiliated Hospital of Nantong University, Nantong, 226001, China.
| | - Shao Bo Su
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 S Xianlie Road, Guangzhou, 510060, China.
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Klefter ON, Holfort SK, Larsen M. Baseline haemoglobin A1c influences retinal function after long-term insulin pump therapy. Graefes Arch Clin Exp Ophthalmol 2015; 254:467-73. [PMID: 26108526 DOI: 10.1007/s00417-015-3083-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 05/14/2015] [Accepted: 06/03/2015] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The purpose of the study was to characterize the long-term effect of insulin pump therapy (CSII) on electroretinography and dark adaptometry and to examine the influence of baseline glycaemic control on retinal function in patients with type 1 diabetes mellitus. METHODS This prospective observational extension study enrolled 13 patients out of 17 who completed a primary 1-year study of the effect of CSII on retinal function. Twelve patients were still on CSII at follow-up. The extension study included a single examination 3.5 years (range 3.0-4.0 years) after initiation of CSII of one study eye per patient. Procedures included full-field electroretinography (ERG), dark adaptometry, optical coherence tomography, and fundus photography. RESULTS Mean ERG amplitudes 3.5 years after initiation of CSII were 15-43 % lower than at baseline (all p < 0.05) and 21-45 % lower than after 1 year on CSII. The mean rate of dark adaptation had returned to baseline after a transient 13 % (p = 0.0024) acceleration at the 1-year visit. Reduction of ERG amplitudes between 1 and 3.5 years was statistically associated predominantly with baseline haemoglobin A1c (HbA1c) ≥ 8.7 % and, to a smaller extent, with HbA1c reductions larger than 1.9 % after initiation of CSII. No significant changes in ERG amplitudes were found in patients with baseline HbA1c < 8.7 % and HbA1c reductions smaller than 1.9 %. CONCLUSIONS Deterioration of subclinical retinal function from 1 to 3.5 years after initiation of CSII was associated predominantly with poorer metabolic control before initiation of CSII. Analyses of retinal function may supplement structural and morphological characteristics in the study of diabetic complications.
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Affiliation(s)
- Oliver N Klefter
- Department of Ophthalmology, Glostrup Hospital, Ndr. Ringvej 57, DK-2600, Glostrup, Denmark.
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Stig K Holfort
- Department of Ophthalmology, Glostrup Hospital, Ndr. Ringvej 57, DK-2600, Glostrup, Denmark
| | - Michael Larsen
- Department of Ophthalmology, Glostrup Hospital, Ndr. Ringvej 57, DK-2600, Glostrup, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zhu T, Ma J, Li Y, Zhang Z. Association between retinal neuronal degeneration and visual function impairment in type 2 diabetic patients without diabetic retinopathy. SCIENCE CHINA-LIFE SCIENCES 2015; 58:550-5. [PMID: 25951931 DOI: 10.1007/s11427-015-4858-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 03/08/2015] [Indexed: 11/30/2022]
Abstract
The changes in retinal thickness and visual function in type 2 diabetic patients without clinical evidence of diabetic retinopathy were evaluated. A total of 141 diabetic subjects without retinopathy and 158 healthy subjects were enrolled in this study. Superior macular ganglion cell complex thicknesses were significantly decreased in diabetic cases, and no significant peripapillary retinal nerve fiber layer thickness changes were observed. The contrast sensitivities at all space frequencies were significantly different between diabetic patients and controls. The mean P50 amplitude from pattern electroretinogram results was reduced significantly in the diabetic group. In the diabetic group, average superior ganglion cell complex thicknesses positively correlated with both contrast sensitivities at high spatial frequencies and P50 amplitudes. The results indicated that ganglion cell complex thickness and visual function changes could be observed in diabetic subjects before the onset of any significant diabetic retinopathy. Macular ganglion cell complex reduction occurred much earlier than peripapillary retinal nerve fiber layer thinning in diabetic patients without retinopathy.
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Affiliation(s)
- TiePei Zhu
- Eye Hospital of Wenzhou Medical University, Hangzhou, 310020, China
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Simó R, Hernández C. Novel approaches for treating diabetic retinopathy based on recent pathogenic evidence. Prog Retin Eye Res 2015; 48:160-80. [PMID: 25936649 DOI: 10.1016/j.preteyeres.2015.04.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/13/2015] [Accepted: 04/21/2015] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy remains as a leading cause of blindness in developed countries. Current treatments target late stages of DR when vision has already been significantly affected. A better understanding of the pathogenesis of DR would permit the development of more efficient preventional/interventional strategies against early stages of DR. In this article a critical review of the state of the art of this issue is provided along with a discussion of problems which have yet to be overcome. Neuroprotection as a new approach for the treatment of the early stages of DR has been particularly emphasized. The development and progression of DR is not homogeneous and, apart from blood glucose levels and blood pressure, it depends on genetic factors which remain to be elucidated. In addition, the role of the pathogenic pathways is not the same in all patients. All these factors should be taken into account in the near future when an individualized oriented treatment for DR could become feasible. The new techniques in retinal imaging acquisition, the identification of useful circulating biomarkers and the individualized analysis of biological samples could facilitate the development of early and personalized therapy in the setting of DR. Finally, it should be noted that only a coordinated action among ophthalmologists, diabetologists, basic researchers, experts in pharmaco-economics and health care providers addressed to the design of rational strategies targeting prevention and the early stages of DR will be effective in reducing the burden and improving the clinical outcome of this devastating complication of diabetes.
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Affiliation(s)
- Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| | - Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
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Abstract
Although photoreceptors account for most of the mass and metabolic activity of the retina, their role in the pathogenesis of diabetic retinopathy has been largely overlooked. Recent studies suggest that photoreceptors might play a critical role in the diabetes-induced degeneration of retinal capillaries, and thus can no longer be ignored. The present review summarizes diabetes-induced alterations in photoreceptor structure and function, and provides a rationale for further study of a role of photoreceptors in the pathogenesis of the retinopathy.
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Affiliation(s)
- Timothy S Kern
- Case Western Reserve University, Department of Medicine and Center for Diabetes Research Cleveland, Ohio, USA ; Veterans Administration Medical Center Research Service 151 Cleveland, Ohio, USA
| | - Bruce A Berkowitz
- Wayne State University School of Medicine, Departments of Anatomy and Cell Biology and Ophthalmology Detroit, Michigan, USA
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Pardue MT, Barnes CS, Kim MK, Aung MH, Amarnath R, Olson DE, Thulé PM. Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes. Transl Vis Sci Technol 2014; 3:6. [PMID: 24959388 DOI: 10.1167/tvst.3.3.6] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/28/2014] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To evaluate the utility of low luminance stimuli to functionally probe inner retinal rod pathways in the context of diabetes mellitus in both rat and human subjects. METHODS Inner retinal dysfunction was assessed using oscillatory potential (OP) delays in diabetic rats. Scotopic electroretinograms (ERGs) in response to a series of increasing flash luminances were recorded from streptozotocin (STZ)-treated and control Sprague-Dawley rats after 7, 14, 20, and 29 weeks of hyperglycemia. We then evaluated OP delays in human diabetic subjects with (DR) and without (DM) diabetic retinopathy using the International Society for Clinical Electrophysiology in Vision (ISCEV) standard scotopic protocol and two additional dim test flashes. RESULTS Beginning 7 weeks after STZ, OP implicit times in diabetic rats were progressively delayed in response to dim, but not bright stimuli. In many diabetic subjects the standard ISCEV dim flash failed to illicit measureable OPs. However, OPs became measurable using a brighter, nonstandard dim flash (Test Flash 1, -1.43 log cd s/m2), and exhibited prolonged implicit times in the DM group compared with control subjects (CTRL). CONCLUSIONS Delays in scotopic OP implicit times are an early response to hyperglycemia in diabetic rats. A similar, inner retinal, rod-driven response was detected in diabetic human subjects without diabetic retinopathy, only when a nonstandard ISCEV flash intensity was employed during ERG testing. TRANSLATIONAL RELEVANCE The addition of a dim stimulus to standard ISCEV flashes with assessment of OP latency during ERG testing may provide a detection method for early retinal dysfunction in diabetic patients.
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Affiliation(s)
- Machelle T Pardue
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA ; Neuroscience Program, Emory University, Atlanta, GA
| | - Claire S Barnes
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moon K Kim
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moe H Aung
- Neuroscience Program, Emory University, Atlanta, GA
| | - Raj Amarnath
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA
| | - Darin E Olson
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
| | - Peter M Thulé
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
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The db/db mouse: a useful model for the study of diabetic retinal neurodegeneration. PLoS One 2014; 9:e97302. [PMID: 24837086 PMCID: PMC4023966 DOI: 10.1371/journal.pone.0097302] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 04/17/2014] [Indexed: 01/20/2023] Open
Abstract
Background To characterize the sequential events that are taking place in retinal neurodegeneration in a murine model of spontaneous type 2 diabetes (db/db mouse). Methods C57BLKsJ-db/db mice were used as spontaneous type 2 diabetic animal model, and C57BLKsJ-db/+ mice served as the control group. To assess the chronological sequence of the abnormalities the analysis was performed at different ages (8, 16 and 24 weeks). The retinas were evaluated in terms of morphological and functional abnormalities [electroretinography (ERG)]. Histological markers of neurodegeneration (glial activation and apoptosis) were evaluated by immunohistochemistry. In addition glutamate levels and glutamate/aspartate transporter (GLAST) expression were assessed. Furthermore, to define gene expression changes associated with early diabetic retinopathy a transcriptome analyses was performed at 8 week. Furthermore, an additional interventional study to lower blood glucose levels was performed. Results Glial activation was higher in diabetic than in non diabetic mice in all the stages (p<0.01). In addition, a progressive loss of ganglion cells and a significant reduction of neuroretinal thickness were also observed in diabetic mice. All these histological hallmarks of neurodegeneration were less pronounced at week 8 than at week 16 and 24. Significant ERG abnormalities were present in diabetic mice at weeks 16 and 24 but not at week 8. Moreover, we observed a progressive accumulation of glutamate in diabetic mice associated with an early downregulation of GLAST. Morphological and ERG abnormalities were abrogated by lowering blood glucose levels. Finally, a dysregulation of several genes related to neurotransmission and oxidative stress such as UCP2 were found at week 8. Conclusions Our results suggest that db/db mouse reproduce the features of the neurodegenerative process that occurs in the human diabetic eye. Therefore, it seems an appropriate model for investigating the underlying mechanisms of diabetes-induced retinal neurodegeneration and for testing neuroprotective drugs.
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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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Wittström E, Nordling M, Andréasson S. Genotype-phenotype correlations, and retinal function and structure in von Hippel-Lindau disease. Ophthalmic Genet 2014; 35:91-106. [PMID: 24555745 DOI: 10.3109/13816810.2014.886265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE To investigate genotype-phenotype correlation and to analyze functional and structural changes in the retina of patients with von Hippel-Lindau (VHL) disease. METHODS Thirteen patients from four families (A, B, C and D) with known VHL disease and known mutations in the VHL gene were examined. All patients underwent clinical examination and optical coherence tomography (OCT). Full-field electroretinography (full-field ERG) was performed in twelve patients. RESULTS Family A, with deletion of exon 3 in the VHL gene, and family B, with the missense mutation p.R79P, exhibited type 1 VHL characterized by the absence of pheochromocytoma and a high incidence of central nervous system hemangioblastomas. One member of family B exhibited Goldenhar syndrome. A novel missense mutation (p.L198P) was identified in the VHL gene in the patient from family C. This p.L198P mutation caused a phenotype with early onset of a neuroendocrine tumor of the pancreas, bilateral pheochromocytomas, and optic nerve hemangioblastoma. Full-field ERG showed significantly prolonged implicit times of the b-wave and maximal combined a-wave in VHL patients, compared to controls. Examination of the retinal structure in all patients with VHL, using OCT, showed a significant decrease in retinal thickness in VHL patients without ocular hemangioblastomas, compared to controls. CONCLUSIONS Our findings support previously established genotype-phenotype correlations. However, we here describe an unusual phenotype with a novel missense mutation, p.L198P, and report the finding that VHL disease can be associated with Goldenhar syndrome. Electrophysiological and structural findings suggest that VHL disease is a progressive, neurodegenerative disease of the retina.
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Abstract
In this review article, we first present a brief overview of the vascular and neural components of diabetic retinopathy. Next, the multifocal electroretinogram (mfERG) technique, which can map neuroretinal function noninvasively, is described. Findings in diabetic retinal disease using the mfERG are reviewed. We then describe the progress that has been made to predict the onset and progression of diabetic retinopathy and edema in specific retinal locations, using quantitative models based on the mfERG. Finally, we consider the implications for the future of these predictive models.
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Affiliation(s)
- Marcus A Bearse
- School of Optometry, University of California, Berkeley, 360 Minor Hall, Berkeley, CA, 94720-2020, USA,
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Simó R, Hernández C. Neurodegeneration in the diabetic eye: new insights and therapeutic perspectives. Trends Endocrinol Metab 2014; 25:23-33. [PMID: 24183659 DOI: 10.1016/j.tem.2013.09.005] [Citation(s) in RCA: 324] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/02/2013] [Accepted: 09/27/2013] [Indexed: 11/29/2022]
Abstract
Diabetic retinopathy (DR), one of the leading causes of preventable blindness, has been considered a microcirculatory disease of the retina. However, there is emerging evidence to suggest that retinal neurodegeneration is an early event in the pathogenesis of DR, which participates in the development of microvascular abnormalities. Therefore, the study of the underlying mechanisms leading to neurodegeneration and the identification of the mediators in the crosstalk between neurodegeneration and microangiopathy will be essential for the development of new therapeutic strategies. In this review, an updated discussion of the mechanisms involved in neurodegeneration, as well as the link between neurodegeneration and microangiopathy, is presented. Finally, the therapeutic implications and new perspectives based on identifying those patients with retinal neurodegeneration are given.
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Affiliation(s)
- Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| | - Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain
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Ly A, Scheerer MF, Zukunft S, Muschet C, Merl J, Adamski J, Hrabě de Angelis M, Neschen S, Hauck SM, Ueffing M. Retinal proteome alterations in a mouse model of type 2 diabetes. Diabetologia 2014; 57:192-203. [PMID: 24078137 PMCID: PMC3855476 DOI: 10.1007/s00125-013-3070-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 09/11/2013] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Diabetic retinopathy is a major complication of type 2 diabetes and the leading cause of blindness in adults of working age. Neuronal defects are known to occur early in disease, but the source of this dysfunction is unknown. The aim of this study was to examine differences in the retinal membrane proteome among non-diabetic mice and mouse models of diabetes either with or without metformin treatment. METHODS Alterations in the retinal membrane proteome of 10-week-old diabetic db/db mice, diabetic db/db mice orally treated with the anti-hyperglycaemic metformin, and congenic wild-type littermates were examined using label-free mass spectrometry. Pathway enrichment analysis was completed with Genomatix and Ingenuity. Alterations in Slc17a7 mRNA and vesicular glutamate transporter 1 (VGLUT1) protein expression were evaluated using real-time quantitative PCR and IMMUNOFLUORESCENCE. RESULTS A total of 98 proteins were significantly differentially abundant between db/db and wild-type animals. Pathway enrichment analysis indicated decreases in levels of proteins related to synaptic transmission and cell signalling. Metformin treatment produced 63 differentially abundant proteins compared with untreated db/db mice, of which only 43 proteins were found to occur in both datasets, suggesting that treatment only partially normalises the alterations induced by diabetes. VGLUT1, which is responsible for loading glutamate into synaptic vesicles, was found to be differentially abundant in db/db mice and was not normalised by metformin. The decrease in Slc17a7/VGLUT1 was confirmed by transcriptomic and immunocytochemical analysis. CONCLUSIONS/INTERPRETATION These findings expand the knowledge of the protein changes in diabetic retinopathy and suggest that membrane-associated signalling proteins are susceptible to changes that are partially ameliorated by treatment
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Affiliation(s)
- Alice Ly
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Markus F. Scheerer
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Sven Zukunft
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Genome Analysis Center, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Caroline Muschet
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Genome Analysis Center, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Juliane Merl
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Jerzy Adamski
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Genome Analysis Center, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Center of Life and Food Sciences Weihenstephan, Technische Universität München, Weihenstephan, Freising, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Center of Life and Food Sciences Weihenstephan, Technische Universität München, Weihenstephan, Freising, Germany
| | - Susanne Neschen
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Stefanie M. Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Marius Ueffing
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Center of Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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Johnson LE, Larsen M, Perez MT. Retinal adaptation to changing glycemic levels in a rat model of type 2 diabetes. PLoS One 2013; 8:e55456. [PMID: 23408985 PMCID: PMC3568153 DOI: 10.1371/journal.pone.0055456] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 01/02/2013] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Glucose concentrations are elevated in retinal cells in undiagnosed and in undertreated diabetes. Studies of diabetic patients suggest that retinal function adapts, to some extent, to this increased supply of glucose. The aim of the present study was to examine such adaptation in a model of type 2 diabetes and assess how the retina responds to the subsequent institution of glycemic control. METHODS Electroretinography (ERG) was conducted on untreated Zucker diabetic fatty (ZDF) rats and congenic controls from 8-22 weeks of age and on ZDFs treated with daily insulin from 16-22 weeks of age. Retinal sections from various ages were prepared and compared histologically and by immunocytochemistry. PRINCIPAL FINDINGS/CONCLUSIONS Acute hyperglycemia did not have an effect on control rats while chronic hyperglycemia in the ZDF was associated with scotopic ERG amplitudes which were up to 20% higher than those of age-matched controls. This change followed the onset of hyperglycemia with a delay of over one month, supporting that habituation to hyperglycemia is a slow process. When glycemia was lowered, an immediate decrease in ZDF photoreceptoral activity was induced as seen by a reduction in a-wave amplitudes and maximum slopes of about 30%. A direct effect of insulin on the ERG was unlikely since the expression of phosphorylated Akt kinase was not affected by treatment. The electrophysiological differences between untreated ZDFs and controls preceded an activation of Müller cells in the ZDFs (up-regulation of glial fibrillary acidic protein), which was attenuated by insulin treatment. There were otherwise no signs of cell death or morphological alterations in any of the experimental groups. These data show that under chronic hyperglycemia, the ZDF retina became abnormally sensitive to variations in substrate supply. In diabetes, a similar inability to cope with intensive glucose lowering could render the retina susceptible to damage.
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Affiliation(s)
- Leif E Johnson
- Department of Ophthalmology, Glostrup Hospital, Glostrup, Denmark.
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