O presente estudo avaliou diferentes aspectos funcionais da visão de diabéticos do tipo 2 com e sem retinopatia diabética. A visão desses pacientes foi avaliada em diferentes níveis do sistema visual por meio da aplicação de uma bateria de testes psicofísicos e eletrofisiológicos de grande sensibilidade. O objetivo foi caracterizar as alterações visuais provocadas pela doença antes do aparecimento de retinopatia, e avaliar o efeito da presença da retinopatia sobre as alterações funcionais precoces. Materiais e métodos: 31 pacientes diabéticos com retinopatia não proliferativa leve (15 , 16 ; idade = 59 ± 09; tempo de diabetes = 10 ± 06 anos); 36 pacientes diabéticos sem retinopatia (16 , 20 idade = 56 ± 11; tempo de diabetes = 06 ± 04 anos) e 30 sujeitos controle (13 , 17 ; idade = 44 ± 10 anos) foram submetidos a exames de (1) eletrorretinograma multifocal - mfERG; (2) sensibilidade ao contraste acromático segregada em componentes magno (MC) e parvocelulares (PC) Teste do pedestal; (3) perimetria visual computadorizada branco/branco e azul/amarelo e (4) teste quantitativo de visão de cores Teste de cores de Cambridge. A comparação dos dados de pacientes e controles foi feita com ANOVA e a comparação da capacidade de detecção do dano funcional entre os testes foi feita por meio da análise de curvas ROC. Resultados: ambos os grupos de pacientes manifestaram perdas significantes no mfERG, sensibilidade ao contraste e visão de cores. Em ambos os protocolos de perimetria apenas os pacientes com retinopatia tiveram perdas significativas. As respostas de pacientes com e sem retinopatia não foram significantemente diferentes na maior parte das medidas. Diferenças significativas foram encontradas entre os dois grupos em parte das latências do mfERG e na visão de cores, nos limiares do eixo tritan,. Na análise entre testes, o mfERG teve os maiores índices de sensibilidade e especificidade, seguido por visão de cores, sensibilidade ao contraste e perimetria, nesta ordem. Na comparação das áreas sob as curvas ROC não houve diferença significativa apenas entre os testes 1, 2 e 4. Conclusões: foram encontradas perdas funcionais estatisticamente significativas na avaliação psicofísica e eletrofisiológica da visão de pacientes diabéticos do tipo 2 sem e com retinopatia diabética. O presente trabalho confirma e amplia o crescente corpo de evidencias de perdas funcionais observadas precocemente no curso da diabetes, na ausência de alterações morfológicas (vasculares) detectáveis na retina. A interpretação dessas perdas precoces é de que tenham origem neural. Nossos achados indicam que a presença de retinopatia leve não teve efeito significativo sobre a maior parte dos aspectos funcionais analisados, corroborando a noção de origem neural das perdas. O efeito da diabetes sobre a função neural não parece ser específico a nenhuma das vias de processamento visual, como indicado pelos testes de sensibilidade ao contraste e de visão de cores. Os achados deste trabalho confirmam a hipótese de que, para o sistema visual, a diabetes seja uma doença neurodegenerativa da retina que pode estabelecer- se mesmo na ausência de retinopatia. Assim, a avaliação dos aspectos funcionais da visão deve ser melhor que a avaliação morfológica da retina para a identificação de pacientes diabéticos sob risco de perda visual. / The present study evaluated different aspects of visual function in type 2 diabetics both with and without retinopathy. The approach was to evaluate vision at several levels of the visual system by means of application of a battery of modern, sensitive psychophysical and electrophysiological tests. The goals were to characterize the changes in visual function underlying the disease prior to the onset of retinopathy, and to verify how the early losses are affected once retinopathy has occurred. Materials and methods: 31 diabetic patients with non-proliferative retinopathy (15 , 16 ; age = 59 ± 09 years; duration of diabetes = 10 ± 06 years); 36 diabetic patients without retinopathy (16 , 20 ; age = 56 ± 11 years; duration of diabetes = 06 ± 04 years) and 30 controls (13 , 17 ; age = 44 ± 10 years) were evaluated with: (1) multifocal electroretinogram - mfERG; (2) achromatic contrast sensitivity segregated into magno- (MC) and parvocellular (PC) pathways Pedestal test; (3) white-onwhite and blue-on-yellow computerized visual perimetry and (4) quantitative computerized color vision test Cambridge Colour Test (CCT). An ANOVA was performed for the statistical comparison among groups and ROC curve analysis was used to compare the diagnostic power of the different tests. Results: both diabetic patient groups manifested significant functional losses compared to controls in the mfERG, the Pedestal test and the CCT. In the mfERG, both patient groups had significantly smaller amplitudes and longer latencies than controls in one or more of the signature mfERG waveform components. For the Pedestal Test, both patient groups manifested losses in both the M-targeting and P-targeting paradigms. The CCT chromatic discrimination test found significant losses along all three color confusion axes (protan, deutan, tritan) in both patient groups. In the visual fields, only the patients with retinopathy exhibited significant losses compared to controls. In the comparison between patients with and without retinopathy, no statistical differences between results were found, except for some of the mfERG latencies and the color discrimination in the tritan axis. The ROC analysis showed that the mfERG had the higher combined sensitivity and specificity indexes, followed by the CCT, pedestal test and perimetry with decreasing indexes in this order. Conclusions: statistically significant losses were found in psychophysical and electrophysiological assessment of visual function of type 2 diabetic patients with and without diabetic retinopathy. The present work strongly confirms the growing body of evidence that functional losses with neural etiology occur in type 2 diabetes before any vascular changes are clinically detectable in the retina. In the majority of the measures, the presence of retinopathy increased the functional losses, but did not determine significant differences in relation to the losses observed in the diabetics with normal fundus. According to our results from the Pedestal Test and the Cambridge Colour Test, the neural damage is not selective to either of the visual processing pathways. The results are consistent with the hypothesis that diabetes is a neurodegenerative disease of the retina whose establishment may occur even in the presence of retinopathy. Thus, the assessment of functional status rather than morphological examination seems a better approach to identify diabetic patients under vision threat.

Cette thèse a pour objet l’étude de nouvelles méthodes de traitement d’image appliquées à l’analyse d’images numériques du fond d'œil de patients diabétiques. En particulier, nous nous sommes concentrés sur le développement algorithmique supportant un système de dépistage automatique de la rétinopathie diabétique. Les techniques présentées dans ce document peuvent être classées en trois catégories: (1) l’évaluation et l’amélioration de la qualité d’image, (2) la segmentation des lésions, et (3) le diagnostic. Pour la première catégorie, nous présentons un algorithme rapide permettant l’estimation numérique de la qualité d’une seule image à partir de caractéristiques extraites de la vascularisation et de la couleur du fond d'œil. De plus, nous démontrons qu’il est possible d’augmenter la qualité des images et de supprimer les artefacts de réflexion en fusionnant les informations extraites de plusieurs images d’un même fond d'œil (images capturées en changeant le point d’attention regardé par le patient). Pour la deuxième catégorie, deux familles de lésion sont ciblées: les exsudats et les microanévrysmes. Deux nouveaux algorithmes pour l’analyse des images du fond d'œil sont proposés et comparés avec les techniques existantes afin de démontrer leur efficacité. Dans le cas des microanévrismes, une nouvelle méthode basée sur la transformée de Radon a été développée. Dans la dernière catégorie, nous présentons un algorithme permettant de diagnostiquer la rétinopathie diabétique et les œdèmes maculaires en analysant les lésions détectées par segmentation d’image; à partir d’une seule image, notre algorithme permet de diagnostiquer une rétinopathie diabétique et/ou un œdème maculaire en ~ 22 secondes sur une machine à 1,6 GHz avec 4 Go de RAM; de plus, nous montrons les premiers résultats de notre algorithme de détection d'œdème maculaire basé sur des images du fond d'œil multiples, qui peut éventuellement permettre d’identifier le gonflement de la macula même si aucune lésion n’est visible. / In this Ph.D. thesis, we study new methods to analyse digital fundus images of diabetic patients. In particular, we concentrate on the development of the algorithmic components of an automatic screening system for diabetic retinopathy. The techniques developed can be categorized in: quality assessment and improvement, lesion segmentation and diagnosis. For the first category, we present a fast algorithm to numerically estimate the quality of a single image by employing vasculature and colour-based features; additionally, we show how it is possible to increase the image quality and remove reflection artefacts by merging information gathered in multiple fundus images (which are captured by changing the stare point of the patient). For the second category, two families of lesion are targeted: exudate and microaneurysms; two new algorithms which work on single fundus images are proposed and compared with existing techniques in order to prove their efficacy; in the microaneurysms case, a new Radon transform-based operator was developed. In the last diagnosis category, we have developed an algorithm that diagnoses diabetic retinopathy and diabetic macular edema based on the lesions segmented; starting from a single unseen image, our algorithm can generate a diabetic retinopathy and ma cular edema diagnosis in _22 seconds on a 1.6 GHz machine with 4 GB of RAM; additionally, we show the first results of a macular edema detection algorithm based on multiple fundus images, which can potentially identify the swelling of the macula even when no lesions are visible.

Orientador: Carlos Eduardo Steiner / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T13:53:01Z (GMT). No. of bitstreams: 1 Assis_NilmaAlmeidade_M.pdf: 1405023 bytes, checksum: 12e3861c31dae0e759ab571d2d029476 (MD5) Previous issue date: 2006 / Resumo: A retinopatia diabética é uma complicação freqüente no diabetes melito tipo 1, acometendo quase a totalidade de pacientes, em graus variados, após 20 anos de doença. A interferência de fatores ambientais como a manutenção de um estado hiperglicêmico na sua fisiopatologia já foi comprovada, mas ainda não foi esclarecido porque alguns pacientes desenvolvem essa complicação de maneira grave e precoce. Nos últimos anos, diversos estudos têm sugerido a participação de fatores genéticos nesse processo. O fator de crescimento endotelial vascular (VEGF), potente indutor da angiogênese, foi associado à retinopatia diabética por alguns autores, pelo aumento da sua expressão, em virtude de mutações em sua região promotora. Neste trabalho foi realizada uma avaliação clínico-laboratorial, a análise do SNP rs833061 (- 460) e a pequisa da deleção de 18 pares de bases em -2549, ambas na região promotora do gene VEGF em 114 pacientes com diabetes melito tipo 1, de três centros de referência em diabetes no Brasil ¿ Hospital das Clínicas da Unicamp, Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione (RJ) e Santa Casa da Misericórdia de São Paulo (SP). Houve associação entre retinopatia diabética proliferativa e nefropatia, porém nenhum paciente apresentou a deleção em -2549, nem o alelo -460 C em homozigose. Tais resultados sugerem que esses polimorfismos na região promotora do gene VEGF não interferem na predisposição à retinopatia diabética na população estudada e que outros agentes ambientais e/ou genéticos devem ser significativos / Abstract: Diabetic retinopathy is a frequent complication of diabetes mellitus type 1 and almost all patients develop it after twenty years of disease. The causes of these complications are not clear, but several environmental factors such as chronic hyperglicaemia may act in this predisposition, however, it is not clearly understood why some individuals develop it in a severe and precocious way. The participation of genetic factors as the vascular endothelial growth factor (VEGF), a potent angiogenic mediator, was already confirmed for some authors. In this study we investigate whether polymorphisms in VEGF gene are associated with proliferative diabetic retinopathy. One hundred-fourteen patients with diabetes mellitus type 1 underwent a clinical and laboratorial study, as well as the analysis of two polymorphisms: rs833061 and the deletion of 18 bp at -2549 both on the promoter region of the VEGF gene. There was an association between nephropathy and retinopathy in our patients but none of the individuals presented the deletion at -2549 or the allele C in rs833061 in homozygous state. These results suggest that such polymorphisms in the promoter region of the VEGF gene do not interfere in the predisposition to diabetic retinopathy in our population and that other environmental and/or genetic factor may be more relevant / Mestrado / Genetica Medica / Mestre em Ciências Médicas

Orientadores: Jacqueline Mendonça Lópes de Faria, José Butori Lopes de Faria / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T10:41:17Z (GMT). No. of bitstreams: 1 Rosales_MarianaAparecidaBrunini_D.pdf: 28953374 bytes, checksum: e9a2824bad639c7cbd3628c24c4308ad (MD5) Previous issue date: 2014 / Resumo: A patogênese da retinopatia diabética (RD) está associada ao estresse nitrosativo. Alterações na barreira hemato-retiniana (BHR) externa, formada pelas células do epitélio pigmentar da retina (EPR), estão associadas às fases precoces da RD e podem acarretar no desequilíbrio da manutenção dos fotorreceptores e consequentemente promoverem mudanças nas células neuronais da retina. O estresse nitrosativo como conseqüência do aumento da produção de óxido nítrico (NO¿) produzido pela super expressão da óxido nítrico sintetase induzida (iNOS) esteve presente em todas as camadas da retina, inclusive no EPR em condições de RD experimental in vivo precoce ou na linhagem celular humana do EPR (ARPE-19) expostas à alta concentração de glicose. O tratamento com agentes químicos como a S-nitrosoglutationa (GSNO), ou naturais (cacau enriquecido com polifenol) atuaram em diferentes vias de inibição da iNOS, prevenindo o estresse nitrosativo. Para o estudo in vivo com o colírio de GSNO (artigo I) foram utilizados animais espontaneamente hipertensos (SHR) com 4 semanas de idade. O diabetes (DM) foi induzido por STZ. Após a confirmação do DM (48 horas), os animais foram divididos em 6 grupos: controles (CTs) veículo; GSNO 900nm e GSNO 10?m ou DMs veículo; GSNO 900nm e GSNO 10?m. O efeito do tratamento com colírio de GSNO foi dependente da presença ou ausência da condição do DM. Nos animais CT, o GSNO atuou como um agente nitrosativo e nos animais DM preveniu o aumento da expressão da iNOS, preservando a retina funcional. Os estudos in vitro, demonstraram que o efeito do GSNO foi deletério ou protetor dependente da concentração de glicose. Nas células ARPE-19 expostas a condições normais de glicose, o tratamento promoveu um aumento na produção de NO¿ sem aumentar a expressão de iNOS e nas células sob alta glicose induziu uma modificação pós-translacional de proteína, a S-glutationilação da iNOS prevenindo o estresse nitrosativo. No estudo do cacau (artigo II), foi avaliado in vitro (ARPE-19 exposta a alta concentração de glicose) o seu efeito protetor dependente da concentração de polifenóis. Para isso foram testadas duas formulações de cacau que diferiram somente na concentração de polifenol: 0,5% para o cacau com baixo teor de polifenol e 60,5% para o cacau com alto teor de polifenol. A epicatequina (EC), encontrada na concentração de 12% no cacau com alto teor de polifenol foi tão eficaz quanto o próprio e esteve envolvida no controle da expressão da iNOS através da estimulação do receptor ?-opióide (DOR) diminuindo os níveis de TNF-?. A modulação da iNOS, preveniu a S-nitrosilação da caveolina-1 (CAV-1) e diminuição da expressão das junções intercelulares claudina-1 e ocludina através da prevenção da interação CAV-1?junções. Em ambos os estudos, o alvo terapêutico foi a iNOS em duas diferentes modalidades: modificação pós-translacional de proteína e modulação do TNF-? via DOR no EPR em modelos experimentais de RD. Os tratamentos apresentados neste trabalho demonstraram a iNOS como alvo terapêutico e mostraram-se eficaz em conter danos funcionais e morfológicos promovidas pela situação de mimetismo do DM no EPR demonstrando o importante papel da iNOS no desenvolvimento da RD / Abstract: The pathogenesis of diabetic retinopathy (DR) is associated with nitrosative stress. Changes in outer blood-retinal barrier (BRB), formed by retinal pigment epithelium cells (RPE) are associated in the early stages of DR and can cause imbalance in the maintenance of photoreceptors and thereby cause changes on retinal neuronal cells. The nitrosative stress as a result of increased production of nitric oxide (NO) produced by overexpression of nitric oxide synthase (iNOS) was present in all layers of the retina and mainly in RPE cells in early in vivo experimental DR or in human RPE cell line (ARPE-19) exposed to high glucose condition. Therapy with chemical agents such as S-Nitrosoglutathione (GSNO) or natural compounds (enriched cocoa polyphenol) acted in different pathways of iNOS inhibition, preventing nitrosative stress. For the in vivo study with GSNO eye drops (article I), it were used spontaneously hypertensive rats (SHR) rats with 4 week old. Diabetes (DM) was induced by streptozotocin (STZ). After DM confirmation (48 hours), the animals were divided into 6 groups: controls (CTs) vehicle; GSNO 900nm and GSNO 10?m or DMs vehicle; GSNO 900nm e GSNO 10?m. The effects of treatments were dependent on glucose concentration. In CT animals, GSNO acted as a nitrosative agent and in DM rats prevented iNOS overexpression, preserving the retina function. In vitro study showed that GSNO protective or deleterious effects were dependent on the glucose concentration. In ARPE-19 cells exposed to normal glucose, the treatment promoted an increase of NO¿ production without increase iNOS expression and in cells under high glucose (HG) condition induced post-translational protein modification, S-glutationylation of iNOS, preventing nitrosative stress. In the study with cocoa (article II), it was evaluated its protective effect dependent on concentration of polyphenols in ARPE-19 cells under HG condition. For this study, the composition of cocoa was the same in both preparations with the only difference in the amounts of polyphenol, 0.5% for low polyphenol cocoa (LPC) and 60.5% for high polyphenol cocoa (HPC). Epicatechin (EC), found in 12% of HPC was similarly protective compare to HPC and it was involved in controlling iNOS expression by stimulation of the delta opioid receptor decreasing TNF- ? levels. The modulation of iNOS prevented S-nitrosylation of caveolin-1 (CAV-1) and decreased expression of claudin-1 and occluding tight junctions by preventing CAV-1/junctions interactions. The treatments presented here showed iNOS as a therapeutic target containing functional and morphological changes promoted by DM milieu in RPE showing the important role of iNOS in the development of DR / Doutorado / Clinica Medica / Doutora em Clínica Médica

No description available.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22320号 / 医博第4561号 / 新制||医||1041(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 椛島 健治, 教授 大森 孝一, 教授 森田 智視 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Purpose The aim of this study was to audit the knowledge and practices regarding eye care and eye complications of diabetes mellitus (DM) among diabetic patients 18 years and above in Kampala, Uganda. Methods. A cross-sectional study was done to collect data on the demographics, level of awareness and practices of the 409 diabetic patients regarding eye care and eye complications of DM. Data collected was captured in EPIDATA version 3.1, exported to STATA version 15.0 for further management and analysis. Participants characteristics were summarized using summary statistics and graphs. Using a standard questionnaire, scores for knowledge and practice for diabetes; knowledge and practice on diabetic retinopathy were generated and in all the four scores aforesaid, participants were classified as having good or poor knowledge and practice1. Proportions of participants demonstrating good awareness and good practice were reported. Fishers and Pearson chi- square tests were used to test for associations between patient’s characteristics and knowledge and practice on DM. Bivariable and logistic regression analysis was performed and variables with a p-value of < 0.2 of the unadjusted odds ratio were further analyzed at multivariate logistic regression analysis to find out factors that significantly predict patient’s knowledge and practice on diabetes mellitus. Results. A total of 409 participants were interviewed in the study, majority were females 293 (71.6%) and mean age (SD) was 50 (12) years. A high proportion of participants 314 (76.9%) was aware that DM could affect the eyes but only 24 (5.9%) stated diabetic retinopathy as an eye complication in diabetic patients. Good knowledge about diabetes mellitus was demonstrated by 178 (43.5%) of the study participants. However, only 33.3% had good knowledge on eye care and diabetic retinopathy. It was determined that female diabetic patients and those who stayed with DM for 10 years and beyond were less likely to have good practice on DM compared to male patients and those who had been with DM for less than five years (OR, 95% CI: 0.58, 0.36-0.95, P=0.029: OR, 95% CI: 0.53, 0.32-0.87, P=0.011). It was also found that diabetic patients with good knowledge of DM were at least three times more likely to have good practice compared to those with the poor knowledge (OR, 95% CI: 3.2, 2.1 -4.8, P <0.001). Conclusion Lack of knowledge regarding the importance and need for periodic eye check-up for diabetic retinopathy was a significant finding in his study. Good knowledge on diabetes, gender and duration of DM had significant association with the patients practice patterns.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21629号 / 医博第4435号 / 新制||医||1033(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊佐 正, 教授 柳田 素子, 教授 宮本 享 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Bakgrund: Ögonsjuksköterskor möter många patienter med diabetesretinopati, vilkakan vara utmanande för ögonsjuksköterskorna då det förekommer att patienter saknar sjukdomsinsikt. Det leder till svårigheter att få patienten delaktig i sin vård, men även att ge tillräckligt med information då patienten även kan vara orolig vid dessa möten. Syfte: Syftet med studien var att undersöka ögonsjuksköterskors upplevelser av att informera patienter med diabetesretinopati. Metod: En kvalitativ studie med semistrukturerade intervjuer användes där totalt sju ögonsjuksköterskor från Västra Götalandsregionen och Region Halland deltog. Resultat: Analysen resulterade i två huvudkategorier Bygga en relation och Behov av kunskap. De fem subkategorierna var Ögonsjuksköterskans roll, Patienternas delaktighet, Brist på sjukdomsinsikt, Patienternas oro och rädsla samt Vikten av information. Konklusion: Resultatet visade att ögonsjuksköterskorna upplevde att det är av vikt att informera och även få patienten delaktig i sin vård då patienternauttrycker en rädsla och oro. Studien kan vara ett stöd för ögonsjuksköterskorna infördessa möten och vidareutveckla dem både utifrån ett sjuksköterske- och patientperspektiv. I vidare forskning vore det av intresse att få en fördjupad kunskap om patienternas upplevelser av ögonbottenfotografering samt information i samband med den. / Background: Ophthalmic nurses meet many patients with diabetic retinopathy. These meetings can be challenging for the ophthalmic nurses as some patients lack insight about the disease, which makes it difficult to get the patient involved and provide enough information as the patient may also be worried at these meetings. Aim: The aim of the study was to investigate ophthalmic nurses’ experiences of informing patients with diabetic retinopathy. Method: A qualitative study with semi-structured interviews was used where seven ophthalmic nurses from Västra Götaland Countyand the Halland County participated. Results: The analysis resulted in two main categories Building a Relationship and Need for Knowledge and five subcategories; The Ophthalmic Nurse's role, Patient participation, Lack of disease insight, Patients' anxiety and fear and The importanceof information. Conclusion: The results showed that the ophthalmic nurses felt that it was important to inform and also get the patient involved in their care as the patients express fear and anxiety. The study can be a support for the ophthalmic nurses in these meetings and further develop them from both a nurse and patient perspective. In further research, it would be of interest to gain an in-depth knowledge of patients´ experiences of fundus photography and the information they receive.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24877号 / 医博第5011号 / 新制||医||1068(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川上 浩司, 教授 森田 智視, 教授 長船 健二 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM