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Diabetic Retinopathy (DR) is one of the principal sources of blindness due to diabetes mellitus. It can be identified by lesions of the retina, namely microaneurysms, hemorrhages, and exudates. DR can be effectively prevented or delayed if discovered early enough and well-managed. Prior studies on diabetic retinopathy typically extract features manually but are time-consuming and not accurate. In this research, we propose a research framework using advanced retina image processing, deep learning, and a boosting algorithm for high-performance DR grading. First, we preprocess the retina image datasets to highlight signs of DR, then follow by a convolutional neural network to extract features of retina images, and finally apply a boosting tree algorithm to make a prediction based on extracted features. Experimental results show that our pipeline has excellent performance when grading diabetic retinopathy images, as evidenced by scores for both the Kaggle dataset and the IDRiD dataset. / Master of Science

La détérioration de la barrière hémato rétinienne et l'oedème maculaire consécutif est une manifestation cardinale de la rétinopathie diabétique (RD) et la caractéristique clinique la plus étroitement associée à la perte de la vue. Alors que l'oedème maculaire affecte plus de 25% des patients souffrant de diabète, les modalités de traitement actuellement disponibles tels que les corticostéroïdes administrés localement et les thérapies anti-VEGF récemment approuvés présentent plusieurs inconvénients. Bien que le lien entre une rupture de l’unité neuro-vasculaire et la pathogénèse de la RD ait récemment été établi, l’influence de la signalisation neuro-vasculaire sur la vasculopathie oculaire diabetique a jusqu’à présent reçu peu d’attention. Ici, à l’aide d’ètudes humaines et animales, nous fournissons la première preuve du rôle essentiel de la molécule de guidage neuronale classique Sémaphorine 3A dans l’instigation de la perméabilité vasculaire maculaire pathologique dans le diabète de type 1. L’étude de la dynamique d’expression de Sémaphorine 3A révèle que cette dernière est induite dans les phases précoces hyperglycèmiques du diabète dans la rétine neuronale et participe à la rupture initiale de la fonction de barrière endothéliale. En utilisant le modèle de souris streptozotocine pour simuler la rétinopathie diabétique humaine, nous avons démontré par une série d’approches analogue que la neutralisation de Sémaphorine 3A empêche de façon efficace une fuite vasculaire rétinienne. Nos résultats identifient une nouvelle cible thérapeutique pour l’oedème maculaire diabétique en plus de fournir d’autres preuves de communication neuro-vasculaire dans la pathogènese de la RD. / The deterioration of the blood retinal barrier and consequent macular edema is a cardinal manifestation of diabetic retinopathy (DR) and the clinical feature most closely associated with loss of sight. While macular edema affects over 25% of patients suffering from diabetes, currently available treatment modalities such as locally administered corticosteroids and recently approved anti-VEGF therapies, present several drawbacks. Although recent insight on the pathogenesis of DR points to a breakdown in the neurovascular unit, neurovascular cross-talk and its influence on diabetic ocular vasculopathy has thus far received limited attention. Here we provide the first evidence from both human and animal studies for the critical role of the classical neuronal guidance cue Semaphorin3A in instigating pathological macular vascular permeability in type I diabetes. Investigation of the dynamics of expression reveal that Semaphorin3A is induced in the early hyperglycemic phases of diabetes within the neuronal retina and precipitates initial breakdown of endothelial barrier function. Using the streptozotocin mouse model as a proxy for human diabetic retinopathy, we demonstrate by a series of orthogonal approaches (gene silencing or treatment with soluble Neuropilin-1 employed as a Semaphorin3A trap), that neutralization of Semaphorin3A efficiently prevents retinal vascular leakage. Our findings identify a new therapeutic target for DME and provide further evidence for neurovascular cross-talk in pathogenesis of DR.

INTRODUÇÃO: Os relatos de alterações da acuidade visual no pósoperatório são esporádicos e acredita-se que apenas os mais graves estejam descritos na literatura. Trata-se de complicação grave e não existem estudos comparativos de avaliação visual antes e após os procedimentos anestésico-cirúrgicos. OBJETIVOS: Analisar a incidência e os fatores de risco para alterações visuais pós-operatórias em pacientes idosos. MÉTODOS: Após aprovação pela Comissão Institucional de Ética em Pesquisa foram estudados 107 pacientes entre 60 anos e 80 anos submetidos a cirurgias com duração superior a 120 minutos. Pacientes com pontuação inferior a 18 pontos na avaliação cognitiva pelo teste de Mini Mental (MMSE) foram excluídos do estudo e também aqueles candidatos a cirurgia oftalmológica, de coluna, cardiovascular, neurocirurgia, de cabeça e pescoço ou otorrinolaringológica, ou os portadores de distúrbios psiquiátricos ou alterações oftalmológicas significativas. Realizou-se avaliação da acuidade visual no dia anterior à cirurgia e no 3º e 21º dias de pósoperatório, sendo esta última realizada apenas nos pacientes que apresentaram algum tipo de alteração visual no 3º PO. As avaliações da acuidade visual foram realizadas utilizando a tabela de Snellen, tabela de Jaeger, biomicroscopia, tonometria óptica, refração, motilidade ocular e fundoscopia. As variáveis independentes preditoras de risco de alteração visual foram selecionadas pelo modelo de regressão logística múltipla. RESULTADOS: A incidência de alteração visual no 3o PO foi de 19,6% (n=21), dos quais 33% (n=7) persistiram com a alteração visual até o 21o PO. A principal alteração foi encontrada ao exame da tabela de Snellen com redução de 30% (p < 0,05) da acuidade visual no 3o PO. Esta alteração foi acompanhada de aumento da refração e da pressão intraocular. Os pacientes diabéticos tipo II, com aumento da frequência cardíaca após a indução anestésica, redução da saturação de oxigênio ao final da cirurgia e submetidos a cirurgias mais prolongadas apresentaram maior risco de alteração visual pós-operatória. DISCUSSÃO: A avaliação por meio de testes específicos permitiu identificar a incidência de alteração visual pósoperatória em pacientes idosos submetidos a anestesia geral para cirurgias com mais de 120 minutos de duração. Os fatores de risco identificados sugerem que pacientes idosos e diabéticos submetidos a cirurgias prolongadas, com aumento da frequência cardíaca e hipotensão após a indução anestésica, redução da saturação de oxigênio ao final da cirurgia e apresentam maior risco de desenvolvimento de alteração visual pósoperatória. Estudos adicionais sobre as causas e formas de prevenção são desejáveis para a melhor compreensão deste evento adverso / BACKGROUND: Reports of changes in visual acuity in the postoperative period are sporadic and it is believed that only the most serious are described in the literature. It is a serious complication and there are no comparative studies evaluating visual function before and after anestheticsurgical procedures. OBJECTIVES: To analyze the incidence and risk factors for postoperative visual changes in elderly patients. METHODS: After approval by the Institutional Ethics Committee, 107 patients between 60 and 80 years of age and candidates for surgery lasting more than 120 minutes were evaluated. Patients with less than 18 points on the cognitive evaluation by the mini-mental state evaluation (MMSE) were excluded from the study and also those candidates to ophthalmologic, spinal, cardiovascular, neurosurgery, head and neck or otorhinolaryngologic surgery, or those with psychiatric disorders or ophthalmological changes. Visual acuity assessment was performed on the day before surgery and on the 3rd and 21st postoperative days (POD), the latter being performed only in patients who presented some type of visual alteration in the 3rd POD. Visual acuity assessments were performed using the Snellen table, Jaeger table, biomicroscopy, optical tonometry, refraction, ocular motility and fundoscopy. The independent predictors of risk of visual impairment were selected by the multiple logistic regression model. RESULTS: The incidence of visual impairment in the 3rd POD was 19.6% (n = 21), of which 33% (n = 7) persisted with the visual alteration until the 21st POD. The main alteration was found when examining the Snellen chart with a 30% reduction (p < 0.05) in visual acuity in the 3rd POD. This alteration was accompanied by an increase in refraction and intraocular pressure. Type II diabetic patients with increased heart rate after anesthetic induction, reduction of oxygen saturation at the end of surgery, and submitted to more prolonged surgeries presented a greater risk of postoperative visual changes. DISCUSSION: The evaluation through specific tests allowed the identification of the incidence of postoperative visual alteration in elderly patients submitted to general anesthesia for surgeries lasting more than 120 minutes. The risk factors identified suggest that elderly and diabetic patients undergoing prolonged surgeries, with increased heart rate and hypotension after induction, and reduction of oxygen saturation at the end of surgery present a higher risk of developing postoperative visual changes. Additional studies on the causes and forms of prevention are desirable for the better understanding of this adverse event

Made available in DSpace on 2016-01-26T12:51:35Z (GMT). No. of bitstreams: 1 carloseduardocuryjunior_dissert.pdf: 414169 bytes, checksum: 77abecaf5a67d52db441c24d19b9c2af (MD5) Previous issue date: 2010-12-15 / Diabetic retinopathy (DR) is one of the most frequent causes of legal blindness worldwide and the most common microvascular complication of the disease. During the first two decades, almost all patients of type I and more than 60% of the patients of type II have developed the disease. Studies to determinate the prevalence of DR in a certain population are an important measure to delineate screening programs. Objective: To determine the prevalence of Diabetic Retinopathy in public health care units of São José do Rio Preto-SP-Brazil. Material and methods: Population-based cross-sectional study. The study sample, of 710 patients, was derived from the HIPERDIA (Diabetes and High-blood pressure social health care program) of São José do Rio Preto. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the realization of previous fundoscopic eye examination All patients, known to have diabetes, underwent an eye examination by indirect ophthalmoscope to check for any signs of DR through dilated pupils.. Statistical studies were done with t-Student test, Fisher test or chi-square test.. Results: The prevalence of DR were 16,3%. Patients were divided in two groups: Group I, patients with DR 112 (16,3%) and Group II , patients without microvascular complication of diabetes 597 (83,7%) . In Group I 90 (80,4%) demonstrated non-proliferative and (22) 19,6% with proliferative diabetic retinopathy. Only 143 patients (68,7%) had a history of previous fundoscopic eye examination. Conclusions: The prevalence of DR in São José do Rio Preto is 16,3%. The main risk factors associated with DR were time of disease and glicemic control. Type of DM and nephropathy were considered secondary risk factors. The presence of high blood pressure, in this study, was not a risk factor associated with DR. / A retinopatia diabética (RD) é uma das principais causas de cegueira em todo o mundo e a principal complicação microvascular da doença. Durante as duas primeiras décadas da evolução da doença, praticamente todos os pacientes com diabetes do tipo 1 e mais de 60% dos pacientes com diabetes do tipo 2 desenvolvem retinopatia. Estudos para determinar a prevalência da RD em uma determinada população são uma importante medida. Estes facilitam o planejamento de campanhas para a prevenção e a detecção da doença.Objetivo: Determinar a prevalência e o estadiamento da retinopatia diabética (RD) em unidades básicas de saúde de São José do Rio Preto-SP - Brasil.Casuística e métodos: Estudo epidemiológico descritivo transversal, no qual foram examinados 710 pacientes diabéticos, cadastrados no programa HIPERDIA (Hipertensos e Diabéticos) da Secretaria Municipal de Saúde de SJRP. Os pacientes responderam a questionário, que incluía: idade, tempo de duração do diabetes, medicação utilizada para o controle glicêmico, tratamento para hipertensão arterial sistêmica, hiperlipidemia ou nefropatia e realização de exame fundoscópico prévio. Os dados complementares, como o valor da HbA1c e como o tipo do diabetes (tipos 1 ou 2), foram extraídos dos respectivos prontuários. Após a dilatação pupilar, foi realizado o exame de fundo de olho, por oftalmoscopia indireta. Os métodos estatísticos utilizados para a análise foram: teste t-Student, teste de Fisher ou teste qui-quadrado. Em todos os testes estatísticos, o nível de significância adotado foi de 5%.Resultados: A prevalência da RD foi de 16,3%. Os pacientes estudados foram divididos em dois grupos: Grupo I, de pacientes com RD 112 (16,3%) e Grupo II, de pacientes sem a complicação microvascular do diabetes 597 (83,7%). Com relação à classificação da RD, apresentada pelos pacientes do Grupo I, verificou-se que noventa (80,4%) dos pacientes apresentaram a forma não proliferativa da doença (RDNPF). Do total de pacientes, 68,7% foram anteriormente submetidos ao exame de fundoscopia. Conclusões: A prevalência da RD, em São José do Rio Preto, está estimada em 16,3%. Os principais fatores de risco associados à RD foram o tempo de doença e o controle glicêmico. O tipo de DM e a presença de nefropatia foram considerados fatores de risco secundários para o desenvolvimento da RD. Neste estudo, a presença de HAS não foi considerada fator de risco associado a RD.

Studies demonstrate localized neuro-retinal dysfunction in patients with diabetes and no visible diabetic retinopathy (DR). Poor glycemic control is a strong risk factor for DR. We hypothesized that poor glycemic control predicts increased areas of localized neuro-retinal dysfunction in patients with diabetes. Forty-eight adolescents with diabetes and 45 controls were tested using the standard (103 hexagons) multifocal electroretinogram (mfERG). Negative binomial regression analysis was conducted with number of abnormal hexagons (delayed responses) as the dependent variable and glycated hemoglobin (HbA1c), disease duration, age and sex as covariates. Results indicate that a one-unit increase in HbA1c predicts an 80% (p = 0.002) increase in the number of abnormal hexagons when controlling for age. Increased areas of neuro-retinal dysfunction are predicted by worsening glycemic control in patients with no visible DR. Standard mfERG may be useful in monitoring patients with diabetes and identifying those who may be at risk of developing DR.

Studies demonstrate short-wavelength cone pathway dysfunction in patients with diabetes and no clinically visible DR. Poor glycemic control, as measured by hemoglobin A1c (HbA1c), is a strong risk factor for DR. We hypothesized that raised HbA1c was associated with short-wavelength cone sensitive visual evoked potential (S-VEP) and electroretinogram (sERG) dysfunction. Forty adolescents with diabetes and 39 controls were tested using the S-VEP. Latencies to a short-wavelength stimulus were delayed in patients at low contrasts. Patient S-VEP latencies were not associated with HbA1c when controlling for age and time since diagnosis. Twenty-one adolescents with diabetes and 19 controls were tested using the sERG. Implicit times of the b-wave were delayed but not associated with HbA1c when controlling for time since diagnosis.Patient PhNR amplitudes were reduced. A one-unit increase in HbA1c was associated with a 15% sERG PhNR amplitude reduction (p=0.004). The sERG PhNR may be a potential biomarker for DR.

Studies demonstrate localized neuro-retinal dysfunction in patients with diabetes and no visible diabetic retinopathy (DR). Poor glycemic control is a strong risk factor for DR. We hypothesized that poor glycemic control predicts increased areas of localized neuro-retinal dysfunction in patients with diabetes. Forty-eight adolescents with diabetes and 45 controls were tested using the standard (103 hexagons) multifocal electroretinogram (mfERG). Negative binomial regression analysis was conducted with number of abnormal hexagons (delayed responses) as the dependent variable and glycated hemoglobin (HbA1c), disease duration, age and sex as covariates. Results indicate that a one-unit increase in HbA1c predicts an 80% (p = 0.002) increase in the number of abnormal hexagons when controlling for age. Increased areas of neuro-retinal dysfunction are predicted by worsening glycemic control in patients with no visible DR. Standard mfERG may be useful in monitoring patients with diabetes and identifying those who may be at risk of developing DR.

Studies demonstrate short-wavelength cone pathway dysfunction in patients with diabetes and no clinically visible DR. Poor glycemic control, as measured by hemoglobin A1c (HbA1c), is a strong risk factor for DR. We hypothesized that raised HbA1c was associated with short-wavelength cone sensitive visual evoked potential (S-VEP) and electroretinogram (sERG) dysfunction. Forty adolescents with diabetes and 39 controls were tested using the S-VEP. Latencies to a short-wavelength stimulus were delayed in patients at low contrasts. Patient S-VEP latencies were not associated with HbA1c when controlling for age and time since diagnosis. Twenty-one adolescents with diabetes and 19 controls were tested using the sERG. Implicit times of the b-wave were delayed but not associated with HbA1c when controlling for time since diagnosis.Patient PhNR amplitudes were reduced. A one-unit increase in HbA1c was associated with a 15% sERG PhNR amplitude reduction (p=0.004). The sERG PhNR may be a potential biomarker for DR.

Bakgrund: Diabetes är en av de främsta orsakerna till synnedsättning och blindhet. Dåförekomsten av diabetes ökar utgör de synrelaterade komplikationerna ett växande globalt hälsoproblem. En ökad förståelse för hur personer med diabetesretinopati upplever att synnedsättning påverkar deras dagliga kan vara till stor hjälp i mötet med dessa personer. Syfte:Syftet med studien var att beskriva personers upplevelser av att leva med diabetesretinopati. Metod: Studien genomfördes som en allmän litteraturstudie. Vetenskapliga, empiriska studier med kvalitativ och kvantitativ ansats ligger till grund för studien. Resultat: Studiens resultat redovisas utifrån tre olika teman: känsla av delaktighet, känsla av begränsningar och känsla av otillräcklighet. Diskussion: Sjuksköterskan bör vara professionell i mötet med patienten. Kommunikation, undervisning och en helhetssyn av personens upplevelse av sin livssituation ligger till grund för personens vård och behandling. Det är viktigt med hälsofrämjande insatser för att kunna förebygga komplikationer. / Background: Diabetes is one of the leading causes of vision loss and blindness. Since the prevalence of diabetes is increasing, the sight-related complications are a growing global health problem. A better understanding of how people with diabetic retinopathy are experiencing vision loss that affects their daily may be helpful in meeting with these people. Purpose: The purpose of this study was to describe people's experiences of living with diabetic retinopathy. Method: The study was conducted as a general literature review. Scientific, empirical studies using qualitative and quantitative approach is the basis for the study. Results: The results are reported from three different themes: sense of ownership, sense of limitations and feelings of inadequacy. Discussions: Nurse should be professional in the meeting with the patient. Communication, education and a holistic view of the person's experience of their lives is the basis for the person's care and treatment. It is important with health promotion efforts to prevent complications.