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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Avaliação estrutural do disco óptico e da camada de fibras nervosas retinianas peripapilares em pacientes com retinopatia diabética submetidos a panfotocoagulação retiniana / Structural evaluation of the optic disc and peripapillary retinal nerve fiber layer in patients with diabetic retinopathy submitted to panretinal photocoagulation

Azevedo, Breno Marques da Silva 04 April 2019 (has links)
Objetivos: Determinar o efeito da panfotocoagulação retiniana (PFC) nos parâmetros topográficos do disco óptico e na camada de fibras nervosas da retina (CFNR) peripapilar em pacientes com retinopatia diabética proliferativa (RDP). Métodos: Este é um estudo observacional prospectivo, de centro único. Trinta e oito olhos de 26 pacientes diabéticos foram submetidos a PFC para retinopatia diabética proliferativa. As estereofotografias (EFs) e os parâmetros do disco óptico foram avaliados usando o retinógrafo Visucam da Zeiss e a Tomografia de varredura a laser (TVL), respectivamente. A espessura da CFNR peripapilar foi medida por tomografia de coerência óptica (OCT) e polarimetria de varredura a laser (PVL). Todas as medições foram realizadas no início e 12 meses após a conclusão da PFC. Resultados: Trinta e oito olhos de 26 pacientes (15 mulheres) com média de idade de 53,7 anos (faixa etária de 26 a 74 anos) foram recrutados. Nenhuma diferença significativa foi encontrada entre a média horizontal e vertical para relação escavação/disco óptico (E/D) determinadas pelas EFs antes e após o tratamento com PFC (P = 0,461 e 0,839, respectivamente). Os valores globais dos parâmetros do disco óptico analisados com a TVL não mostraram nenhuma mudança significativa entre o baseline e 12 meses após o tratamento (área do disco, área da escavação, área da rima, volume da escavação, volume da rima, relação área da escavação/área do disco, relação linear do tamanho da escavação/disco, profundidade média da escavação, profundidade máxima da escavação, medida do formato da escavação, variação na altura do contorno, espessura média da CFNR e área transversal da CFNR). O OCT e o PVL não encontraram diferença significativa entre a CFNR peripapilar antes e após a PFC (P = 0,114 e P = 0,813, respectivamente). Conclusões: Nossos resultados sugerem que a PFC nos padrões realizados no presente estudo não causa significantes alterações morfológicas no disco óptico em pacientes diabéticos com RDP após um ano de acompanhamento / Purpose: To determine the effect of panretinal photocoagulation (PRP) on optic disc topographic parameters and peripapillary retinal nerve fiber layer (RNFL) in nonglaucomatous patients with proliferative diabetic retinopathy (PDR). Methods: This is a prospective, single center, observational study. Thirty-eight eyes of 26 diabetic patients underwent PRP for proliferative diabetic retinopathy. Stereoscopic disc photographs and optic nerve head (ONH) parameters were evaluated using the Zeiss fundus camera and the confocal scanning laser ophthalmoscopy (CSLO), respectively. The peripapillary RNFL thickness was measured by optical coherence tomography (OCT) and scanning laser polarimetry (SLP). All measurements were performed at baseline and 12 months after completion of PRP. Results: Thirty-eight eyes of 26 patients (15 female) with a mean age of 53.7 years (range 26 to 74 years) were recruited. No significant difference was found between mean horizontal and vertical cup to disc (C/D) ratio determined by stereoscopic disc photographs before and after PRP treatment (P=0.461 and 0.839, respectively). The global values of ONH parameters analyzed with the CSLO showed no significant change from baseline to 12 months (disc area, cup area, rim area, cup volume, rim volume, C/D area ratio, linear C/D ratio, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean retinal nerve fiber layer thickness and cross-sectional area). The OCT and SLP did not find significant difference between peripapillary RNFL before and after PRP (P=0.114 and P=0.813, respectively). Conclusion: Our results suggest that PRP as performed in this study does not cause significant morphological optic disk changes in diabetic PDR patients after one year of follow-up
242

Avaliação estrutural e funcional da mácula nos pacientes com retinopatia diabética proliferativa submetidos à panfotocoagulação associada a injeções intravítreas de bevacizumabe / Structural and functional assessment of the macula in patients with proliferative diabetic retinopathy submitted to panretinal photocoagulation associated with intravitreal injections of bevacizumab

Preti, Rony Carlos 23 November 2012 (has links)
INTRODUÇÃO: O presente estudo avaliou o tratamento com injeções intravítreas de Bevacizumabe (IVB) associadas à panfotocoagulação (PFC) da retina na retinopatia diabética proliferativa (RDP) de alto risco com ou sem edema macular (EM). MÉTODOS: Ensaio clínico randomizado, prospectivo, aberto e mascarado composto por pacientes com Diabetes melitos (DM) tipo 2. A acuidade visual (AV) foi medida com a tabela Early Treatment Diabetic Retinopathy Study e a sensibilidade ao contraste (SC) pela da tabela Vistech Consultants Incorporation 6500. Os pacientes foram submetidos a exame de angiofluoresceinografia para observação de neovascularização retiniana e isquemia macular e à tomografia de coerência óptica (OCT), para se obter a espessura foveal (EF) e o volume macular (VM). Após os exames, um dos olhos do mesmo paciente foi randomizado para realizar somente PFC, grupo controle (GC), e o outro para PFC associado a injeções IVB, grupo de estudo (GE). A hemorragia vítrea (HV) e a presença de complicações também foram avaliadas. RESULTADOS: Dos 42 pacientes incluídos, 35 completaram o estudo. A média de idade foi de 56±8 anos, com predominância do gênero masculino 21 (60%). Vinte e seis (74%) pacientes eram portadores de Hipertensão Arterial Sistêmica com média de duração de 9±10 anos. A média de duração do DM foi de 18±9 anos sendo 23 (66%) usuários de insulina e 21 (68,5%), fácicos. A AV e a SC não demonstraram diferença entre os grupos no total da amostra. O GE demonstrou melhora em comparação ao GC na EF no 1º mês, e no VM nos 1° e 3º meses de seguimento. Quanto aos 12 pacientes com EM bilateral somente a EF demonstrou redução no GE no 1º mês de seguimento. Ao se avaliar os grupos separadamente, o GC apresentou agravamento da AV e SC durante todo seguimento. Houve também aumento da EF nos 1º e 6º meses e VM nos 1º , 3º e 6º meses de seguimento. O GE demonstrou estabilização da AV, SC, EF e VM. Correlacionado às funções visuais, AV com a SC, toda vez que houve piora da AV esta foi acompanhada pelo agravamento da SC em todos os momentos no GC e GE. Quando correlacionadas as AV e SC com as EF e VM, toda vez que a espessura macular aumentava, havia piora da função visual. Dos sete pacientes excluídos do estudo por apresentarem HV, cinco integravam o GC e dois o GE. Não houve aparecimento de catarata, endoftalmite e/ou aumento significativo da pressão ocular. CONCLUSÃO: Na RDP de alto risco, o uso adjuvante de injeções intravítreas de Bevacizumabe associadas à panfotocoagulação da retina pode estabilizar a AV, SC, EF e VM, diminuir a incidência de HV e reduzir a da espessura macular. Em relação à correlação entre as variáveis, quando houve piora da AV, esta foi acompanhada da piora da SC e o aumento da EF e VM causaram piora da AV e SC / INTRODUCTION: This study evaluated the treatment with intravitreal injections of Bevacizumab (IVB) associated with panretinal photocoagulation (PRP) in high-risk proliferative diabetic retinopathy (PDR) with or without diabetic macular edema (DME). METHODS: Prospective, open and masked, randomized clinical trial, composed of patients with type 2 Diabetes Mellitus (DM). The visual acuity (VA) was measured with the Early Treatment Diabetic Retinopathy Study charts and the contrast sensitivity (CS) through the chart of Vistech Consultants Incorporation 6500. Patients were submitted to a fluorescein angiography examination to observe retinal neovascularization and macular ischemia and to an optical coherence tomography (OCT) to obtain the foveal thickness (FT) and macular volume (MV). After the tests, one of the eyes from the same patient was randomized to realize only the PRP, the control group (CG), and the other for PRP associated to IVB injections, the study group (SG). Vitreous hemorrhage (VH) and presence of complications were also evaluated. RESULTS: Thirty-five of the forty-two patients included, completed the study. The mean age was 56±8 years, with a predominance of 21 (60%) males. Twenty-six (74%) patients had systemic hypertension with a mean duration of 9±10 years. The mean duration of DM was 18±9 years, of which 23 (66%) were insulin users and 21 (68.5%) were phakic. The VA and CS showed no difference between groups in the total sample. The SG showed improvement compared to the CG in FT for the 1st month, and in MV for the 1st and 3rd month of follow-up. As for the 12 patients with bilateral ME, only the FT showed a reduction in the SG for the 1st month of follow-up. When evaluating the groups separately, the CG showed worsening of VA and CS at all times. There was also an increase of FT for the 1st and 6th months and of MV for the 1st, 3rd and 6th month follow-up. The SG showed stabilization of VA, CS, FT and MV. When correlated to visual functions, VA and CS, a worsening of the VA was accompanied every time by a worsening of the CS in both the CG and SG. When VA and CS are correlated to FT and MV, there was worsening of visual function whenever macular thickness increased. Of the seven patients excluded from the study by presenting VH, 5 belonged to the CG and the 2 to the SG. There was no incidence of cataracts, endophthalmitis and/or significant increase in intraocular pressure. CONCLUSION: In high-risk PDR, intraocular injections of Bevacizumab as an adjuvant treatment to PRP, can stabilize VA, CS, FT and MV, reduce of the incidence of VH and decrease the macular thickness. Regarding the correlation between variables, when there was a worsening of VA, this was accompanied by a worsening of the CS, and an increase in FT and MV caused the worsening of the VA and CS
243

L'impact des cellules souches issues de la moelle sur la néovascularisation dans un modèle de souris de rétinopathie induite par l'oxygène

Blais, Martine 08 1900 (has links)
La rétinopathie induite par l’oxygène (RIO) est un modèle animal semblable aux rétinopathies vue chez l’homme. Dans ce modèle, une destruction des microvaisseaux rétiniens est suivie d’une néovascularisation pathologique qui chez l’homme peut mener à un détachement de la rétine et subséquemment une perte de vision. Afin de remédier à cette revascularisation anarchique, un traitement de cellules souches (hématopoïétiques et mésenchymateuses) a été effectué chez des souris soumises à ce modèle. Les cellules injectées ont pu migrer à la rétine et induire une revascularisation saine (surtout les cellules souches mésenchymateuses). L’injection du milieu de culture de ces cellules induit aussi une revascularisation semblable à celle vue chez les souris traitées avec les cellules indiquant que l’effet thérapeutique des cellules semble être accompli par l’entremise de facteurs paracrines. Ces résultats suggèrent que ces cellules peuvent jouer un rôle au niveau de l’angiogénèse et indiquent un potentiel thérapeutique pour les rétinopathies. / Oxygen induced retinopathy (OIR) is an animal model that mimics the developing phases of retinopathies seen in humans such as diabetic retinopathy and retinopathy of prematurity. An initial destruction of retinal microvasculature is followed by pathological neovascularization that can lead to retinal detachment in humans and therefore blindness. Utilizing bone marrow derived stem cells (mesenchymal and hematopoietic), we aimed to repopulate the retina with normal vessels which are affected in the OIR model. Cells injected into the vitreous migrated to the retina and reduced both the area of vasoobliteration and neovascularization. Injection of conditioned cell medium also induced proper vascular repair similar to that seen in mice injected with cells indicating that the cells therapeutic effect is achieved through paracrine action. These results suggest that bone marrow stem cells play a role in angiogenesis and could be a potential therapeutic aid in treating retinopathies.
244

Estudo comparativo de fotocoagulação panretiniana com e sem ranibizumabe intravítreo no tratamento da retinopatia diabética proliferativa / A comparative study of panretinal photocoagulation with and without intravitreal ranibizumab in treatment of proliferative diabetic retinopathy

Daniel Araujo Ferraz 28 August 2015 (has links)
Objetivo: Comparar o efeito da terapia da fotocoagulação panretiniana (PFC) associada à injeção intravítrea de Ranibizumabe (RBZ) versus terapia isolada com PFC em pacientes com retinopatia diabética proliferativa (RDP) precoce, virgens de tratamento, com ou sem edema macular diabético (DME) durante 6 meses de acompanhamento. Projeto: Estudo prospectivo intervencionista, randomizado e controlado. Métodos: Sessenta olhos de 30 pacientes com RDP bilateral precoce foram randomizados para o grupo de estudo (GE) que foram tratados com PFC associado a duas injeções de RBZ intravítreo (0.5mg/0.05ml) ou para o grupo controle (GC) tratados apenas com PFC. Mudanças na acuidade visual (AV) corrigida, na sensibilidade ao contraste (SC) e na espessura foveal (EF) foram comparados no início, e nos 1, 3 e 6 meses após o tratamento. Resultados: No GE, a diferença na média da AV do baseline para o mês 6 teve um aumento significativo de + 3,4 letras (p = 0,006) e uma diminuição significativa na EF de - 47.6um (p < 0,001). No GC, a diferença na média da AV teve uma diminuição de - 3,4 letras (p = 0,04) e uma mudança na EF de -3.8 um (p = 0,96). Com relação ao teste de SC dentre os 28 olhos do GE, houve uma melhora no mês 6 em relação ao baseline nos ciclos: 1,5 (p < 0.001) e 3,0 ciclo (p=0.023). Dentre os 30 olhos do GC, não houve uma diferença estatística nos momentos estudados. Conclusão: A injeção intravítrea de RBZ associado com PFC pode ser um tratamento eficaz em olhos de pacientes com RDP precoce e EMD / Purpose: To compare the efficacy of therapy with panretinal photocoagulation (PRP) and intravitreal ranibizumab (RBZ) injection versus PRP alone in patients with treatment-naive bilateral non-high risk proliferative diabetic retinopathy (PDR) with and without diabetic macular edema (DME) with a 6-month follow-up. Design: Prospective, interventional, randomized controlled trial. Methods: Sixty eyes of 30 patients with bilateral non-high risk PDR were randomized either to the study group (SG) receiving PRP plus two intravitreal ranibizumab injections (0.5mg/0.05ml), the first one week before and the second four weeks after the PRP or to the control group (CG) receiving PRP alone. Mean change in best-corrected visual acuity (BCVA), contrast sensitivity (CS) and central macular thickness (CMT) were compared at baseline and 1, 3 and 6 months after treatment. Results: Changes from baseline to 6 months showed in the SG an increased in the BCVA by + 3.4 letters (p= 0.006) with a decrease in CMT by - 47.6um (p < 0.001). In the CG, a decrease by - 3.4 letters (p = 0.04) and an decrease by -3.8um (p= 0.96). Regarding the CS in the SG, there was an improvement compared to baseline for the sixth month in the 1.5 (p < 0.001) and 3.0 cycles (p = 0.023). The CG did not show significant results from baseline to month 6. Conclusion: Intravitreal RBZ associated with PRP can be an effective treatment in eyes with non-high risk PDR and DME
245

Avaliação estrutural e funcional da mácula nos pacientes com retinopatia diabética proliferativa submetidos à panfotocoagulação associada a injeções intravítreas de bevacizumabe / Structural and functional assessment of the macula in patients with proliferative diabetic retinopathy submitted to panretinal photocoagulation associated with intravitreal injections of bevacizumab

Rony Carlos Preti 23 November 2012 (has links)
INTRODUÇÃO: O presente estudo avaliou o tratamento com injeções intravítreas de Bevacizumabe (IVB) associadas à panfotocoagulação (PFC) da retina na retinopatia diabética proliferativa (RDP) de alto risco com ou sem edema macular (EM). MÉTODOS: Ensaio clínico randomizado, prospectivo, aberto e mascarado composto por pacientes com Diabetes melitos (DM) tipo 2. A acuidade visual (AV) foi medida com a tabela Early Treatment Diabetic Retinopathy Study e a sensibilidade ao contraste (SC) pela da tabela Vistech Consultants Incorporation 6500. Os pacientes foram submetidos a exame de angiofluoresceinografia para observação de neovascularização retiniana e isquemia macular e à tomografia de coerência óptica (OCT), para se obter a espessura foveal (EF) e o volume macular (VM). Após os exames, um dos olhos do mesmo paciente foi randomizado para realizar somente PFC, grupo controle (GC), e o outro para PFC associado a injeções IVB, grupo de estudo (GE). A hemorragia vítrea (HV) e a presença de complicações também foram avaliadas. RESULTADOS: Dos 42 pacientes incluídos, 35 completaram o estudo. A média de idade foi de 56±8 anos, com predominância do gênero masculino 21 (60%). Vinte e seis (74%) pacientes eram portadores de Hipertensão Arterial Sistêmica com média de duração de 9±10 anos. A média de duração do DM foi de 18±9 anos sendo 23 (66%) usuários de insulina e 21 (68,5%), fácicos. A AV e a SC não demonstraram diferença entre os grupos no total da amostra. O GE demonstrou melhora em comparação ao GC na EF no 1º mês, e no VM nos 1° e 3º meses de seguimento. Quanto aos 12 pacientes com EM bilateral somente a EF demonstrou redução no GE no 1º mês de seguimento. Ao se avaliar os grupos separadamente, o GC apresentou agravamento da AV e SC durante todo seguimento. Houve também aumento da EF nos 1º e 6º meses e VM nos 1º , 3º e 6º meses de seguimento. O GE demonstrou estabilização da AV, SC, EF e VM. Correlacionado às funções visuais, AV com a SC, toda vez que houve piora da AV esta foi acompanhada pelo agravamento da SC em todos os momentos no GC e GE. Quando correlacionadas as AV e SC com as EF e VM, toda vez que a espessura macular aumentava, havia piora da função visual. Dos sete pacientes excluídos do estudo por apresentarem HV, cinco integravam o GC e dois o GE. Não houve aparecimento de catarata, endoftalmite e/ou aumento significativo da pressão ocular. CONCLUSÃO: Na RDP de alto risco, o uso adjuvante de injeções intravítreas de Bevacizumabe associadas à panfotocoagulação da retina pode estabilizar a AV, SC, EF e VM, diminuir a incidência de HV e reduzir a da espessura macular. Em relação à correlação entre as variáveis, quando houve piora da AV, esta foi acompanhada da piora da SC e o aumento da EF e VM causaram piora da AV e SC / INTRODUCTION: This study evaluated the treatment with intravitreal injections of Bevacizumab (IVB) associated with panretinal photocoagulation (PRP) in high-risk proliferative diabetic retinopathy (PDR) with or without diabetic macular edema (DME). METHODS: Prospective, open and masked, randomized clinical trial, composed of patients with type 2 Diabetes Mellitus (DM). The visual acuity (VA) was measured with the Early Treatment Diabetic Retinopathy Study charts and the contrast sensitivity (CS) through the chart of Vistech Consultants Incorporation 6500. Patients were submitted to a fluorescein angiography examination to observe retinal neovascularization and macular ischemia and to an optical coherence tomography (OCT) to obtain the foveal thickness (FT) and macular volume (MV). After the tests, one of the eyes from the same patient was randomized to realize only the PRP, the control group (CG), and the other for PRP associated to IVB injections, the study group (SG). Vitreous hemorrhage (VH) and presence of complications were also evaluated. RESULTS: Thirty-five of the forty-two patients included, completed the study. The mean age was 56±8 years, with a predominance of 21 (60%) males. Twenty-six (74%) patients had systemic hypertension with a mean duration of 9±10 years. The mean duration of DM was 18±9 years, of which 23 (66%) were insulin users and 21 (68.5%) were phakic. The VA and CS showed no difference between groups in the total sample. The SG showed improvement compared to the CG in FT for the 1st month, and in MV for the 1st and 3rd month of follow-up. As for the 12 patients with bilateral ME, only the FT showed a reduction in the SG for the 1st month of follow-up. When evaluating the groups separately, the CG showed worsening of VA and CS at all times. There was also an increase of FT for the 1st and 6th months and of MV for the 1st, 3rd and 6th month follow-up. The SG showed stabilization of VA, CS, FT and MV. When correlated to visual functions, VA and CS, a worsening of the VA was accompanied every time by a worsening of the CS in both the CG and SG. When VA and CS are correlated to FT and MV, there was worsening of visual function whenever macular thickness increased. Of the seven patients excluded from the study by presenting VH, 5 belonged to the CG and the 2 to the SG. There was no incidence of cataracts, endophthalmitis and/or significant increase in intraocular pressure. CONCLUSION: In high-risk PDR, intraocular injections of Bevacizumab as an adjuvant treatment to PRP, can stabilize VA, CS, FT and MV, reduce of the incidence of VH and decrease the macular thickness. Regarding the correlation between variables, when there was a worsening of VA, this was accompanied by a worsening of the CS, and an increase in FT and MV caused the worsening of the VA and CS
246

Associação dos achados morfofuncionais cardíacos, renais e vasculares com as alterações do índice tornozelo-braço em pacientes hipertensos diabéticos / Association of cardiac, renal and vascular morphological and functional findings with changes in ankle brachial index in diabetic hypertensive patients

José Carlos Jucá Pompeu Filho 12 August 2015 (has links)
Introdução: Inúmeros estudos estabeleceram correlações entre o índice tornozelo-braço (ITB), um marcador de aterosclerose subclínica, e o prognóstico cardiovascular em diferentes populações. No entanto, poucos estudos avaliaram a correlação entre os valores do ITB e lesões cardiovasculares e renais, exclusivamente, em pacientes com hipertensão arterial e diabetes. Objetivo: Estudar a prevalência de alterações morfofuncionais cardíacas, carotídeas, retinianas e renais de acordo com a presença ou não de valores de ITB alterados (ITB <= 0,9 ou ITB > 1,4) em pacientes hipertensos com diabetes tipo 2. Métodos: Foram incluídos no estudo 99 pacientes hipertensos diabéticos com idade entre 50 e 80 anos. A aferição do ITB foi realizada em todos os pacientes por método validado e estes foram classificados em Grupo 1 (ITB normal, n = 49) ou Grupo 2 (ITB alterado, n =50). Todos os pacientes foram submetidos, em até 06 meses, à realização de ecodopplercardiograma, ultrassonografia de carótidas, retinografia colorida, aferição da taxa de filtração glomerular (TFG) e da albuminúria de 24h. Os pacientes foram analisados para a ocorrência ou não de um desfecho-composto ecocardiográfico que incluiu alterações morfológicas e funcionais cardíacas relevantes para a prática clínica. Os pacientes dos grupos 1 e 2 foram também comparados quanto à prevalência de placas carotídeas com ou sem repercussão hemodinâmica, TFG < 60 ml/mim/m2, albuminúria de 24h > 30mg e presença ou não de retinopatia. Por fim, foram comparadas as frequências médias das seguintes lesões de órgãos-alvo de ambos os grupos, considerando-se valor unitário para a presença de cada uma delas: hipertrofia do ventrículo esquerdo, retinopatia hipertensiva, TFG < 60 ml/min/m2 e estenose da artéria carótida interna > 50% do seu diâmetro. Resultados: A média de idade dos pacientes foi 65,4 ± 7 anos, sendo 61,6% deles do sexo feminino. A presença de níveis elevados de pressão arterial sistólica (153,4 ± 18 versus 170 ± 26 mmHg), de albuminúria de 24h > 30mg (55,3% versus 82,6%) e de TFG < 60 ml/min/m2 (12,8% versus 33,3%) foi significativamente maior (p < 0.05) entre os pacientes do Grupo 2. O desfecho-composto ecocardiográfico foi mais prevalente no grupo 2 (84,0% versus 59,2%; p = 0,006) e a frequência média de lesões de órgãos-alvo também foi maior nos pacientes do grupo 2 (0,36 ± 0,31 versus 0,19 ± 0,19; p = 0,001). Análise por regressão logística binária revelou que o ITB foi uma das variáveis preditoras independentes para o desfecho-composto ecocardiográfico (OR = 3,43; IC 95% = 1,07 - 11,0; p = 0,04). A partir da análise por regressão linear obteve-se um modelo final no qual o ITB foi uma das três variáveis preditoras independentes para a estimativa da frequência média de lesões de órgãos-alvo com coeficiente beta = 13,22 (1,81 - 24,63), ao lado da idade e do infarto prévio. Conclusão: Nossos dados mostram que valores de ITB alterados estão associados à maior prevalência de lesões em órgãos-alvo, principalmente alterações ecocardiográficas, em pacientes com hipertensão arterial e diabetes / Introduction: A lot of studies have established strong correlations between the ankle-brachial index (ABI), a marker of subclinical atherosclerosis and cardiovascular prognosis in different populations. However, few studies have assessed the correlation between the values of the ABI and cardiovascular and renal lesions in patients with hypertension and diabetes. Objective: To study the prevalence of cardiac, carotid, renal and retinal morphological and functional changes according to the presence or not of altered ABI values (ABI <= 0.9 or ABI > 1.4) in hypertensive patients with type 2 diabetes. Methods: It was included 99 diabetic hypertensive patients aged between 50 and 80 years. The measurement of the ABI was performed in all patients by validated method and they were classified in Group 1 (normal ABI, n = 49) or group 2 (altered ABI, n = 50). All patients were submitted, up to 6 months, to Doppler echocardiography, carotid ultrasound, color retinography, assessment of glomerular filtration rate (GFR) and 24h albuminuria. Patients were analyzed for the occurrence or not of a composite echocardiographic outcome which included morphological and functional cardiac alterations relevant to clinical practice. Patients in groups 1 and 2 were compared regarding the prevalence of carotid plaques with or without hemodynamic repercussion, TFG < 60 ml/min/m2, 24h albuminuria > 30 mg and the presence or not of retinopathy. Finally, we compared the prevalence of mean frequency of the following end-organ lesions of both groups, considering unit value for each one: left ventricular hypertrophy, hypertensive retinopathy, TFG < 60 ml/min/m2 and internal carotid artery stenosis > 50%. Results: The mean age of the patients was 65.4 ± 7 years, with 61.6% of them female. The presences of elevated levels of systolic blood pressure (153.4 ± 18 versus 170.0 ± 26 mmHg), of 24h albuminuria > 30 mg (55.3% versus 82.6%) and TFG < 60 ml/min/m2 (12.8% vs. 33.3%) were significantly greater (p < 0.05) among the patients of Group 2. The composite echocardiographic outcome was more prevalent in Group 2 (84.0% versus 59.2%, p = 0.006) and the average frequency of subclinical injury of target organs was also greater in patients of Group 2 (0.36 ± 0.31 versus 0.19 ± 0.19; p = 0.001). Binary logistic regression analysis revealed that the ABI was one of the independent predictors of composite echocardiographic outcome (OR = 3.43; IC 95% = 1.07 - 11.0; p = 0.04). From the linear regression analysis it was obtained a final model in which the ABI was one of three independent predictors for the estimation of the average frequency of end-organ damage with ? coefficient = 13.22 (1.81-24.63), besides age and previous myocardial infarction. Conclusion: Our data demonstrates that changed ABI values are associated with higher prevalence of subclinical end-organ lesions, principally changes in echocardiographic parameters, in patients with hypertension and diabetes
247

Analysis of non-steady state physiological and pathological processes

Hill, Nathan R. January 2008 (has links)
The analysis of non steady state physiological and pathological processes concerns the abstraction, extraction, formalisation and analysis of information from physiological systems that is obscured, hidden or unable to be assessed using traditional methods. Time Series Analysis (TSA) techniques were developed and built into a software program, Easy TSA, with the aim of examining the oscillations of hormonal concentrations in respect to their temporal aspects – periodicity, phase, pulsatility. The Easy TSA program was validated using constructed data sets and used in a clinical study to examine the relationship between insulin and obesity in people without diabetes. In this study fifty-six non-diabetic subjects (28M, 28F) were examined using data from a number of protocols. Fourier Transform and Autocorrelation techniques determined that there was a critical effect of the level of BMI on the frequency, amplitude and regularity of insulin oscillations. Second, information systems formed the background to the development of an algorithm to examine glycaemic variability and a new methodology termed the Glycaemic Risk in Diabetes Equation (GRADE) was developed. The aim was to report an integrated glycaemic risk score from glucose profiles that would complement summary measures of glycaemia, such as the HbA1c. GRADE was applied retrospectively to blood glucose data sets to determine if it was clinically relevant. Subjects with type 1 and type 2 diabetes had higher GRADE scores than the non-diabetic population and the contribution of hypo- and hyperglycaemic episodes to risk was demonstrated. A prospective study was then designed with the aim to apply GRADE in a clinical context and to measure the statistical reproducibility of using GRADE. Fifty-three (Male 26, Female 27) subjects measured their blood glucose 4 times daily for twenty-one days. The results were that lower HbA1c’s correlated with an increased risk of hypoglycaemia and higher HbA1c’s correlated with an increased risk of hyperglycaemia. Some subjects had HbA1c of 7.0 but had median GRADE values ranging from 2.2 to 10.5. The GRADE score summarized diverse glycaemic profiles into a single assessment of risk. Well-controlled glucose profiles yielded GRADE scores <= 5 and higher GRADE scores represented increased clinical risk from hypo or hyperglycaemia. Third, an information system was developed to analyse data-rich multi-variable retinal images using the concept of assessment of change rather than specific lesion recognition. A fully Automated Retinal Image Differencing (ARID) computer system was developed to highlight change between retinal images over time. ARID was validated using a study and then a retrospective study sought to determine if the use of the ARID software was an aid to the retinal screener. One hundred and sixty images (80 image pairs) were obtained from Gloucestershire Diabetic Eye Screening Programme. Images pairs were graded manually and categorised according to how each type of lesion had progressed, regressed, or not changed between image A and image B. After a 30 day washout period image pairs were graded using ARID and the results compared. The comparison of manual grading to grading using ARID (Table 4.3) demonstrated an increased sensitivity and specificity. The mean sensitivity of ARID (87.9%) was increased significantly in comparison to manually grading sensitivity (84.1%) (p<0.05). The specificity of the automated analysis (87.5%) increased significantly from the specificity (56.3%) achieved by manually grading (p<0.05). The conclusion was that automatic display of an ARID differenced image where sequential photographs are available would allow rapid assessment and appropriate triage. Forth, non-linear dynamic systems analysis methods were utilised to build a system to assess the extent of chaos characteristics within the insulin-glucose feedback domain. Biological systems exist that are deterministic yet are neither predictable nor repeatable. Instead they exhibit chaos, where a small change in the initial conditions produces a wholly different outcome. The glucose regulatory system is a dynamic system that maintains glucose homeostasis through the feedback mechanism of glucose, insulin, and contributory hormones and was ideally suited to chaos analysis. To investigate this system a new algorithm was created to assess the Normalised Area of Attraction (NAA). The NAA was calculated by defining an oval using the 95% CI of glucose & Insulin (the limit cycle) on a phasic plot. Thirty non-diabetic subjects and four subjects with type 2 diabetes were analysed. The NAA indicated a smaller range for glucose and insulin excursions with the non-diabetics subjects (p<0.05). The conclusion was that the evaluation of glucose metabolism in terms of homeostatic integrity and not in term of cut-off values may enable a more realistic approach to the effective treatment and prevention of diabetes and its complications.
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Uloga inhibitora vaskularnog endotelnog faktora rasta u terapiji dijabetičnog makularnog edema / The role of an inhibitor of vascular endothelial growth factor in the treatment of diabetic macular edema

Jovanović Sandra 25 March 2015 (has links)
<p>Dijabetesna retinopatija je među vodećim uzročnicima stečenog slepila, kako u razvijenim zemljama, tako i zemljama u razvoju. Dijabetesna retinopatija je jedna od<br />najče&scaron;ćih komplikacija Dijabetes Mellitus-a. U sklopu dijabetesne retinopatije jedan od najranijih razloga koji dovodi do pada vidne o&scaron;trine je dijabetični makularni edem (DME). Pad vidne o&scaron;trine kod pacijenata sa dijabetesom naru&scaron;ava njihov kvalitet života i umanjuje radnu sposobnost. Dosada&scaron;nji oblik lečenja laserfotokoaguacijom makule, nije dao zadovoljavajuće rezultate. U novije vreme sve vi&scaron;e je zastupljeno farmakolo&scaron;ko lečenje edema koje podrazumeva intrvitrealnu aplikaciju lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta (VEGF inhibitori), koji dovodi do stabilizacije zidova krvnih sudova.&nbsp;<br />Cilj ove studije je da se ispita efikasnost lečenja DME uz pomoć intravitrealno aplikovanih lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta u odnosu na konvencionalno do sada priznato lečenje laserfotokogulacijom makule.&nbsp;<br />Efikasnost lečenja je procenjivana na dva načina: anatomski, na osnovu smanjenja centralne makularne debljine izražene u &mu;m, merene metodom optičke koherentne tomografije, i funkcionalno, na osnovu pobolj&scaron;anja vidne o&scaron;trine koja je izražavana u log MAR jedinicama. U ovoj prospektivnoj, randomiziranoj kliničkoj studiji sa minimumom praćenja od 6 meseci, u eksperimentalnoj grupi tretiran je 51 pacijent,<br />odnosno 84 oka aplikacijom bevacizumaba (anti VEGF agens) u dozi od 1,25 mg, sa ili bez dodatnog laser tretmana.&nbsp;<br />Uz prosečno 2,46 inekcije postignuta je prosečna redukcija centralne makularne debljine od 139,15 &mu;m.&nbsp; Dobijene vrednosti su nakon svake aplikovane doze su značajno bolje u odnosu na početnu. Edemi sa većom centralnom makularnom debljinom su zahtevali tretman sa većim brojem inekcija. Kod većih edema je postignuta i veća redukcija centralne makularne debljine. U odnosu na vidnu o&scaron;trinu u eksperimentalnoj grupi postignuto je pobolj&scaron;anje od 0,135 log MAR jedinica. Efekat lasera kao samostalne terapije u kontrolnoj grupi (50 pacijenata, 92 oka) nije bio<br />značajan ni u pogledu smanjenja centralne makularne debljine kao ni na osnovu pobolj&scaron;nja vidne o&scaron;trine. Tretman bevacizumabom samostalno ili u kombinaciji sa laserom je efikasniji u tretmanu DME u odnosu na konvencionalni tretman laserfotokoaguacijom koji potvrđeno dovodi do stabilizacije stanja. Značaj ove studije je potvrda efikasnosti i bezbednosti jednog novog oblika lečenja koji samostalno ili u kombinaciji sa laser tretmanom predstavlja novi protokol lečenja dijabetičnog makularnog edema.</p> / <p>Diabetic retinopathy is among the leading causes of acquired blindness in developed countries, as well as in developing countries. Diabetic retinopathy is one of the most frequent Diabetes Mellitus complications. Within diabetic retinopathy, diabetic macular edema (DME) is one of the earliest causes of the loss of visual acuity. Impaired vision causes decline in life quality in diabetic patients and it decreases their<br />working ability. Up to this date, laser photocoagulation treatment has not given<br />satisfactory results. Recently, new promising treatment forms have emerged, including the intravitreal application of vascular endothelium growth factor (VEGF inhibitors), which lead to stabilization of the vessel wall. The aim of this study is to evaluate the efficacy of DME treatment consisting of intravitreal&nbsp; VEGF inhibitor application alone or as a part of combined treatment (intravitreal VEGF inhibitor plus laser photocoagulation) compared with conventional laser treatment alone. The effect of treatment was evaluated according to morphological parameters by measuring central macular thickness (CMT) in &mu;m with optical coherence tomography, and according to functional parameter by visual acuity in log MAR scale. In this prospective randomized clinical trial, with minimum follow up of 6 months, in experimental group 51 patient, or 84 eyes were treated with bevacizumab (VEGF inhibitor) in 1.25 mg dosage, alone or in combination with laser. The mean reduction in was 139.15 &mu;m, which was achieved with 2.46 doses on average. The difference between the final and initial CMT values after each dos age was tatistically significant.<br />Edemas with high central macular thickness required high number of intraviteal<br />aplicatons and the reduction was higher. In our study, mean visual acuity improved significantly in 0.135 log MAR. In control group (50 patient, 92 eyes) treated with laserphotocolagulation alone, the effect on visual acuity and central acular thickness was not statistically significant. The treatment with bevacizumab alone or in combined<br />treatment is more effective in treating DME than conventional macular laser treatment alone, from both - anatomical and functional perspective. The importance of this study is confirmation of the efficacy and safety of a new form of treatment and the introduction of a new protocol for the treatment of diabetic macular edema.</p>
249

Le rôle du récepteur B1 des kinines dans le développement de la rétinopathie diabétique

Pouliot, Mylène 11 1900 (has links)
La rétinopathie diabétique est associée à plusieurs changements pathologiques du lit vasculaire rétinien, incluant l’ouverture de la barrière hémato-rétinienne, l’inflammation vasculaire et la modification du débit sanguin. Récemment, il a été proposé que le récepteur B1 des kinines, qui est surexprimé dans la rétine diabétique, puisse être impliqué dans le développement de ces altérations vasculaires. Ainsi, cette thèse présente les effets de traitements pharmacologiques avec des antagonistes du récepteur B1 sur la perfusion rétinienne, la perméabilité vasculaire, l’infiltration des leucocytes (leucostasie), l’expression de médiateurs de l’inflammation et la production d’anion superoxyde dans la rétine du rat rendu diabétique avec la streptozotocine (STZ). Les résultats obtenus montrent que l’application oculaire (10 µl d’une solution à 1%, deux fois par jour pendant 7 jours) de LF22-0542, un antagoniste hydrosoluble du récepteur B1, bloque significativement l’hyperperméabilité vasculaire, la leucostasie, le stress oxydatif et l’expression génique de médiateurs de l’inflammation (B1R, iNOS, COX-2, VEGF-R2, IL-1β et HIF-1α) dans la rétine chez le rat à 2 semaines de diabète. L’administration orale (3 mg/kg) d’un antagoniste non-peptidique et sélectif pour le récepteur B1, le SSR240612, entraîne une diminution du débit sanguin rétinien 4 jours après l’induction du diabète mais n’a aucun effet sur la réduction de la perfusion rétinienne à 6 semaines. Le récepteur B1 joue donc un rôle protecteur au tout début du diabète en assurant le maintien d’un débit sanguin normal dans la rétine; un effet qui n’est toutefois pas maintenu pendant la progression du diabète. Ces données présentent ainsi la dualité du récepteur B1 avec des effets à la fois protecteurs et délétères. Elles suggèrent aussi un rôle important pour le récepteur B1 dans l’inflammation rétinienne et le développement des altérations vasculaires. Le récepteur B1 pourrait donc représenter une nouvelle cible thérapeutique pour le traitement de la rétinopathie diabétique. / Diabetic retinopathy is associated with retinal vascular changes, including blood retinal barrier breakdown, vascular inflammation and blood flow alterations. It has been proposed that kinin B1 receptor, which is upregulated in the diabetic retina, could be involved in the development of these pathological features of diabetic retinopathy. In a rat model of diabetes induced by Streptozotocin (STZ), the effects of kinin B1 receptor antagonists on retinal perfusion, vascular permeability, leukostasis, gene expression of inflammatory mediators and production of superoxide anion in the retina were evaluated. The results show that in 2-week diabetic rats, topical ocular application of the water soluble kinin B1 receptor antagonist LF22-0542 (10 µl of 1% solution, twice per day) for a 7-day period reverses vascular hyperpermeability, leukostasis, oxidative stress and gene expression of inflammatory mediators (B1R, iNOS, COX-2, VEGF-R2, IL-1β and HIF-1α) in the retina. Single oral administration (3 mg/kg) of SSR240612, a selective non-peptide B1 receptor antagonist, induces a decrease of retinal blood flow in 4-day diabetic rats but has no effect on retinal blood flow reduction present at 6 weeks of diabetes. Therefore, B1 receptor has a protective role in early diabetes by preserving a normal blood flow in the retina. These data suggest that B1 receptor exerts protective and adverse effects in the diabetic retina. They also support a key role for B1 receptor in retinal inflammation and the development of vascular alterations. B1 receptor could therefore represent a promising therapeutic target for the treatment of diabetic retinopathy.
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Tratamento do edema macular difuso do diabético com triancinolona intravítrea e fotocoagulação com laser de argônio / Use of intravitreal triamcinolone and laser photocoagulation for the treatment of diffuse diabetic macular edema

Saraiva, Fábio Petersen 17 March 2008 (has links)
INTRODUÇÃO: O edema macular difuso é uma importante causa de baixa visual em portadores de diabetes mellitus. O tratamento clássico deste tipo de retinopatia consiste na fotocoagulação, entretanto, esta terapêutica é ineficaz em muitos casos. Neste trabalho, avaliou-se a eficácia do uso intravítreo da triancinolona acetonida associada à fotocoagulação com laser de argônio no tratamento do edema macular difuso diabético. Esta associação terapêutica foi comparada com o uso isolado de cada tratamento. MÉTODOS: Neste estudo, realizado entre junho de 2005 e setembro de 2006, foram estudados 30 pacientes diabéticos clinicamente controlados e portadores de edema macular difuso. Estes pacientes foram alocados de forma aleatória e proporcional em um dos seguintes grupos de tratamento: (1) fotocoagulação macular em grade com laser de argônio; (2) aplicação intravítrea de 4 mg de triancinolona acetonida; (3) associação dos itens anteriores. O seguimento foi realizado em intervalos pré-determinados de um dia, uma semana e mensalmente, até completar 6 meses. Foram analisados os parâmetros: acuidade visual corrigida LogMAR; espessura macular central e volume macular total medido pela tomografia de coerência óptica; e pressão intra-ocular aferida pelo tonômetro de Goldmann. RESULTADOS: A fotocoagulação com laser não reduziu de forma estatisticamente significativa a espessura macular central (p=0,0862) e o volume macular total (p=0,11). Esta redução foi significativa e estatisticamente semelhante nos outros dois grupos (p<0,001). Todos os grupos apresentaram melhora da acuidade visual (p=0,003), entretanto, o grupo que recebeu a associação do laser com a triancinolona intravítrea, obteve maior percentagem de pacientes com ganho de 10 ou mais letras de visão no quarto e quinto mês de seguimento (p=0,026; p=0,034). A pressão intra-ocular elevou-se em 5 mmHg ou mais em 12 pacientes, sendo seis no grupo submetido apenas a triancinolona e os outros seis no grupo que recebeu a associação de tratamento (p<0,001).Todos estes casos foram bem controlados com colírio de maleato de timolol 0,5%. CONCLUSÕES: O uso simultâneo da fotocoagulação com a triancinolona intravítrea proporcionou maior ganho de linhas de visão do que o uso isolado de cada tratamento. A fotocoagulação com laser foi a única terapia que não reduziu de forma significativa a espessura e o volume macular total e, também, foi a única que não apresentou casos de hipertensão ocular durante o seguimento. / INTRODUCTION: The diffuse macular edema is an important cause of visual impairment in diabetic subjects. Laser photocoagulation is the main treatment for this disorder, however, it is not effective in a large number of patients. In this study, we evaluated the efficacy of intravitreal use of triamcinolone acetonide combined with laser photocoagulation for the treatment of diffuse diabetic macular edema and we compare it with either laser alone or intra-vitreal triancinolone. METHODS: In this study, performed between june 2005 and september 2006, we studied 30 well controlled diabetic patients with diffuse macular edema. These patients were randomly divided into the following treatment groups: (1) macular grid photocoagulation; (2) intravitreal injection of 4 mg of triamcinolone acetonide; (3) combination of the two previous therapies. Follow up was scheduled at predetermined intervals of one day, one week and monthly until completion of six months. The following parameters were analyzed: LogMAR best corrected visual acuity; central macular thickness and total macular volume measured by ocular coherence tomography; and intraocular pressure assessed by Goldman\'s tonometer. RESULTS: Grid photocoagulation did not significantly reduce the central macular thickness (p=0,0862) or the total macular volume (p=0,11). On the other side, this reduction was significant and statistically similar in the others two groups (p<0,001). All groups improved the mean visual acuity (p=0,003), however, the group that received the association treatment had a higher percentage of patients gaining 10 or more letters at the fourth and fifth month of follow up (p=0,026; p=0,034). A rise in 5 or more mmHg in intraocular pressure was observed in 12 patients; half of them was in the triamcinolone group and the other half was in the group that received combined therapies (p<0,001). These cases with elevated intraocular pressure were well controlled with timolol maleate 0,5% drops. CONCLUSION: The simultaneous use of photocoagulation and intravitreal triamcinolone provided a higher gain of visual lines than the isolated use of each treatment. The laser photocoagulation was the only therapy that did not significantly reduce the macular volume and the macular thickness, however, it was also the only one that did not present cases of ocular hypertension during follow up.

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