Spelling suggestions: "subject:"corneal"" "subject:"korneal""
301 |
Avaliação multidimensional da dor no pós-operatório da ceratectomia fotorrefrativa e fatores preditivos de dor / Improved multidimensional pain evaluation and predictors of early postoperative pain after photorefractive keratectomyGarcia, Renato 11 November 2016 (has links)
OBJETIVOS: Validar o uso de questionários multidimensionais, como o Inventário Resumido da Dor (BPI) e o Questionário de Dor de McGill (MPQ) no pós-operatório da ceratectomia fotorefrativa (PRK). Comparar o perfil da dor no pós-operatório da PRK entre os dois olhos operados sob as mesmas condições e verificar preditores de dor como sexo, estado de ansiedade, conhecimento prévio da cirurgia e equivalente esférico do erro refrativo (EEER). MÉTODOS: Oitenta e seis olhos de 43 pacientes submeteram-se à PRK com intervalo de 14 dias entre cada olho. Uma hora antes da cirurgia, os pacientes responderam ao Inventário de Estado de Ansiedade (IDEA). No pós-operatório os pacientes receberam tratamento usual para dor e responderam aos questionários Escala Visual Analógica (EVA), BPI e MPQ após uma, 24, 48, 72 e 96 horas. Estudaram-se a consistência interna e as correlações de cada questionário. Compararam-se as pontuações de dor e a ansiedade entre primeiros e segundos olhos operados usando o teste de Wald, pareados através do teste t de Student. Utilizou-se o teste de Wald para comparar o comportamento da dor de acordo com sexo e EEER. RESULTADOS: Os questionários MPQ e BPI demonstraram alta consistência interna. Os questionários apresentaram pontuações mais elevadas na primeira mensuração da EVA (4.93 ± 2.38), MPQ - Índice de Estimativa de Dor (PRI) (26.95 ± 10.58), BPI - Índice de Intensidade de Dor (IID) (14.53 ± 7.36) e o BPI - índice de Interferência Funcional de Dor (IIFD) (22.30 ± 15.13), reduzindo-se gradativamente a cada momento subseqüente de avaliação. O MPQ-PRI na subescala subjetiva, apresentou curva de dor com redução lentificada. Todas as escalas apresentaram redução média estatisticamente significativa de um momento para o outro (p < 0.05) no pósoperatório, exceto no MPQ-PRI Subjetivo. Observaram-se correlações positivas entre as subescalas BPI e MPQ com a EVA (p < 0.05). Não houve diferença estatisticamente significativa nas pontuações de dor da EVA, BPI e MPQ-PRI entre ambos os olhos para todos os momentos avaliados. Os pacientes estavam menos ansiosos antes da PRK do segundo olho (p < 0.001), mas isto não apresentou correlação com níveis de dor após a cirurgia. O sexo e o conhecimento prévio do procedimento cirúrgico não influenciou significativamente em qualquer das escalas de dor. O EEER entre -3D to -5D correlacionou-se (p=0.035) com o BPI. CONCLUSÃO: O BPI e o MPQ apresentaram boas propriedades psicométricas em relação a confiabilidade e validade. Questionários multidimensionais fornecem uma avaliação mais abrangente sobre o perfil de dor após a PRK, se comparados à EVA, principalmente nos aspectos afetivos e cognitivos. O perfil da dor pósoperatória da PRK apresentou-se similar em ambos os olhos sob as mesmas condições. O EEER entre -3D to -5D foi o único fator preditor deste estudo para elevado nível de dor pós-operatória / PURPOSE: to validate the use of multidimensional questionnaires, such as the Brief Pain Inventory (BPI) and the McGill Pain Questionnaire (MPQ) in the postoperative photorefractive keratectomy (PRK). To compare the profiles of postoperative PRK pain between both eyes operated under the same conditions and to verify the preoperative predictors of pain such as gender, anxiety, knowledge of the procedure, and spherical equivalent refractive error (SERE). METHODS: eighty-six eyes of 43 patients with myopia underwent PRK in both eyes at an interval of 14 days between the procedures. One hour before surgery, subjects answered the State Anxiety Inventory (SAI). After surgery, usual PRK pain treatment was given and subjects answered to the Visual Analogue Scale (VAS), BPI and MPQ pain questionnaires at one, 24, 48, 72 and 96 hours intervals. The internal consistency was evaluated and convergent validity of each questionnaire was assessed using correlation testing. Pain scores and anxiety were compared between each eye using the Wald test and paired Student t test. Wald test was also used to test gender and SERE for each eye separately. RESULTS: both BPI and MPQ questionnaires showed internal consistency higher than 0.70. Subjects reported higher postoperative pain scores at the first measurement of the VAS (4.93 ± 2.38), MPQ - Pain Rating Index (26.95 6 10.58), BPI - Pain Severity Index (14.53 ± 7.36), and BPI- Pain Interference Index (22.30 ± 15.13) with decreasing scores at each subsequent observation period in all scales. All scales showed statistically significant (p < 0.05) pain reduction from one measurement to the next postoperatively, except the MPQ-PRI Evaluative. The majority of the scales and subscales showed a statistically significant (p < 0.05) direct correlation with the VAS at all of the evaluation periods. There were no statistically significant differences between the two eyes at all examination intervals regarding the VAS, BPI, and MPQ scores. Subjects were less anxious on average before the second surgery compared to the first surgery (p < 0.001), but this finding was not related to pain ratings after surgery. Gender and knowledge of the procedure did not significantly interfere with any scale of pain. The SERE between -3 D (diopters) and -5 D (p=0.035) revealed interference on the BPI. CONCLUSION: the BPI and the MPQ showed good psychometric properties regarding reliability and validity. The multidimensional questionnaires expanded the assessment of the PRK postoperative pain profile, compared to VAS, mainly in cognitive and affective aspects. The profiles of postoperative pain after PRK were similar between both eyes under the same conditions. In this study, a high SERE was the only predictor for increased pain after PRK
|
302 |
Reconstruction cornéenne : traitement des déficiences en cellules souches limbiques totales et bilatérales associées ou non à une atteinte du stroma / Corneal reconstruction : treatment of limbal stem cells deficiencies with or without stromal lesionRovere, Maria 30 November 2018 (has links)
Certaines brûlures oculaires graves ou d'autres pathologies oculaires rares peuvent être associées à une perte totale de cellules souches épithéliales de la cornée (DCSL), ce qui conduit à une opacification de la cornée par invasion de la conjonctive. Lorsque la DCSL est totale et bilatérale, le limbe controlatéral n'est pas disponible pour la greffe de limbe autologue ou la culture de cellules souches autologues limbiques et la transplantation allogénique de la cornée est impossible car toujours rejetée en raison de la néovascularisation. Une thérapie innovante testée avec succès au sein de notre laboratoire, en collaboration avec le service d'ophtalmologie des HCL, consiste en une greffe autologue de Feuillet Epithélial (FE) dérivé de Muqueuse Orale (MO). Cette approche permet de restaurer la transparence et autorise, si nécessaire, une greffe cornéenne complémentaire. Cette technique a montré son efficacité lors d'un essai clinique conduit dans notre hôpital mais le dispositif breveté permettant le détachement non enzymatique des feuillets cultivés n'est plus disponible en Europe. Nous avons donc mis au point un nouveau procédé de production de FE dérivant de la MO dont la preuve de concept a été obtenue à partir d'études in-vitro et ex-vivo. En effet, un détachement avec 0,5 mg / mL de collagénase n'endommage pas le FE de MO et les protéines de la membrane basale, et, dans un modèle de stroma porcin exvivo, ces feuillets adhérents au stroma, continuent à se renouveler sous la forme d'épithélium différencié. De plus, dans le cas d'une opacité stromale associée à une DCSL, une greffe secondaire de cornée est nécessaire pour améliorer l'Acuité Visuelle (AV), c'est pourquoi nous avons cherché à développer pour ces patients à haut risque de rejet, un stroma décellularisé. Ce stroma pourrait également répondre à la pénurie de cornées dans les pays en voie de développement grâce à sa conservation longue et facile. La lyophilisation a été combinée à la décellularisation des cornées au SDS à 0,1 %, validée sur les cornées humaines sur le maintien de leur transparence et de l'ultrastructure du stroma associé à l'absence des antigènes HLA-ABC et HLA-DR. Enfin, dans un modèle de Kératoplastie Lamellaire Antérieure Profonde (KLAP) ex-vivo, nous avons montré que les cellules épithéliales et stromales de la cornée humaine receveuse colonise le stroma décellularisé. Ainsi, nos travaux permettent de proposer un traitement des DSCL totales et bilatérales associées ou non à une atteinte du stroma / Some severe ocular burns or other rare ocular pathologies may be associated with a complete loss of corneal epithelial stem cells (LSCD), leading to an opacification of the cornea by invasion of the conjunctiva. When DCSL is total and bilateral, contralateral limbus is not available for autologous limb transplant or limbal autologous stem cell culture, and allogeneic transplantation of the cornea is not an option since neovascularization is constantly responsible for graft rejection. An innovative therapy tested with success in our laboratory, in collaboration with the ophthalmology department of the HCL, consists in an autologous Epithelial Cell Sheet (ECS) graft derived from Oral Mucosa (MO). This approach restores transparency and allows in a second step a complementary corneal graft when necessary. This technique has been shown to be effective in a clinical trial conducted in our hospital, but the patented device for the non-enzymatic detachment of cultivated ECS is no longer available in Europe. We have therefore developed a new method for the production of ECS from OM, the proof of concept of which has been obtained from in-vitro and ex-vivo studies. Indeed, detachment with 0.5 mg / mL of collagenase does not damage ECS from OM and basement membrane proteins, and in an ex-vivo porcine stroma model, these cell sheets adhered on corneal stroma, continued to self-renew and generated a differentiated epithelium. Since stromal opacity associated with DCSL requires a secondary corneal graft to improve Visual Acuity (VA), we also sought to develop for these patients with high rejection risk, a new approach for the generation of decellularized stroma. Such a procedure for the production of decellularized stroma was also aimed at allowing a money-saving and reliable long-term storage for stromal grafts and thus circumventing the shortage of corneas in developing countries. Our process, combining lyophilization with decellularization of the corneas at 0.1 % SDS, was validated on human corneas regarding the maintenance of stroma transparency, the stromal ultrastructure associated with the absence of HLA-ABC and HLA-DR antigens. Finally, in an ex-vivo model of Deep Anterior Lamellar Keratoplasty (DALK), we have shown that the epithelial and stromal cells of the recipient human cornea colonized efficiently the decellularised stroma. Overall, our work makes it possible to propose a treatment for total and bilateral LSCD associated or not with lesions of the stroma
|
303 |
Gentransfer in korneale EndothelzellenDannowski, Haike 10 November 2004 (has links)
Bei der Hornhauttransplantation (Keratoplastik) handelt es sich um die häufigste Transplantation humanen Gewebes. Das Hornhautendothel, eine empfindliche Zellschicht auf der Innenseite der Kornea, verfügt nicht über die Fähigkeit, Zellverluste durch Proliferation auszugleichen. Zwei grundsätzliche Probleme ergeben sich aus dieser Eigenschaft des kornealen Endothels für die Keratoplastik: ein Endothelzellverlust tritt zum einen während der Hornhautkonservierung vor Keratoplastik auf und führt zu einem Ausschluss vieler Transplantate, zum anderen ist er oftmals im Zuge von immunvermittelten Abstoßungsreaktionen oder in Folge chronischer Vorgänge nach Keratoplastik zu beobachten. Aus diesem Grund ist eine möglichst hohe Endothelzelldichte auf kornealen Transplantaten eine Voraussetzung für den Erfolg einer Keratoplastik. Das erste Ziel dieser Arbeit war deshalb die Übertragung des Gens für den aziden FGF (aFGF) in korneale Endothelzellen mit Hilfe des nicht-viralen Gentransfers. Dazu wurden verschiedene Lipid-Formulationen für den Gentransfer in humane korneale Endothelzellen in vitro optimiert. Der Einsatz von DAC-30 und Lipofectin für den aFGF-Gentransfer führte zu einer deutlichen Proliferationssteigerung (um ca. 50 %) der Zellen, womit der Einsatz dieses Wachstumsfaktors eine gute Möglichkeit darzustellen scheint, die prä-operative Ausgangssituation kornealer Transplantate zu verbessern. Der zweite Teil dieser Arbeit befasste sich mit Untersuchungen zur Immunmodulation nach Keratoplastik. Eine Hauptrolle bei der Abstoßung kornealer Transplantate spielen CD4+ T- Lymphozyten. In anderen Transplantationsmodellen konnte durch die lokale Überexpression immunmodulatorischer Zytokine die Entstehung und Aktivierung dieser Zellen gehemmt und eine verlängerte Transplantatüberlebenszeit erzielt werden. Mit Hilfe gentherapeutischer Vektoren (Adenoviren, Liposomen) wurden die immunmodulatorischen Zytokine vIL-10 und rIL-4 ex vivo in korneale Transplantate eingebracht. Nach erfolgreichen in vitro- Untersuchungen zur Genexpression wurden die transduzierten/transfizierten Hornhäute in einem starken Abstoßungsmodell der Ratte transplantiert, was jedoch zu keiner signifikanten Verlängerung der Transplantatüberlebenszeit führte. Diese Arbeit liefert Hinweise darauf, dass der lokale Gentransfer von vIL-10 in der Keratoplastik nicht für eine Immunmodulation geeignet ist, und dass sowohl die Zytokindosis, als auch der Zeitpunkt und der Ort der Vektorapplikation eine entscheidende Rolle für den Transplantationserfolg spielen. / Keratoplasty is the most common transplantation of human tissue. The corneal endothelium constitutes a damagable cell layer on the inner surface of the cornea, unable to proliferate. From this, two general problems arise for the outcome of keratoplasty: loss of corneal endothelial cells occurs on the one hand during corneal long time storage before keratoplasty and enforces the lack of donor tissue, on the other hand it is often correlated with immune mediated rejections as well as with chronic processes after keratoplasty. Therefore an endothelial cell number as high as possible on corneal grafts displays a requirement for successful keratoplasties. The first aim of this study was non-viral gene transfer of the aFGF (acidic FGF) gene in corneal endothelial cells. Different lipid formulations were optimized for gene transfer in human corneal endothelial cells in vitro. Application of DAC-30 and Lipofectin for aFGF gene transfer clearly showed a stimulating effect on cell proliferation (approximately 50 %). Thus, the use of aFGF seems to be a good possibility for improving the pre-operative situation of corneal allografts. The second part of this study deals with the immune modulation after keratoplasty. CD4+ T- lymphocytes play a key role in rejection processes after keratoplasty. Local over expression of immunomodulatory cytokines in different transplantation models could inhibit the development and activation of these cells and was able to prolong the allograft survival time. Using different gene therapeutic vectors (adenoviruses, liposomes) the immunomodulatory cytokines vIL-10 and rIL-4 were transferred ex vivo in corneal allografts. After successfully determined gene expression in vitro, the transduced/transfected corneal allografts were transplanted in a strong rejection model of the rat. However, this was not sufficient in prolonging the graft survival time significantly. This study provides indications, that local gene transfer of vIL-10 in keratoplasty is not suitable for an immune modulation, and that both cytokine dose as well as time point and site of vector application play an important role for successful transplantation.
|
304 |
Alterações biomecânicas da córnea de suínos induzidas pela confecções de lamelas pediculadas de diferentes espessuras por laser de femtossegundo / Biomechanical changes after flap creation with different thicknesses with the femtosecond laser in swinish corneaFabricio Witzel de Medeiros 22 July 2011 (has links)
Objetivo: Investigar as alterações biomecânicas da córnea de suínos induzidas pela confecção de lamelas pediculadas de diferentes espessuras pelo laser de femtossegundo. Métodos: Para a formação dos dois grupos, 12 olhos de porcos foram usados: lamelas pediculadas de 100 e de 300 micrômetros confeccionadas pelo laser de femtossegundo. Cada olho foi submetido aos seguintes exames, antes da criação das lamelas: topografia por rasterstereography, Ocular Response Analyzer (ORA), tomografia do segmento anterior por coerência óptica para a avaliação paquimétrica corneal e das lamelas criadas e sistema de velocidade de onda (SVO), que mede a velocidade de propagação de ondas acústicas entre dois transdutores posicionados na superfície corneal antes e imediatamente, após a feitura da lamela. O primerio passo foi desenhado para o estudo das diferenças em relação à histerese corneal, fator de resistência corneal, mudanças na curvatura e velocidade de propagação de onda acústica entre córneas com lamelas finas e espessas. Posteriormente, as lamelas foram amputadas, e as medidas do sistema de velocidade de onda foram repetidas. Resultados: A média de espessura das lamelas ± desviopadrão (DP) foi de 108,5±6,9 (8,5% da espessura total) e 307,8±11,5 m (22,9% da espessura total), para os grupos de lamelas finas e espessas, respectivamente (p< 0,001). Histerese corneal e o fator de resistência corneal não apresentaram diferença estatística, após a criação de lamelas finas (p = 0,81 e p = 0,62, respectivamente). Histerese corneal foi significantemente mais baixa, depois da confecção de lamelas mais espessas (8,0±1,0 para 5,1±1,5 mmHg para medidas pré e pós-operatórias, respectivamente, p = 0,003, diminuição de 36,25%) e fator de resistência corneal também mostrou significante diminuição nesse grupo, após o procedimento cirúrgico; valores médios pré e pós-operatórios de 8,2±1,6 e 4,1±2,5 mmHg respectivamente (p= 0,007), diminuição de 50%. A ceratometria média simulada apresentou maiores valores, após a confecção das lamelas mais espessas em relação ao pré-operatório (ceratometria pré e pós-operatória de 39,5±1 D e 45,9±1,2 D, respectivamente, p= 0,003). Para o grupo de lamelas finas, não houve diferença estatisticamente significante (ceratometria pré e pós-operatória de 40,6±0,6 D e 41,4±1,0 D, respectivamente, p=0,55). Em relação ao Sistema de Velocidade de Onda, após a criação das lamelas e sua amputação, houve diminuição da velocidade de propagação acústica, embora na maior parte das posições não fosse estatisticamente significante. Conclusão: Nas condições experimentais estabelecidas por este estudo, a criação de lamelas de maior espessura pareceu exercer efeito mais relevante sobre a biomecânica da córnea de suínos / Purpose: To study the impact of programmed flaps at two different thicknesses on the biomechanical properties of the swine corneas. Methods: Twelve pig eyes were enrolled in this study and were formed two groups: 100m and 300 m flaps performed with the femtosecond laser. Each eye had the following procedure before the flap creation: raster photograph topographic maps, Ocular Response Analyzer (ORA), Optical Coherence Tomography to measure the pachymetry and flap thickness and Surface Wave Velocity system which is a prototype system that measures sonic wave propagation time between two transducers positioned on the corneal surface before and after flap creation. This first step was designed to investigate the differences in respect to corneal hysteresis, corneal resistance factor, curvature change and ultrasonic wave propagation between the groups with thinner and thicker flaps. After this initial procedure, flap amputation was performed and new measurements with the surface wave velocity system were taken again. Results: Measured flap thicknesses averaged 108.5±6.9 (8.5% of the total cornea) and 307.8±11.5 m (22.9% of the total cornea) for thin and thick flap groups, respectively (p< 0.001). Hysteresis and corneal resistance factor did not change significantly after flap creation in the thin flap group (p = 0.81 and p = 0.62, respectively). With thicker flaps, both parameters decreased significantly from 8.0±1.0 to 5.1±1.5 mmHg (p=0.003, reduction of 36.25%) and from 8.2±1.6 to 4.1±2.5 mmHg, respectively (p = 0.007), reduction of 50%. Simulated keratometry values increased in the thick flap group (from 39.5±1 D to 45.9±1.2 D, p=0.003) after flap creation and not in the thin flap group (from 40.6±0.6D to 41.4±1.0D, p= 0.55). Regarding surface wave velocity analysis, the surgical procedures induced lower values in some positions although most of them did not present statistically different results. Conclusion: In this experimental model, thicker flaps seemed to have a greater effect on the biomechanics of the swinish cornea
|
305 |
Transplante de córnea no Brasil: progresso e dificuldades em 16 anos / Corneal transplantation in Brazil: progress and difficulties in 16 yearsHirlana Gomes Almeida 15 June 2018 (has links)
Introdução: As doenças da córnea são responsáveis por cerca de 5% da cegueira reversível no mundo e o transplante de córnea (TC) é importante para o tratamento dessas enfermidades. A partir de fontes de dados oficiais e públicas, foram analisados o progresso e as dificuldades relacionados ao TC no Brasil nos últimos 16 anos, bem como desigualdades regionais, gastos do Sistema Único de Saúde (SUS) e indicadores de qualidade dos bancos de tecido ocular (BTOs). Métodos: Estudo retrospectivo e analítico com dados sobre TCs e BTOs no Brasil, no período de janeiro de 2001 a dezembro de 2016, divulgados pelo Sistema Nacional de Transplantes (SNT), pela Associação Brasileira de Transplante de Órgãos (ABTO) e pela Agência Nacional de Vigilância Sanitária (ANVISA). Para verificação de existência de tendência, comparação de médias entre as regiões e verificação da diferença de médias, foram utilizados o teste de Cochran-Armitage, a Análise de Variância e as comparações múltiplas de Duncan, respectivamente. Em todos os testes foi utilizado um nível de significância de 5%. Resultados: No Brasil, houve aumento: de 2,4 vezes no número de TCs (de 6.193 - 35,2 pmp para 14.641 - 71,0 pmp - p < 0,001); de 50,7% na eficácia do atendimento à demanda populacional por TCs (de 35,3% para 53,2% - p < 0,001); de 27,8% no número de globos e córneas in situ doados (de 24.608 - 127,1 pmp para 31.450 - 152,6 pmp - p < 0,001); de 31,7% nas córneas preservadas (de 21.012 para 27.674); de 2,4 vezes no gasto financeiro total com TCs (de R$ 9.179.688 para R$ 22.060.973); e de 2,2 vezes no gasto unitário com TC (de R$ 716 para R$ 1.603). A fila de espera para TC reduziu em 45,4% (de 23.549 - 123,0 pmp para 12.865 - 62,4 pmp - p < 0,001). As duas principais causas para a não doação foram as contraindicações médicas (média de 42,5%) e a recusa familiar (média de 36,6%). As principais causas de descarte de córneas foram a sorologia positiva para hepatite B (média de 33%), validade tecidual (média de 30,9%) e qualidade imprópria do tecido (16,8%). A Eficácia na Preservação de Córnea (EPC), o Coeficiente de Descarte de Córnea (CDC) e a Eficácia no Fornecimento de Córnea para Transplante (ECT) foram em média 88%, 37% e 63% ao longo dos anos, respectivamente. Os melhores índices foram apresentados nas regiões Sul, Centro-Oeste e Sudeste e os piores no Norte e Nordeste. Conclusão: No Brasil, o pequeno número de doações e a grande taxa de descarte de córneas são as principais dificuldades ao adequado atendimento à demanda populacional por TCs. Contudo, o país aumentou a capacidade de transplantar córneas e reduziu as filas de espera em 16 anos / Introduction: Corneal diseases account for about 5% of reversible blindness in the world and Corneal Transplantation (CT) is important for the treatment of these diseases. From official and public data sources, the progress and difficulties related to CT in Brazil in the last 16 years were analyzed, as well as regional inequalities, expenses for the Unified Health System (SUS) and quality indicators of ocular tissue banks (OTBs). Methods: A retrospective and analytical study with data on CT and OTB in Brazil, from January 2001 to December 2016, published by the National Transplantation System (SNT), the Brazilian Organ Transplantation Association (ABTO) and the National Surveillance Agency Sanitary (ANVISA). The Cochran-Armitage test, the Analysis of Variance and the Duncan\'s multiple comparisons were used to verify the existence of trend, comparison of means between regions and verification of the mean difference, respectively. A significance level of 5% was used in all tests. Results: In Brazil, there was an increase: of 2.4 times in the number of CTs (from 6,193 - 35.2 pmp to 14,641 - 71.0 pmp - p < 0.001); of 50.7% in the efficacy of meeting the population demand for CTs (from 35.3% to 53.2% - p < 0.001); of 27.8% in the number of donated globes and corneas in situ (from 24,608 - 127.1 pmp to 31,450 - 152.6 pmp - p < 0.001); of 31.7% in preserved corneas (from 21,012 to 27,674); of 2.4 times in the total finance expense with CTs (from R$ 9,179,688 to R$ 22,060,973); and 2.2 times the unit expense with CT (from R$ 716 to R$ 1,603). The waiting list for CT decreased by 45.4% (from 23,549 - 123.0 pmp to 12,865 - 62.4 pmp - p < 0.001). The two main causes for non-donation were medical contraindications (mean of 42.5%) and family refusal (mean of 36.6%). The main causes of corneal discard were positive serology for hepatitis B (mean of 33%), tissue validity (mean of 30.9%) and inadequate tissue quality (16.8%). Efficacy in Corneal Preservation (EPC), Corneal Discarding Coefficient (CDC) and Efficacy Supply of Corneas for Transplantation (ECT) averaged 88%, 37%, and 63% over the years, respectively. The best indexes were presented in the South, Midwest and Southeast regions and the worst in the North and Northeast. Conclusion: In Brazil, the small number of donations and the high rate of discard of corneas are the main difficulties to the adequate attendance to the population demand by CTs. However, the country increased the ability to transplant corneas and reduced waiting lists in 16 years
|
306 |
Alterações biomecânicas da córnea de suínos induzidas pela confecções de lamelas pediculadas de diferentes espessuras por laser de femtossegundo / Biomechanical changes after flap creation with different thicknesses with the femtosecond laser in swinish corneaMedeiros, Fabricio Witzel de 22 July 2011 (has links)
Objetivo: Investigar as alterações biomecânicas da córnea de suínos induzidas pela confecção de lamelas pediculadas de diferentes espessuras pelo laser de femtossegundo. Métodos: Para a formação dos dois grupos, 12 olhos de porcos foram usados: lamelas pediculadas de 100 e de 300 micrômetros confeccionadas pelo laser de femtossegundo. Cada olho foi submetido aos seguintes exames, antes da criação das lamelas: topografia por rasterstereography, Ocular Response Analyzer (ORA), tomografia do segmento anterior por coerência óptica para a avaliação paquimétrica corneal e das lamelas criadas e sistema de velocidade de onda (SVO), que mede a velocidade de propagação de ondas acústicas entre dois transdutores posicionados na superfície corneal antes e imediatamente, após a feitura da lamela. O primerio passo foi desenhado para o estudo das diferenças em relação à histerese corneal, fator de resistência corneal, mudanças na curvatura e velocidade de propagação de onda acústica entre córneas com lamelas finas e espessas. Posteriormente, as lamelas foram amputadas, e as medidas do sistema de velocidade de onda foram repetidas. Resultados: A média de espessura das lamelas ± desviopadrão (DP) foi de 108,5±6,9 (8,5% da espessura total) e 307,8±11,5 m (22,9% da espessura total), para os grupos de lamelas finas e espessas, respectivamente (p< 0,001). Histerese corneal e o fator de resistência corneal não apresentaram diferença estatística, após a criação de lamelas finas (p = 0,81 e p = 0,62, respectivamente). Histerese corneal foi significantemente mais baixa, depois da confecção de lamelas mais espessas (8,0±1,0 para 5,1±1,5 mmHg para medidas pré e pós-operatórias, respectivamente, p = 0,003, diminuição de 36,25%) e fator de resistência corneal também mostrou significante diminuição nesse grupo, após o procedimento cirúrgico; valores médios pré e pós-operatórios de 8,2±1,6 e 4,1±2,5 mmHg respectivamente (p= 0,007), diminuição de 50%. A ceratometria média simulada apresentou maiores valores, após a confecção das lamelas mais espessas em relação ao pré-operatório (ceratometria pré e pós-operatória de 39,5±1 D e 45,9±1,2 D, respectivamente, p= 0,003). Para o grupo de lamelas finas, não houve diferença estatisticamente significante (ceratometria pré e pós-operatória de 40,6±0,6 D e 41,4±1,0 D, respectivamente, p=0,55). Em relação ao Sistema de Velocidade de Onda, após a criação das lamelas e sua amputação, houve diminuição da velocidade de propagação acústica, embora na maior parte das posições não fosse estatisticamente significante. Conclusão: Nas condições experimentais estabelecidas por este estudo, a criação de lamelas de maior espessura pareceu exercer efeito mais relevante sobre a biomecânica da córnea de suínos / Purpose: To study the impact of programmed flaps at two different thicknesses on the biomechanical properties of the swine corneas. Methods: Twelve pig eyes were enrolled in this study and were formed two groups: 100m and 300 m flaps performed with the femtosecond laser. Each eye had the following procedure before the flap creation: raster photograph topographic maps, Ocular Response Analyzer (ORA), Optical Coherence Tomography to measure the pachymetry and flap thickness and Surface Wave Velocity system which is a prototype system that measures sonic wave propagation time between two transducers positioned on the corneal surface before and after flap creation. This first step was designed to investigate the differences in respect to corneal hysteresis, corneal resistance factor, curvature change and ultrasonic wave propagation between the groups with thinner and thicker flaps. After this initial procedure, flap amputation was performed and new measurements with the surface wave velocity system were taken again. Results: Measured flap thicknesses averaged 108.5±6.9 (8.5% of the total cornea) and 307.8±11.5 m (22.9% of the total cornea) for thin and thick flap groups, respectively (p< 0.001). Hysteresis and corneal resistance factor did not change significantly after flap creation in the thin flap group (p = 0.81 and p = 0.62, respectively). With thicker flaps, both parameters decreased significantly from 8.0±1.0 to 5.1±1.5 mmHg (p=0.003, reduction of 36.25%) and from 8.2±1.6 to 4.1±2.5 mmHg, respectively (p = 0.007), reduction of 50%. Simulated keratometry values increased in the thick flap group (from 39.5±1 D to 45.9±1.2 D, p=0.003) after flap creation and not in the thin flap group (from 40.6±0.6D to 41.4±1.0D, p= 0.55). Regarding surface wave velocity analysis, the surgical procedures induced lower values in some positions although most of them did not present statistically different results. Conclusion: In this experimental model, thicker flaps seemed to have a greater effect on the biomechanics of the swinish cornea
|
307 |
Synthese und Charakterisierung von Limbusepithel-Amnion-Transplantaten aus langzeitorgankonservierten Hornhäuten und kryokonservierten AmnionmembranenHenkel, Tassilo 05 January 2011 (has links) (PDF)
In dieser Arbeit wurden Methoden entwickelt und verglichen, um aus Corneoskleralringen langzeitorgankonservierter Hornhäute und intakten, kryokonservierten Amnionmembranen Limbusepithel-Amnion-Transplantate herzustellen. Als erfolgreichste Kultivierungsmethode stellte sich hierbei signifikant die Explantat-Technik mit nach unten gerichtetem Limbusepithel heraus. Hier konnte eine Auswachsrate von 42 % erzielt werden. Es wurde weiterhin gezeigt, dass das ausgewachsene, mehrschichtige Limbusepithel proliferationsfähige TACs (Transient Amplifying Cells) enthält.
Weiterhin konnten mittels Regressionsanalyse signifikante Zusammenhänge zwischen Spenderalter, Post-mortem-Zeit, Organkultur-Dauer und der Auswachsrate beschrieben werden. Kurzgefasst wurde die Vermutung bestätigt, dass jede Verlängerung der unterschiedlichen Zeiten eine Verringerung der Auswachsrate zur Folge hat.
Die hergestellten Limbusepithel-Amnion-Transplantate könnten für Patienten mit Limbusstammzellinsuffizienz unterschiedlicher Genese verwendet werden.
|
308 |
Endothelial colony forming cells (ECFCs) identification, specification and modulation in cardiovascular diseases /Huang, Lan. January 2009 (has links)
Thesis (Ph.D.)--Indiana University, 2009. / Title from screen (viewed on February 2, 2010). Department of Biochemistry and Molecular Biology, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Mervin C. Yoder, Jr., David A. Ingram, Jr., Lawrence A. Quilliam, Mark D. Pescovitz. Includes vitae. Includes bibliographical references (leaves 171-194).
|
309 |
La fonte cornéenne post-kératoprothèse de Boston type I : épidémiologie, pathophysiologie et approche novatrice pour sa préventionRobert, Marie-Claude 08 1900 (has links)
No description available.
|
310 |
Možnosti a limity stanovení specifických markerů zánětu oka na základě analýzy slz / Determination of inflammatory markers of the eye based on the analysis of tears - potential and limitsMandíková, Šárka January 2018 (has links)
In this study, we aimed to determine the levels of cytokines IL-1β, IL-4, IL-10, IFN-γ, MIF and VEGF in tears derived from healthy subjects. We tested cytokines as potential markers of inflammation for their potential use in clinical practice. Having reliable method for measuring cytokine levels in tears would enable an early diagnosis of eye diseases. In two phases, cytokines in tears of healthy individuals were analyzed using Bio-Plex Cytokine Assay (Bio-Rad). We assessed the suitability of methods for diagnostic purposes as well as the suitability of our selected cytokines. Statistically significant positive correlations of cytokines were confirmed: IL-10 with IFN-γ (r = 0,81), MIF with VEGF (r = 0,42 / r = 0,49), IL-1β with IL-10 (r = 0,52), IL-1β with IFN-γ (r = 0,55), IL-1β with VEGF (r = 0,38), IFN-γ with VEGF (r = 0,45) and IL-4 with VEGF (r = 0,48) in healthy subjects in tears. IL-4 (r = -0,37) and IFN-γ (r = -0,42) correlate negatively with age. In healthy individuals, there seem to be no differences with regard to gender, BMI, body fat, time of meal consumption prior to tear collection, eye strain when using a computer, dry eyes. Thus, studied cytokines are suitable for diagnostic purposes. Significant differences in concentrations of four (IL-1β, IL-10, IFN-γ a VEGF) of the five...
|
Page generated in 0.0348 seconds