No description available.

Modulation of corneal transplant rejection using gene therapy shows promise in experimental models but the most appropriate vector for gene transfer is yet to be determined. The overarching aim of the thesis was to evaluate the potential of a lentiviral vector for use in human corneal transplantation. Specific aims were: (i) to assess the ability of an HIV-1-based lentiviral vector to mediate expression of the enhanced yellow fluorescent protein (eYFP), and a model secreted protein interleukin-10 (IL10), in ovine and human corneal endothelium; and (ii) to examine the influence of lentivirus-mediated IL10 expression on the survival of ovine corneal allografts. Four lentiviral vectors expressing eYFP under the control of different promoters, were tested: the simian virus type-40 (SV40) early promoter, the phosphoglycerate kinase (PGK) promoter, the elongation factor-1alpha (EF) promoter, and the cytomegalovirus (CMV) promoter. Two lentiviral vectors expressing IL10 were tested: one containing the SV40 promoter and another containing a steroid-inducible promoter (GRE5). Lentivirus-mediated expression in transduced ovine and human corneal endothelium was assessed by fluorescence microscopy, real-time quantitative RT-PCR and ELISA, following alterations of transduction period duration (2–24 hr) and vector dose, as well as in the presence or absence of polybrene or dexamethasone (GRE5 vector). It was also compared to expression mediated by adenoviral vectors. Orthotopic transplantation of ex vivo transduced donor corneas was performed in outbred sheep. Allografts were reviewed daily for vascularisation and signs of immunological rejection. Lentivirus-mediated eYFP expression was delayed in ovine corneal endothelium compared to human. However, in both species the final transduction rate was greater than 80% and expression was stable for at least 14 d in vitro. Lentivirus-mediated expression in ovine and human corneal endothelium was higher with the viral promoters in comparison to the mammalian promoters. A 24 h transduction of ovine corneal endothelium with the lentiviral vector encoding IL10 resulted in expression levels which were increasing after 15 d of organ culture but logarithmically lower than those achieved by adenovirus. Shortening the lentiviral transduction period to 2 h led to a reduction in expression, but the addition of polybrene (40 micrograms / ml) to the transduction mixture restored expression to levels comparable to those attained after a 24 h transduction period. Lentivirus-mediated IL10 expression was higher and more rapid in human corneal endothelium compared to ovine corneas. Dexamethasone-responsive transgene expression was observed in both ovine and human corneal endothelium using the lentiviral vector containing the GRE5 promoter. Lentivirus-mediated expression in ovine corneal endothelium was stable for 28 d in vivo. A modest prolongation of ovine corneal allograft survival (median of 7 d) was achieved by transduction of donor corneas for 2–3 h with the lentivirus expressing IL10. Attempts to increase the expression of IL10 by the addition of polybrene (40 micrograms / ml) to the transduction mixture, resulted in a toxic effect on corneal allografts which abrogated the beneficial effect of IL10. The lentiviral vector shows potential for the stable expression of therapeutic transgenes in human corneal transplantation. However, the mechanisms underlying the species-specific differences in HIV-1-mediated transgene expression will need to be elucidated and overcome if the ovine preclinical model is to provide justification for a clinical trial.

Corneal transplantation is performed to restore vision or to relieve pain in patients with damaged or diseased corneas. However, approximately 40% of corneal allografts fail after 10 years. The most common cause of graft failure is irreversible immunological rejection, primarily mediated by CD4+ T cells, despite the topical application of glucocorticosteroids. The aim of this project was to investigate the anatomic site of antigen presentation during corneal transplantation in the rat, by using a lentiviral vector to express an anti-CD4 antibody fragment at potential sites of antigen presentation, including the donor corneal endothelium, the anterior segment of the eye and the cervical lymph nodes. Dual-gene lentiviral vectors were constructed by inserting the 2A self-processing sequence between two transgenes. This allowed expression of two transgenes within a single open reading frame. In vitro characterisation of the dual-gene vectors was performed in cell culture experiments, which showed that transgenic proteins were expressed at lower levels from dual-gene vectors compared to the expression from single-gene vectors and expression was lowest when the transgene was situated downstream of the 2A self-processing sequence. To locate the anatomic site of antigen presentation during corneal transplantation in rats, a lentiviral vector carrying an anti-CD4 antibody fragment was delivered to the corneal endothelium either immediately prior to corneal transplantation by ex vivo transduction of the donor corneas, or 5 days prior to corneal transplantation by anterior chamber injection into both the recipient and the donor rats. A separate group of recipient rats received intranodal injections of the lentiviral vector carrying an anti-CD4 antibody fragment into the cervical lymph nodes 2 days prior to corneal transplantation. Another group of rats underwent bilateral lymphadenectomy of the cervical lymph nodes 7 days prior to corneal transplantation. Corneal allografts were scored daily for opacity, inflammation and neovascularisation. Expression of the anti-CD4 antibody fragment from transduced tissues was detected using flow cytometry and polymerase chain reaction. Modest, but significant prolongation of corneal allograft survival was experienced by rats that received ex vivo transduction of the donor corneas with a lentiviral vector carrying an anti-CD4 antibody fragment immediately prior to corneal transplantation, but all grafts did eventually reject. Anterior chamber injection of the lentiviral vector carrying the anti-CD4 antibody fragment 5 days prior to corneal transplantation into both recipient and donor eyes did not prolong allograft survival. Intranodal injection of a lentiviral vector carrying an anti-CD4 antibody fragment did not prolong the survival of the corneal allografts, nor did bilateral lymphadenectomy of the cervical lymph nodes 7 days prior to corneal transplantation. Neither expression of the anti-CD4 antibody fragment in the cervical lymph nodes nor the removal of these nodes was able to prolong corneal allograft survival in rats, suggesting that T cell sensitisation could potentially occur elsewhere in the body. However, expression of the anti-CD4 antibody fragment from the donor corneal endothelium was able to prolong corneal allograft survival, suggesting that some antigen presentation might occur within the anterior segment of the eye. Based on the findings described in this thesis and those of others, I propose that antigen presentation in the rat occurs within anterior segment of the eye and within the secondary lymphoid tissues such as the cervical lymph nodes, and that inhibiting antigen presentation at one of these sites will delay graft rejection. However, to completely abolish antigen presentation during corneal transplantation in the rat, I hypothesise that antigen presentation within both the anterior segment of the eye and within the secondary lymphoid tissues must be inhibited.

Objetivo: Avaliar a função visual de pacientes submetidos a transplante lamelar anterior profundo (DALK) utilizando a dissecção com tunelizador manual e fio. Métodos: Foram incluídos 33 pacientes com ceratocone que apresentavam BCVA <= 0,60 LogMar, miopia e astigmatismo entre 8,00 e 10,00D, K central médio > 53,00D, ausência de cicatrizes, espessura corneana mínima entre 300 e 400 um. Foi feita avaliação oftalmológica completa no pré e no pós-operatório de 6 a 8 meses. Estas avaliações foram complementadas com exame topográfico da córnea, microscopia especular para avaliação da densidade das células endoteliais corneanas, aberrometria corneana e exame de tomografia de coerência óptica do segmento anterior. As variáveis BCVA, UCBA e os valores totais das aberrações corneanas de alta ordem foram correlacionadas com a espessura do leito estromal residual. Resultados: Os pacientes submetidos à DALK apresentaram BCVA de 0,68 ± 0,27 LogMar o que representa BCVA superior a 20/40 em 60% da amostra analisada. Não foram observadas micro ou macroperfurações. Houve diminuição na contagem endotelial de 2702,87 ± 548,87 células por mm2 para 2282,10 ± 525,66 células por mm2 . A dissecção do estroma profundo com o fio facilitou a remoção de tecido estromal posterior, fato corroborado com o achado de que o leito residual estromal aferido foi de 49,18 ± 18,36 ?m na região central e foi inferior a 80 ?m em grande parte dos pacientes estudados. No que se refere à regularidade da dissecção, observou-se tendência a valores mais elevados de espessura residual na periferia (60,09 ± 17,70 ?m). Não houve correlação da BCVA, UCVA e do total de aberrações de alta ordem da córnea com a espessura do leito estromal residual. Conclusão: A apreciação dos resultados desse estudo mostrou que com a técnica utilizada para realização de DALK em portadores de ceratocone obteve-se resultados topográficos e funcionais semelhantes a outras técnicas consagradas pela literatura. A facilidade na dissecção do estroma profundo, a regularidade da dissecção e a presença de baixíssimo índice de conversão para transplantes penetrantes são encorajadores / Objective: Evaluate the visual function of patients undergoing deep anterior lamellar keratoplasty (DALK) using a manual spatula and a wire dissection. Methods: Thirty three keratoconus patients were included, meeting the following inclusion criteria: BCVA logMAR <=0,60, myopia and astigmatism between 8.00 and 10,00D, K central average > 53.00D, no corneal scars and minimal corneal thickness between 300 and 400 um. Complete ocular evaluation was performed preoperatively and postoperatively in 6-8 months. These assessments were supplemented by topographical survey of the cornea, specular microscopy to evaluate the density of corneal endothelial cells, corneal wavefront analysis and examination of optical coherence tomography of the anterior segment (Visante). The BCVA variables, UCVA and the total amounts of corneal higher-order aberrations were correlated with the the residual stromal bed thickness. Results: Patients that undergone to DALK with the described technique presented a BCVA of 0.68 ± 0.27 logMAR which represents a BCVA of more than 20/40 at 60% of the analyzed sample. There were no micro or macroperforations. We observed a small decrease in the endothelial cell count from 2702.87 ± 548.87 cells per mm2 to 2282.10 ± 525.66 cells per mm2. The dissection of the deep stroma with a wire facilitated the posterior stromal tissue removal, thus the measured stromal bed thickness was 49.18 ± 18.36 ?m in the central region and less than 80 ?m in the majority of the studied patients. As regards the dissection regularity, we showed a tendency to higher values of residual thickness at the periphery (60.09 ± 17.70 ?m). There was no correlation of the BCVA, UCVA and total corneal higher-order aberrations with the residual stromal bed thickness. Conclusion: The assessment of the study data showed that the described technique achieved a topographical and functional result similar to other techniques consecrated by literature. The shallow learning curve, the ease to perform the dissection of the deep stroma, the postoperative stromal regularity and the presence of very low conversion rate for penetrating keratoplasty are encouraging

Objetivo: Avaliar a função visual de pacientes submetidos a transplante lamelar anterior profundo (DALK) utilizando a dissecção com tunelizador manual e fio. Métodos: Foram incluídos 33 pacientes com ceratocone que apresentavam BCVA <= 0,60 LogMar, miopia e astigmatismo entre 8,00 e 10,00D, K central médio > 53,00D, ausência de cicatrizes, espessura corneana mínima entre 300 e 400 um. Foi feita avaliação oftalmológica completa no pré e no pós-operatório de 6 a 8 meses. Estas avaliações foram complementadas com exame topográfico da córnea, microscopia especular para avaliação da densidade das células endoteliais corneanas, aberrometria corneana e exame de tomografia de coerência óptica do segmento anterior. As variáveis BCVA, UCBA e os valores totais das aberrações corneanas de alta ordem foram correlacionadas com a espessura do leito estromal residual. Resultados: Os pacientes submetidos à DALK apresentaram BCVA de 0,68 ± 0,27 LogMar o que representa BCVA superior a 20/40 em 60% da amostra analisada. Não foram observadas micro ou macroperfurações. Houve diminuição na contagem endotelial de 2702,87 ± 548,87 células por mm2 para 2282,10 ± 525,66 células por mm2 . A dissecção do estroma profundo com o fio facilitou a remoção de tecido estromal posterior, fato corroborado com o achado de que o leito residual estromal aferido foi de 49,18 ± 18,36 ?m na região central e foi inferior a 80 ?m em grande parte dos pacientes estudados. No que se refere à regularidade da dissecção, observou-se tendência a valores mais elevados de espessura residual na periferia (60,09 ± 17,70 ?m). Não houve correlação da BCVA, UCVA e do total de aberrações de alta ordem da córnea com a espessura do leito estromal residual. Conclusão: A apreciação dos resultados desse estudo mostrou que com a técnica utilizada para realização de DALK em portadores de ceratocone obteve-se resultados topográficos e funcionais semelhantes a outras técnicas consagradas pela literatura. A facilidade na dissecção do estroma profundo, a regularidade da dissecção e a presença de baixíssimo índice de conversão para transplantes penetrantes são encorajadores / Objective: Evaluate the visual function of patients undergoing deep anterior lamellar keratoplasty (DALK) using a manual spatula and a wire dissection. Methods: Thirty three keratoconus patients were included, meeting the following inclusion criteria: BCVA logMAR <=0,60, myopia and astigmatism between 8.00 and 10,00D, K central average > 53.00D, no corneal scars and minimal corneal thickness between 300 and 400 um. Complete ocular evaluation was performed preoperatively and postoperatively in 6-8 months. These assessments were supplemented by topographical survey of the cornea, specular microscopy to evaluate the density of corneal endothelial cells, corneal wavefront analysis and examination of optical coherence tomography of the anterior segment (Visante). The BCVA variables, UCVA and the total amounts of corneal higher-order aberrations were correlated with the the residual stromal bed thickness. Results: Patients that undergone to DALK with the described technique presented a BCVA of 0.68 ± 0.27 logMAR which represents a BCVA of more than 20/40 at 60% of the analyzed sample. There were no micro or macroperforations. We observed a small decrease in the endothelial cell count from 2702.87 ± 548.87 cells per mm2 to 2282.10 ± 525.66 cells per mm2. The dissection of the deep stroma with a wire facilitated the posterior stromal tissue removal, thus the measured stromal bed thickness was 49.18 ± 18.36 ?m in the central region and less than 80 ?m in the majority of the studied patients. As regards the dissection regularity, we showed a tendency to higher values of residual thickness at the periphery (60.09 ± 17.70 ?m). There was no correlation of the BCVA, UCVA and total corneal higher-order aberrations with the residual stromal bed thickness. Conclusion: The assessment of the study data showed that the described technique achieved a topographical and functional result similar to other techniques consecrated by literature. The shallow learning curve, the ease to perform the dissection of the deep stroma, the postoperative stromal regularity and the presence of very low conversion rate for penetrating keratoplasty are encouraging

Orientador: Jose Paulo Cabral de Vasconcellos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T23:02:33Z (GMT). No. of bitstreams: 1 Okanobo_Andre_M.pdf: 2897473 bytes, checksum: 5bad5928ff037c8396c72781f5829cc1 (MD5) Previous issue date: 2014 / Resumo: Avaliação da qualidade de Vida dos Pacientes Antes e Após Realização de Transplante Penetrante de Córnea. OBJETIVO Verificar o impacto do transplante de córnea sobre a qualidade de vida dos indivíduos submetidos à cirurgia no serviço de Oftalmologia HC-UNICAMP no período de outubro de 2005 a outubro de 2006. METODO: O estudo foi aprovado pelo comitê de ética e pesquisa da FCM-UNICAMP. Foram inclusos indivíduos com indicação de transplante de córnea do ambulatório de Doenças Externas da Oftalmologia do HC UNICAMP no período de outubro de 2005 a outubro de 2006 e que aceitaram em participar do estudo. Foram incluídos 32 indivíduos. Os critérios de exclusão foram transplante tectônico, indivíduos com déficit visual importante causado por outra afecção ocular além das alterações corneanas. Realizou-se exame oftalmológico assim como aspectos demográficos e história ocular dos pacientes incluídos no estudo. Métodos objetivos como claridade do transplante e melhor acuidade visual corrigida e método subjetivo, a qualidade de vida, através do questionário SF-36 adaptado. RESULTADOS: Houve diferença significativa de satisfação entre gêneros com maior escore no sexo masculino (p = 0.0319). No método objetivo como a acuidade visual corrigida teve aumento significativo do olho transplantado (p<0.0001); A AV média antes do transplante era de 0,98 ± 0,1 logMAR e após 0,48 ± 0.38 logMAR. Quanto o escore de qualidade de vida (SF-36), método subjetivo, após o transplante houve um aumento significativo (p<0.0001). O escore do SF-36 antes do transplante foi de 49,11% ± 19,28 (média ± DP) e após o transplante de 71, 98% ± 24,28 (média ± DP) com uma melhora de 22, 87% (p<0.0001).Os indivíduos mais satisfeitos foram aqueles que tiveram a pontuação mais alta no SF-36 (r = 0.60; P = 0.0002). A satisfação parece não estar correlacionada com a melhora da AVCC no olho transplantado (r = 0.3186; P = 0.0755). Ocorreu uma fraca correlação entre a melhora da AVCC no olho transplantado e a melhora do SF-36 (r=0.28382; p=0.1154). Não houve diferença significativa do SF-36 nos indivíduos com visão baixa nos dois olhos quando comparado com os pacientes com visão boa em um dos olhos (p=0.2998 ) CONCLUSÃO: O transplante penetrante de córnea proporcionou melhora na pontuação dos métodos subjetivo e objetivos. Os indivíduos com maior satisfação foram melhor avaliados através do método subjetivo (SF-36). Não houve diferença significativa na qualidade de vida dos indivíduos com pior acuidade visual no olho contralateral quando comparado com os indivíduos com boa visão no olho contralateral, mas análise de um maior número de indivíduos é necessária / Abstract: Purpose: To assess and measures the patient satisfaction before and after penetrating keratoplasty. Methods: The study of approved by the ethics committee of FCM-UNICAMP. Data were collected from 32 patients who underwent penetrating keratoplasty (PK) between October 2005 and October 2006. Demographic, ocular history, objective treatment outcome measures such as clarity of the graft and best-corrected visual acuity (BCVA) of both eyes were collected prospectively. In addition to assessment of quality of life were obtained by an interview before the PK and after at least one year of postoperative. Results: The average age of subjects was 42 ± 22 (mean ± SD) years and 68.75 % were women. On average, men were most satisfied. BCVA was 0,98 ± 0,1 logMAR before and 0,48 ± 0.38 logMAR after PK showing a significant improvement on BCVA (P < 0.0001). SF-36 score was 49.11% ± 19.28% before and 71.98% ± 24.28% after PK showing a significant improvement after the PK (p< 0.0001). The most satisfied patients where those who had a better score on SF-36 (r = 0.60; p = 0.0002). Satisfaction seems not to be correlated to improvement in BCVA at the transplanted eye (r = 0.3186; p = 0.0755). There was weak correlation between improvement in BCVA on the transplanted eye and improvement of SF-36 score (r = 0.28382; p=0.1154). There was no significant improvement in SF-36 in patients with worse BCVA in the other eye (p = 0.2998). Conclusions: Penetrating keratoplasty has a positive effect on objective and subjective outcome measures. Patient satisfaction is better predicted by subjective outcomes. There is no significant difference in quality of life in patients with worse BCVA in the contralateral eye when compared to eye with good BCVA in the contralateral eye, but analysis of a larger number of patients is necessary to confirm that / Mestrado / Oftalmologia / Mestre em Ciências Médicas

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-20T17:53:34Z No. of bitstreams: 1 flaviabatistabarbosadesa.pdf: 1013858 bytes, checksum: 1e5c85e290deeb77a83c4367e5c61db1 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-02T11:27:01Z (GMT) No. of bitstreams: 1 flaviabatistabarbosadesa.pdf: 1013858 bytes, checksum: 1e5c85e290deeb77a83c4367e5c61db1 (MD5) / Made available in DSpace on 2016-07-02T11:27:01Z (GMT). No. of bitstreams: 1 flaviabatistabarbosadesa.pdf: 1013858 bytes, checksum: 1e5c85e290deeb77a83c4367e5c61db1 (MD5) Previous issue date: 2012-03-26 / Objetivo: Analisar os fatores que influenciam o processo de doação de córneas entre os potenciais doadores de um Hospital Público e de um Hospital Privado de Juiz de Fora. Métodos: estudo seccional do tipo descritivo. Foram rastreados os óbitos ocorridos em um Hospital Público e um Hospital Privado de Juiz de Fora no período de 01 janeiro de 2010 a 31 de dezembro de 2010, identificados os potenciais doadores de córneas, verificado se os óbitos foram notificados à Central de Notificação, Captação e Distribuição de Órgãos (CNCDO) da Zona da Mata de Juiz de Fora e se esta notificação resultou ou não em doação. Caso não tenha ocorrido doação, foi justificada a causa da não efetivação da mesma, e caso tenha ocorrido, foi analisado o destino da córnea captada (transplante ou perda). Os dados foram processados e discutidos utilizando-se a análise estatística feita através do Programa SPSS (Statistical Package for the Social Sciences), versão 13.0. Resultados: A população em estudo se caracteriza por serem em sua maioria pacientes do sexo masculino (53,1%), com idade entre 2 a 80 anos (69,1%), com causas mortis que não contraindicaram o transplante de córneas (59,1%). Dos 863 óbitos, 138 (16%) não foram notificados à CNCDO-Zona da Mata e destes, 54 eram potenciais doadores. Do total de óbitos, 210 (24,3%) foram classificados como potenciais doadores. O percentual de captação efetiva dos casos entrevistados foi de 34,9%. Foram realizadas 30 doações de córneas (19,2%). Observou-se que das 60 córneas captadas (30 doadores), 75,0% (45) foram descartadas. A não efetivação da doação foi justificada pela recusa familiar em 58 casos (7,0%), pelos problemas logísticos ou estruturais em 125 casos (15,0%) e pelas contraindicações médicas registradas na CNCDO-Zona da Mata em 650 casos (78,0%). Conclusão: Da população estudada, 24,3% eram potenciais doadores de córneas. A contraindicação médica foi a maior justificativa para a não efetivação da doação de córneas, correspondendo a 78,0% das causas. Considerando que apenas 25% das córneas captadas foram transplantadas, conclui-se que há uma grande desigualdade entre o número de doadores potenciais e o número de doadores reais para o transplante de córneas, pois muito se perde durante todo o processo de doação. / Objective: To analyze factors that influence the process of cornea donation among potential donors for a Public Hospital and a Private Hospital in Juiz de Fora. Methods: A descriptive cross sectional study. We traced the deaths occurred in a Public Hospital and a Private Hospital in Juiz de Fora in the period from January 1, 2010 to December 31, 2010, identified the potential donors of corneas, checked whether the deaths were reported to the Central Notification, Procurement and Distribution organs (CNCDO) from Zona of Mata in Juiz de Fora and whether or not this notification resulted in donation. If there were no donation, it was justified the cause of not being done, and if it has occurred, we analyzed the fate of the captured cornea (transplantation or loss). The data were analyzed and discussed using the statistical analysis performed using the SPSS (Statistical Package for Social Sciences) version 13.0. Results: The mortality profile of the institutions under study is characterized by being mostly male (53.1%), aged from 2 to 80 years (69.1%), with cause of death that did not prevent corneal transplantation to be done (59.1%). Of the 863 deaths, 138 (16%) were not notified to CNCDO-Zona of Mata and of these, 54 were potential donors. Of the total deaths, 210 (24.3%) were classified as potential donors. The percentage of effective capture of the cases surveyed was 34.9%. 30 donations of corneas were performed (19.2%). It was observed that from 60 corneal grafts (30 donors), 75.0% (45) were discarded. The effectiveness of the donation was not justified by family refusal in 58 cases (7.0%), by logistical or structural problems in 125 cases (15.0%) and recorded in the medical contraindications CNCDO-Zona da Mata in 650 cases (78.0 %). Conclusion: The study population, 24.3% were potential donors of corneas. The medical contraindication was the biggest reason for not effecting the donation of corneas, corresponding to 78.0% of the causes. Whereas only 25% of corneal grafts were transplanted, it is concluded that a considerable difference between the number of potential donors and the number of actual donors for transplantation of corneas, since much is lost during the donation process.

Objetivo: Analisar a influência da espessura corneana central na acuidade visual (AV) corrigida após transplante de córnea endotelial lamelar profundo (TCELP). Métodos: Foram estudados de forma prospectiva 155 olhos de 127 pacientes portadores de ceratopatia bolhosa ou distrofia endotelial de Fuchs no sexto mês de pós-operatório do TCELP, entre março de 2000 e março de 2005. Foram excluídos pacientes com outras alterações oculares que justificassem baixa AV. Todos os pacientes foram submetidos à avaliação oftálmica, quando foram determinadas AV corrigida, por meio de exame refratométrico, e espessura corneana central, através da paquimetria ultra-sônica. As técnicas usada foram previamente descritas. Os olhos foram agrupados de acordo com as medidas de AV: grupo I (20/20 - 20/30), grupo II (20/40 - 20/50), grupo III (20/60 - 20/80), grupo IV (20/100 - 20/400). Para correlação com paquimetria e análise estatística, as medidas de AV foram convertidas da tabela de Snellen para a tabela logarítmica (logMAR). Foram criadas variáveis categóricas para expressar status de faixa de normalidade de espessura corneana (entre 495 e 651 ?m), usando como pontos de corte valores encontrados na literatura. Resultados: A média, o desvio padrão e a variação da paquimetria foi: grupo I (n=38) 571 ±80 um, 408 a 784 um; grupo II (n=79) 598 ±80 um, 437 a 816 um; grupo III (n=30) 605 ±99 um, 454 a 945 um e grupo IV (n=8) 607 ±120 ?m, 410 a 781 ?m. Analisando o resultado da AV e a porcentagem de casos com espessura corneana acima de 651 um, foi observada associação linear significativa (P=0,037; ?2 de tendência linear) entre o aumento da paquimetria e a piora da AV. Analisando a associação entre os grupos de AV e a porcentagem de casos com espessura corneana abaixo da faixa de normalidade (<495 um), não foi encontrada significância estatística (P=0,92; x2 de Pearson). Quando analisado o resultado visual do grupo I em relação ao resultado dos grupos II+III+IV em conjunto, observou-se que somente 13% dos casos do grupo I e 30% dos casos dos demais grupos apresentaram espessura corneana maior do que 651 ?m. Essa correlação demonstrou significância estatística limítrofe (P=0,066; x2 de Pearson com correção de Yates). Conclusão: Observou-se associação linear significativa entre piora da AV corrigida e aumento da espessura corneana central. Quando analisados somente casos com paquimetria abaixo da faixa de normalidade, não foi observada associação significativa entre piora da AV corrigida e espessura corneana central / Purpose: To analyze the influence of central corneal thickness in the corrected visual acuity (VA) after deep lamellar endothelial corneal keratoplasty (DLEK). Methods: Retrospective study of 155 eyes of 127 patients 6 months post-op DLEK between March 2000 and March 2005. These patients had been previously diagnosed with either bullous keratopathy or Fuch\'s endothelial dystrophy. Patients with other ophthalmic conditions that could cause loss of vision were excluded. All patients underwent ophthalmic evaluation to determine corrected VA by means of refraction and central corneal thickness by means of ultrasonic pachymetry. Eyes were grouped according to visual acuity into 4 groups: I (20/20 - 20/30), II (20/40 - 20/50), III (20/60 - 20/80), IV (20/100 - 20/400). For statistical analysis and corelation with pachymetry, VA measurements were converted to logMAR. Categorical variables were created to express normal range corneal thickness status (from 495 to 651 um) using values published on the literature. Results: Mean and standart deviation pachymetry values were: group I (n=38) 571 ±80 ?m, ranging from 408 to 784 um; group II (n=79) 598 ±80 um, ranging from 437 to 816 ?m; group III (n=30) 605 ±99 um, ranging from 454 to 945 um and group IV (n=8) 607 ±120 um, ranging from 410 to 781 ?m. Analyzing the VA results and the percentage of cases with corneal thickness above 651 um, a significant linear correlation between higher pachymetry and worse VA was observed (P=0.037; linear trend). Analyzing the association between the different groups and the percentage of cases with corneal thickness bellow 495 um, there was no statistical significance (P=0.92; Pearson\'s x2). When analyzing the visual results of group I compared to groups II+III+IV together, it was observed that only 13% of group I cases and 30% of cases from the other groups presented corneal thickness greater then 651 um. This correlation showed borderline statistical significance (P=0.066; Pearson\'s x2 with Yates\' correction). Conclusions: A significant linear correlation between increased corneal thickness and worse VA was observed. When analyzing only cases bellow normal pachymetry, there was no correlation between corneal thickness and worse VA

Les agressions graves de la surface oculaire peuvent se compliquer d'ulcérations cornéennes épithéliales, de néovascularisation, d'opacification et d'inflammation chroniques, échappant à tout traitement médical. Les progrès dans la compréhension de la physiologie du renouvèlement de l'épithélium et du stroma cornéen ont permis d'introduire une approche thérapeutique, la greffe de cellules souches. L'objectif de notre étude est d'apporter une source de cellules souches cornéennes par thérapie cellulaire afin de restituer une fonction épithéliale et stromale permettant l'obtention d'une cornée claire chez l'animal. Les cellules souches épithéliales limbiques (LSC) et les cellules stromales limbiques (SSC) ont été isolées dans un milieu exempt de produits animaux tout en gardant leur caractère indifférencié. L'effet régénérateur des SSC a été étudié in vivo dans un modèle de fibrose cornéenne chez la souris. Les SSC ont été injectées dans le stroma cornéen et ont permis la restitution d'un stroma organisé et d'une cornée transparente. Le projet a aussi consisté à élaborer et mettre en forme une matrice à base de collagène I afin de favoriser la culture concomitante de tous les types cellulaires présents dans la cornée tout en préservant organisation, transparence et propriétés mécaniques. La connaissance des conditions physico-chimique du collagène a permis de produire des matrices transparentes qui ont pu être colonisées par les SSC et les LSC. Notre étude ouvre de nouvelles perspectives dans le traitement des pathologies provocant des opacités cornéennes afin de faire face au manque de dons de cornée. / Cornea, the outer part of the eye, features high transparency crucial for good vision. The maintenance of a healthy cornea is linked to the presence of corneal stem cells in the limbus (peripheral region of the cornea). Several diseases can lead to its opacification requiring transplantation of donor tissue to restore vision. Although corneal transplantation has achieved clinical success, there is a shortage of donor corneas worldwide. To solve this problem, cell therapy and tissue-engineered artificial cornea are promising approaches that could eventually outperform current treatment. Corneal epithelial stem cells (LSC) and stromal stem cells (SSC) were isolated in feeder free and xeno free medium. The therapeutic effect of SSC was investigated in vivo by their injection in mouse cornea treated with liquid nitrogen. SSC have the ability to restore the extracellular matrix organization and corneal transparency. Transparent collagen I fibrillated matrices have been synthesized and were evaluated for fibril organization, transparency, mechanical properties and their ability to be repopulated by corneal stromal stem cells and to support limbal epithelial stem cell growth. We show that the matrices were organized and transparent. SSC and LSC were able to repopulate and to grow into the collagen matrix. These cells present a potential for stem cell-based treatment of corneal blindness.

Objetivo: Analisar a influência da espessura corneana central na acuidade visual (AV) corrigida após transplante de córnea endotelial lamelar profundo (TCELP). Métodos: Foram estudados de forma prospectiva 155 olhos de 127 pacientes portadores de ceratopatia bolhosa ou distrofia endotelial de Fuchs no sexto mês de pós-operatório do TCELP, entre março de 2000 e março de 2005. Foram excluídos pacientes com outras alterações oculares que justificassem baixa AV. Todos os pacientes foram submetidos à avaliação oftálmica, quando foram determinadas AV corrigida, por meio de exame refratométrico, e espessura corneana central, através da paquimetria ultra-sônica. As técnicas usada foram previamente descritas. Os olhos foram agrupados de acordo com as medidas de AV: grupo I (20/20 - 20/30), grupo II (20/40 - 20/50), grupo III (20/60 - 20/80), grupo IV (20/100 - 20/400). Para correlação com paquimetria e análise estatística, as medidas de AV foram convertidas da tabela de Snellen para a tabela logarítmica (logMAR). Foram criadas variáveis categóricas para expressar status de faixa de normalidade de espessura corneana (entre 495 e 651 ?m), usando como pontos de corte valores encontrados na literatura. Resultados: A média, o desvio padrão e a variação da paquimetria foi: grupo I (n=38) 571 ±80 um, 408 a 784 um; grupo II (n=79) 598 ±80 um, 437 a 816 um; grupo III (n=30) 605 ±99 um, 454 a 945 um e grupo IV (n=8) 607 ±120 ?m, 410 a 781 ?m. Analisando o resultado da AV e a porcentagem de casos com espessura corneana acima de 651 um, foi observada associação linear significativa (P=0,037; ?2 de tendência linear) entre o aumento da paquimetria e a piora da AV. Analisando a associação entre os grupos de AV e a porcentagem de casos com espessura corneana abaixo da faixa de normalidade (<495 um), não foi encontrada significância estatística (P=0,92; x2 de Pearson). Quando analisado o resultado visual do grupo I em relação ao resultado dos grupos II+III+IV em conjunto, observou-se que somente 13% dos casos do grupo I e 30% dos casos dos demais grupos apresentaram espessura corneana maior do que 651 ?m. Essa correlação demonstrou significância estatística limítrofe (P=0,066; x2 de Pearson com correção de Yates). Conclusão: Observou-se associação linear significativa entre piora da AV corrigida e aumento da espessura corneana central. Quando analisados somente casos com paquimetria abaixo da faixa de normalidade, não foi observada associação significativa entre piora da AV corrigida e espessura corneana central / Purpose: To analyze the influence of central corneal thickness in the corrected visual acuity (VA) after deep lamellar endothelial corneal keratoplasty (DLEK). Methods: Retrospective study of 155 eyes of 127 patients 6 months post-op DLEK between March 2000 and March 2005. These patients had been previously diagnosed with either bullous keratopathy or Fuch\'s endothelial dystrophy. Patients with other ophthalmic conditions that could cause loss of vision were excluded. All patients underwent ophthalmic evaluation to determine corrected VA by means of refraction and central corneal thickness by means of ultrasonic pachymetry. Eyes were grouped according to visual acuity into 4 groups: I (20/20 - 20/30), II (20/40 - 20/50), III (20/60 - 20/80), IV (20/100 - 20/400). For statistical analysis and corelation with pachymetry, VA measurements were converted to logMAR. Categorical variables were created to express normal range corneal thickness status (from 495 to 651 um) using values published on the literature. Results: Mean and standart deviation pachymetry values were: group I (n=38) 571 ±80 ?m, ranging from 408 to 784 um; group II (n=79) 598 ±80 um, ranging from 437 to 816 ?m; group III (n=30) 605 ±99 um, ranging from 454 to 945 um and group IV (n=8) 607 ±120 um, ranging from 410 to 781 ?m. Analyzing the VA results and the percentage of cases with corneal thickness above 651 um, a significant linear correlation between higher pachymetry and worse VA was observed (P=0.037; linear trend). Analyzing the association between the different groups and the percentage of cases with corneal thickness bellow 495 um, there was no statistical significance (P=0.92; Pearson\'s x2). When analyzing the visual results of group I compared to groups II+III+IV together, it was observed that only 13% of group I cases and 30% of cases from the other groups presented corneal thickness greater then 651 um. This correlation showed borderline statistical significance (P=0.066; Pearson\'s x2 with Yates\' correction). Conclusions: A significant linear correlation between increased corneal thickness and worse VA was observed. When analyzing only cases bellow normal pachymetry, there was no correlation between corneal thickness and worse VA