Fundamentos: A caracterização precisa da interação da placa aterosclerótica no momento do implante do stent é crucial para o entendimento da complacência e da cicatrização vasculares. Objetivamos investigar se a composição da placa avaliada pela tomografia de coerência óptica (OCT), influencia as alterações agudas no procedimento índice do implante do stent e na cicatrização vascular no seguimento tardio. Métodos: Os pacientes tratados com um único tipo de stent eluidor de fármaco (cromo cobalto, eluidor de sirolimus e polímero bioabsorvível) foram incluídos prospectivamente, seguindo um protocolo com etapas de dilatações progressivas do vaso. As imagens de OCT sequenciais foram realizadas no procedimento índice (basal e a cada etapa do protocolo) e no seguimento tardio, co-registradas e analisadas a cada 0,6mm. A avaliação semiquantitativa da placa foi realizada dividindo-se secções transversas em 4 quadrantes, com cada quadrante rotulado de acordo com o seu componente mais prevalente (fibrótico, calcificado, lipídico, normal). A interação stent-vaso avaliada pela OCT foi utilizada como indicador substituto para lesão e cicatrização vasculares após o implante do stent. Resultados: Um total de 22 lesões (1stent/lesão) de 20 pacientes e 2298 seções transversas de OCT foram analisadas no procedimento índice. O reestudo com OCT foi realizado em 17 pacientes e 19 lesões (86%). O componente de placa predominante foi fibrótico (fibrótico = 46.84 ± 16%; lipídico = 17.63 ± 10.72%; calcificado = 4.63 ± 5.9%; normal = 29.16 ± 12.24; não analizável=1.74 ± 5.35%). Houve um aumento nas áreas da luz (10atm = 5.5 (4.5 - 7.4) mm2, 14-16atm = 6.0 (4.7 - 7.70) mm2, 20atm = 6.7 (5.5 - 8.2) mm2; P < 0.001) e do stent (10atm = 5.2 (4.3 - 7.0) mm2, 14-16atm = 5.7 (4.5 - 7.5) mm2, 20atm = 6.5 (5.3 - 7.9) mm2; P < 0.001), com um aumento na área do prolapso tecidual (10atm =0.09 (0.06 - 0.12) mm2, 14-16atm =0.10 (0.06 - 0.15) mm2, 20atm =0.15 (0.08 - 0.20) mm2; P < 0.01). Segmentos com muito tecido fibrocalcificado tiveram áreas luminais menores ao longo das etapas da intervenção. Por outro lado, placas com muito conteúdo lipídico ou vaso normal tiveram maiores ganhos nas medidas das áreas luminais mínimas ao longo das dilatações sequenciais. Além disso, placas com muito tecido fibrocalcificado no momento basal apresentaram menor crescimento neointimal no seguimento tardio, enquanto que o grau de conteúdo lipídico e de vaso normal não tiveram impacto sobre a formação do tecido neointimal. Os indicadores substitutos de lesão vascular após o implante do stent correlacionaram-se significativamente com o crescimento neointimal no seguimento tardio. Conclusões: A composição tecidual das placas subjacentes influencia significativamente o comportamento mecânico agudo e a longo prazo dos vasos coronarianos submetidos ao implante de stent. Além disso, a lesão vascular após o implante do stent está potencialmente ligada ao futuro crescimento neointimal no seguimento tardio / Background Accurate characterization of atherosclerotic plaque interaction during stent deployment is crucial to understand vascular compliance and healing. We sought to determine whether plaque composition assessed by optical coherence tomography (OCT), influences acute changes at index procedure and vascular healing at follow up. Methods Patients treated with a single drug-eluting stent type (cobalt chromium with bioabsorbable polymer eluting sirolimus stent) were prospectively included, following a pre-defined step-by-step progressive vessel dilatation. Sequential OCT imaging were performed at the index procedure (baseline and at each time point of the protocol) and at follow up, co-registered and analyzed every 0.6mm for quantitative measurements. Semi-quantitative plaque assessment was performed at baseline by dividing cross-sections into 4 quadrants, with each quadrant labeled according to its most prevalent component (fibrotic, calcific, lipid). OCT assessments of stent-vessel interactions were used as a surrogate for vessel injury and healing after stent implantation. Results A total of 22 lesions (1stent/lesion) of 20 patients and 2298 OCT crosssections were analyzed at the index procedure. For an average of 19.7 months (591.88 ± 60.52 days), 17 of the patients and 19 lesions (86%) underwent OCT imaging at follow up. The predominant percentage plaque component was fibrotic (fibrotic = 46.84 ± 16%; lipid = 17.63 ± 10.72%; calcific = 4.63 ± 5.9%; normal = 29.16 ± 12.24; non-analyzable = 1.74 ± 5.35%). There was an increase in lumen (10atm = 5.5 (4.5 - 7.4) mm2, 14-16atm = 6.0 (4.7 - 7.70) mm2, 20atm = 6.7 (5.5 - 8.2) mm2; P < 0.001) and stent (10atm = 5.2 (4.3 - 7.0) mm2, 14-16atm = 5.7 (4.5 - 7.5) mm2, 20atm = 6.5 (5.3 - 7.9) mm2; P < 0.001) areas, with an increase in tissue prolapse area (10atm =0.09 (0.06 - 0.12) mm2, 14-16atm =0.10 (0.06 - 0.15) mm2, 20atm =0.15 (0.08 - 0.20) mm2; P < 0.01). Segments with high fibrocalcific content tended to have decreased minimal luminal areas along the intervention time-points. Conversely, plaques with high lipid content had increased minimal luminal areas during sequential dilatations. Moreover, plaques with high fibrocalcific tissue at baseline had significantly smaller neointimal growth at follow-up, whereas the degree of lipid content or normal tri-layered vessel had no impact on neointimal formation. OCT surrogates of vessel injury after coronary stenting significantly correlated with neointimal growth at follow-up. Conclusions: Tissue composition of underlying plaques significantly influences the acute mechanical and the long-term behavior of coronary vessels undergoing stent implantation. In addition, vessel injury after coronary stenting is potentially linked to future neointimal growth at follow-up

Pacientes com compressão quiasmática apresentam perda das fibras nervosas da retina nasal que decussam no quiasma óptico. Por conseguinte, ocorre perda das fibras nervosas, predominantemente, no setor nasal e temporal do disco óptico, que se manifesta por atrofia em banda do nervo óptico ao exame oftalmoscópico e hemianopsia temporal ao exame de campo visual. Trabalhos anteriores mostraram que o tomógrafo de coerência óptica é capaz de diferenciar pacientes com atrofia em banda do nervo óptico associada à hemianopsia temporal completa de indivíduos normais através da análise da camada de fibras nervosas peripapilar. Estudos em glaucoma têm sugerido que a avaliação da espessura macular poderia ser útil na quantificação da perda neural como um método alternativo ou complementar ao estudo da camada de fibras nervosas da retina. No presente estudo, a espessura macular e da camada de fibras nervosas foram avaliadas pelo tomógrafo de coerência óptica em pacientes com atrofia em banda do nervo óptico e graus variados de hemianopsia temporal. O desempenho dos parâmetros maculares para detecção da atrofia em banda do nervo óptico foi avaliado pela área sob a curva ROC (AROC) e sensibilidades para especificidades fixas e os resultados foram comparados aos parâmetros da camada de fibras nervosas peripapilar. Para identificar os parâmetros do Stratus OCT que apresentaram melhor desempenho para diferenciar pacientes com AB do nervo óptico de indivíduos normais, modelos de regressão logística foram utilizados. A correlação estrutura-função foi realizada entre o grau do defeito temporal e os valores de espessura macular e da camada de fibras peripapilar através do coeficiente de correlação de Spearman. A categorização diagnóstica dos parâmetros da camada de fibras nervosas através do banco de dados normativos foi avaliada pelos valores de sensibilidade e especificidade calculados pelo teste exato de Fisher. Quarenta e quatro olhos com atrofia em banda e 47 olhos normais foram avaliados no estudo. Entre os parâmetros maculares, os parâmetros da retina nasal apresentaram melhor desempenho para detectar atrofia em banda do nervo óptico comparados aos parâmetros da retina temporal. Não houve diferença significante (p=0,32) entre as áreas sob a curva ROC do melhor parâmetro macular (AROC=0,97) e do melhor parâmetro da camada de fibras nervosas retiniana (AROC=0,99). Na avaliação da correlação estrutura-função, os parâmetros da retina nasal apresentaram maior correlação com o defeito campimétrico comparados aos parâmetros da camada de fibras nervosas da retinal. Entre os parâmetros maculares, a espessura nasal média apresentou a maior correlação (rs=0,618). Entre os parâmetros da camada de fibras nervosas da retina, a espessura média apresentou a maior correlação (rs=0,479). Os parâmetros espessura média, espessura nasal e espessura temporal da camada de fibras nervosas da retina apresentaram melhor desempenho diagnóstico baseado na categorização diagnóstica do banco de dados normativos. Os resultados obtidos no estudo mostraram que os parâmetros maculares discriminam olhos com atrofia em banda do nervo óptico em pacientes com graus variados de defeito temporal. Além disso, os parâmetros da retina nasal podem colaborar com o exame perimétrico e os parâmetros da camada de fibras nervosas para o seguimento dos pacientes com compressão quiasmática. / Patients with chiasmal compression present damage of crossed fibers of nasal retina. Therefore, retinal nerve fiber layer loss occurs predominantly on the nasal and temporal sides of the optic disc, a pattern that can be identified on ophthalmoscopy as band atrophy of the optic nerve and on visual field as temporal hemianopia. Previous studies have been demonstrated that optical coherence tomography is able to detect retinal nerve fiber layer loss in patients with lesions of the optic chiasm and complete temporal hemianopia. Studies in glaucoma have been suggested that macular thickness measurements could be useful in quantification of optical nerve axonal loss as alternative or complement method to evaluate the retinal nerve fiber layer. The purpose of the present study was to compare macular thickness and retinal nerve fiber thickness measurements in patients with band atrophy of the optic nerve and different severities of visual field defect using optical coherence tomography. Area under the receiver operating characteristic curve (AROC) and sensitivities at fixed specificities were performed for evaluation of diagnostic accuracy of macular and retinal nerve fiber layer parameters. To identify the best optical coherence tomography measurements to differentiate band atrophy of the optic nerve patients from normal individuals, logistic regression models were performed. Association between optical coherence tomography parameters and temporal field defect were examined by Spearman coefficient of correlation. Fisher\'s exact test was performed to evaluate diagnostic ability of retinal nerve fiber parameters by optical coherence tomography in eyes with band atrophy using comparison with its internal normative database. A total of 44 eyes with band atrophy of the optic nerve and 47 normal eyes were studied. Among macular parameters, nasal retina measurements showed diagnostic accuracy better than temporal retina measurements. No statistically significant difference (p=0.32) was found between areas under ROC curve for the best macular parameter (AROC=0.97) and the best retinal nerve fiber layer parameter (AROC=0.99). Nasal retina parameters correlations were higher than retinal nerve fiber parameters. The highest correlation was observed for the mean nasal thickness (rs=0.618) for macular parameters. In retinal nerve fiber parameters, the highest correlation was observed for the average thickness (rs=0.479). In evaluation of diagnostic ability of normative database, the average thickness parameter demonstrated the highest sensitivity for detection of abnormalities in eyes with band atrophy, followed by the parameters related to the nasal and temporal quadrants. These results suggest that macular thickness measurements discriminate eyes with band atrophy of the optic nerve with different severities of temporal field defect. Results also suggest that nasal retina thickness measurements could potentially be used to evaluate retinal ganglion cell loss in patients with chiasmal compression.

Introdução: a ataxia espinocerebelar tipo 7 (SCA7) é um distúrbio neurodegenerativo autossômico dominante causado por uma repetição CAG expandida (CAGexp) no gene ATXN7, resultando na inserção de uma poliglutamina (poliQ) alongada na proteína ataxina-7. Em consequência, pacientes com SCA7 desenvolvem ataxia, espasticidade e outros sintomas neurológicos. A SCA 7 se destaca de outras SCAs por se associar à distrofia retiniana, causando deficiências visuais que podem levar à cegueira. Sendo uma das mais raras SCAs, pequenas séries de casos têm aparecido na literatura. Poucas delas buscaram correlacionar os achados neurológicos com os oftalmológicos; e a fase pré-clínica jamais foi sistematicamente investigada. Objetivo: descrever os achados neurológicos e oftalmológicos de uma coorte de casos de SCA 7, comparando as manifestações encontradas em sujeitos sintomáticos com as encontradas em portadores assintomáticos e em parentes não portadores, em uma abordagem exploratória que buscou levantar potenciais biomarcadores de progressão da doença. Métodos: trata-se de um estudo transversal onde pacientes com diagnóstico molecular de SCA7 realizado na nossa instituição foram identificados em nossos arquivos protegidos. Tanto eles como seus parentes foram convidados a participar da presente investigação. Sujeitos em risco de 50% foram incluídos se tivessem mais de 18 anos. Após o consentimento, dados clínicos e demográficos foram coletados entre junho de 2016 e setembro de 2017. A seguir, todos os participantes realizaram uma bateria de escalas clínicas voltadas à medida da ataxia (SARA, CCFS, PATA e 8 MW) e das manifestações neurológicas (NESSCA e INAS); um questionário de qualidade de vida relacionada à visão (NEI-VFQ 25); avaliação da acuidade visual melhor corrigida (AVMC), desvio médio em campimetria computadorizada (MD) e espessuras da mácula e da camada de células ganglionares na tomografia de coerência óptica (OCT). A escala SARA e a AVMC foram escolhidas como as variáveis de referência para a gravidade dos quadros. A análise molecular do ATXN7 foi feita, mas participantes do estudo e avaliadores foram mantidos cegos para seus resultados; os indivíduos em risco interessados em receber seus resultados foram enviados para o programa de testes pré-sintomáticos. Como não houve critérios a priori para estimar tamanhos de efeito e como a SCA7 é uma condição rara, não houve como decidir um tamanho de amostra. O estudo foi exploratório e por isso não foram feitas correções para múltiplas testagens. Um p de 0,05 foi eleito para definir significância, e testes estatísticos foram aplicados de acordo com as características das variáveis em estudo. Resultados: 12 portadores sintomáticos (grupo 2) e 8 indivíduos em risco (3 portadores - grupo 1 - e 5 não-portadores - grupo 0) foram incluídos neste estudo. Todas as variáveis contínuas à exceção da CAGexp tiveram distribuição 4 normal. A AVMC estava reduzida em todos os participantes sintomáticos e claramente diferente entre estes e os outros dois grupos (p <0,0001, ANOVA), enquanto os portadores assintomáticos e os não portadores tiveram resultados semelhantes. A AVMC média foi 20/143, 20/18 e 20/20 nos grupos 2, 1 e 0, respectivamente. Não surpreendentemente, o NEI-VFQ 25 também demonstrou uma diferença estatisticamente significativa, mas o que foi inesperado foi a forma progressivamente diferente entre os 3 grupos (grupo 0 = 92,76 ± 6,7; grupo 1 = 74,9 ± 55,5; grupo 2 = 58,0 ± 21,3) (p= 0,012, ANOVA com Tukey) O MD mostrou um padrão linear estatisticamente significativo para piorar do grupo controle (-1,34 ± 1,15dB) para o assintomático (-2,81 ± 1,66dB) e do grupo assintomático para sintomático (-10,54 ± 6,95dB) (p = 0,027, ANOVA com Tukey). Além disso, o MD correlacionou-se com a AVMC (p = 0,020; r = 0,660) e apresentou tendência de correlação com a SARA (p= 0,073; r= -0,535). As medidas de espessura macular distinguem completamente os 3 grupos (grupo 0 = 243,6 ± 22,2 μ; grupo 1 = 204,5 ± 14,1 μ; grupo 2 = 137,95 ± 34,6 μ) (p = 0,0001, ANOVA) e também se correlacionou significativamente com os dois critérios planejados de gravidade, SARA (p = 0,050; r = -0,577) e AVMC (p = 0,007; r = 0,730). Discussão: alterações oftalmológicas estavam presentes já nas fases pré-clínicas da doença, quando os escores obtidos das escalas neurológicas ainda não distinguem portadores assintomáticos de não portadores: a espessura macular medida por OCT e o MD medido pela campimetria computadorizada. Esses achados demonstram que o processo neurodegenerativo já se encontra em curso e é detectável por essas medidas anatômicas e funcionais da retina. Além disso, ambas as alterações detectadas em fases pré-clínicas, ao serem estudadas no grupo total de portadores sintomáticos e assintomáticos, se correlacionaram com os nossos padrões-ouro da gravidade da doença, SARA e AVMC. Os dois achados - início em fase pré-clínica e correlação com a progressão da doença medida por escores independentes - sugerem que a espessura macular medida por OCT e o MD medido pela campimetria computadorizada são potenciais candidatos a biomarcadores de estado (de progressão da doença) desde fases pré-manifestas na SCA7. / Background: spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant neurodegenerative disorder caused by an expanded CAG repeat (CAGexp) at ATXN7 gene, resulting in the insertion of an elongated polyglutamine (polyQ) into the ataxin-7 protein. As a consequence, patients with SCA7 develop ataxia, spasticity and other neurological symptoms. SCA7 stands out from other SCAs by associating it with retinal dystrophy, causing visual deficiencies that can lead to blindness. Being one of the rarest SCAs, small series of cases appear in the literature. Few of them sought to correlate neurological findings with ophthalmologic findings; and the preclinical stage has never been systematically investigated. Objective: to describe the neurological and ophthalmological findings of a cohort of cases of SCA7, comparing the manifestations found in symptomatic subjects with those found in asymptomatic carriers and in non-carrier relatives in an approach exploratory study that sought to raise potential biomarkers of disease progression. Methods: patients with a molecular diagnosis of SCA7 performed at our institution were identified in our protected files. Both they and their relatives were invited to participate in the present investigation. Subjects at risk of 50% were included if they were older than 18 years. After consent, clinical and demographic data were collected between June 2016 and September 2017. All participants then performed a battery of clinical scales aimed at the measurement of ataxia (SARA, CCFS, PATA and 8 MW) and neurological manifestations (NESSCA and INAS); a visual function questionnaire (NEI-VFQ 25); assessment of better corrected visual acuity (AVMC), mean deviation in computerized campimetry (MD), and thickness of the macula and ganglion cell layer on OCT. The SARA and AVMC scale were chosen as the reference variables for the severity of the frames. Molecular analysis of ATXN7 was done, but study participants and evaluators were kept blind to their results; the individuals at risk interested in receiving their results were sent to the presymptomatic testing program. As there were no a priori criteria for estimating effect sizes and because SCA7 is a rare condition, there was no way to decide on a sample size. The study was exploratory and therefore no corrections were made for multiple tests. A p of 0.05 was chosen to define significance, and statistical tests were applied according to the characteristics of the variables under study. Results: 12 symptomatic carriers (group 2) and 8 individuals at risk (5 carriers - group 1 - and 3 non-carriers - group 0) were included in this study between June 2016 and September 2017. All continuous variables with the exception of CAGexp had normal distribution. AVMC was reduced in all symptomatic participants and clearly different between these and the other two groups (p <0.0001, ANOVA), while asymptomatic and non-carriers had similar results. The mean BCVA was 20/143, 20/18 and 20/20 in groups 2,1 and 6 0, respectively. Not surprisingly, NEI-VFQ 25 also showed a statistically significant difference, but what was unexpected was the progressively different form between the 3 groups (group 0 = 92.76 ± 6.7, group 1 = 74.9 ± 55, 5, group 2 = 58.0 ± 21.3) (p = 0.012, ANOVA with Tukey). The MD showed a statistically significant linear pattern to worsen from the control group (-1.34 ± 1.15dB) to the asymptomatic (-2.81 ± 1.66dB) and from the asymptomatic to the symptomatic group (-10.54 ± 6, 95dB) (p = 0.027, ANOVA with Tukey). In addition, MD correlated with AVMC (p = 0.020; r = 0.660) and showed a correlation tendency with ARDS (p = 0.073; r = -0.535). The macular thickness scores completely distinguish the 3 groups (group 0 = 243.6 ± 22.2 μ, group 1 = 204.5 ± 14.1 μ, group 2 = 137.95 ± 34.6 μ) (p = 0.0001, ANOVA ...) and also correlated significantly with the two planned criteria of severity, SARA (p = 0.050, r = -0.577) and AVMC (p = 0.007, r = 0.730). Conclusion: ophthalmologic changes were present already in the preclinical stages of the disease, when the scores obtained from the neurological scales did not yet distinguish asymptomatic non-carrier patients: macular thickness measured by OCT and MD measured by computerized campimetry. These findings demonstrate that the neurodegenerative process is already underway and is detectable by these anatomical and functional measures of the retina. In addition, both changes detected in preclinical stages, when studied in the total group of symptomatic and asymptomatic carriers, correlated with our gold standard of disease severity, SARA and AVMC. The two findings - pre-clinical onset and correlation with disease progression measured by independent scores - suggest that the macular thickness measured by OCT and MD as measured by computerized campimetry are potential candidates for disease biomarkers (disease progression) from pre-manifest stages in SCA7.

Made available in DSpace on 2014-07-29T15:25:16Z (GMT). No. of bitstreams: 1 Tese Rosana Zacarias Honnouche.pdf: 1939926 bytes, checksum: d4fdb3cd4d741d0cf72b9b9269fceb63 (MD5) Previous issue date: 2011-11-29 / Diabetic macular edema (DME) is the main cause of visual loss in diabetic patients and is characterized by retinal thickening, whose evaluation is important for the diagnosis and management of diabetic retinopathy. The aim of this research was to measure the central subfield thickness (CST), the best-corrected visual acuity (BCVA) and the macular volume, and compare these data to those of diabetic patients without DME, using spectral-domain optical coherence tomography (SD-OCT), for quantitative analysis of DME.Two hundred patients with nonproliferative diabetic retinopathy (NPDR) were enrolled in a transversal study, from which 55 eyes with macular edema were detected by fundus biomicroscopy. Twenty seven diabetic patients without DME and with normal ophthalmological exam served as control group. Measurements of CST (main variable), BCVA and macular volume were taken, considering the variables age, gender, NPDR classification, external limitant membrane (ELM) integrity and type of DME. Biomicroscopy with noncontact lens, fluorescein angiography and spectral optical coherence tomography were performed using Cirrus SD-OCT. Besides descriptive statistics, additional tests were applied to analyze the results, such as variance analysis, t-Student, chisquare, Fischer s exact test, Mann-Whitney and Kruskall-Wallis. The relation between CST and BCVA was studied by linear regression, with logarithmic scale of minimal angle of resolution (logMAR). It was found that there is no significant difference between case and control groups for the variables age and gender. However, there was significant difference for variables CST, BCVA and macular volume. It was found significant correlation between retinopathy severity according to NPDR classification and the mean value of CST,which is the greater the retinopathy severity, the greater the CST. Most of the patients presented moderate NPDR. A strong correlation between macular volume and CST was found. Patients with serous retinal detachment presented higher mean value of CST, and those with CME presented worse BCVA. Patients with disrupted ELM showed greater mean value of CST and worse BCVA. It was concluded that SD-OCT allows quantitative measurement of CST in DME and, for identifying the retinal layers individually, also detects retinal structural changes and correlates them to visual functions. / O edema macular diabético é a principal causa de perda visual em diabéticos e é caracterizado pelo espessamento retiniano, cuja avaliação é importante para o diagnóstico e conduta da retinopatia diabética. O objetivo deste trabalho foi comparar as medidas da espessura do subcampo central (ESCC), a acuidade visual e o volume macular de pacientes com edema macular diabético (EMD) com diabéticos sem EMD, usando tomografia de coerência óptica de domínio espectral (SD-OCT) para análise quantitativa do EMD. Foi realizado um estudo transversal em que foram avaliados 55 pacientes com EMD, selecionados pela biomicroscopia de fundo, de um grupo de 200 pacientes com retinopatia diabética não proliferativa (RDNP). Um grupo de 27 pacientes diabéticos sem edema macular e com exame oftalmológico normal serviu como controle. Mediu-se a espessura do subcampo central (principal variável), a acuidade visual , o volume macular e avaliou-se a idade, o sexo, a classificação RDNP, a integridade da membrana limitante externa (MLE) e a morfologia do edema macular. Realizou-se biomicroscopia com lente de não contato, angiofluoresceinografia e tomografia de coerência óptica de domínio espectral com Cirrus SD-OCT. Além da estatística descritiva, utilizou-se testes para análise dos resultados: análise de variância, t-Student, qui-quadrado, teste exato de Fisher, Mann-Whitney e Kruskall-Wallis. A relação entre a ESCC e a acuidade visual foi estuda da através de análise de regressão linear com escala logarítmica de mínimo ângulo de resolução (logMAR). Registrou-se não haver diferença significativa entre casos e controles nas variáveis idade e sexo. Entretanto, houve diferença significativa para as variáveis ESCC, acuidade visual e volume macular. Foi encontrada correlação significativa entre a gravidade da retinopatia na classificação RDNP e a média da ESCC, sendo que quanto maior a gravidade da retinopatia, maior a ESCC. A maior parte dos pacientes apresentou RDNP moderada. Foi encontrada correlação significativa entre o volume e a ESCC. Pacientes com descolamento seroso apresentaram maior média da ESCC; e aqueles com EMC apresentaram pior acuidade visual. Pacientes com MLE descontínua apresentaram maior média da ESCC e pior acuidade visual. Concluiu-se que o SD-OCT mede quantitativamente a ESCC no EMD e, por identificar individualmente as camadas retinianas, detecta suas mudanças estruturais. Estas medidas podem ser correlacionadas com a função visual e auxiliar na conduta de pacientes com retinopatia diabética.

Pacientes com compressão quiasmática apresentam perda das fibras nervosas da retina nasal que decussam no quiasma óptico. Por conseguinte, ocorre perda das fibras nervosas, predominantemente, no setor nasal e temporal do disco óptico, que se manifesta por atrofia em banda do nervo óptico ao exame oftalmoscópico e hemianopsia temporal ao exame de campo visual. Trabalhos anteriores mostraram que o tomógrafo de coerência óptica é capaz de diferenciar pacientes com atrofia em banda do nervo óptico associada à hemianopsia temporal completa de indivíduos normais através da análise da camada de fibras nervosas peripapilar. Estudos em glaucoma têm sugerido que a avaliação da espessura macular poderia ser útil na quantificação da perda neural como um método alternativo ou complementar ao estudo da camada de fibras nervosas da retina. No presente estudo, a espessura macular e da camada de fibras nervosas foram avaliadas pelo tomógrafo de coerência óptica em pacientes com atrofia em banda do nervo óptico e graus variados de hemianopsia temporal. O desempenho dos parâmetros maculares para detecção da atrofia em banda do nervo óptico foi avaliado pela área sob a curva ROC (AROC) e sensibilidades para especificidades fixas e os resultados foram comparados aos parâmetros da camada de fibras nervosas peripapilar. Para identificar os parâmetros do Stratus OCT que apresentaram melhor desempenho para diferenciar pacientes com AB do nervo óptico de indivíduos normais, modelos de regressão logística foram utilizados. A correlação estrutura-função foi realizada entre o grau do defeito temporal e os valores de espessura macular e da camada de fibras peripapilar através do coeficiente de correlação de Spearman. A categorização diagnóstica dos parâmetros da camada de fibras nervosas através do banco de dados normativos foi avaliada pelos valores de sensibilidade e especificidade calculados pelo teste exato de Fisher. Quarenta e quatro olhos com atrofia em banda e 47 olhos normais foram avaliados no estudo. Entre os parâmetros maculares, os parâmetros da retina nasal apresentaram melhor desempenho para detectar atrofia em banda do nervo óptico comparados aos parâmetros da retina temporal. Não houve diferença significante (p=0,32) entre as áreas sob a curva ROC do melhor parâmetro macular (AROC=0,97) e do melhor parâmetro da camada de fibras nervosas retiniana (AROC=0,99). Na avaliação da correlação estrutura-função, os parâmetros da retina nasal apresentaram maior correlação com o defeito campimétrico comparados aos parâmetros da camada de fibras nervosas da retinal. Entre os parâmetros maculares, a espessura nasal média apresentou a maior correlação (rs=0,618). Entre os parâmetros da camada de fibras nervosas da retina, a espessura média apresentou a maior correlação (rs=0,479). Os parâmetros espessura média, espessura nasal e espessura temporal da camada de fibras nervosas da retina apresentaram melhor desempenho diagnóstico baseado na categorização diagnóstica do banco de dados normativos. Os resultados obtidos no estudo mostraram que os parâmetros maculares discriminam olhos com atrofia em banda do nervo óptico em pacientes com graus variados de defeito temporal. Além disso, os parâmetros da retina nasal podem colaborar com o exame perimétrico e os parâmetros da camada de fibras nervosas para o seguimento dos pacientes com compressão quiasmática. / Patients with chiasmal compression present damage of crossed fibers of nasal retina. Therefore, retinal nerve fiber layer loss occurs predominantly on the nasal and temporal sides of the optic disc, a pattern that can be identified on ophthalmoscopy as band atrophy of the optic nerve and on visual field as temporal hemianopia. Previous studies have been demonstrated that optical coherence tomography is able to detect retinal nerve fiber layer loss in patients with lesions of the optic chiasm and complete temporal hemianopia. Studies in glaucoma have been suggested that macular thickness measurements could be useful in quantification of optical nerve axonal loss as alternative or complement method to evaluate the retinal nerve fiber layer. The purpose of the present study was to compare macular thickness and retinal nerve fiber thickness measurements in patients with band atrophy of the optic nerve and different severities of visual field defect using optical coherence tomography. Area under the receiver operating characteristic curve (AROC) and sensitivities at fixed specificities were performed for evaluation of diagnostic accuracy of macular and retinal nerve fiber layer parameters. To identify the best optical coherence tomography measurements to differentiate band atrophy of the optic nerve patients from normal individuals, logistic regression models were performed. Association between optical coherence tomography parameters and temporal field defect were examined by Spearman coefficient of correlation. Fisher\'s exact test was performed to evaluate diagnostic ability of retinal nerve fiber parameters by optical coherence tomography in eyes with band atrophy using comparison with its internal normative database. A total of 44 eyes with band atrophy of the optic nerve and 47 normal eyes were studied. Among macular parameters, nasal retina measurements showed diagnostic accuracy better than temporal retina measurements. No statistically significant difference (p=0.32) was found between areas under ROC curve for the best macular parameter (AROC=0.97) and the best retinal nerve fiber layer parameter (AROC=0.99). Nasal retina parameters correlations were higher than retinal nerve fiber parameters. The highest correlation was observed for the mean nasal thickness (rs=0.618) for macular parameters. In retinal nerve fiber parameters, the highest correlation was observed for the average thickness (rs=0.479). In evaluation of diagnostic ability of normative database, the average thickness parameter demonstrated the highest sensitivity for detection of abnormalities in eyes with band atrophy, followed by the parameters related to the nasal and temporal quadrants. These results suggest that macular thickness measurements discriminate eyes with band atrophy of the optic nerve with different severities of temporal field defect. Results also suggest that nasal retina thickness measurements could potentially be used to evaluate retinal ganglion cell loss in patients with chiasmal compression.

Cette thèse traite de l’étude et du développement d’un système d’optique adaptative pour la tomographie par cohérence optique plein champ (AO-FFOCT en anglais) appliquée à l’imagerie haute résolution de la rétine. L’analyse de l’effet des aberrations géométriques sur les performances en FFOCT a montré que pour une illumination spatialement incohérente, la résolution transverse est insensible aux aberrations et ne fait que diminuer le niveau du signal. Comme ce sont des aberrations de bas ordres comme la myopie et l’astigmatisme qui prédominent pour l’œil humain, une méthode d’optique adaptative avec une configuration sans conjugaison qui utilise une correction de front d’onde en transmission est suggérée, puis appliquée à la correction de ces ordres afin de simplifier le système d’AO-FFOCT. Des corrections de front d’onde sont effectuées sans analyseur de surface d’onde, en utilisant le niveau du signal de FFOCT comme métrique. Des expériences avec des échantillons diffusants et un œil artificiel sont menées pour démontrer la faisabilité d’un système d’AO-FFOCT conçu pour la correction d’aberration. Afin de résoudre les problèmes posés par les mouvements oculaires et de compenser en temps réel la différence de chemin optique entre les deux bras de l’interféromètre, l’instrument de FFOCT est couplé à un système d’OCT spectral. Avec cette combinaison de systèmes, l’imagerie FFOCT in vivo cellulaire de la rétine à haute résolution a été réalisée pour la première fois sur l’œil humain. / This thesis follows the study and development of an adaptive optics full-field optical coherence tomography (AO-FFOCT) system, aiming for high resolution en face human retinal imaging. During the quantification of the effects of geometrical aberrations on the FFOCT system performance, it is shown that, with spatially incoherent illumination, the lateral resolution of FFOCT is insensitive to aberrations, which only cause the FFOCT signal reduction. Since low order aberrations like myopia and astigmatism dominate in human eye, a non-conjugate AO configuration by using transmissive wavefront corrector is suggested and applied for low order aberrations correction to simplify the AO-FFOCT system. Wavefront corrections are done with a wavefront sensorless method by using FFOCT signal level as the metric. Experiments with scattering samples and artificial eye model are conducted to demonstrate the feasibility of the customized AO-FFOCT system for aberration correction. In order to resolve the eye motion effects and employ real-time matching of the optical path lengths of the two interferometric arms in FFOCT, a system combination of traditional spectral-domain OCT (SDOCT) with FFOCT is adopted. With this combined system, high resolution FFOCT cellular retinal imaging is achieved in human eye in vivo for the first time.

La tomographie de cohérence optique plein champ est une technique de microscopie permettant d’imager un plan d’intérêt en profondeur dans un milieu diffusant. Cette technique a été utilisée pour l’examen de pièces opératoires dans un but de diagnostic en cancérologie. L’utilisation de cette technique permettrait en effet de fournir un outil de diagnostic peropératoire rapide et fiable, évitant ainsi de nombreuses procédures de réopération. Ces réopérations peuvent survenir lorsque – lors du diagnostic final par analyse de coupes histologiques – le pathologiste décèle la présence de tissus cancéreux restant, non retirés au cours de l’opération.L’OCT plein champ a montré de bons résultats pour cette application. Néanmoins, cette technique ne fournit qu’un contraste morphologique des tissus, ne permettant pas d’utiliser des critères de qualification des pièces opératoires basées – par exemple – sur la morphologie ou la densité cellulaire.Nous avons développé une nouvelle modalité d’imagerie basée sur l’OCT plein champ permettant de révéler un contraste métabolique dans le tissu à une échelle subcellulaire. Ce contraste permet de révéler les cellules précédemment non distinguées en OCT plein champ. Nous avons également utilisé la mesure quantitative de cette modalité pour réaliser des outils d’aide au diagnostic utilisant des approches d’apprentissage par ordinateur. / Full filed optical coherence tomography is a microscopy imaging technique allowing to image a specific slice in a scattering medium, in depth. This technique has been used for the diagnosis of biopsy in cancerology. This technique could be an efficient and fast way to diagnose excised tissues during surgery. This would avoid numerous reoperations procedures. These reoperations are necessary when a pathologist suspects cancerous tissue to still be present in the patient, based on histological slide examination.FFOCT has shown promising results for that purpose. Nevertheless, this technique only gives a morphological contrast of tissues, which is not enough for applying some diagnostic criteria such as cell morphology or cell density.We developed a new imaging modality based on FFOCT allowing to reveal metabolic contrast in tissues at the subcellular scale. This contrast reveals cells previously indistinguishable with FFOCT. We also used this quantitative metric to propose tools to facilitate diagnosis, using machine learning approaches.

Cette thèse porte sur l’étude de l’anatomie de la cornée après 3 techniques de greffe soient, la greffe totale traditionnelle (GTT) et des techniques de greffe lamellaire postérieur (GLP) telles que la greffe lamellaire endothéliale profonde (DLEK) et la greffe endothélium/membrane de Descemet (EDMG) pour le traitement des maladies de l’endothélium, telles que la dystrophie de Fuchs et de la kératopathie de l’aphaque et du pseudophaque. Dans ce contexte, cette thèse contribue également à démontrer l’utilité de la tomographie de cohérence optique (OCT) pour l’étude de l’anatomie des plaies chirurgicales la cornée post transplantation. Au cours de ce travail nous avons étudié l'anatomie de la DLEK, avant et 1, 6, 12 et 24 mois après la chirurgie. Nous avons utilisé le Stratus OCT (Version 3, Carl Zeiss, Meditec Inc.) pour documenter l’anatomie de la plaie. L'acquisition et la manipulation des images du Stratus OCT, instrument qui à été conçu originalement pour l’étude de la rétine et du nerf optique, ont été adaptées pour l'analyse du segment antérieur de l’oeil. Des images cornéennes centrales verticales et horizontales, ainsi que 4 mesures radiaires perpendiculaires à la plaie à 12, 3, 6 et 9 heures ont été obtenues. Les paramètres suivants ont été étudiés: (1) Les espaces (gap) entre les rebords du disque donneur et ceux du receveur, (2) les dénivelés de surface postérieure (step) entre le les rebords du disque donneur et ceux du receveur, (3) la compression tissulaire, (4) le décollement du greffon, 6) les élévations de la surface antérieure de la cornée et 7) la pachymétrie centrale de la cornée. Les mesures d’épaisseur totale de la cornée ont été comparées et corrélées avec celles obtenues avec un pachymètre à ultra-sons. Des mesures d’acuité visuelle, de réfraction manifeste et de topographie ont aussi été acquises afin d’évaluer les résultats fonctionnels. Enfin, nous avons comparé les données de DLEK à celles obtenues de l’EDMG et de la GTT, afin de caractériser les plaies et de cerner les avantages et inconvénients relatifs à chaque technique chirurgicale. Nos résultats anatomiques ont montré des différences importantes entre les trois techniques chirurgicales. Certains des paramètres étudiés, comme le sep et le gap, ont été plus prononcés dans la GTT que dans la DLEK et complètement absents dans l’EDMG. D’autres, comme la compression tissulaire et le décollement du greffon n’ont été observés que dans la DLEK. Ceci laisse entrevoir que la distorsion de la plaie varie proportionnellement à la profondeur de la découpe stromale du receveur, à partir de la face postérieure de la cornée. Moins la découpe s’avance vers la face antérieure (comme dans l’EDMG), moins elle affecte l’intégrité anatomique de la cornée, le pire cas étant la découpe totale comme dans la GTT. Cependant, tous les paramètres d’apposition postérieure sous-optimale et d’élévation de la surface antérieure (ce dernier observé uniquement dans la GTT) finissent par diminuer avec le temps, évoluant à des degrés variables vers un profil topographique plus semblable à celui d’une cornée normale. Ce processus paraît plus long et plus incomplet dans les cas de GTT à cause du type de plaie, de la présence de sutures et de la durée de la cicatrisation. Les valeurs moyennes d’épaisseur centrale se sont normalisées après la chirurgie. De plus, ces valeurs moyennes obtenues par OCT étaient fortement corrélées à celles obtenues par la pachymétrie à ultra-sons et nous n’avons remarqué aucune différence significative entre les valeurs moyennes des deux techniques de mesure. L’OCT s’est avéré un outil utile pour l’étude de l’anatomie microscopique des plaies chirurgicales. Les résultats d’acuité visuelle, de réfraction et de topographie des techniques de GLP ont montré qu’il existe une récupération visuelle rapide et sans changements significatifs de l’astigmatisme, contrairement à la GTT avec et sans suture. La GLP a permis une meilleure conservation de la morphologie de la cornée, et par conséquence des meilleurs résultats fonctionnels que la greffe de pleine épaisseur. Ceci nous permet d’avancer que la GLP pourrait être la technique chirurgicale à adopter comme traitement pour les maladies de l’endothélium cornéen. / This thesis aims to study the anatomy of the corneal wound following 3 techniques of corneal graft: traditional penetrating keratoplasy (PK) and two techniques of posterior lamellar keratoplasy (PLK) which are deep lamellar endothelial keratoplasy (DLEK) and Endothelial-Descemet’s Membrane Graft (EDMG) for the treatment of the endothelial corneal diseases, such as Fuch’s dystrophy and aphakic and pseudopakic bullous keratopathy. In this context, this thesis also contributes to show the utility of the time domain optical coherence tomography (TD-OCT) for studying the anatomy of surgical wounds after corneal transplantation. In this work we studied the anatomy of DLEK, before and 1,6,12 and 24 months after surgery. We used the Stratus OCT. (Version 3, Carl Zeiss, Meditec Inc.) to document the anatomy of the wound. The acquisition and the handling of the images of the Stratus OCT, an instrument originally designed for the study of the retina and the optic nerve, were adapted to analyse the anterior segment of the eye. Vertical and horizontal central images of the cornea, in addition to 4 radial measurements perpendicular to the wound at 12, 3, 6 and 9 hours were obtained. The following parameters were studied: (1) the gap between the edges of the donor disc and those of the recipient, (2) posterior surface mismatch (step) between the edges of the disc donor and those of the recipient, (3) tissue compression, (4) graft detachment, 6) elevations of the anterior corneal surface and 7) the central pachymetry of the cornea. Measurements of the total thickness were compared and correlated with those obtained with an ultrasound pachymeter. Measurements of visual acuity, manifest refraction and topography were also acquired in order to evaluate the functional results. Lastly, we compared the data of DLEK with those obtained from the EDMG and the PK, in order to characterize the wounds and to highlight the advantages and disadvantages relative to each surgical technique.Our anatomical results showed important differences between the three surgical techniques. Some of the studied parameters, like the step and the gap, were more pronounced in PK than in DLEK and completely absent in the EDMG group. Others, like tissue compression and graft detachment were observed only in the DLEK group. This let us predict that the distortion of the wound varies proportionally with the depth of recipient posterior stromal dissection. The less dissection towards the anterior surface (as in EDMG), the less it affects the anatomical integrity of the cornea, the worst case being full thickness trephination as in PK. However, all the parameters of sub-optimal posterior surface apposition and anterior surface elevation (this last only observed in PK) ended up decreasing with time, evolving with variable degrees to a topographic profile more similar to that of a normal cornea. This process appears longer and more incomplete in the cases of PK because of the type of wound, the presence of sutures and the longer healing period. The mean values of central thickness were normal after surgery. Moreover, these mean values obtained by OCT. were strongly correlated with those obtained by ultrasound pachymetry and we did not notice any significant difference between the mean values of the two measurement techniques. OCT proved to be a useful tool for the study of the microscopic anatomy of the corneal surgical wounds. The results of vision, refraction and topography of the techniques of posterior lamellar grafts showed that there was a fast visual recovery and without significant changes in astigmatism, contrary to PK with and without sutures. Posterior lamellar grafts allowed a better conservation of the morphology of the cornea, and consequently better functional results than PK. This enabled us to conclude that posterior lamellar corneal grafts could be the surgical technique of choice for the treatment of corneal endothelial diseases.

CAPES; CNPq; Fundação Araucária / Esta tese de doutorado apresenta um sistema de monitoração heterogêneo para a caracterização do processo de secagem e cura de filmes poliméricos e resina odontológica. Essa caracterização é de suma importância para aperfeiçoar o processo de fabricação e a escolha das matérias-primas dos mesmos, uma vez que parâmetros como a variação da espessura e a deformação mecânica no material estão diretamente ligadas à sua qualidade e durabilidade. O sensor heterogêneo emprega técnicas complementares para a quantificação de múltiplos parâmetros físicos, visando a compreensão das etapas que acontecem durante o processo de secagem e cura. Os ensaios se deram em períodos de 24 horas analisando amostras de tinta e verniz acrílicos e resina dentária. Foram quantificadas deformações longitudinais, variação de massa, espessura e índice de refração médio. Nas amostras de tinta e verniz acrílicos, obteve-se redução entre 60% e 70% no valor inicial da espessura, enquanto o comportamento do índice de refração do verniz foi associado às diferentes etapas do processo de secagem. As amostras de resina odontológica apresentaram redução da espessura menor que 5% em todos os ensaios realizados, percentual semelhante à variação do índice de refração. Todavia, as redes de Bragg identificaram um aumento de temperatura da resina odontológica de aproximadamente 20°C durante a fotoativação. A flexibilidade do sistema sensor heterogêneo demonstrado permite a análise do processo de secagem ou cura de uma ampla gama de filmes poliméricos e resinas, sem a necessidade de adaptações significativas no arranjo experimental. Com uma caracterização correta das etapas envolvidas na secagem ou cura, todo o processo que vai desde a formulação do produto à aplicação final pode ser otimizado, levando à melhoria da relação custo-benefício para cada aplicação pretendida. / This thesis presents a heterogeneous system to characterize the drying and curing process of polymer films and dental resin. This characterization is important to improve the manufacturing process and the choice of the raw materials, since parameters such as thickness variation and the mechanical deformation in the material are directly related to their quality and durability. The sensor employs heterogeneous complementary techniques for the quantification of multiple physical parameters, aimed to understand the steps that occur during drying and curing. The tests took place in periods of 24 hours analyzing samples of both acrylic paint and varnish, as well as dental resin. Longitudinal deformation, mass variation, thickness and mean refractive index were quantified. In samples of acrylic paint and varnish, a reduction between 60% and 70% in the initial value of the thickness was obtained, while the behavior of the refractive index of the varnish was associated with the different stages of the drying process. Samples of dental resin presented thickness decreasing less than 5% in all tests, percentage similar to the variation of the refractive index. However, fiber Bragg gratings have identified a temperature increase of the dental resin about 20 ° C during the polymerization. The flexibility of the heterogeneous sensor system demonstrated allows the analysis of drying or cure processes of a great variety of polymer films and resins, without the need for important changes in the experimental setup. With the correct characterization of the stages involved in the drying or cure, the whole process from the product formulation to the final application may result in an optimized and cost effective product for any intended application.

SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) est une nouvelle technologie innovante de spectrométrie qui permet une réduction radicale de la taille des spectromètres à Transformée de Fourier, tout en conservant, et même en améliorant leurs performances. Grâce aux avancées de l'optique intégrée et des nanotechnologies, SWIFTS repose sur une méthode de détection optique originale, sans aucune partie mobile, où des nanoplots métalliques échantillonnent directement le champ évanescent d'une onde stationnaire dans un guide d'onde.Dans cette thèse, nous proposons de présenter le cheminement complet qui a mené, en partant du concept original, au développement puis à la mise en pratique de la technologie SWIFTS. Le document illustre notamment les caractérisations optiques, les choix technologiques et les optimisations entrepris pour la réalisation de spectromètres fonctionnels dans le domaine visible et proche-infrarouge. Des procédures de calibrages novatrices et complémentaires, basées sur du multiplexage fréquentiel et sur de l'interférométrie à faible cohérence temporelle, ont été développées pour déterminer avec précision les différentes irrégularités de fabrication et de comportement de l'appareil complètement intégré. Les spectromètres calibrés permettent à présent d'aborder des applications diverses en industrie et en recherche, de la caractérisation hautes performances de lasers, à l'interrogation de capteurs fibrés à réseaux de Bragg, aux techniques de spectrométries Raman et LIBS, et de tomographie optique OCT, jusqu'aux sciences de l'Univers (géophysique, astrophysique).SWIFTS est une innovation de rupture qui, de part sa miniaturisation obtenue sans compromis avec de hautes performances d'analyse spectrale, a la capacité de faire passer la spectrométrie du stade de la mesure complexe en laboratoire à celle d'un simple composant intégré pour des applications exigeantes. / SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) is a new innovative technology of spectrometry that allows a drastic reduction of the size of Fourier transform spectrometers, while maintaining, and even improving their performance. With advances in integrated optics and nanotechnology, SWIFTS is based on an original method of optical detection, without any moving part, where metallic nanodots directly sample the evanescent field of a standing wave in a waveguide.In this thesis, we propose to present the complete process that led, starting from the original concept, to the development and the applications of the technology. The document illustrates the optical characterizations, the technological choices and the optimizations made for the realization of functional spectrometers in the visible and near-infrared range. Innovative and complementary procedures of calibrations, based on frequency multiplexing and low coherence interferometry, have been developed to accurately determine the various irregularities of the manufacturing and of the behavior of the integrated device. The calibrated spectrometers allow to address various applications in industry and research, such as high performance characterization of lasers, interrogation of fiber Bragg gratings sensors, Raman and LIBS spectrometry, optical coherence tomography OCT, and sciences of the Universe (geophysics, astrophysics).SWIFTS is a breakthrough innovation in spectrometry, without trade-off between miniaturization and high performance, that opens the way for product development based on the most demanding applications currently performed in research laboratories.