O presente trabalho experimental, tem como objetivo avaliar \"in vitro\" possíveis falhas na cimentação de fragmentos cerâmicos sobre substrato de esmalte dentário previamente submetido ao clareamento dental e analisados pelo sistema de tomografia por coerência ótica. O ensaio experimental foi realizado in vitro, fazendo uso de trinta pré-molares superiores humanos. Cada elemento dental teve sua porção de esmalte vestibular aplainada por meio de disco de sílica na granulação 120, foram cimentados fragmentos cerâmicos retangulares de 1.5mm de espessura. Os dentes foram distribuídos aleatoriamente em 3 grupos de 10 dentes cada (n=10), Grupo 1: Fragmentos cimentados sem serem submetidos ao tratamento clareador; Grupo 2: Fragmentos cimentados 24 hrs. Após serem submetidos ao clareamento dental; Grupo 3: Fragmentos cimentados 7 dias após serem submetidos ao clareamento dental. Os espécimes foram transferidos para o sistema de tomografia por coerência óptica para seus respectivos monitoramentos após exposição ao agente clareador e cimentação da restauração indireta e ao final dos ensaios de envelhecimento artificial por termociclagem. A variável de resposta, falhas na interface esmalte e cimento resinoso, foi avaliada por escores (0,1 e 2) que representam em ordem crescente as falhas entre o substrato dental e a restauração indireta. Os valores obtidos foram analisados por meio de testes não paramétricos (Kruskal-Wallis e Wilcoxon). Os resultados constituíram de 60 escores de fendas referentes aos 3 grupos (G1;G2;G3) analisados imediatamente após a cimentação e após a termociclagem. A comparação entre os 3 grupos após termociclagem demonstrou haver diferença estatisticamente significante (p<0,0001) pela comparação dois a dois pelo teste complementar de Dunn e detectou-se que o G2 cimentado após 24 horas do clareamento apresentou mais fendas que G1 e G3. Com base nestes resultados e na metodologia utilizada pode-se concluir que, dentes submetidos ao tratamento clareador, o protocolo clinico de cimentação de restaurações cerâmicas indiretas, quando realizado 7 dias após o clareamento gerou menor quantidade de fendas na interface, propondo assim melhor qualidade na adaptação dente/restauração. / The present experimental study has the objective of evaluating in vitro possible failures in the cementation of ceramic fragments over dental enamel substrate previously submitted to dental bleaching and analyzed by optical coherence tomography system. The experimental trial was performed in vitro using thirty human maxillary premolars. Each dental element had have it\'s portion of vestibular enamel planed by a silic disk in granulation 120, ceramic fragments with a diameter of 1.5mm thickness were cemented. The teeth were randomly distributed in 3 groups of 10 teeth each (n = 10), Group 1: Bonded Veneer without being subjected to bleaching treatment Group 2: Bonded Veneer 24 hours after being submitted to dental bleaching Group 3: Bonded Veneer 7 days after being submitted to dental bleaching. The specimens were transferred to the optical coherence tomography system for their respective monitoring after being exposured to the whitening agent and cementation of the indirect restoration and at the end of the artificial aging tests by thermocycling. The variable of response, at faults in the interface enamel and resin cement, was evaluated by scores (0,1 and 2) that represent in increasing order the failures between dental substrate and indirect restoration. The values obtained were analyzed by non-parametric tests (Kruskal-Wallis and Wilcoxon). The results consisted of 60 gaps scores for the three groups (G1, G2, G3) analyzed immediately after bonding and after thermocycling. The comparison between the 3 groups after thermocycling, showed a statistically significant difference (p <0.0001) by the two-to-two comparison by Dunn\'s complementary test and it was detected that G2 after 24 hours of bleaching, showed more gaps than G1 and G3. Based on these results and the methodology used, it was concluded that, when teeth were submitted to the bleaching treatment, the clinical cementation protocol of indirect ceramic restorations, when performed 7 days after bleaching, generated fewer gaps at the interface, thus proposing a better quality in the relation Tooth / restoration.

A terapia fotodinâmica (PDT) é uma alternativa promissora de tratamento para lesões pré-cancerosas e para câncer de pele não-melanoma, como o carcinoma espinocelular, agressivo e potencialmente metastático. Visando melhorar a eficiência da terapia fotodinâmica de carcinoma espinocelular de pele, este estudo otimizou o tempo para início da terapia, avaliou a eficácia dos fotossensibilizadores ácido aminolevulínico (ALA- 20%) e o metil-ester aminolevulínico (MEALA-10%) e verificou o coeficiente de atenuação relativo à pele normal dos grupos experimentais, por meio de Tomografia por Coerência Óptica. Para a indução do tumor foi realizada a carcinogênese química (DMBA/TPA) por um período de 28 semanas. A espectroscopia de fluorescência foi utilizada para monitoração da emissão da molécula de protoporfirina IX, induzida pelo ALA e MEALA. A aquisição de dados a cada 30 minutos totalizando um período de 360 minutos, permitiu verificar a máxima incorporação de ALA e MEALA em 300 e 330 minutos após a aplicação, respectivamente. Após a otimização foi realizada a PDT, avaliação clínica, histopatológica e análise por OCT dos grupos experimentais, por meio das quais verificou-se maior eficiência do grupo tratado com MEALA. No período de 20 dias, o percentual de lesões com redução de área maior que 50%, foi de 33% na PDT com ALA e 83% para o MEALA. Os coeficientes de atenuação ópticos para os grupos com neoplasia foram maiores do que os do grupo controle. Os grupos tratados com PDT apresentaram valores de coeficiente de atenuação que se aproximam dos valores obtidos para a pele sadia, evidenciando a resposta ao tratamento. Entretanto para ambos os fotossensibilizadores utilizados, a PDT mostrou-se eficaz quando iniciada nos tempos determinados neste estudo, e a técnica de OCT mostrou-se uma potencial ferramenta na avaliação deste tratamento. / Photodynamic therapy (PDT) is a promising alternative for pre-cancerous lesions and non-melanoma skin cancer treatment as squamous cells carcinoma, which is aggressive and potentially metastatic. Aiming the improvement of photodynamic therapy efficiency for skin squamous cells carcinoma, this study has optimized the time to start the therapy, it also evaluated the effectiveness of the aminolevulinic acid (ALA-20%) and methyl-ester aminolevulinic (MEALA-10%) as photosensitizers as well as verified the optical attenuation coefficient relative to normal skin of the experimental groups by optical coherence tomography (OCT). A chemical carcinogenesis was performed (DMBA/TPA), by a period of 28 days. Fluorescence Spectroscopy was used to monitor the emission of protoporphyrin IX induced by ALA and MEALA. Signal acquisition was performed every 30 minutes for a total period of 360 minutes, showing a maximum incorporation of ALA and MEALA, 300 and 330 minutes after the application. PDT was conducted after the optimization of the irradiation time. Clinical and histopathologic evaluation and OCT analysis of the experimental groups showed higher efficiency of the MEALA-treated group. After 20 days of treatment, the percentage of lesions with area reduction greater than 50%, was 33% for the ALA group and 83% for the MEALA group. The optical attenuation coefficients for groups with cancer were higher than those in the control group. The groups treated with PDT presented attenuation coefficient values that are close to the values obtained for healthy skin, showing the positive response to the treatment. This study showed that PDT was effective for both photosensitizers when initiated at the times determined in this study, and OCT technique proved to be a potential tool in the assessment of this treatment.

OBJETIVO: Avaliar a capacidade dos parâmetros do eletrorretinograma de padrão reverso de campo total e hemianópico em diferenciar olhos com atrofia em banda do nervo óptico e, a correlação entre as amplitudes do eletrorretinograma de padrão reverso, a espessura da camada de fibras nervosas da retina e macular obtidas pela tomografia de coerência óptica e a perda de campo visual nestes pacientes. MÉTODOS: Quarenta e um olhos de 41 pacientes com perda de campo visual temporal permanente por compressão do quiasma óptico e 41 controles normais foram submetidos ao eletrorretinograma de padrão reverso de estimulação de campo total e hemianópicos (temporal e nasal), a tomografia de coerência óptica, para avaliação das medidas da espessura da camada de fibras nervosas da retina e macular e, ao exame de campo visual, pela perimetria automatizada padrão. O desvio do normal da sensibilidade dos 18º centrais do campo visual foram expressos em decibéis e unidades 1/Lambert. As comparações foram feitas pelo teste t de Student. A correlação entre os parâmetros do campo visual central, do eletrorretinograma de padrão reverso e da tomografia de coerência óptica foi avaliada pela correlação de Pearson e análise de regressão linear. RESULTADOS: Os valores das amplitudes P50, N95, and P50+N95 do eletrorretinograma de padrão reverso de campo total, e de estimulação hemianópica e os valores das medidas da espessura macular e da camada de fibras nervosas da retina obtidas pela tomografia de coerência óptica foram significativamente menores nos olhos com atrofia em banda do que nos controles (P<0,001). Uma correlação significativa foi encontrada entre a perda de sensibilidade no campo visual central e as amplitudes do eletrorretinograma de padrão reverso de estimulação de campo total e nasal, mas não para o temporal. Uma correlação significativa positiva foi observada entre os parâmetros de perda de sensibilidade no campo visual e a maioria dos parâmetros da espessura da camada de fibras nervosas da retina e macular obtidas pela tomografia de coerência óptica. Nenhuma correlação significativa foi observada entre os parâmetros do eletrorretinograma de padrão reverso e a tomografia de coerência óptica, exceto para amplitude P50+N95 do eletrorretinograma de padrão reverso de estimulação de hemicampo nasal. Uma correlação significativa foi observada entre os parâmetros de espessura macular e da camada de fibras nervosas pela tomografia de coerência óptica, exceto entre a espessura da camada de fibras nervosas no segmento de 30º, correspondente as 9 horas do relógio e os parâmetros maculares. CONCLUSÕES: Os valores das amplitudes do eletrorretinograma de padrão reverso foram eficazes em diferenciar olhos com atrofia em banda do nervo óptico de controles normais. Em pacientes com atrofia em banda do nervo óptico, as amplitudes do eletrorretinograma de padrão reverso e medidas da espessura da camada de fibras nervosas da retina e macular correlacionaram de forma significativa com a perda de campo visual, mas não houve correlação entre eles. O eletrorretinograma de padrão reverso e a tomografia de coerência óptica detectaram a perda neural e ambos são métodos diagnósticos úteis na compreensão da correlação estrutura-função em pacientes com compressão do quiasma óptico / PURPOSE: To evaluate the ability of full-field and hemifield pattern electroretinogram parameters to differentiate between healthy eyes and eyes with band atrophy of the optic nerve and also to evaluate the relationship between pattern electroretinogram amplitude, macular and retinal nerve fiber layer thickness by optical coherence tomography, and visual field loss on standard automated perimetry in eyes with BA of optic nerve. METHODS: Forty-one eyes from 41 patients with permanent temporal visual field defects from chiasmal compression and 41 healthy subjects underwent transient fullfield and hemifield (temporal or nasal) stimulation pattern electroretinogram, standard automated perimetry and time domain- optical coherence tomography macular and retinal nerve fiber layer thickness measurements. Comparisons were made using Students t-test. Deviation from normal visual field sensitivity for the central 18° was expressed in dB and 1/Lambert units. Correlations between measurements were verified by Pearsons correlations and linear regression analysis. RESULTS: Full-field P50, N95, and P50+N95 amplitude values were significantly smaller in eyes with band atrophy than in control eyes (P<0.001). Nasal and temporal hemifield pattern electroretinogram studies revealed significant differences in N95 and P50+N95 amplitudes measurements. Pattern electroretinogram and optical coherence tomography measurements were significantly lower in eyes with temporal hemianopia than in normal eyes. A significant correlation was found between visual field sensitivity loss and full-field or nasal, but not temporal, hemifield pattern electroretinogram amplitude. Likewise a significant correlation was found between visual field sensitivity loss and most optical coherence tomography parameters. No significant correlation was observed between optical coherence tomography and pattern electroretinogram parameters, except for nasal hemifield amplitude. A significant correlation was observed between several macular and retinal nerve fiber layer thickness parameters. CONCLUSIONS: Transient pattern electroretinogram amplitude measurements were efficient at differentiating eyes with band atrophy and permanent visual field defects from normal controls. In patients with chiasmal compression, pattern electroretinogram amplitude and optical coherence tomography thickness measurements were significant related to visual field loss, but not to each other. Pattern electroretinogram and optical coherence tomography quantify neuronal loss differently, but both technologies are useful in understanding structure-function relationship in patients with chiasmal compression

A exposição crônica à radiação ultravioleta (UV) resulta no fotoenvelhecimento da pele humana. A fim de tratá-lo, a terapia fotodinâmica (TFD) - técnica que utiliza luz, um fotossensibilizador (FS) e oxigênio molecular - tem sido utilizada em ambientes clínicos, no entanto são escassas as investigações que revelam os achados histopatológicos desse tratamento na pele fotoenvelhecida. Com isso, o objetivo deste trabalho foi analisar experimentalmente os efeitos da TFD na pele fotoenvelhecida de camundongos por meio de técnicas ópticas e histológicas. Portanto, foram utilizados camundongos hairless (sem pelo) distribuídos aleatoriamente em diferentes grupos, tais como: Controle, animais de pele sadia envelhecida intrinsecamente, não irradiados com luz UV e não tratados; UV, animais irradiados com luz UV e não tratados; UV/Luz, animais irradiados com luz UV e tratados com fototerapia; UV/TFD, animais fotoenvelhecidos (irradiados com luz UV) e tratados com a TFD; e Controle/TFD, animais de pele sadia envelhecida intrinsecamente e tratados com TFD. A indução do fotoenvelhecimento foi realizada por diferentes fontes de luz contendo, principalmente, a banda espectral UV; para a TFD, foram utilizadas fontes de luz com comprimento de onda de 415, 630 e 635 nm (azul e vermelho) juntamente com o ácido 5-aminolevulínico (ALA), precursor do FS endógeno protoporfirina IX (PpIX). Para fazer o seguimento da TFD por técnicas ópticas, foram realizadas espectroscopia de fluorescência, imagem de fluorescência de campo amplo e tomografia por coerência óptica (OCT, do inglês optical coherence tomography). A avaliação histopatológica pós-TFD foi realizada com os corantes HE, Tricrômio de Masson (TM) e Verhoeff a fim de analisar a espessura da epiderme, o infiltrado inflamatório, o conteúdo de colágeno na derme e sua espessura e a qualidade das fibras elásticas. Como resultado, observouse aumento significativo da espessura da epiderme pela regeneração dos queratinócitos e deposição de novas fibras colágenas dérmicas apenas nos animais tratados com ALA-TFD, tanto irradiados quanto não-irradiados com luz UV (grupos UV/TFD e Controle/TFD, respectivamente). Assim, torna-se evidente que a TFD trata a pele fotoenvelhecida do camundongo hairless pelos achados histopatológicos e através das imagens de OCT. Com isso, este trabalho agrega informação às investigações clínicas a respeito da TFD no tratamento da pele fotoenvelhecida, atestando seu uso para o fotorrejuvenescimento cutâneo. / The chronic exposure to ultraviolet radiation (UVR) leads to photoaging of the human skin. As a treatment, the photodynamic therapy (PDT) which brings together light, a photosensitizer, and molecular oxygen has been extensively used on clinical trials; however, there are few studies that highlight the histopathologic findings regarding this technique on photoaged skin. Thus, the aim of this study was to analyze experimentally the effects of PDT on photoaged skin of hairless mice by means of optical and histopathologic assessments. For this, hairless mice were randomly allocated in different groups, such as: Control, animals with healthy aged skin, neither exposed to an UV lamp nor treated; UV, animals exposed to an UV lamp with no treatment; UV/Light, animals exposed to an UV lamp and treated just with light; UV/PDT, animals exposed to an UV lamp and treated with PDT; and Control/PDT, animals with healthy aged skin treated with PDT. The photoaging process was induced by different light sources, which had mainly the UV spectrum; for the PDT, light sources of different wavelengths (415, 630, 635 nm) were used (blue and red light sources) and the 5-aminolevulinic acid (ALA), PS precursor of the endogenous protoporphyrin IX (PpIX). In order to follow the PDT protocol up by means of optical techniques, we used fluorescence spectroscopy, fluorescence images and optical coherence tomography. The histopathologic assessment after the PDT procedure was performed with H&E, Massons Trichrome and Verhoeff stains for epidermal thickness, inflammatory infiltrate, dermal collagen content, dermal thickness, and quality of elastic fibers. As a result, it has been observed a significant epidermal thickening due to keratinocytes regeneration and newly formed dermal collagen fibers only on the groups treated with PDT-ALA (UV/PDT and Control/PDT groups). Therefore, it is evident that PDT treats the photoaged skin of hairless mice since histopatologic findings and OCT images have shown those morphology changes. In conclusion, this work add information to the clinical trials regarding the PDT as a reliable technique to treat photoaged skin, proving its use for the skin photorejuvenation.

OBJETIVO: avaliar a capacidade do eletrorretinograma de padrão reverso de campo total (PERG) e multifocal (PERGmf) de detectar alterações funcionais da retina em pacientes com afecções desmielinizantes e compressivas da via óptica anterior; estudar a correlação entre as amplitudes do PERG e PERGmf com as espessuras das camadas internas da retina obtidas pela tomografia de coerência óptica (TCO) e com a perda de campo visual avaliada pela perimetria computadorizada padrão (PCP). MÉTODOS: cento e cinquenta e dois olhos de 28 pacientes com esclerose múltipla (EM), 38 com espectro da neuromielite óptica (NMO) com ou sem neurite óptica (NO) prévia e 30 olhos de 26 controles normais foram submetidos ao PERG, à TCO para avaliação da camada de fibras nervosas da retina (CFNR) peripapilar e camadas internas da retina na mácula e à PCP. Os olhos estudados foram divididos em 4 grupos: grupo 1. EM com NO; grupo 2. EM sem NO; grupo 3. NMO; grupo 4. Mielite transversa longitudinal extensa. Os achados foram comparados utilizando-se as equações de estimativas generalizadas. As correlações entre os achados do PERG, da TCO e da PCP foram avaliadas pela correlação de Pearson ou Spearman e pela análise de regressão linear. Para avaliação dos pacientes com doenças compressivas da via óptica anterior, foram estudados 25 olhos de pacientes com defeito campimétrico temporal e atrofia em banda (AB) do nervo óptico decorrente de compressões quiasmáticas já tratadas e 25 olhos de 25 controles normais pelo PERGmf, a TCO e a PCP. As comparações entre olhos com AB e controles foram feitas usando análise de variância (ANOVA). As correlações entre achados do PERGmf, da TCO e da PCP foram avaliadas pela correlação de Pearson ou Spearman e pela análise de regressão linear. RESULTADOS: comparado com controles, as amplitudes do PERG foram significativamente reduzidas em olhos de pacientes com NMO e EM com NO, mas não mostraram diferenças significativas em olhos de pacientes com EM sem NO e mielite transversa longitudinal extensa. Correlações significantes foram encontradas entre os valores de amplitude de N95, a espessura da camada de células ganglionares da retina e a espessura da CFNR peripapilar. As reduções de amplitudes do PERG também foram significativamente associadas à perda de sensibilidade do campo visual. Na avaliação de pacientes com AB do nervo óptico, as amplitudes do PERGmf foram significativamente reduzidas nos quadrantes temporais quando comparados com controles. Não houve diferenças de amplitude nos setores nasais. Correlações significativas foram encontradas entre as amplitudes do PERGmf, a espessura macular total e a CFNR peripapilar no setor temporal e a perda de sensibilidade do campo visual. CONCLUSÕES: O PERG foi capaz de detectar perda funcional em pacientes com EM e NMO com NO prévia e suas amplitudes foram significativamente correlacionadas com a espessura das camadas internas da retina e camada de fibras nervosas peripapilar. As amplitudes do PERGmf foram capazes de demonstrar perda funcional em pacientes com AB do nervo óptico e apresentaram correlações significantes com a perda de sensibilidade do campo visual e as medidas de espessura macular total e da CFNR peripapilar / PURPOSE: To evaluate the ability of full-field and multifocal (mf) pattern electroretinogram (PERG) parameters to detect functional changes of the retina in patients with demyelinating and compressive diseases of the anterior visual pathway; to study the relationship between the PERG (full field and multifocal) amplitudes, optical coherence tomography (OCT)-measured inner retinal layers measurements and visual field sensitivity loss on standard automated perimetry (SAP). METHODS: one hundred fifty-two eyes of 28 patients with multiple sclerosis (MS), 38 with neuromyelitis optica (NMO) spectrum with or without previous episodes of optic neuritis (ON) and 30 eyes of 26 normal controls underwent PERG, OCT macular and peripapillary retinal nerve fiber layer measurements and SAP. The eyes of the patients were divided into 4 groups: group 1. EM with ON; group 2. EM without ON; group 3. NMO; group 4. Longitudinally extensive transverse myelitis (LETM). The findings were compared using the generalized estimating equations (GEE). The correlations between the findings of the PERG, OCT and SAP were assessed by Pearson correlation coefficients or Spearman\'s rank correlation coefficients and linear regression analysis. For evaluation of patients with compressive diseases of the anterior visual pathway, 25 eyes of patients with temporal visual field defect and band atrophy (BA) of the optic nerve due to chiasmal compression and 25 eyes of 25 normal controls were studied by mfPERG, OCT and SAP. Comparisons between BA and control eyes were made using variance analysis (ANOVA). The correlations between the findings mfPERG, OCT and SAP were evaluated by Pearson correlation coefficients or Spearman\'s rank correlation coefficients and linear regression analysis. RESULTS: compared to controls, PERG amplitudes were significantly reduced in eyes of patients with MS with ON and NMO, but not in eyes with MS without ON and longitudinal extensive transverse myelitis. Significant correlations were found between N95 amplitudes values, OCT-measured macular ganglion cell layer thickness, total retinal thickness, and temporal peripapillary RNFL thickness.The reduced mfPERG amplitudes were also significantly associated with loss of visual field sensitivity. In the evaluation of patients with BA of the optic nerve, mfPERG amplitudes were significantly reduced in the temporal quadrants when compared with controls. There were no differences in the amplitudes values in the nasal sectors. Significant correlations were found between mfPERG amplitudes, OCT-measured total macular thickness and peripapillary RNFL in the temporal sector and the loss of sensitivity of the visual field. CONCLUSIONS: full-field PERG measurements were able to detect functional loss in patients with MS and NMO with previous episodes of ON and PERG amplitudes were significantly correlated with inner retinal layers thicknesses and peripapillary RNFL. Multifocal PERG amplitudes were able to demonstrate functional loss in patients with BA of the optic nerve and showed significant correlations with visual field sensitivity loss and OCT-measured total macular and peripapillary RNFL thickness

OBJETIVO: avaliar a capacidade do eletrorretinograma de padrão reverso de campo total (PERG) e multifocal (PERGmf) de detectar alterações funcionais da retina em pacientes com afecções desmielinizantes e compressivas da via óptica anterior; estudar a correlação entre as amplitudes do PERG e PERGmf com as espessuras das camadas internas da retina obtidas pela tomografia de coerência óptica (TCO) e com a perda de campo visual avaliada pela perimetria computadorizada padrão (PCP). MÉTODOS: cento e cinquenta e dois olhos de 28 pacientes com esclerose múltipla (EM), 38 com espectro da neuromielite óptica (NMO) com ou sem neurite óptica (NO) prévia e 30 olhos de 26 controles normais foram submetidos ao PERG, à TCO para avaliação da camada de fibras nervosas da retina (CFNR) peripapilar e camadas internas da retina na mácula e à PCP. Os olhos estudados foram divididos em 4 grupos: grupo 1. EM com NO; grupo 2. EM sem NO; grupo 3. NMO; grupo 4. Mielite transversa longitudinal extensa. Os achados foram comparados utilizando-se as equações de estimativas generalizadas. As correlações entre os achados do PERG, da TCO e da PCP foram avaliadas pela correlação de Pearson ou Spearman e pela análise de regressão linear. Para avaliação dos pacientes com doenças compressivas da via óptica anterior, foram estudados 25 olhos de pacientes com defeito campimétrico temporal e atrofia em banda (AB) do nervo óptico decorrente de compressões quiasmáticas já tratadas e 25 olhos de 25 controles normais pelo PERGmf, a TCO e a PCP. As comparações entre olhos com AB e controles foram feitas usando análise de variância (ANOVA). As correlações entre achados do PERGmf, da TCO e da PCP foram avaliadas pela correlação de Pearson ou Spearman e pela análise de regressão linear. RESULTADOS: comparado com controles, as amplitudes do PERG foram significativamente reduzidas em olhos de pacientes com NMO e EM com NO, mas não mostraram diferenças significativas em olhos de pacientes com EM sem NO e mielite transversa longitudinal extensa. Correlações significantes foram encontradas entre os valores de amplitude de N95, a espessura da camada de células ganglionares da retina e a espessura da CFNR peripapilar. As reduções de amplitudes do PERG também foram significativamente associadas à perda de sensibilidade do campo visual. Na avaliação de pacientes com AB do nervo óptico, as amplitudes do PERGmf foram significativamente reduzidas nos quadrantes temporais quando comparados com controles. Não houve diferenças de amplitude nos setores nasais. Correlações significativas foram encontradas entre as amplitudes do PERGmf, a espessura macular total e a CFNR peripapilar no setor temporal e a perda de sensibilidade do campo visual. CONCLUSÕES: O PERG foi capaz de detectar perda funcional em pacientes com EM e NMO com NO prévia e suas amplitudes foram significativamente correlacionadas com a espessura das camadas internas da retina e camada de fibras nervosas peripapilar. As amplitudes do PERGmf foram capazes de demonstrar perda funcional em pacientes com AB do nervo óptico e apresentaram correlações significantes com a perda de sensibilidade do campo visual e as medidas de espessura macular total e da CFNR peripapilar / PURPOSE: To evaluate the ability of full-field and multifocal (mf) pattern electroretinogram (PERG) parameters to detect functional changes of the retina in patients with demyelinating and compressive diseases of the anterior visual pathway; to study the relationship between the PERG (full field and multifocal) amplitudes, optical coherence tomography (OCT)-measured inner retinal layers measurements and visual field sensitivity loss on standard automated perimetry (SAP). METHODS: one hundred fifty-two eyes of 28 patients with multiple sclerosis (MS), 38 with neuromyelitis optica (NMO) spectrum with or without previous episodes of optic neuritis (ON) and 30 eyes of 26 normal controls underwent PERG, OCT macular and peripapillary retinal nerve fiber layer measurements and SAP. The eyes of the patients were divided into 4 groups: group 1. EM with ON; group 2. EM without ON; group 3. NMO; group 4. Longitudinally extensive transverse myelitis (LETM). The findings were compared using the generalized estimating equations (GEE). The correlations between the findings of the PERG, OCT and SAP were assessed by Pearson correlation coefficients or Spearman\'s rank correlation coefficients and linear regression analysis. For evaluation of patients with compressive diseases of the anterior visual pathway, 25 eyes of patients with temporal visual field defect and band atrophy (BA) of the optic nerve due to chiasmal compression and 25 eyes of 25 normal controls were studied by mfPERG, OCT and SAP. Comparisons between BA and control eyes were made using variance analysis (ANOVA). The correlations between the findings mfPERG, OCT and SAP were evaluated by Pearson correlation coefficients or Spearman\'s rank correlation coefficients and linear regression analysis. RESULTS: compared to controls, PERG amplitudes were significantly reduced in eyes of patients with MS with ON and NMO, but not in eyes with MS without ON and longitudinal extensive transverse myelitis. Significant correlations were found between N95 amplitudes values, OCT-measured macular ganglion cell layer thickness, total retinal thickness, and temporal peripapillary RNFL thickness.The reduced mfPERG amplitudes were also significantly associated with loss of visual field sensitivity. In the evaluation of patients with BA of the optic nerve, mfPERG amplitudes were significantly reduced in the temporal quadrants when compared with controls. There were no differences in the amplitudes values in the nasal sectors. Significant correlations were found between mfPERG amplitudes, OCT-measured total macular thickness and peripapillary RNFL in the temporal sector and the loss of sensitivity of the visual field. CONCLUSIONS: full-field PERG measurements were able to detect functional loss in patients with MS and NMO with previous episodes of ON and PERG amplitudes were significantly correlated with inner retinal layers thicknesses and peripapillary RNFL. Multifocal PERG amplitudes were able to demonstrate functional loss in patients with BA of the optic nerve and showed significant correlations with visual field sensitivity loss and OCT-measured total macular and peripapillary RNFL thickness

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the United States in people who are 50 and older. The safety and efficacy of aflibercept for the treatment of late stage neovascular AMD (NAMD) has been demonstrated by clinical trials among several populations; however, it is unclear whether all NAMD patients respond in the same manner as was studied in the clinical trials. The purpose of this study was to examine if populations of patients treated with aflibercept for the treatment of NAMD were significantly different from one another in terms of health characteristics, treatment regimens, and treatment outcomes. The burden of treatment theory was used to guide this study. Data collected from electronic medical records were used to investigate NAMD characteristics 199 patients from 3 private, retinal practices in the United States. Data were analyzed using one-way ANOVA, 2, Spearman's correlation, and point-biserial correlation tests. The results of this study showed the specific retinal practice populations of NAMD patients treated with aflibercept were generally similar with respect to selected health characteristics, treatment regimens, and treatment outcomes. By using the information reported from this research, public health initiatives can be developed that focus on the need for early detection of AMD to capture changes that represent NAMD and move to early treatment for better outcomes. The positive social change that could result from this research is that retinal specialists may gain insight into the use and outcomes of aflibercept treatment.

<p>Optical coherence tomography is an imaging modality with an outstanding resolution. During the project, a time domain OCT system based on a Michelson fibre interferometer was implemented and put into operation. A super-luminescent diode with a centre wavelength of 1295nm and a bandwidth of 45nm was selected as light source and a linear variable delay line as reference. Basic tests were made on phantoms constructed of filter foils and on gel-like agar slices with optical properties similar to human tissue. It was shown that the achievable resolution was at least 36um and can be increased. The system can easily be enhanced to create two-dimensional images.</p> / <p>Optische Kohärenztomographie ist ein bildgebendes Verfahren mit einer hervorragenden räumlichen Auflösung. Im Laufe des Projekts wurde ein OCT-System basierend auf einem faseroptischen Michelson-Interferometer implementiert und in Betrieb genommen. Als Lichtquelle wurde eine Superlumineszenzdiode mit einer Mittenwellenlänge von 1295nm und einer Bandbreite von 45nm gewählt. Eine variable optische Verzögerungsleitung diente als Referenz. Erste Messungen an Filterfolien und gelähnlichen Agarphantomen, die die optischen Eigenschaften von menschlichem Gewebe nachbildeten, lieferten eine räumliche Auflösung von mindestens 36um. Durch die modulare Bauweise ist das System leicht für zweidimensionale Aufnahmen erweiterbar.</p>

Optical coherence tomography is an imaging modality with an outstanding resolution. During the project, a time domain OCT system based on a Michelson fibre interferometer was implemented and put into operation. A super-luminescent diode with a centre wavelength of 1295nm and a bandwidth of 45nm was selected as light source and a linear variable delay line as reference. Basic tests were made on phantoms constructed of filter foils and on gel-like agar slices with optical properties similar to human tissue. It was shown that the achievable resolution was at least 36um and can be increased. The system can easily be enhanced to create two-dimensional images. / Optische Kohärenztomographie ist ein bildgebendes Verfahren mit einer hervorragenden räumlichen Auflösung. Im Laufe des Projekts wurde ein OCT-System basierend auf einem faseroptischen Michelson-Interferometer implementiert und in Betrieb genommen. Als Lichtquelle wurde eine Superlumineszenzdiode mit einer Mittenwellenlänge von 1295nm und einer Bandbreite von 45nm gewählt. Eine variable optische Verzögerungsleitung diente als Referenz. Erste Messungen an Filterfolien und gelähnlichen Agarphantomen, die die optischen Eigenschaften von menschlichem Gewebe nachbildeten, lieferten eine räumliche Auflösung von mindestens 36um. Durch die modulare Bauweise ist das System leicht für zweidimensionale Aufnahmen erweiterbar.

A new approach to the absolute measurement of two-dimensional optical path differences is presented in this thesis. The method, which incorporates a white light interferometer and a hyperspectral imaging system, is referred to as Hyperspectral Interferometry. A prototype of the Hyperspectral Interferometry (HSI) system has been designed, constructed and tested for two types of measurement: for surface profilometry and for depth-resolved displacement measurement, both of which have been implemented so as to achieve single shot data acquisition. The prototype has been shown to be capable of performing a single-shot 3-D shape measurement of an optically-flat step-height sample, with less than 5% difference from the result obtained by a standard optical (microscope) based method. The HSI prototype has been demonstrated to be able to perform single-shot measurement with an unambiguous 352 (m depth range and a rms measurement error of around 80 nm. The prototype has also been tested to perform measurements on optically rough surfaces. The rms error of these measurements was found to increase to around 4× that of the smooth surface. For the depth-resolved displacement field measurements, an experimental setup was designed and constructed in which a weakly-scattering sample underwent simple compression with a PZT actuator. Depth-resolved displacement fields were reconstructed from pairs of hyperspectral interferograms. However, the experimental results did not show the expected result of linear phase variation with depth. Analysis of several possible causes has been carried out with the most plausible reasons being excessive scattering particle density inside the sample and the possibility of insignificant deformation of the sample due to insufficient physical contact between the transducer and the sample.