495 resultados para Neovascular glaucoma
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Introdução: A doença de Behçet é uma vasculite inflamatória sistémica, de etiologia desconhecida, caraterizada por episódios de recidiva de úlceras orais e genitais, lesões oculares e cutâneas, podendo atingir virtualmente todos os sistemas. As manifestações oculares são comuns e com consequências visuais importantes. O objectivo deste trabalho foi analisar os parâmetros demográficos, manifestações clinicas, terapêutica e principais complicações em doentes com doença de Behçet ocular. Métodos: Estudo descritivo e retrospetivo, que incluiu 11 doentes com o diagnóstico de doença de Behçet, segundo os critérios do ISG, observados na consulta de Inflamação Ocular do Hospital Prof. Doutor Fernando da Fonseca nos últimos 3 anos. Resultados: Identificaram-se 11 doentes, 5 homens e 6 mulheres, todos caucasianos. A idade média ao diagnóstico foi de 33,45±6,49 anos. A manifestação ocular foi o primeiro sinal da doença em 2 doentes. Em 72,7% dos casos as manifestações oculares foram bilaterais. Identificaram-se 4 casos de panuveíte, 3 de uveíte posterior, 2 de uveíte anterior, 1 de queratite e 1 caso de episclerite. O glaucoma e a catarata foram a complicação ocular mais frequente. O tratamento sistémico incluiu a corticoterapia oral em associação com terapêutica adjuvante imunossupressora, sendo os mais utilizados a azatioprina e a ciclosporina. Em 3 doentes houve necessidade de terapêutica biológica com infliximab para controlo da doença. Conclusão: A manifestação ocular mais frequente foi a panuveite. Esta doença pode condicionar complicações oculares com diminuição irreversível da acuidade visual. A orientação destes doentes exige uma abordagem global e inter-disciplinar.
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Introdução: A alcaptonúria é uma doença rara do metabolismo da fenilalanina e tirosina. As manifestações oculares desta doença são comuns, afectam várias estruturas oculares e podem auxiliar no diagnóstico da doença. Métodos: Descrição clínica de um doente com alcaptonúria Resultados: Homem 70 anos, que recorreu ao serviço de urgência por queixa de baixa acuidade visual progressiva. Apresentava lesões hiperpigmentadas na conjuntiva, esclera e córnea perilímbica e pressão intraocular elevada. Como antecedentes pessoais referia o diagnóstico de artropatia ocronótica, litíase renal e lesões hiperpigmentadas na pele. Estabeleceu-se o diagnóstico de alcaptonúria e glaucoma secundário. Conclusōes:. Várias estruturas oculares são afectadas, sendo a hiperpigmentação da esclera, sobretudo na área interpalpebral, a principal manifestação ocular e a deposição de pigmento em “oil drop” na córnea perilímbica considerada patognomónica da doença. É fundamental conhecer esta patologia, seus achados clínicos e tê-la em consideração no diagnóstico diferencial de hiperpigmentação das estruturas oculares.
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Introdução A maculopatia cupuliforme é uma identidade clínica recentemente descrita, caracterizada por uma convexidade da área macular, associada a diferenças regionais da espessura da esclerótica em míopes. Material e Métodos Mulher de 64 anos que recorreu ao serviço de urgência por queixa de baixa acuidade visual em ambos os olhos com agravamento nos últimos meses. Referia antecedentes oftalmológicos de miopia (-5,25 dioptrias) e DMI exsudativa, tendo realizado 20 injecções de anti-angiogénico, sem melhora. Apresentava acuidade visual de 2/10 no OD e 1/10 no OE, sem alterações de relevo no segmento anterior. Á fundoscopia destacavam-se alterações pigmentares na região macular, sem drusa ou hemorragia em ambos os olhos. Realizou OCT que evidenciou a presença de líquido subretinianano subfoveolar, sem tracção vítreo-macular mas associado a convexidade das camadas da retina. A angiografia fluoresceinica não revelou pontos de extravasamento de contraste sugestivos de membrana neovascular activa nem coriorretinopatia serosa central. Resultados Com base nos achados do OCT macular e após exclusão de outras hipóteses estabeleceu-se o diagnóstico de maculopatia cupuliforme. Após 3 meses houve remissão espontânea do edema subretiniano no OD. Conclusão Para o diagnóstico da maculopatia cupuliforme, o OCT spectral-domain é essencial, sendo característico observar-se uma convexidade da área macular, em pelo menos um eixo (scan vertical ou horizontal) e daí a importância da realização sistemática dos 2 scans. Uma complicação associada à maculopatia cupuliforme é o descolamento seroso da retina, para o qual não existe, até ao momento, um tratamento eficaz, apesar de relatos de remissão espontânea. Este caso ilustra a importância do conhecimento desta patologia e do seu diagnóstico diferencial.
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International audience
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Dinucleoside polyphosphates comprises a group of dinucleotides formed by two nucleosides linked by a variable number of phosphates, abbreviated NpnN (where n represents the number of phosphates). These compounds are naturally occurring substances present in tears, aqueous humour and in the retina. As the consequence of their presence, these dinucleotides contribute to many ocular physiological processes. On the ocular surface, dinucleoside polyphosphates can stimulate tear secretion, mucin release from goblet cells and they help epithelial wound healing by accelerating cell migration rate. These dinucleotides can also stimulate the presence of proteins known to protect the ocular surface against microorganisms, such as lysozyme and lactoferrin. One of the latest discoveries is the ability of some dinucleotides to facilitate the paracellular way on the cornea, therefore allowing the delivery of compounds, such as antiglaucomatous ones, more easily within the eye. The compound Ap4A has been described being abnormally elevated in patient's tears suffering of dry eye, Sjogren syndrome, congenital aniridia, or after refractive surgery, suggesting this molecule as biomarker for dry eye condition. At the intraocular level, some diadenosine polyphosphates are abnormally elevated in glaucoma patients, and this can be related to the stimulation of a P2Y2 receptor that increases the chloride efflux and water movement in the ciliary epithelium. In the retina, the dinucleotide dCp4U, has been proven to be useful to help in the recovery of retinal detachments. Altogether, dinucleoside polyphosphates are a group of compounds which present relevant physiological actions but which also can perform promising therapeutic benefits.
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Purpose.: 5-Methoxy-carbonylamino-N-acetyltryptamine (5-MCA-NAT, a melatonin receptor agonist) produces a clear intraocular pressure (IOP) reduction in New Zealand White rabbits and glaucomatous monkeys. The goal of this study was to evaluate whether the hypotensive effect of 5-MCA-NAT was enhanced by the presence of cellulose derivatives, some of them with bioadhesive properties, as well as to determine whether these formulations were well tolerated by the ocular surface. Methods.: Formulations were prepared with propylene glycol (0.275%), carboxymethyl cellulose (CMC, 0.5% and 1.0%) of low and medium viscosity and hydroxypropylmethyl cellulose (0.3%). Quantification of 5-MCA-NAT (100 μM) was assessed by HPLC. In vitro tolerance was evaluated by the MTT method in human corneal-limbal epithelial cells and normal human conjunctival cells. In vivo tolerance was analyzed by biomicroscopy and specular microscopy in rabbit eyes. The ocular hypotensive effect was evaluated measuring IOP for 8 hours in rabbit eyes. Results.: All the formulations demonstrated good in vitro and in vivo tolerance. 5-MCA-NAT in CMC medium viscosity 0.5% was the most effective at reducing IOP (maximum IOP reduction, 30.27%), and its effect lasted approximately 7 hours. Conclusions.: The hypotensive effect of 5-MCA-NAT was increased by using bioadhesive polymers in formulations that are suitable for the ocular surface and also protective of the eye in long-term therapies. The use of 5-MCA-NAT combined with bioadhesive polymers is a good strategy in the treatment of ocular hypertension and glaucoma.
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Over the last few decades, the importance of ophthalmic examination in neurodegenerative diseases of the CNS has reportedly increased. The retina is an extension of the CNS and thus should not be surprising to find abnormal results in both the test exploring visual processing and those examining the retina of patients with CNS degeneration. Current in vivo imaging techniques are allowing ophthalmologists to detect and quantify data consistent with the histopathological findings described in the retinas of Alzheimer’s disease (AD) patients and may help to reveal unsuspected retinal and optic‐nerve repercussions of other CNS diseases. In this chapter, we perform an analysis of the physiological changes in ocular and cerebral ageing. We analyse the ocular manifestations in CNS disorders such as stroke, AD and Parkinson’s disease. In addition, the pathophysiology of both the eye and the visual pathway in AD are described. The value of the visual psychophysical tests in AD diagnosis is reviewed as well as the main findings of the optical coherence tomography as a contribution to the diagnosis and monitoring of the disease. Finally, we examine the association of two neurodegenerative diseases, AD and glaucoma, as mere coincidence or possible role in the progression of the neurodegeneration.
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This thesis presents an investigation on endoscopic optical coherence tomography (OCT). As a noninvasive imaging modality, OCT emerges as an increasingly important diagnostic tool for many clinical applications. Despite of many of its merits, such as high resolution and depth resolvability, a major limitation is the relatively shallow penetration depth in tissue (about 2∼3 mm). This is mainly due to tissue scattering and absorption. To overcome this limitation, people have been developing many different endoscopic OCT systems. By utilizing a minimally invasive endoscope, the OCT probing beam can be brought to the close vicinity of the tissue of interest and bypass the scattering of intervening tissues so that it can collect the reflected light signal from desired depth and provide a clear image representing the physiological structure of the region, which can not be disclosed by traditional OCT. In this thesis, three endoscope designs have been studied. While they rely on vastly different principles, they all converge to solve this long-standing problem.
A hand-held endoscope with manual scanning is first explored. When a user is holding a hand- held endoscope to examine samples, the movement of the device provides a natural scanning. We proposed and implemented an optical tracking system to estimate and record the trajectory of the device. By registering the OCT axial scan with the spatial information obtained from the tracking system, one can use this system to simply ‘paint’ a desired volume and get any arbitrary scanning pattern by manually waving the endoscope over the region of interest. The accuracy of the tracking system was measured to be about 10 microns, which is comparable to the lateral resolution of most OCT system. Targeted phantom sample and biological samples were manually scanned and the reconstructed images verified the method.
Next, we investigated a mechanical way to steer the beam in an OCT endoscope, which is termed as Paired-angle-rotation scanning (PARS). This concept was proposed by my colleague and we further developed this technology by enhancing the longevity of the device, reducing the diameter of the probe, and shrinking down the form factor of the hand-piece. Several families of probes have been designed and fabricated with various optical performances. They have been applied to different applications, including the collector channel examination for glaucoma stent implantation, and vitreous remnant detection during live animal vitrectomy.
Lastly a novel non-moving scanning method has been devised. This approach is based on the EO effect of a KTN crystal. With Ohmic contact of the electrodes, the KTN crystal can exhibit a special mode of EO effect, termed as space-charge-controlled electro-optic effect, where the carrier electron will be injected into the material via the Ohmic contact. By applying a high voltage across the material, a linear phase profile can be built under this mode, which in turn deflects the light beam passing through. We constructed a relay telescope to adapt the KTN deflector into a bench top OCT scanning system. One of major technical challenges for this system is the strong chromatic dispersion of KTN crystal within the wavelength band of OCT system. We investigated its impact on the acquired OCT images and proposed a new approach to estimate and compensate the actual dispersion. Comparing with traditional methods, the new method is more computational efficient and accurate. Some biological samples were scanned by this KTN based system. The acquired images justified the feasibility of the usage of this system into a endoscopy setting. My research above all aims to provide solutions to implement an OCT endoscope. As technology evolves from manual, to mechanical, and to electrical approaches, different solutions are presented. Since all have their own advantages and disadvantages, one has to determine the actual requirements and select the best fit for a specific application.
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Desarrollamos un estudio epidemiológico transversal observacional en la población de la provincia de Málaga para determinar la incidencia y prevalencia de periodo de uveítis durante 12 meses (desde el 1 de Mayo de 2011 al 30 de Abril de 2012). Objetivos: Determinar la incidencia y prevalencia de la uveítis en nuestra provincia. Evaluar la posible relación entre el género y la edad al diagnóstico de la uveítis, con las características clínicas de esta enfermedad en nuestra población (curso clínico, localización anatómica, clasificación etiológica, complicaciones). Establecer cuales son los principales factores de riesgo para desarrollar complicaciones. Material y métodos: Se recogieron los datos correspondientes a todos los pacientes diagnosticados de uveítis en los seis centros participantes (todos los hospitales públicos de la provincia de Málaga) durante el periodo comprendido entre el 1 de Mayo de 2011 al 30 de Abril de 2012. Resultados: La frecuencia y las características de las uveítis en nuestra provincia son similares a las obtenidas por otros estudios de países del mundo occidental. Su prevalencia en nuestro medio es de 36,2 por 100.000 habitantes (IC 95%: 33,4-39,3) y la incidencia de 12,1 por 100.000 habitantes (IC 95%: 10-5-13,9). La etiología es habitualmente desconocida (41,9%). La edad media de inicio es de 40,3±19,2 años. La etnia más frecuente es la caucásica (92,5%). La uveítis en nuestro estudio muestra un ligero predominio femenino (58,6%), un curso clínico recurrente (50,5%) y una localización anatómica mayoritariamente anterior (69,3%). El 40,1% de la población desarrolla al menos una complicación, siendo las más prevalentes la catarata (28,5%) y el glaucoma (12,3%). La edad también influye en la caracterización de las uveítis: 1. La diferencia de género es mayor en las edades extremas de la vida, siendo más prevalentes las uveítis en mujeres en edades pediátricas (71,2%) o en mayores de 60 años (62,2%). 2. Las formas crónicas fueron mucho más frecuentes en menores de 16 años (36.40%). 3. Las uveítis de localización intermedia son mucho más comunes en la edad pediátrica (19,2%). 4. Las uveítis idiopáticas son la causa más frecuente en todas las edades, excepto en los niños, donde las enfermedades asociadas a patología sistémica son la etiología más común (54,8%). 5. Las complicaciones fueron más frecuentes en las personas de mayor edad (50,5%), siendo la catarata y el glaucoma las más prevalentes. 6. En nuestra población los casos de ceguera legal son muy poco frecuentes, aunque su prevalencia es mayor en los pacientes de mayor edad (2,3%). Destacar que los principales factores de riesgo para el desarrollo de complicaciones en la uveítis fueron el tiempo de evolución de la enfermedad, la mayor edad del paciente, las panuveítis, y el curso clínico crónico. Conclusiones: En un área bien definida del sur de España, la frecuencia y las caraterísticas de la uveítis son similares a otros estudios realizados en el mundo occidental. Es una patología rara, de causa desconocida, con un curso clínico recurrente y que desarrolla con frecuencia complicaciones severas. La uveítis presenta diferentes características según la edad de inicio. Los principales factores de riesgo para el desarrollo de complicaciones son el mayor tiempo de evolución de la enfermedad, la mayor edad de los pacientes, la forma anatómica tipo panuveítis y la evolución clínica crónica.
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Introducción: La diminución de la capacidad de expansión del tejido adiposo juega un papel crucial en el origen y desarrollo de los trastornos asociados al síndrome metabólico. Hipótesis y Objetivos: Considerando que la expansión del tejido adiposo depende del estado de sus células mesenquimales multipotenciales (ASCs), es probable que las condiciones tisulares asociadas a los períodos de balance energético positivo generen alteraciones en los patrones heredables de transcripción génica mediante los que las ASCs quedan predispuestas a favor del fenotipo fibrótico e inflamatorio, en detrimento de su función adipogénica y neovascular. Para corroborar ésta hipótesis nos propusimos revelar la implicación de las ASCs en la remodelación tisular adiposa; su contribución a la disminución de la capacidad angiogénica del tejido adiposo; y evaluar su respuesta neovascular, migratoria e inflamatoria ante la hipoxia. Metodología: Aplicamos técnicas de cultivo celular, citometría de flujo, qPCR, western blot y ELISA a las ASCs aisladas del tejido adiposo visceral y subcutáneo de 69 sujetos agrupados en normopesos, y obesos con (SM) y sin síndrome metabólico (NoSM). Resultados: Los adipocitos generados a partir de las ASC visceral y subcutáneo evidenciaronn una disminución en los niveles intrínsecos de expresión del transportador de glucosa GLUT4 conforme aumenta la expresión de proteínas fibróticas, el BMI y el HOMA-IR de los pacientes. El empeoramiento del perfil metabólico de los sujetos estuvo acompañado por la disminución de la tasa proliferativa, el potencial clonogénico y la exportación del FGF2 hacia la superficie celular de las ASC derivadas de ambos tejidos. Las ASC visceral y subcutáneo de los sujetos SM también mostraron una disminución en la capacidad de formación de túbulos respecto a las ASCs de los sujetos obesos NoSM así como alteraciones en los niveles de expresión de proteínas implicadas en el balance redox celular y vinculadas al fenotipo secretor asociado a senescencia. El deterioro de las propiedades neovasculares de las ASC subcutáneo de los sujetos SM se evidenció además en los niveles de secreción del VEGF durante la adipogénesis y en los efectos del medio condicionado adipogénico sobre la formación de túbulos por células endoteliales. Aunque las ASC visceral de los sujetos SM cultivadas bajo hipoxia mostraron mayor porcentaje de células CD140b+/CD44+ y CD140b+/CD184+ así como mayor capacidad migratoria que las ASC visceral de los sujetos NoSM, también evidenciaron menor capacidad de formación de túbulos, transcribieron más RNAm NOX5 y su medio condicionado disminuyó la supervivencia de las células endoteliales. Conclusiones: El funcionamiento del tejido adiposo parece condicionar el deterioro de sus propias células precursoras y ante el cual las ASCs de los sujetos que desarrollan síndrome metabólico son más vulnerables.
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In the medical field images obtained from high definition cameras and other medical imaging systems are an integral part of medical diagnosis. The analysis of these images are usually performed by the physicians who sometimes need to spend long hours reviewing the images before they are able to come up with a diagnosis and then decide on the course of action. In this dissertation we present a framework for a computer-aided analysis of medical imagery via the use of an expert system. While this problem has been discussed before, we will consider a system based on mobile devices. Since the release of the iPhone on April 2003, the popularity of mobile devices has increased rapidly and our lives have become more reliant on them. This popularity and the ease of development of mobile applications has now made it possible to perform on these devices many of the image analyses that previously required a personal computer. All of this has opened the door to a whole new set of possibilities and freed the physicians from their reliance on their desktop machines. The approach proposed in this dissertation aims to capitalize on these new found opportunities by providing a framework for analysis of medical images that physicians can utilize from their mobile devices thus remove their reliance on desktop computers. We also provide an expert system to aid in the analysis and advice on the selection of medical procedure. Finally, we also allow for other mobile applications to be developed by providing a generic mobile application development framework that allows for access of other applications into the mobile domain. In this dissertation we outline our work leading towards development of the proposed methodology and the remaining work needed to find a solution to the problem. In order to make this difficult problem tractable, we divide the problem into three parts: the development user interface modeling language and tooling, the creation of a game development modeling language and tooling, and the development of a generic mobile application framework. In order to make this problem more manageable, we will narrow down the initial scope to the hair transplant, and glaucoma domains.
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Introduction: Fluocinolone acetonide slow release implant (Iluvien®) was approved in December 2013 in UK for treatment of eyes which are pseudophakic with DMO that is unresponsive to other available therapies. This approval was based on evidence from FAME trials which were conducted at a time when ranibizumab was not available. There is a paucity of data on implementation of guidance on selecting patients for this treatment modality and also on the real world outcome of fluocinolone therapy especially in those patients that have been unresponsive to ranibizumab therapy. Method: Retrospective study of consecutive patients treated with fluocinolone between January and August 2014 at three sites were included to evaluate selection criteria used, baseline characteristics and clinical outcomes at 3-month time point. Results: Twenty two pseudophakic eyes of 22 consecutive patients were included. Majority of patients had prior therapy with multiple intravitreal anti-VEGF injections. Four eyes had controlled glaucoma. At baseline mean VA and CRT were 50.7 letters and 631 μm respectively. After 3 months, 18 patients had improved CRT of which 15 of them also had improved VA. No adverse effects were noted. One additional patient required IOP lowering medication. Despite being unresponsive to multiple prior therapies including laser and anti-VEGF injections, switching to fluocinolone achieved treatment benefit. Conclusion: The patient level selection criteria proposed by NICE guidance on fluocinolone appeared to be implemented. This data from this study provides new evidence on early outcomes following fluocinolone therapy in eyes with DMO which had not responded to laser and other intravitreal agents.
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Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes andM¨uller cells (retinal macroglia) provide physical support to neurons and supplement them with several metabolites and growth factors.Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB), play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD), diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases.The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.
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The research on the effect of melatonin on intraocular pressure (IOP) is reviewed from the hystorical point of view of our laboratory. The original idea of melatonin modulating intraocular pressure has been improved by using selective compounds for MT2 and specially melatonin MT3 receptors. The selective compound 5-methoxyamino N-acetyltryptamine (5-MCA-NAT) has been an attractive compound due to its ability to reduce IOP about 40%, therefore being a good candidate to the treatment of the ocular hypertension linked to glaucoma. More compounds have been developed and tested permitting us to have a more accurate panorama of those receptors controlling the relevant process of intraocular pressure.
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Age related macular degeneration (AMD) is a major concern regarding blindness in the world. In western countries, where visual alterations due to minor pathologies as cataract and uncorrected refractive errors are easily resolved, AMD represent the main cause of blindness. Of the two existing forms of the disease, while the neovascular is more aggressive and progress quickly, geographic atrophy is the one still lacking an appropriate therapy. My PhD program was focused on investigating AMD features, trying to understand if some approaches I tested could be able to provide some suggestion about potential future therapies on “dry” AMD. In my research I developed three main projects. The most important part of the work regards the study of integrins and their fundamental role in cell adhesion in a context of interaction between retinal pigmented epithelium (RPE) and immune cells. I investigated how co-culture of these different cell lines can lead to simulate an inflammatory state inducing cell signaling, cytokine production and cell death. The use of integrin antagonists developed in our laboratory, showed how these effects can be reverted. A secondary approach regards the use of antioxidants and their role in epigenetic modifications in ARPE-19 cells to investigate how these compounds might exert their well-known protective role on AMD. Commonly used antioxidants as Lutein and Quercetin do not induce clear epigenetic modifications through histone H3 acetylation indicating only a limited involvement.