Orientador: José Paulo Cabral de Vasconcellos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T03:03:06Z (GMT). No. of bitstreams: 1 Bittencourt_MauraKrahembuhlWanderley_D.pdf: 4949840 bytes, checksum: 022f99304656d76ae232d1c85d47077b (MD5) Previous issue date: 2014 / Resumo: Objetivo: Descrever a ação da toxina botulínica do tipo A quando aplicada no músculo elevador da pálpebra superior, investigar a sua segurança e eficácia na produção de ptose protetora em cães. Métodos: Neste estudo do tipo longitudinal, série de casos com intervenção, um total de 10 cães foram submetidos à quimiodenervação do músculo elevador da pálpebra superior, através da aplicação por via transcutânea de 15 unidades de toxina botulínica do tipo A. Alterações sistêmicas, mobilidade ocular, função visual, pressão intraocular, produção lacrimal, o aparecimento, grau e duração da ptose foram avaliados diariamente durante os sete primeiros dias e posteriormente nos dias 14, 21 e 28 após a aplicação. Resultados: O início do efeito clínico foi observado entre 2 e 3 dias após a aplicação da toxina, o tempo necessário para desenvolver a máxima ptose variou entre 4 e 7 dias (média de 5 dias), a duração média do efeito da toxina foi de 21 dias. O percentual médio de redução máxima do tamanho da fenda palpebral foi 42,9 % (DP ± 35,7%). Não houve diferença estatisticamente significativa na pressão intraocular antes e depois da aplicação da toxina (P = 0,974 ), bem como na avaliação da produção lacrimal (P = 0,276). Não houve alteração na mobilidade ocular e nenhum outro efeito adverso foi observado em associação com a administração do medicamento em estudo. Conclusão: A aplicação da toxina botulínica do tipo A no músculo elevador da pálpebra superior em cães foi eficaz e segura para promover a ptose protetora com uma cobertura temporária da córnea / Abstract: Purpose: Describe the action of botulinum toxin type A when applied into levator palpebral superioris muscle, verifying its safety and efficacy to promote protective ptosis in dogs. Methods: In this prospective interventional study, a total of 10 dogs underwent transcutaneous anterior chemodenervation of levator palpebral superioris with 15 units of botulinum toxin type A. The systemic changes, ocular mobility, visual function, intraocular pressure (IOP), tear production and the onset, degree and duration of ptosis were evaluated on a daily basis during the first seven days and on days 14, 21 and 28 after application. Results: The onset of the clinical effect was observed between 2 and 3 days after application of the toxin, the time taken for maximum ptosis develop varied from 4 to 7 days (mean 5 days), average duration of the toxin effect was 21 days. The mean percentage reduction in palpebral fissure height was 42.8% (SD ± 35.7%). There was not a statistically significant difference in IOP before and after the BoNT/A application (P = 0.974), or lacrimal production evaluation (P = 0.276). There was no change in ocular mobility and no other adverse effect was observed in association with the administration of the study drug. Conclusion: The application of botulinum toxin type A into levator palpebral superioris muscle in dogs was effective and safe to promote protective ptosis with a temporary covering of the cornea / Doutorado / Ciencias Biomedicas / Doutora em Ciências Médicas

La bioimpression assistée par laser (LAB) permet de positionner des gouttesde cellules avec une précision micrométrique. Il est ainsi possible de donner uneorganisation initiale aux cellules au sein d’une structure tissulaire 3D. Notre objectif estd’utiliser le LAB pour reproduire l’histo-architecture du stroma cornéen. Le stroma cornéenest un assemblage transparent de lamelles d’une épaisseur totale de 500 μm. Au sein dechaque lamelle, les fibres de collagène ont une même direction, un même diamètre et sontrégulièrement espacées grâce à la présence de protéoglycanes spécifiques du stromacornéen. Pour reproduire cette organisation, nous avons fait l’hypothèse qu’en alignant desfibroblastes du stroma sur un hydrogel de collagène à l’aide du LAB, il serait possibled’aligner les fibres de collagène dans la même direction. Du fait que les cellules impriméessont vivantes et dynamiques, le motif cellulaire initialement imprimé est soumis à desprocessus d’auto-organisation. Il a donc fallu déterminer les paramètres, à la foisd’impression et de culture, permettant d’obtenir de façon reproductible des alignements decellules stables dans le temps. Grâce à la microscopie à génération de secondeharmonique, le remaniement des fibres de collagène par les fibroblastes cornéens a pu êtreobservé. La direction des fibres de collagène correspond à celle de l’alignement cellulaire.En imprimant les fibroblastes de cornée sur des couches successives de collagène, noussommes parvenus à reproduire les variations de direction des fibres de collagène d’unelamelle à l’autre qui sont observées dans le stroma cornéen natif. / Laser-Assisted Bioprinting allows positioning of cell droplets with amicrometric precision. It is thus possible to give an initial organization to the cells within a3D tissue structure. Our objective is to use LAB to reproduce the corneal stroma histoarchitecture.The corneal stroma is a transparent assembly of lamellae with a totalthickness of 500 μm. Within each lamella, collagen fibers have the same direction, thesame diameter, and a regular spacing thanks to the presence of proteoglycans which arespecific from the corneal stroma. To reproduce this organization, we make the hypothesisthat through corneal fibroblasts alignment, using LAB, on a collagen hydrogel, it would bepossible to align collagen fibers in the same direction. Because printed cells are alive anddynamic, the cell pattern initially printed is subjected to self-organization processes. It isthus necessary to determine the printing and culture parameters that promote reproducibleand stable cell alignments. By using second harmonic generation microscopy, collagenfiber reorganization by corneal fibroblasts has been observed. Collagen fiber direction ismatching with cell alignment. Corneal fibroblasts have been printed on successive collagenlayers; it allows reproducing the variations in collagen fiber direction from one lamella toanother that are observed in the native corneal stroma.

Topografias da córnea consistem em medir a forma da córnea, que é um fator chave para a acuidade visual. O exame é usado, por exemplo, na detecção de ceratocone, ajuste personalizado de lentes de contato, e pre e pós procedimentos associados com cirurgias refrativas e transplante de córnea. Esta dissertação apresenta, uma abordagem acessível e portátil para realizar topografias da córnea. Os resultados obtidos com o nosso protótipo mostram uma diferença média por volta de 0.02 milimetros, equivalente a 0.5% do raio médio da córnea, quando comparadas com topografias adquiridas com um topografo comercial. Nossa abordagem é baseada no disco de Plácido, a um conjunto de círculos concêntricos que são colocados na frente do olho do paciente e refletidos na córnea. Observando a deformação do padrão projetado, podemos identificar algumas condições refrativas (e.g. astigmatismo, ceratocone) e estimar a topografia da córnea do paciente. Nós construimos um dispositivo para ser utilizado com um celular para emitir os padrões, estes são então capturados pela câmera do celular. Nós usamos um sequência de procedimentos para melhor as imagens, segmentar os padrões, associar o padrão capturado com o emitido para amostrar o sinal, e finalmente estimar a superfície da córnea. A forma estimada é então decomposta, usando-se os polinômios de Zernike, em componentes com significado ótico específico. Nós avaliamos os resultados obtidos com o nosso protótipo de três maneiras: inspeção visual de ceratoscopias, detecção de ceratocone, e comparação com os resultados produzidos por um topográfo de córnea comercial. De acordo com essa análise, nosso dispositivo pode ser utilizado para o exame de indivíduos com ceratocone, e obter topografias com 0.02 milimetros de diferença em relação aos resultados obtidos com um topógrafo comercial. / Corneal topography consists of measuring the corneal shape, which is a key factor for visual acuity. The exam is used, for instance, in keratoconus detection, personalized contact lens fitting, in pre- and post-procedures associated with refractive surgery and corneal transplants. This thesis presents an accessible, inexpensive and portable approach to perform corneal topographies. The results obtained with our prototype show a mean difference of about 0.02 millimeters, equivalent to 0.5% of the mean corneal radius, when compared to topographies acquired with a commercial device. Our approach is based on Placido’s disks, a set of concentric disks that are placed in front of the patient’s eye and reflected on the cornea. Observing the deformation of the projected pattern, one can identify some refractive conditions (e.g., astigmatism, keratoconus) and estimate the patient’s corneal topography. We have built a clip-on device to be used with a cell phone to emit the patterns, which are then captured by the cell phone camera. We use a software pipeline to enhance the images, segment the patterns, associate the emitted pattern with the captured one to sample the signal, and finally estimate the corneal surface. The estimated shape is then decomposed using Zernike polynomials in components with specific optical meanings. We have evaluated the results obtained with our prototype in three ways: visual inspection of keratoscopies, keratoconus detection, and comparison with the results produced by a commercial corneal topographer. According to such analysis, our device can be used for screening of individuals with keratoconus, and to obtain corneal topographies with 0.02-millimeter differences with respect to the results obtained with a commercial corneal topographer.

The majority of ancient people worshipped the sun and viewed it as a health - bringing deity. During the eighteenth and nineteenth century therapeutic benefits of sunlight exposure were beginning to be understood and by the end of the nineteenth century the importance of ultraviolet radiation was being realized. Danish physician Niels Finsen, whom many regard as the father of ultraviolet phototherapy, also stressed that it was ultraviolet radiation in the solar spectrum which cause sunburn. We now recognize that the small portion of ultraviolet radiation which reaches the earth's surface is not necessarily therapeutic, but in fact could be harmful to humans. There are numerous accounts of the harmful effects of UV radiation to the skin and the eye as a whole. These effects may be caused by either acute or chronic exposure to UV radiation. For example, some acute effects of UV-B radiation include conjunctivitis and photokeratitis. "Snow blindness" and "arc welders eye" are further examples of acute ultraviolet damage specifically to the surface of the cornea. On the other hand, chronic exposure to ultraviolet radiation is thought to be responsible for pterygia, climatic droplet keratopathy Hill and Maske (1989), cancers of the external eye, cataracts and various types of retinal diseases. The present study is an extension of ongoing studies on ultraviolet radiation damage to the cornea in the Department of Ophthalmology, University of Cape Town and Groote Schuur Hospital. Their specific interest lies in the causes and treatment of climatic droplet keratopathy. The aims of the present study are: 1) Establish a possible role of ultraviolet B radiation in human corneal diseases such as climatic droplet keratopathy and pterygium using the rabbit as an animal model. 2) Determine by means of SEM the initial effects and subsequent recovery of the epithelium after a 3-hour dose of ultraviolet B radiation. We refer to this study as "acute" response to ultraviolet B radiation. 3) To try and confirm the effects observed by SEM with ultrastructural studies using TEM. 4) In addition, we are also looking at the possible effects after exposing rabbit cornea to a daily dose of low level ultraviolet B radiation, over a long period of time. We refer to this as chronic exposure to ultraviolet B radiation. It is hoped that by exposing rabbits to ultraviolet light, principally ultraviolet B radiation, diseases similar to those found in humans could be simulated and disease progression studied. People are generally exposed to substantial amounts of UV radiation for a very long time. Since people generally live longer they will be exposed to an ever-increasing amount of solar UV radiation and subsequently, there is an increasing risk of developing corneal diseases. The possible threat to the ozone is also a real possibility and could lead to increased levels of ultraviolet radiation reaching the earth's surface. This will require a greater understanding of the very nature of corneal damage due to acute and chronic exposure. This study focusses mainly on the acute response to UV-B radiation since most studies have investigated effects of prolonged exposure to UV light. Accordingly, much less is known about acute exposure. Many people suffering from acute UV B radiation effects probably never visit the ophthalmologist or wait for a couple of days. This could also contribute to the fact that effects of short-term damage is not well documented.

Introduction: The development of molecular genetic methods has in many fields necessitated their inclusion in routine clinical practice, including ophthalmology. The main aim of this thesis was detailed clinical characterization of Czech patients with suspected inherited corneal disorders, followed by genetic testing to determine or specify their clinical diagnosis and subsequently to use the knowledge gained in clinical and genetic counselling and to apply preventive measures in order to avoid loss of vision. Material and Methods: Individuals included in this research were either followed up or newly referred to the Cornea clinic of the Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague. Detailed clinical examination included corneal tomography, specular microscopy, spectral domain optical coherence tomography, biometry and genealogical analysis. DNA was extracted from peripheral blood leucocytes or buccal cells. Disease-causing variants were searched for using Sanger or massively parallel sequencing, variant pathogenicity was assessed in silico using various algorithms and by segregation analyses within the families. In some cases assessment of the functional impact on the pre-mRNA splicing process was performed. In patients with...

Syfte: Studiens syfte var att kontrollera repeterbarhet och jämförbarhet hos tre kliniska instrument som används för att mäta hornhinnans tjocklek i friska ögon. Instrumenten som användes har flera olika användningsområden men fokus i denna studie ligger specifikt på pakymetri: mätning av hornhinnetjocklek. Metod: Det var 64 personer som deltog i studien. Alla var över 18 år och befann sig på Linnéuniversitetet i Kalmar vid tidpunkterna för mättillfällena. De tre optiska pakymetri instrumenten som användes var Topcon TRK-2P, Bon Sirius samt Essilor Wavefront Analyzer Medica 700+. Tre mätningar utfördes vid varje instrument på deltagarnas båda ögon. All data sammanställdes i Google Kalkyl och analyserades vidare i Graphpad Prism (version 9). Resultat: Repeterbarheten testades med ICC vilket var över 0,98 på samtliga instrument, CR var mellan 5,28-8,80 μm och CV var mellan 6,29-6,74%. Jämförbarheten visade att det finns en signifikant skillnad mellan de tre instrumenten (One-way RM- ANOVA,  p<0,0001). Slutsats: Samtliga instrument som användes inom studien visade på en utmärkt repeterbarhet vid mätning av friska ögon, däremot förekom signifikanta skillnader dem emellan. Detta innebär att man bör hålla sig till ett och samma instrument vid uppföljning av patienter. / Purpose: The purpose of this study was to examine the repeatability and comparability of three clinical instruments used to measure the corneal thickness in healthy eyes. The different instruments all have various fields of usage but the focus in this study is pachymetry: measurement of the corneal thickness. Method: In total, 64 people participated in this study. Everyone that participated were above the age of 18 and were located at Linneaus university in Kalmar, Sweden at the time the measurements took place. The three optical pachymetry instruments used were Topcon TRK-2P, Bon Sirius and Essilor Wavefront Analyzer Medica 700+. Three measurements were taken on each instrument on the participants’ both eyes. All collected data was collated in Google Sheets and analyzed in Graphpad Prism (version 9).  Results: The repeatability was tested with ICC that was above 0,98 on all the instruments. CR was between 5,28-8,80 μm and CV was between 6,29-6,74%. The comparability showed that there was a significant difference between the three instruments (One-way RM- ANOVA,  p<0,0001). Conclusion: All three instruments that were used during this study showed an excellent repeatability when measuring healthy eyes. However, there were significant differences between the instruments themselves. This means that you should stick to the same instrument while following up patients.

Confocal microscopy demonstrated its value in the diagnosis of Acanthamoeba and fungal keratitis which considered sight-threatening corneal diseases. However, it can be difficult to find and train confocal microscopy graders to accurately detect Acanthamoeba cysts and fungal filaments in the images. Use of an automated system could overcome this problem and help to start the correct treatment more quickly. Also, response to treatment can be difficult to assess in infectious keratitis using clinical examination alone, but there is evidence that the morphology of filaments and cysts may change over time with the use of correct treatment. An automated system to analyse confocal microscopy images for such changes would also assist clinicians in determining whether the ulcer is improving, or whether a change of treatment is needed. This research proposes a fully automated novel system with GUI to detect cysts and hyphae (filaments) and measure useful quantitative parameters for them through many stages; Image enhancement, image segmentation, quantitative analysis for detected cysts and hyphae, and registration and tracking of ordered sequence of images. The performance of the proposed segmentation procedure is evaluated by comparing between the manual and the automated traced images of the dataset that was provided by the Manchester Royal Eye Hospital. The positive predictive values rate of cysts for Acanthamoeba images was 76%. For detected hyphae in Fusarium images, many standard measurements were computed. The accuracy of their values was quantified by calculating the percent error rate for each measurement and which ranged from 23% to 49%.

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