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Saia, Paula Simone. "Sistema ceratométrico de apoio a suturas na córnea." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-26032008-153951/.
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Um sistema para auxílio à cirurgias oftálmicas foi desenvolvido com o objetivo de se minimizar o astigmatismo induzido devido ao formato irregular da córnea pelo ato de sutura. O sistema projeta 48 pontos de luz no filme lacrimal da córnea, provenientes de LEDs, dispostos num diâmetro precisamente circular. O deslocamento, a dimensão e a deformação da imagem refletida destes pontos luminosos são analisados proporcionando a ceratometria e a circularidade da sutura. O intervalo de medidas do sistema é de 32D - 55D (astigmatismos até 23D podem ser medidos) e um sistema para calibração do sistema foi projetado para manter o sistema calibrado. Esferas de aço de precisão foram submetidas ao sistema e uma correlação de 99% entre as medidas obtidas e os valores dos fabricantes foi obtida. O sistema foi testado em 13 voluntários para avaliação de sua aplicabilidade clínica e comparado a um ceratômetro comercial Topcon OM-4. Os fatores de correlação entre o sistema desenvolvido e o Topcon OM-4, para o astigmatismo, foi de \'R POT.2\' = 0,92, e em relação ao eixo, o fator é \'R POT.2\' = 0,99. O sistema indica que o cirurgião deve obter uma circularidade \'> OU =\' 98% para que astigmatismos acima de 3D não sejam induzidos na sutura.<br>A system for ophthalmic surgery support has been developed in order to minimize the residual astigmatism due to the induced irregular shape of the cornea by corneal suture. The system projects 48 light spots, from LEDs, displayed in a precise circle at the lachrymal film of the examined cornea. The displacement, the size and deformation of the reflected image of these light spots are analyzed providing the keratometry and the circularity of the suture. Measurements in the range of 32D - 55D (up to 23D of astigmatism are possible to be obtained) and a self-calibration system has been designed in order to keep the system calibrated. Steel precision spheres have been submitted to the system and the results show 99% of correlation with the fabricant\'s nominal values. The system has been tested in 13 persons in order to evaluate its clinical applicability and has been compared to a commercial keratometer Topcon OM-4. The correlation factors are 0,92 for the astigmatism and 0.99 for the associated axis. The system indicates that the surgeon should achieve circularity \'> OR =\' 98% in order to do not induce astigmatisms over 3D.
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Chmulíková, Mária. "Očné centrum Cornea." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372034.
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The subject of the master thesis is the design of an eye center. It’s a three-floored building, where in the first floor is designed eye optics, pharmacy and main entrance to the eye center. During the design of the building, emphasis is placed on people with reduced mobility and orientation, technical building solution, thermal technical solution, as well as the assessment of fire safety. On the second floor there is an eye clinic and an operating theatre. On the third floor there are designed an operating theatre, a conference room and offices. The two types of roofs are designed - a vegetation flat roof and a walkable flat roof.
3
Podskochy, Alexander. "Ultraviolet radiation and cornea /." Stockholm : Karolinska institutet, 2002. http://diss.kib.ki.se/2002/91-7349-118-7/.
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Gehlen, Marcelo Luiz. "Avaliação espectrofotométrica de reação inflamatória corneana." reponame:Repositório Institucional da UFPR, 2013. http://hdl.handle.net/1884/29074.
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Resumo: Introdução: o azul de Evans constitui-se num corante inócuo que tem alta afinidade pela albumina e pode ser mensurado espectrofotometricamente como demonstram vários estudos. Objetivos: a) Constatar a presença do azul de Evans na córnea normal estipulando o período de tempo de concentração máxima do corante após inoculação endovenosa; b) Verificar o mecanismo de difusão do corante no tecido; c) Mensurar a exsudação do azul de Evans em processo inflamatório após indução de queimadura química corneana com NaOH. Material e métodos: Utilizou-se 50 coelhos albinos machos que foram divididos em 3 grupos: Grupo I: composto de 25 animais e que inoculou-se via endovenosa 20 mg/Kg de azul de Evans e sacrificou-se os animais em 8, 10, 12, 14 e 16 horas após injeção do corante. A partir de então extraiu-se o tecido corneano margeado por 1 mm de esclera e quantificou-se o corante através do micrométodo espectrofotométrico. Grupo II: Em 15 animais inoculou-se o corante via endovenosa e posteriormente fragmentou-se centralmente o tecido com trépanos de 6, 8 e 10 mm e procedeu-se a extração do azul de Evans da mesma forma que no grupo I. Grupo III: induziu-se queimadura na córnea do olho direito de 10 animais com NaOH a 1 N. Cinco dias após o procedimento, os animais foram sacrificados, sendo que, 10 horas antes do sacrifício, foi inoculado o azul de Evans para que posteriormente se pudesse quantificá-lo. A córnea esquerda serviu como controle. Resultados: no grupo I, as médias das concentrações do azul de Evans foram: 8 h.: 14,68 ?g/mg; 10 h.: 15,30 ?g/mg; 12 h.: 15,02 ?g/mg; 14 h.: 14,09 ?g/mg; 16 h.: 14,85 ?g/mg. No grupo II, as médias das concentrações do corante foram: 6 mm.: 0,93 ?g/g; 8 mm.: 1,19 ?g/mg; 10 mm.: 1,35 ?g/mg. No grupo III, as médias das concentrações do azul de Evans foram: olho direito (queimadura): 23,74 ?g/mg e olho esquerdo (controle): 16,71 ?g/mg. Discussão e Conclusão: O azul de Evans tem sido motivo de estudo em diversos órgãos e em diferentes animais. Foi possível quantificar pela primeira vez o corante na córnea de coelhos e constatar que, após 10 horas de inoculação endovenosa, o azul de Evans atingiu seu pico de concentração no tecido. As concentrações do corante decresceram a medida que se atingia porções mais centrais da córnea como foi demonstrado no grupo II, revelando um padrão de distribuição centrípeta do corante no tecido estudado. Comprovou-se que o aumento da permeabilidade vascular, induzida pela queimadura química na córnea, está diretamente ligada ao extravazamento do corante ao tecido, aumentando significativamente (p<0,001) sua concentração em relação à córnea normal. Portanto, o azul de Evans serve como um bom método de quantificação da permeabilidade vascular alterada na córnea, especialmente na vigência de processo inflamatório.
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Bianchi, Arianna. "Epithelial-mesenchymal interactions in the cornea : development of a novel 3D culture cornea model and progress towards environmental reprogramming of cornea epithelium." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/3033.
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The unmet need for corneal epithelial cells for treating human eye diseases makes the cornea important in the cell therapy field. Additionally cornea tissue engineering has become valuable for clinical use, research, and for creating representative models replacing animals for chemical/drug testing. This study initially used qPCR to investigate the expression levels of key markers produced by 2D corneal epithelial cell cultures after wounding in a scratch assay. Then an attempt was made to environmentally reprogram human hair follicle keratinocytes into corneal epithelial cells using limbal epithelial stem cell media. Immunohistochemical and qPCR analysis revealed no changes in signature genes but rather a similarity between HFC and LSC’s when cultured in LSC’s culture conditions. Attention then focused on developing a novel three-dimensional bilayered spheroid cornea model using hanging drop culture. It is widely accepted that cells in 3D culture more closely mimic their in vivo counterparts than 2D cultures, and qPCR and immunofluorescence analysis of 3D spheroids made from cultured rabbit corneal stromal cells revealed that they partially reverted back to a quiescent in vivo phenotype. Coating the spheroids with cultured rabbit limbal epithelial cells produced a bilayered model of the cornea. Multiple iterations were produced incorporating variations in media and cell origin, leading to a cornea model that could be maintained for 10 days, expressed appropriate cytokeratins and other corneal markers including Pax6 and that, upregulated the expression of key cornea signature proteins including Aldh1a1 as a result of epithelial-mesenchymal interactions. Preliminary versions of a human bilayered cornea model were then created from equivalent human cell types. Generally this 3D model displays advantages over other in vitro cornea equivalents and has potential, but needs further refinement. The methodology was also used to coat stromal spheroids with skin keratinocytes, highlighting the possibility of reprogramming the former into corneal epithelial cells through epithelial-mesenchymal interactions.
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Zorlutuna, Pinar. "Cornea Engineering On Biodegradable Polyesters." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12605779/index.pdf.
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ABSTRACT
CORNEA ENGINEERING
ON
BIODEGRADABLE POLYESTERS
Zorlutuna, Pinar
M. Sc., Department of Biotechnology
Supervisor: Prof. Vasif Hasirci
Co-Supervisor: Asst. Prof. AySen Tezcaner
January 2005, 66 pages
Cornea is the outermost layer of the eye and has an important role in vision. Damage of cornea due to injuries or infections could lead to blindness lowering the quality of life of the patient severely. In such cases, transplantation or artificial corneas have been used for treatment but both had drawbacks. The novel approach for corneal replacements is the tissue engineering of the cornea, a promising method which would be free of these drawbacks, if successful.
In this study, carriers for tissue engineering of the cornea were designed and tested in vitro. Blends of biodegradable and biocompatible polyesters of natural (PHBV8) and synthetic (PLLA) origin were used to construct these carriers. For the epithelial layer of the cornea, PLLA-PHBV8 micropatterned films were prepared with solvent casting and seeded with D407 (retinal pigment epithelial) cells. In order to achieve proper cell growth, the films were coated with fibronectin. For the stromal layer of the cornea, highly porous foams of PLLA-PHBV8 were prepared by lyophilization and seeded with 3T3 cells (fibroblasts). A new approach was developed to create a combination of the film and the foam to obtain a surface patterned, 3 dimensional cell carrier. These carriers were seeded with Saos-2 cells (osteosarcoma cells) in the preliminary optimization studies and with D407 and 3T3 cells in further studies. The cell numbers on the carriers were quantified by using MTS assay (non-radioactive cell proliferation assay) and the cell proliferation on polymeric carriers was significantly higher than that of control (Tissue culture polystyrene) by the day 14. Characterization of these cells and the carrier was done using a variety of microscopic methods. The micrographs showed that the foam had a highly porous structure and the pores were interconnected. 3T3 cells were found to be distributed quite homogeneously at the seeding site, but due to the high thickness of the foam, the cells could not sufficiently populate the core (central parts of the foam) during the given incubation time. The micropatterned film allowed multilayer formation of D407 cells. The functionality of the cells seeded on the carriers was examined by immunohistochemistry. These analyses proved that the cells retained their phenotype during culturing. D407 cells formed tight junctions characteristic of epithelial cells, and 3T3 cells deposited collagen type I into the foams. Based on the results, it can be concluded that the 3-D PLLA-PHBV8 construct with surface patterns have a serious potential for use as a tissue engineering carrier for the reconstruction of the cornea.
Key words: Tissue engineering, cornea, polymeric carrier, biodegradable, polyester.
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Cooper, Leanne Jane. "Tissue engineering of the cornea." Thesis, Lancaster University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421611.
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Shaw, Alyra J. B. "Eyelid pressure on the cornea." Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/31239/1/Alyra_Shaw_Thesis.pdf.
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The eyelids play an important role in lubricating and protecting the surface of the eye. Each blink serves to spread fresh tears, remove debris and replenish the smooth optical surface of the eye. Yet little is known about how the eyelids contact the ocular surface and what pressure distribution exists between the eyelids and cornea. As the principal refractive component of the eye, the cornea is a major element of the eye’s optics. The optical properties of the cornea are known to be susceptible to the pressure exerted by the eyelids. Abnormal eyelids, due to disease, have altered pressure on the ocular surface due to changes in the shape, thickness or position of the eyelids. Normal eyelids also cause corneal distortions that are most often noticed when they are resting closer to the corneal centre (for example during reading). There were many reports of monocular diplopia after reading due to corneal distortion, but prior to videokeratoscopes these localised changes could not be measured. This thesis has measured the influence of eyelid pressure on the cornea after short-term near tasks and techniques were developed to quantify eyelid pressure and its distribution. The profile of the wave-like eyelid-induced corneal changes and the refractive effects of these distortions were investigated. Corneal topography changes due to both the upper and lower eyelids were measured for four tasks involving two angles of vertical downward gaze (20° and 40°) and two near work tasks (reading and steady fixation). After examining the depth and shape of the corneal changes, conclusions were reached regarding the magnitude and distribution of upper and lower eyelid pressure for these task conditions. The degree of downward gaze appears to alter the upper eyelid pressure on the cornea, with deeper changes occurring after greater angles of downward gaze. Although the lower eyelid was further from the corneal centre in large angles of downward gaze, its effect on the cornea was greater than that of the upper eyelid. Eyelid tilt, curvature, and position were found to be influential in the magnitude of eyelid-induced corneal changes. Refractively these corneal changes are clinically and optically significant with mean spherical and astigmatic changes of about 0.25 D after only 15 minutes of downward gaze (40° reading and steady fixation conditions). Due to the magnitude of these changes, eyelid pressure in downward gaze offers a possible explanation for some of the day-to-day variation observed in refraction. Considering the magnitude of these changes and previous work on their regression, it is recommended that sustained tasks performed in downward gaze should be avoided for at least 30 minutes before corneal and refractive assessment requiring high accuracy. Novel procedures were developed to use a thin (0.17 mm) tactile piezoresistive pressure sensor mounted on a rigid contact lens to measure eyelid pressure. A hydrostatic calibration system was constructed to convert raw digital output of the sensors to actual pressure units. Conditioning the sensor prior to use regulated the measurement response and sensor output was found to stabilise about 10 seconds after loading. The influences of various external factors on sensor output were studied. While the sensor output drifted slightly over several hours, it was not significant over the measurement time of 30 seconds used for eyelid pressure, as long as the length of the calibration and measurement recordings were matched. The error associated with calibrating at room temperature but measuring at ocular surface temperature led to a very small overestimation of pressure. To optimally position the sensor-contact lens combination under the eyelid margin, an in vivo measurement apparatus was constructed. Using this system, eyelid pressure increases were observed when the upper eyelid was placed on the sensor and a significant increase was apparent when the eyelid pressure was increased by pulling the upper eyelid tighter against the eye. For a group of young adult subjects, upper eyelid pressure was measured using this piezoresistive sensor system. Three models of contact between the eyelid and ocular surface were used to calibrate the pressure readings. The first model assumed contact between the eyelid and pressure sensor over more than the pressure cell width of 1.14 mm. Using thin pressure sensitive carbon paper placed under the eyelid, a contact imprint was measured and this width used for the second model of contact. Lastly as Marx’s line has been implicated as the region of contact with the ocular surface, its width was measured and used as the region of contact for the third model. The mean eyelid pressures calculated using these three models for the group of young subjects were 3.8 ± 0.7 mmHg (whole cell), 8.0 ± 3.4 mmHg (imprint width) and 55 ± 26 mmHg (Marx’s line). The carbon imprints using Pressurex-micro confirmed previous suggestions that a band of the eyelid margin has primary contact with the ocular surface and provided the best estimate of the contact region and hence eyelid pressure. Although it is difficult to directly compare the results with previous eyelid pressure measurement attempts, the eyelid pressure calculated using this model was slightly higher than previous manometer measurements but showed good agreement with the eyelid force estimated using an eyelid tensiometer. The work described in this thesis has shown that the eyelids have a significant influence on corneal shape, even after short-term tasks (15 minutes). Instrumentation was developed using piezoresistive sensors to measure eyelid pressure. Measurements for the upper eyelid combined with estimates of the contact region between the cornea and the eyelid enabled quantification of the upper eyelid pressure for a group of young adult subjects. These techniques will allow further investigation of the interaction between the eyelids and the surface of the eye.
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Rosendo, da Silva Rosangela. "Úlcera corneana em serviço oftalmológico de referência." Universidade Federal de Pernambuco, 2007. https://repositorio.ufpe.br/handle/123456789/7483.
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Previous issue date: 2007<br>As úlceras corneanas são importante causa de morbidade ocular e cegueira prevenível. Vários
estudos têm reportado a incidência de patógenos bacterianos e fúngicos isolados de úlceras
corneanas. O objetivo deste estudo foi descrever o perfil microbiológico e os fatores
predisponentes de úlcera corneana em pacientes atendidos na Fundação Altino Ventura,
Recife-PE, no período de novembro de 2005 a novembro de 2006. Foram estudados 40 casos
de úlcera corneana, sendo analisados em cada paciente: etiologia da infecção, padrão de
resistência a antibióticos, características sociodemográficas e fatores predisponentes ao
desenvolvimento da úlcera corneana. Vinte e cinco pacientes (62,5%) foram do sexo
masculino e 15 (37,5%) do sexo feminino; a idade variou entre 10 e 79 anos (média 45,0 ±
16,7). As profissões mais encontradas foram: agricultor/trabalhador rural 11 (27,5%) e donas
de casa 9 (22,5%). As culturas foram positivas em 28 (70,0%) pacientes. Foi isolado um
agente etiológico em 22 culturas (78,6%) e em 6 (21,4%) houve crescimento misto (bactéria +
fungo). Das culturas onde houve isolamento de um único agente, 18 (81,8%) foram de
etiologia bacteriana e 4 (18,2%) de etiologia fúngica. Entre as bactérias isoladas 19 (79,2%)
foram Gram positivas e 5 (20,8%) Gram negativas. A bactéria mais freqüentemente isolada
foi o Staphylococcus coagulase-negativa 8 (33,5%). Staphylococcus aureus e Bacilus sp.
foram isolados em 4 culturas (12,5% respectivamente). Entre as Gram negativas, a mais
freqüente foi Pseudomonas aeruginosa em duas culturas (8,3%). Fungos foram isolados em
10 (35,7%) amostras, sendo o Aspergillus sp. o mais freqüente (30,0%). As bactérias em geral
mostraram-se resistentes a oxacilina (50,0%), cefalotina (33,3%) e tobramicina (33,3%). Os
principais fatores predisponentes identificados neste estudo foram: trauma ocular (25,6%),
doença sistêmica (14.0%), doença ocular (11,6%) e cirurgia ocular realizada no mesmo olho
(11,6%). Neste trabalho, houve um predomínio de úlceras de córnea de origem bacteriana em
relação à de etiologia fúngica. Staphylococcus coagulase-negativa ocorreu na maioria das
úlceras bacterianas e Aspergillus sp. foi o agente responsável pela maior parte da infecções
fúngicas. Estes achados têm importantes implicações para o tratamento e prevenção de úlceras
corneanas
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Lewis, David. "Proteoglycans in normal and diseased cornea." Thesis, Lancaster University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250553.
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Durand, Fernand-Joseph. "Cornéa guttata et chirurgie du cristallin." Bordeaux 2, 1990. http://www.theses.fr/1990BOR25093.
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Astin, Christine L. K. "Dimensional changes in the ageing cornea." Thesis, Aston University, 2005. http://publications.aston.ac.uk/14565/.
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The study investigated the central and peripheral corneal characteristics of groups of subjects from 20 to 90 years of age to assist the understanding of ageing changes in the cornea, and to see whether relationships between ocular parameters were revealed. After age 45 the corneal horizontal radius of curvature gradually decreased with age. This trend was shown by the Aston University subjects (group B). The effect was very significant for the hospital patients undergoing biometry before cataract extraction operation (group D). Vertical radius of curvature showed a slight decrease with age after age 45, but similar to corneal eccentricity, this showed no significant age effect. Corneal astigmatism progressed from with the rule towards against the rule, particularly after age 60. The shift seemed mainly due to the decreasing horizontal corneal curvature. In biometry no significant age relation was found for axial length, but a significant relation was found between curvature and axial length in the larger group D. Lens thickness showed a very significant relation to age and to axial length, but no significant relation to corneal curvature. Anterior chamber depth showed a very significant relation to age, lens thickness and axial length, but no significant relation to corneal curvature. A significant age effect was found for corneal thickness decreasing with age for the central, nasal and temporal regions of the right eye. Analysis of the biometry results indicated the influence of two major factors. Firstly, the natural growth of the eye in youth, leading to greater values of axial length, radius of corneal curvature, lens thickness and anterior chamber depth. Secondly, the typical ageing changes where the increasing lens thickness caused a reduction in anterior chamber depth.
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Fullwood, Nigel James. "Ultrastructural studies of cornea and sclera." Thesis, Open University, 1992. http://oro.open.ac.uk/57389/.
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The work of Goodfellow et al., (J. Mol. BioI. 119: 231. 1918) and Sayers et al., (J. Mol. BioI. 160: 593. 1982), was repeated using fresh, equilibrated cornea, confirming their finding that the plot of interfibrillar spacing against liydration is a linear relationship. Intermolecular spacing in cornea, sclera and rat-tail tendon was shown to increase rapidly over the hydration range H=O to H::1, then tan off (physiological hydration is at H=3.2). Intermolecular and interfibrillar spacings rise in unison over the hydration range H=O to H~1, after which virtually all of the water goes between the fibrils. It was found that freezing corneas to 40oC and then thawing had no effect on normally hydrated or dehydrated corneas, but caused damage to swollen corneas. Freezing to ·180°C and thawing resulted in permanent damage to normally hydrated corneas . The changes in intermolecular spacing, D-period spacing, fibril diameter and fibril packing as a result of processing for TEM and SEM have been described. Low temperature embedding in Lowicryl K4M resin produced least disruption in the cornea. The fibril diameter in cornea at normal hydration was established to be 37.4nm±1.4. X-ray data modelling indicates that fibril packing in the cornea is liquid-like, as proposed by Worthington and Inoyue (Int. J. Macromol. 7: 2. 1985). It was shown that the water in the corneal stroma is evenly distributed around the fibrils over the hydration range H=O to H=4. Above H=4 more water is entering the stroma than can be "accounted for if its distribution is uniform. The transmittance of light through the bovine cornea (excluding interference effects), was calculated as T ==::12%. Thus, most of ~he transparency of the cornea must be due to constructive interference as first proposed by Maurice (J. Physiol. 136: 263. 1951). Examination of keratoconus corneas by the the SEM and TEM and showed abnormal epithelial cells, disrupted lamellae, and abnormally arranged proteoglycans. Analysis of X-ray data proved that stromal thinning in keratoconus was not due to closer fibril packing. Also that keratoconus corneas had increased intermolecular spacing, and an abnormal arrangement of proteoglycans along the fibrils. No differences were found between the corneal stroma of normal and myopic chicks. Myopic chick sclera was shown to have more aggrecan proteoglycan which was associated with larger empty spaces, than normal sclera. The fibril attachment sites of the proteoglycans was the same in normal and myopic sclera.
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Marino, Gustavo Küpper. "Análise da integridade da membrana basal epitelial durante a geração, persistência, e o desaparecimento da opacidade corneana tardia após injúria corneana." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5149/tde-23102018-095642/.
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OBJETIVOS: Determinar a correlação entre a completa regeneração da membrana basal epitelial (MBE) e o desaparecimento de miofibroblastos do estroma anterior e consequente restauração da transparência corneana após diferentes mecanismos de trauma em coelhos. MÉTODOS: Foram utilizados 32 coelhos que tiveram um de seus olhos incluídos em um dos três grupos de estudo: (1) -9 dioptrias (D) ceratectomia fotorrefrativa (PRK), (2) Incisões corneanas verticais de espessura parcial (350 um), ou (3) Ceratite bacteriana, enquanto os olhos contralaterais compuseram o grupo controle. Os animais foram examinados, sacrificados, e tiveram suas córneas analisadas em diferentes momentos afim de investigar com detalhes o processo de cicatrização corneano usando técnicas de imunohistoquímica (IHQ) e microscopia de transmissão eletrônica (MTE). RESULTADOS: No grupo \"-9D PRK\", as córneas apresentavam opacidade corneana densa e nenhuma evidência de regeneração da MBE 1 mês após a cirurgia. Dois meses após a cirurgia, no entanto, pequenas áreas de córnea transparente começaram a surgir em meio à opacidade difusa, correspondendo a pequenas ilhas de MBE completamente regenerada. Após 4 meses da cirurgia a MBE estava completamente regenerada e a transparência corneana havia sido reestabelecida na região ablada pelo laser. No grupo \"incisões corneanas\", o par de densas opacidades corneanas lineares observadas após 1 mês do procedimento tornou-se progressivamente mais tênue ao longo dos próximos 2 meses. A ultraestrutura da MBE estava completamente regenerada e não houve formação de miofibroblastos no local das incisões 1 mês após o procedimento, inclusive ao redor dos plugs epiteliais que se estendiam até o estroma. No grupo \"ceratite bacteriana\", as córneas que haviam sido infectadas apresentaram opacidade densa, vascularização, miofibroblastos em toda a sua espessura, e nenhuma evidência de regeneração da MBE 1 mês após a infecção. Observou-se ao longo dos próximos 3 meses substancial redução da opacidade, evidências ultraestruturais de regeneração da MBE, e desaparecimento de miofibroblastos das porções mais anteriores do estroma, persistindo apenas nas regiões do estroma mais posterior nas quais o endotélio e a membrana de Descemet encontravam-se lesadas. CONCLUSÃO: No modelo animal apresentado, a resolução espontânea da opacidade corneana tardia mediada por miofibroblastos após a ablação com excimer laser ou ceratites infeciosas graves é desencadeada pela completa regeneração da estrutura e função da MBE. As incisões corneanas de espessura parcial em coelhos, no entanto, cicatrizam sem geração de miofibroblastos devido à completa regeneração da MBE após 1 mês do procedimento. Determinou-se, portanto, a correlação entre a reparação da membrana basal epitelial e a consequente redução da opacidade e restauração da transparência corneana<br>PURPOSE: To determine the correlation between epithelial basement membrane (EBM) regeneration and the disappearance of myofibroblasts from anterior stroma and consequent restoration of corneal transparency after different types of injury in rabbits. METHODS: Thirty-two rabbits had one of their eyes included in one of the 3 study groups: (1) -9 diopters (D) photorefractive keratectomy (PRK), (2) Two vertical partial-thickness (350 um) corneal incisions, or (3) Bacterial keratitis, whereas the opposite eyes served as unwounded control group. The animals were examined, sacrificed, and had their corneas analysed in different time points in order to investigate the corneal wound healing process using immunohistochemistry and transmission electron microscopy. RESULTS: In the \"-9D PRK\" group, corneas at 1 month after surgery had dense corneal opacity and no evidence of regenerated EBM. However, by 2 months after surgery small areas of stromal clearing began to appear within the confluent opacity, and these corresponded to small islands of normally regenerated EBM. By 4 months after surgery, the EBM was fully regenerated and the corneal transparency was completely restored in the ablated zone. In the \"corneal incisions\" group, the two dense, linear corneal opacities observed at 1 month after the procedure progressively faded during the next 2 months. The EBM ultrastructure was fully regenerated and there were no myofibroblasts at the site of the incisions by 1 month after the procedure, including around the epithelial plugs that extended into the stroma. In the \"bacterial keratitis\" group, all the corneas that have been infected presented dense stromal scarring, vascularization, myofibroblasts in the full stromal thickness and no evidence of EBM regeneration by 1 month after the infection. There was a definite decrease in opacity during the next 3 months, besides ultrastructural evidence of EBM regeneration and disappearance of myofibroblasts in the most anterior part of the stroma, which persisted only in the most posterior stroma where the endothelium and Descemet\'s membrane were damaged. CONCLUSION: In the rabbit model, spontaneous resolution of myofibroblast-mediated corneal opacity (fibrosis) after high correction PRK or infectious keratitis is triggered by regeneration of normal EBM structure and function. Conversely, incisional wounds heal in rabbit corneas without the development of myofibroblasts because the EBM regenerates normally by 1 month after the injury. Therefore, it has been determined the correlation between the EBM regeneration and the restoration of corneal transparency after different types of corneal injury
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Yang, Juan. "Universal corneal epithelial-like cells derived from human embryonic stem cells in a defined, xeno-free, and albumin-free condition for cellularization of a corneal scaffold." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3953938.
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Vrana, Nihal Engin. "Collagen-based Scaffolds For Cornea Tissue Engineering." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607540/index.pdf.
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In this study, collagen based scaffolds were prepared for cornea tissue engineering. Three different cell carriers (rat tail collagen foam, insoluble collagen foam and patterned collagen film) were produced using two different collagen sources. Scaffolds were designed to mimic the unique topographical features of the corneal stroma. A novel crosslinking method was developed to achieve constant foam thickness. All scaffolds were tested with the primary cells of the native corneal stroma, human keratocytes. Although both foams promoted cell growth and penetration, rat tail foams were found to be superior for keratocyte proliferation. Their degradation rates were high enough but did not compromise their structural integrity during testing. Transparency studies with the foams revealed a progressive improvement. Collagen films degraded significantly over a one month period<br>however, the presence of cells increased the tensile strength of the films over a 21 day period to close to that of the native cornea and compensated for the loss of strength due to degradation. The micropatterned films proved to have higher transparency than the unpatterned scaffolds. In this study, it was possible to prepare collagen based micropatterned scaffolds using a silicon wafer and then a silicone template, successively, starting from original designs. The resultant collagen films were able to control cell growth through contact guidance, restricted cells and secreted-ECM within the pattern grooves, resulting in a higher transparency in comparison to unpatterned films. Thus, the tissue engineered constructs revealed a significant potential for use as total artificial corneal substitutes.
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Shin, Thomas Jungwoog. "The mechanical properties of the human cornea." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/17577.
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Bleshoy, Hans. "Neuropathology and sensitivity in the keratoconic cornea." Thesis, City University London, 1990. http://openaccess.city.ac.uk/7670/.
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Corneal touch threshold (CTT) was investigated by aesthesiometry in patients with keratoconusq with and without contact lens wear. Using a matching control group it was established that CTT was significantly higher for the central corneal position in keratoconus. No difference inCTT was found in four peripheral corneal positions in keratoconic and normal corneas. Central CTT correlated inversely with central corneal curvature and central corneal thickness. Central corneal curvature was the most significant single factor to correlate with central CTT and indicates that CTT increases (sensitivity reduces) as the cornea steepens. Corneal surface irregularityq as measured by mire image distortion, correlated positively with central CTT as did corneal scarring. Central CTT did not show a relationship with duration of the disease nor the visibility of the corneal nerve fibres. Lid margin touch thresholds (LTT) were investigated for the central position on the lower and upper eyelid margins. No statistical differences were found between keratoconic and normal eyes nor between upper and lower eyelid margins. The magnitude of LTT was in the order of that established for the peripheral corneal CTT. Innervation of the human corneal stroma and epithelium was investigated by light and electron microscopy in the central and mid-peripheral positions. All nerve bundles were located in the anterior two thirds of the. corneas. In keratoconic corneas mid-peripheral stromal nerve bundles were disorganised and irregular taking up the shape of the adjacent collagen lamellae. Nerve bundles had a regular oval appearance in the control corneas. In both groups Schwann cell cytoplasm was sparse and of varying degree of electron density; axon varicosities were not uncommon and axon content with respect to organelles were similar. The axon density showed large variation in keratoconic: specimens and averaged more than threefold that of control specimens for stromal and epithelial nerves. The control corneas showed a greater proportion of large diameter stromal axons than in keratoconic corneas. This result was reversed for epithelial axons. The results are discussed with respect to the disease process and influence on tactile sensitivity.
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Wang, Fan. "UVA/Riboflavin-Induced Apoptosis in Mouse Cornea." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133626.
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Background: A mouse model of combined UVA/riboflavin irradiation to eliminate stromal cells and other antigen-presenting cells in the cornea provides the basis for a probably low risk of corneal transplantation. Methods: After abrasion of the epithelium, the central corneas of mouse eyes were treated with UVA/riboflavin in vitro. Histological studies of hematoxylin-eosin and immunohistochemical staining with caspase 3 were performed. Dissected mouse corneas were analyzed by Western blot. Results: Apoptotic cells were shown on the central corneal stroma; a cell-free zone was displayed in the cornea. Numbers of dead cells increased according to cultivation time. However, the endothelium survived due to the adjustment of the irradiation dose. Conclusions: A cell-free zone in the stroma of the mouse cornea was produced by UVA/riboflavin irradiation in vitro. The technique makes possible to prevent or reduce immunological reactions and the risk of graft rejection by pretreatment of the donor cornea, ultimately prolonging graft survival<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Wang, Fan. "UVA/Riboflavin-Induced Apoptosis in Mouse Cornea." Karger, 2008. https://tud.qucosa.de/id/qucosa%3A27521.
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Background: A mouse model of combined UVA/riboflavin irradiation to eliminate stromal cells and other antigen-presenting cells in the cornea provides the basis for a probably low risk of corneal transplantation.
Methods: After abrasion of the epithelium, the central corneas of mouse eyes were treated with UVA/riboflavin in vitro. Histological studies of hematoxylin-eosin and immunohistochemical staining with caspase 3 were performed. Dissected mouse corneas were analyzed by Western blot.
Results: Apoptotic cells were shown on the central corneal stroma; a cell-free zone was displayed in the cornea. Numbers of dead cells increased according to cultivation time. However, the endothelium survived due to the adjustment of the irradiation dose.
Conclusions: A cell-free zone in the stroma of the mouse cornea was produced by UVA/riboflavin irradiation in vitro. The technique makes possible to prevent or reduce immunological reactions and the risk of graft rejection by pretreatment of the donor cornea, ultimately prolonging graft survival.<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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BONZANO, CHIARA. "Cornea to the best of our knowledge." Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1045094.
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The cornea has unique features that make it a useful model for regenerative medicine studies. It is an avascular, transparent, densely innervated tissue, and a multitude of pathological changes may impair visual acuity. The first part of this research work aimed to improve knowledge on corneal epithelium's physiology. To study the corneal epithelium, we introduced for the first time the use of a fluorescent labeling to track the migration and proliferation of the epithelial cells. This experimental system paves the way for further research on epithelial cell migration in the normal cornea and a better understanding of corneal epithelium dynamics. The second part of the thesis aimed to understand corneal biomechanics properties better. We evaluated the role of corneal collagen crosslinking, a para surgical technique of corneal tissue strengthening, in treating infectious corneal disease and its correlation with a delayed corneal re-epithelialization. The last part of this translational research focused on a new therapeutical role of autologous serum tears, and the nerve growth factor eye drops in treating ocular surface disorders unresponsive to conventional medical therapy.
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Ramier, James Charles. "Biomechanics of corneal wound healing /." Online version of thesis, 1992. http://hdl.handle.net/1850/10786.
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Ahearne, Mark. "Mechanical characterisation of cornea and corneal stromal equivalents." Thesis, Keele University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573762.
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Mikolajczak, Janine [Verfasser]. "Veränderungen der Cornea bei neurodegenerativen Erkrankungen / Janine Mikolajczak." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2017. http://d-nb.info/1148426086/34.
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Scarpa, Fabio. "Automatyc analysis of confocal images of the cornea." Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3425676.
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This thesis deals with the automatic analysis of confocal images of the cornea, and with the automatic estimation of clinical parameters.
Corneal diseases and dystrophies (dry-eye, keratoconus, conjunctivitis, herpes keratitis, lattice dystrophy, etc.) affect vision in widely differing ways. Some cause severe visual impairment, while a few cause no vision problems and are discovered during an eye examination. Other dystrophies may cause repeated episodes of pain without leading to permanent loss of vision. Corneal structures are very sensitive to corneal pathologies: nerve fibers, keratocytes, endothelial cells change their morphology. Changes in the morphology of corneal structures are also related to age or prolonged contact lens wear, to surgical interventions on cornea, such as LASIK or PRK, or to transplantation.
In vivo confocal microscopy of the cornea allows to acquire in a rapid and non-invasive way images of the various corneal layers and structures. Analyzing these images has been shown to be quite important to provide clinical information on the cornea state of health. At present, all the analyses of corneal structures are based on manual or semi-automatic methods, and thus the derived clinical parameter values are subjective and error prone.
Thus, a reliable automatic tool for evaluating corneal pathologies is strongly needed. Every automatic method for analyzing the cornea must go through some well defined steps. First, it has to detect the main anatomical structures of the cornea: nerve fibers, keratocytes and endothelial cells. Then it has to quantitatively measure the identified structures. Finally, it has to estimate the parameters of clinical interest.
In this thesis a new algorithm to extract the nerve fibers will be described. Density and morphology of nerve fibers are correlated to corneal pathologies. Then a method for visualizing all corneal structures in the 3D volume will be presented. Keratocytes volumetric density is an important clinical parameter: an algorithm for the automatic recognition of keratocytes in the 3D volume and for the estimation of the volumetric density has been developed. Finally, an algorithm for the automatic endothelial cell contour detection and the estimation of cells density and morphology will be described.
The algorithms presented in this thesis make it possible to conceive a tool to be used for the automatic analyses of the cornea. It will allow to obtain a quantitative and reproducible description of the whole cornea and specific details of the individual structures. It shall provide a diagnostic tool to aid the clinical practice.<br>Questa tesi tratta dell’analisi automatica di immagini confocali della cornea, e della stima automatica di parametri clinici.
Malattie e distrofie della cornea (sindrome dell’occhio secco, cheratocono, congiuntiviti, cheratite erpetica, distrofia reticolare, ecc) pregiudicano la visione in molti modi. Alcune causano grave disabilità visiva, mentre poche altre non causano problemi di vista e sono scoperte nel corso di un esame degli occhi. Altre distrofie posso causare ripetuti episodi di dolore senza provocare la perdita permanente della vista. Le strutture della cornea sono molto sensibili alle patologie corneali: le fibre nervose, i cheratociti, le cellule endoteliali modificano la loro morfologia. Cambiamenti nella morfologia delle strutture della cornea sono anche legati all'età o all’uso prolungato di lenti a contatto, ad interventi chirurgici della cornea, come LASIK o PRK, o al trapianto.
La microscopia confocale della cornea permette di acquisire in vivo, in modo rapido e non invasivo, immagini dei vari strati della cornea e delle sue strutture. Analizzare queste immagini ha dimostrato essere molto importante per fornire informazioni cliniche sullo stato di salute della cornea. Allo stato attuale, tutte le analisi delle strutture corneali sono basate su metodi manuali o semi-automatici, e quindi i valori dei parametri clinici che ne derivano sono soggettivi e inclini all’errore.
Per questi motivi, un affidabile strumento automatico per la valutazione delle patologie della cornea è fortemente raccomandato. Ogni metodo automatico per analizzare la cornea deve passare attraverso alcune fasi ben definite. In primo luogo, deve riuscire ad individuare le principali strutture anatomiche della cornea: fibre nervose, cheratociti e cellule endoteliali. Poi, deve misurare quantitativamente le strutture individuate. Infine, deve stimare i parametri di interesse clinico.
In questa tesi, un nuovo algoritmo per estrarre le fibre nervose verrà descritto. Densità e morfologia dei nervi sono correlate a patologie della cornea. Successivamente, sarà presentato un metodo per la visualizzazione di tutte le strutture della cornea nel volume 3D. La densità volumetrica dei cheratociti è un importante parametro clinico: un algoritmo per il riconoscimento automatico dei cheratociti nel volume 3D e per la stima della densità volumetrica è stato sviluppato. Infine, un algoritmo per il riconoscimento automatico dei bordi delle cellule endoteliali e la stima della densità e morfologia cellulare sarà descritto.
Gli algoritmi presentati in questa tesi rendono possibile pensare ad uno strumento da utilizzare per l'analisi automatica della cornea. Consentirà di ottenere una stima quantitativa e una descrizione riproducibile di tutta la cornea e dettagli quantitativi delle singole strutture. Potrà essere uno strumento diagnostico di aiuto alla pratica clinica.
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Cerra, Wollstein José Luis. "La representación del mar en la Cornisa Cantábrica, 1940-2005." Doctoral thesis, Universidad de Oviedo, 2007. http://hdl.handle.net/10803/11134.
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El presente trabajo consiste en un estudio sistemático de la importancia del mar en la pintura del norte de España de los últimos 70 años. No se trata de un estudio genérico, sino que busca la concreción, no contemplando las obras y autores en los que el mar es un mero acompañamiento, como podría serlo cualquier otro elemento, o en los que el tratamiento de este género ha sido ocasional o puntual. El mar debe ser el protagonista, aunque en ocasiones sea paralelo -o incluso secundario- a otro posible protagonista, de la misma manera que en un cuadro de paisaje consiste en una representación de la naturaleza con otros elementos posibles, incluso con preeminencia. Así pues, es - haciendo una recopilación de pintores que hayan abordado el tema de la marina, de forma directa y en la pintura figurativa- un análisis de la obra general, y ubicarla en su contexto histórico para poder establecer la dinámica de la creación pictórica en este tema y en esta área.
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Barros, Sobrinho Alexandre Augusto Franchi de. "Propriedades anisotrópicas e refrativas de córneas de coelhos, após implantação de inlays de colágeno tipo I extraído de tendão flexor digital superficial de bovino /." Jaboticabal, 2019. http://hdl.handle.net/11449/181956.
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Orientador: José Luiz Laus<br>Coorientador: Marcela Aldrovani Rodrigues<br>Banca: Cláudia Valéria Seullner Brandão<br>Banca: Ivan Ricardo Martinez Padua<br>Banca: Roberta Martins Crivelaro<br>Banca: Marcia Rita Fernandes Machado<br>Resumo: Membranas a base de colágeno tipo I extraído de tendão flexor digital superficial bovino foram estudados como possível matéria prima para confecção de inlays corneais. Elas foram implantadas nos estromas corneais de olhos direitos de 16 coelhos da raça Nova Zelândia Branco, adultos, machos ou fêmeas, em higidez sistêmica. Um "bolso" foi criado na região central de cada córnea para implantação e posicionamento da membrana (inlay) dentro do estroma anterior (grupo CM, 16 coelhos). Córneas com "bolso", sem implantação de membranas (grupo SM, 16 coelhos), bem como córneas intactas (grupo controle, 4 coelhos sem qualquer procedimento cirúrgico) foram estudadas. Os grupos CM e SM foram avaliados clinicamente quanto a presença de blefarospasmo, hiperemia conjuntival, edema, secreção ocular e neovascularização e quanto às propriedades refrativas e a curvatura da córnea imediatamente antes (basal) e transcorridos 3, 7, 14, 21 e 28 dias de pós-operatório. Quatro animais dos grupos CM e SM, escolhidos ao acaso, foram submetidos à eutanásia ativa, em diferentes tempos, para colheita de córneas, as quais juntamente com córneas intactas do grupo controle, foram processadas para estudos comparativos em anisotropias ópticas (birrefringências total, de forma e intrínseca). Todas as variáveis contínuas foram testadas para a normalidade estatística. Diferenças com p < 0,05 foram consideradas significativas. Os procedimentos cirúrgicos realizados na córnea dos animais do grupo SM não alteraram a... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Membranes based on type I collagen extracted from bovine superficial digital flexor tendon were studied as a possible raw material for making corneal inlays. They were implanted in the right-eye, on the corneal stroma of 16 New Zealand White rabbits, male or female, adults, in apparently systemic health. A "pocket" was created in the central region of the cornea for implantation and positioning of the membrane (inlay) within the anterior stroma (CM group, 16 rabbits). Corneas with pocket, without implantation of membranes (SM group, 16 rabbits), as well as intact corneas (control group, 4 rabbits without any surgical procedure) were studied. The CM and SM groups were clinically evaluated for the presence of blepharospasm, conjunctival hyperemia, edema, ocular secretion and neovascularization, and on the refractive properties and curvature of the cornea immediately before (baseline) and after 3, 7, 14, 21 and 28 days of the postoperative period. Four animals, randomly choose from CM and SM groups were submitted to active euthanasia at different times to harvest the corneas, which, together with intact corneas from the control group, were processed for comparative studies in optical anisotropy (total, form and intrinsic birefringences). All continuous variables were tested for statistical normality. Differences with p <0.05 were considered significant. Surgical procedures performed on the corneas of the SM group did not alter the refraction (p = 0.479). The corneas in the CM gr... (Complete abstract click electronic access below)<br>Doutor
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Liu, Lei. "Immunology of herpes simplex keratitis and its treatment by corneal transplantation." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources. Online version available for University member only until Sep. 7, 2010, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=33585.
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McGowan, Sara L. "Stem cell markers in the posterior limbus and cornea." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2007r/mcgowan.pdf.
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Acun, Aylin. "Construction Of A Collagen-based, Split Thickness Cornea Substitute." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615340/index.pdf.
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Cornea is the transparent outermost layer of the eye. It is a thin (500 µ<br>m) multilayer tissue which performes around 75% of the total refraction in the eye. It also protects the inner layers against any type of damage. Since it is avascular, the three cellular layers of cornea always need transport of nutrients and other materials in and out of the tissue via diffusion. Any change in shape, transparency or thickness of cornea, or physical damages and infections, may cause serious defects. The conventional methods are satisfactory in the treatment of mild injuries but severe cases require the substitution of the tissue with an equivalent. Keratoprosthesis and donor corneas that are used as replacements do not completely meet requirements.
Tissue engineering can be an alternative method for preparing a biocompatible and stable cornea equivalent. The ability to choose from a variety of materials and the ability to incorporate bioactive agents allow the researchers to tailor make the construct. The structure needs to be seeded with the patient&rsquo<br>s own cells and cultured in vitro to yield an optimal corneal replacement.
In this study a novel, split thickness cornea replacement is proposed to substitute the two upper cellular layers (epithelium and stroma) of the native cornea. The design includes a chondroitin sulfate impregnated collagen type I (isolated from rat tail) foam (CSXLF) produced by lyophilization carrying electrospun fibers of the same polymer collected directly on top of the foam, forming the bilayer structure (Fo-Fi). The fiber layer was intended to separate the epithelium and the stroma of the reconstructed cornea yet to allow material transfer in between. The foam layer (bottom) was crosslinked by N-ethyl-N-[3-dimethylaminopropyl] carbodiimide (EDC), and N-hydroxy succinimide and after fiber deposition the bilayer was further stabilized with physical crosslinking (DHT method).
The physical characterization of the foam showed that their pore sizes (10-200 µ<br>m) and porosities (around 70%) were well within the desired range for typical tissue engineering applications. The cell free wet thicknesses of both single and bilayer constructs were close to that of the native stroma and light transmittance through these scaffolds was quite high (around 82% in the 500-700 nm range). The scaffolds were also tested for their stability and shown to be suitable for in vitro testing.
In vitro studies were performed using retinal pigment epithelial cells (RPE, D407 cell line) and isolated human corneal keratocytes (HK) to reconstruct the epithelium and the stroma, respectively. Three types of constructs were prepared<br>only HK seeded Fo-Fi constructs, RPE-HK seeded CSXLFs, and RPE-HK seeded Fo-Fi constructs. All were shown to support cell attachment and promoted cell proliferation as was shown by the cells that covered the inner and outer spaces of the scaffolds. The fiber layer prevented the mixing of the two cell types, without hindering material exchange between them. Moreover, when co-cultured for 14 days, the keratocytes started to deposit collagen type I, a specific marker of these cells. In contrast, ECM deposition could not be observed in the single type cell seeded samples. The co-cultured bilayer construct was tested for suturability at the end of 31 days of in vitro incubation and it was shown that it could be successfully sutured without any major tears. Under the light of these results it was concluded that both the single layer and the bilayer constructs show promise for use as split thickness cornea replacements.
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Johnson, Lindsay W. "The mechanical and microstructural analysis of the human cornea." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/17065.
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Carlsson, Elina. "Jämförelse av tre instrument för topografiska mätningar på cornea." Thesis, Linnéuniversitetet, Institutionen för medicin och optometri (MEO), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-35600.
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Syfte: Att jämföra mätvärden från tre instrument som används för topografiska mätningar på två olika patientgrupper: en med friska ögon och en med corneala tillstånd. Instrumenten som användes var Javal Schiøtz keratometer, Topcon CA-200 topograf och Bon Sirius Scheimpflugkamera. Material och metod: Tre mätningar med respektive topograf och en mätning med keratometern utfördes på samtliga 27 patienter som deltog i studien och sammanlagt 54 ögon mättes av. Medelåldern på deltagarna med friska ögon (Grupp 1) var 25 år (21-44 år) och på de med corneala tillstånd (Grupp 2) var medelåldern 34,4 år (22-58 år). Krökningsradie, styrka och gradtal på de två huvudmeridianerna mättes med keratometern. Vid mätning med topograferna noterade värden från Sim-k och för 3, 5 och 7mm; dessa värden jämfördes sedan med varandra. Keratometern jämfördes med topografernas Sim-k värden. Resultat: Resultatet av studien visar ingen signifikant skillnad mellan de tre instrumenten (p=0,48 1-vägs ANOVA för upprepade mätningar) varken för Grupp 1 eller Grupp 2. Sim-k värden som visar astigmatism var lägst enligt Topcon för samtliga mätområden (Sim-k, 3, 5 och 7mm). Bon Sirius visade högre grader av uppmätt astigmatism än Topcon, men lägre än de uppmätta med keratometern. Korrelationen mellan instrumenten var bra för 5mm-zonen och visade signifikant skillnad för Grupp 2 (p=0,03). Jämförelse mellan Javal keratometer och Sirius visade också signifikant skillnad för Grupp 2 (p=0,02). Javal keratometer visade högst standardavvikelse av samtliga instrument. Slutsats: Det fanns ingen signifikant skillnad mellan de olika instrumenten, med undantag för jämförelse mellan Sim-k-värden för Javal keratometer och Bon Sirius topograf, samt för 5mm-zonen mellan Topcon CA-200 och Bon Sirius i gruppen med corneala dystrofier. Detta visar att instrumenten är jämförbara när ögonen inte lider av extrema, onormala formförändringar.
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Green, D. W. "A biological-inspired support frame for an artificial cornea." Thesis, Aston University, 2000. http://publications.aston.ac.uk/12250/.
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Bilateral corneal blindness represents a quarter of the total blind, world-wide. The artificial cornea in assorted forms, was developed to replace opaque non-functional corneas and to return sight in otherwise hopeless cases that were not amenable to corneal grafts; believed to be 2% of corneal blind. Despite technological advances in materials design and tissue engineering no artificial cornea has provided absolute, long-term success. Formidable problems exist, due to a combination of unpredictable wound healing and unmanageable pathology. To have a solid guarantee of reliable success an artificial cornea must possess three attributes: an optical window to replace the opaque cornea; a strong, long term union to surrounding ocular tissue; and the ability to induce desired host responses. A unique artificial cornea possesses all three functional attributes- the Osteo-odonto-keratoprosthesis (OOKP). The OOKP has a high success rate and can survive for up to twenty years, but it is complicated both in structure and in surgical procedure; it is expensive and not universally available. The aim of this project was to develop a synthetic substitute for the OOKP, based upon key features of the tooth and bone structure. In doing so, surgical complexity and biological complications would be reduced. Analysis of the biological effectiveness of the OOKP showed that the structure of bone was the most crucial component for implant retention. An experimental semi-rigid hydroxyapatite framework was fabricated with a complex bone-like architecture, which could be fused to the optical window. The first method for making such a framework, was pressing and sintering of hydroxyapatite powders; however, it was not possible to fabricate a void architecture with the correct sizes and uniformity of pores. Ceramers were synthesised using alternative pore forming methods, providing for improved mechanical properties and stronger attachment to the plastic optical window. Naturally occurring skeletal structures closely match the structural features of all forms of natural bone. Synthetic casts were fabricated using the replamineform process, of desirable natural artifacts, such as coral and sponges. The final method of construction by-passed ceramic fabrication in favour of pre-formed coral derivatives and focused on methods for polymer infiltration, adhesion and fabrication. Prototypes were constructed and evaluated; a fully penetrative synthetic OOKP analogue was fabricated according to the dimensions of the OOKP. Fabrication of the cornea shaped OOKP synthetic analogue was also attempted.
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Jonuscheit, Sven. "Characteristics of the cornea in the myopic human eye." Thesis, Glasgow Caledonian University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492392.
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The objective of the present studies was to assess whether there were predictable differences in the thickness of the human cornea in relation to stable manifest refractive error using a scanning slit optical topography method (Orbscan II).
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Porter, Louise. "Brittle cornea syndrome : molecular characterisation of a multisystem disorder." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/brittle-cornea-syndrome-molecular-characterisation-of-a-multisystem-disorder(6a34fd5d-14ac-40cc-9206-1caf06c9ef51).html.
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Brittle cornea syndrome (BCS) is an autosomal recessive, multisystemic connective tissue disorder characterised by extreme corneal thinning and fragility. Mutations in transcription factors ZNF469 and PRDM5 cause BCS types 1 and 2, respectively. Both genes are believed to regulate the transcription of extracellular matrix (ECM) components, particularly fibrillar collagens, and are suggested to act on a common pathway. Molecular diagnosis is available for affected patients, and those at risk of being heterozygous carriers. Chapter 3 presents the identification of mutations in ZNF469 in 14 families with BCS, and evidence for the downregulation of ECM-associated transcripts in skin fibroblasts from patients with ZNF469-associated disease by Q-PCR.Chapters 4 and 5 focus on PRDM5-associated disease. Chapter 4 highlights previously undescribed and potentially phenotype-related aspects of PRDM5- associated BCS. In chapter 4, a potential role for PRDM5 in development of Bruch’s membrane is suggested, by the observation of significantly reduced expression of major components of Bruch’s membrane, including collagens types I, III, and IV in patients with PRDM5-associated disease using immunohistochemistry. A first description of PRDM5 expression in the human eye is also presented in chapter 4. In chapter 5, a potential role for PRDM5 in retinal vasculogenesis is suggested. PRDM5-related disease also offers an in vivo opportunity to observe a subset of epigenetic regulatory mechanisms in an inherited eye disease, providing mechanistic insights, presented in chapter 5. Examination of PRDM5 interaction partners by pull-down and mass spectrometry reveals the diminished interaction of a PRDM5 construct carrying a BCS-associated mutation with repressive complexes, and, through studies on fibroblasts and retinal tissue from patients, we suggest a role for dysregulation of the repressive histone mark H3K9 di- methylation in vivo. These findings suggest a role for a molecular network surrounding dysregulated H3K9 di-methylation in PRDM5-associated disease. Finally, chapter 6 expands the study of a rare disease into more common diseases investigating the role of genetic variations in ZNF469 and PRDM5 in keratoconus, an ocular disorder resulting in progressive corneal thinning. I identified enrichment of rare potentially pathogenic alleles in ZNF469 in 12.5% of keratoconus patients, highlighting ZNF469 as the most significant genetic factor responsible for keratoconus identified to date. In conclusion, this study of a rare disease, BCS, has provided translational research insights (chapter 3), functional insights (chapter 4) mechanistic insights (chapter 5) and has expanded into other, less rare, diseases (chapter 6).
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Silveira, Camila Pinho Balthazar da. "Propriedades birrefringentes e organização macromolecular dos colágenos fibrilares do estroma corneal de cães /." Jaboticabal, 2019. http://hdl.handle.net/11449/181327.
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Orientador: José Luiz Laus<br>Coorientador: Marcela Aldrovani Rodrigues<br>Banca: Cláudia Valéria Seullner Brandão<br>Banca: Marcia Rita Fernandes Machado<br>Banca: Paula Diniz Galera<br>Banca: Ivan Ricardo Martinez Padua<br>Resumo: Visando compreender como se comporta a organização das fibras colágenas do estroma corneal de cães por meio de propriedades birrefringentes, objetivou-se com a pesquisa mapear a supraorganização das fibras do estroma corneal de cães, de maneira setorizada e comparativa, nos diferentes sítios e fragmentos. Córneas (n=22) foram removidas de 11 cães submetidos a eutanásia por razões não relacionadas à pesquisa. Quatro córneas foram estudadas in totum, após confecção de montagens totais, e 18 foram incluídas em parafina e transversalmente seccionadas para 7 µm. Todo o material foi estudado sob microscópio de luz polarizada (Olympus BX-53 Pol, Tóquio, Japão) munido de luz policromática e monocromática de 546 nm, compensadores de Sénarmont e Brace-Köhler, e sistema para vídeo-análise de imagens. As fibras colágenas foram posicionadas a 45 e 90 graus do plano da luz polarizada (PLP) e avaliadas setorialmente, ou seja, nas regiões anterior, média e profunda dos estromas superior, inferior, central, nasal e temporal das córneas. A supraorganização das fibras colágenas foi estabelecida a partir dos valores da diferença do caminho óptico (OPD) quantificados pelo método de Sénarmont e Brace-Köhler. O tensor de estrutura, foi processado com auxílio do plugin Java "OrientationJ". Diferenças com P<0,05 foram consideradas significativas. Não foram observadas diferenças em alinhamento das fibras colágenas entre as regiões superior, inferior e central da córnea (P>0,05). As fibras colágenas no... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: In order to comprehend the behavior of the organization of the canine cornea stromal collagen fibers by birefringent properties, this research aimed to map the supraorganization of the canine corneal stroma fibers, sectorial and comparatively, in different sites and fragments. Corneas (n =22) were removed from 11 dogs submitted to euthanasia for reasons not related to this research. Four corneas were fully studied, after the total montage confection, and eighteen of those were embedded in Histosec® and transversely sectioned to 7 µm. All material were studied under a polarized-light advanced microscope (Olympus BX-53 Pol, Tokyo, Japan) equipped with polychromatic and 546 nm monochromatic light, Sénarmont and Brace-Köhler compensators, and an image analysis system. The collagen fibers were positioned at 45 e 90 degrees to the polarized light plane (PPL) and evaluated by sector, that is, at the anterior, medium and deep stroma of the superior, inferior, central, nasal and temporal corneal fragments. The supraorganization of the collagen fibers was defined based on values of optical path difference (OPD) quantified by Sénarmont and Brace-Köhler method. The structure tensor, a 2x2 matrix that calculates the coherency coefficient of local pixels to inform about the orientation of the fibers in the X and Y microscopy images planes, was processed with a Java plugin named "OrientationJ". Differences were considered significant when P<0.05. No differences regarding the alignment of th... (Complete abstract click electronic access below)<br>Doutor
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Tsang, K. "Prioritization preferences for corneal transplantation allocation in Hong Kong." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31972226.
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Kobashigawa, Karina Kamachi. "Transplante de membrana amniótica com células epiteliais limbais cultivadas em sanduíche : estudos clínicos e de viabilidade em córneas de coelhos /." Jaboticabal, 2018. http://hdl.handle.net/11449/152785.
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Orientador: José Luis Laus<br>Coorientador; Marcela Aldrovani Rodrigues<br>Banca: João Antonio Tadeu Pigatto<br>Banca: Bruno Watanabe Minto<br>Banca: Alexandre Lima de Andrade<br>Banca: Annelise Carla Camplesi dos Santos<br>Resumo: Visando ao estudo de técnicas para a expansão "ex-vivo" de células destinadas à reconstrução de superfícies oculares com deficiência de células tronco limbais (LSCD), explantes superficiais obtidos do limbo de coelhos foram cultivados sobre membrana amniótica (MA) humana. Dois grupos, diferindo quanto à configuração do sistema de cultivo celular, foram concebidos: G-mono, contendo células epiteliais expandidas sobre a face de uma camada de MA (sistema de cultivo bidimensional), e G-Sand, composto por células "ensanduichadas" entre duas MAs (sistema de cultivo tridimensional). Seis culturas celulares de cada grupo foram avaliadas por imuno-histoquímica quanto à presença de células progenitoras ou indiferenciadas e a de células em proliferação (avaliação pré-transplante), enquanto 21 foram transplantadas para olhos de coelhos com LSCD (n=10). Os olhos receptores de células cultivadas foram clinicamente avaliados, por até 63 dias. A terapia limbal adotada na pesquisa foi autógena. Após avaliações clínicas, os coelhos foram aleatoriamente distribuídos em parcelas e submetidos à eutanásia, para colheita de córneas (dias 14 e 63 após o transplante) que foram avaliadas quanto à morfometria tecidual e à expressão quali-quantitativa de imunomarcadores de indiferenciação celular (fator de transcrição nuclear delta p63), de proliferação celular (antígeno nuclear da proliferação celular, PCNA) e de apoptose (teste de TUNEL). Diferenças com P < 0.05 foram consideradas significativas. As c... (Resumo completo, clicar acesso eletrônico abaixo)<br>In order to study techniques for the ex vivo expansion of cells for the reconstruction ocular surfaces with limbal stem cell deficiency (LSCD), superficial explants obtained from rabbit limbus were cultured on human amniotic membrane (MA). Two groups, differing in the configuration of the cell culture system, were designed: G-mono, containing expanded epithelial cells on an MA layer (two-dimensional culture system), and G-Sand, composed of cells "sandwiched" between two MAs (three-dimensional culture system). Six cell cultures of each group were processed by immunohistochemistry to identify the presence of progenitor or undifferentiated cells and for proliferating cells (pre-transplant evaluation), and 21 constructs were transplanted onto rabbit eyes with LSCD. The limbal therapy adopted in the research was autogenous and the transplanted eyes were clinically evaluated for up to 63 days. After clinical evaluations, the rabbits were randomly distributed into subgroups and submitted to euthanasia, to harvest corneas (days 14 and 63 post-transplant) that were evaluated for tissue morphometry and the qualitative-quantitative expression of imunnomarkers of indiferentiated cells (delta-p63 transcriptional factor), proliferative cells (proliferating cell nuclear antigen, PCNA) and apoptosis (TUNEL assay). Differences with P <0.05 were considered significant. G-Sand... (Complete abstract click electronic access below)<br>Doutor
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Góes, Ana Carolina Almeida de. "Mensuração da sensibilidade corneana e produção lacrimal em cães submetidos à facoemulsificação." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/10/10137/tde-18092014-100228/.
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A facoemulsificação é, atualmente, considerada a técnica de eleição no tratamento da catarata, uma das principais causas de perda de visão, em cães. O procedimento demanda a realização de incisões na córnea para acesso à câmara anterior. Tais incisões, a despeito da extensão reduzida, podem lesar a inervação da córnea, comprometendo sua sensibilidade e, consequentemente, influenciar a produção lacrimal. Objetivando-se avaliar tais intercorrências, concebeu-se aferir a sensibilidade corneana e a produção lacrimal aquosa em cães submetidos à facoemulsificação. Para tanto, tais parâmetros foram investigados em 20 cães com idade, sexo, raça e peso variáveis. Os procedimentos cirúrgicos foram realizados em um único olho (OT), sendo o olho não operado utilizado como controle (OC). A sensibilidade da córnea foi mensurada com o estesiômetro de Cochet-Bonnet® e a produção lacrimal pelos testes do fenol vermelho e de Schirmer, em ambos os olhos. Os parâmetros foram aferidos previamente ao procedimento cirúrgico (M0 - valores basais) e, posteriormente, após sete dias (M1), 15 dias (M2), 30 dias (M3), 90 dias (M4) e 180 dias (M5). Os valores da produção lacrimal aferida com o teste do fenol vermelho, em M1, não diferiram dos obtidos previamente à cirurgia (M0), nos OT e OC; diferenças significativas foram observadas de M2 a M5, com valores superiores aos basais (M0), em ambos os olhos. Os resultados da mensuração lacrimal com o teste de Schirmer e da sensibilidade corneana à estesiometria (em cm e mm/g2) não diferiram dos basais (M0) em quaisquer dos períodos de avaliação (M1 a M5), em ambos os olhos. Os resultados obtidos ao estudo permitiram verificar que a realização da cirurgia de catarata por facoemulsificação, como fora proposto, não resulta em diminuição da sensibilidade corneana e produção lacrimal aquosa.<br>Phacoemulsification is considered the technique of choice for surgical extraction of cataracts, which is a leading cause of blindness in dogs. The procedure requires corneal incisions to enter the anterior chamber. These incisions, despite their reduced extensions, may damage the corneal innervation, compromising its sensitivity and, also, the tear production. Aiming to evaluate these consequences, this study intended to measure the corneal sensitivity and aqueous tear production in dogs undergoing phacoemulsification. These parameters were evaluated in 20 dogs, with different ages, genders, breeds and weights. Surgical procedures were performed in one eye (OT), and the fellow eye was used as a control (OC). Corneal sensitivity was measured with the Cochet-Bonnet® aesthesiometer and tear production by the phenol thread red test and Schirmer tear test, in both eyes. The parameters were measured prior to the surgery (M0 - baseline values) and after seven days (M1), 15 days (M2), 30 days (M3), 90 days (M4) and 180 days (M5). Tear production values measured with the phenol red test, in M1, were not different from the values measured prior to the surgery (M0), in OT and OC; significant differences were noticed from M2 to M5, with higher values when compared to baseline values (M0), in both eyes. Schirmer tear test and corneal sensitivity (in cm and mm/g2) values were not different from basal values (M0) in any of the evaluation times (M1 to M5), in both eyes. Our study outcomes suggest that phacoemulsification, as proposed previously, does not decrease the corneal sensitivity and aqueous tear production.
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Jamacaru, Francisco Vagnaldo Fechine. "QuantificaÃÃo de angiogÃnese corneana in vivo atravÃs de processamento de imagens digitais." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=566.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior<br>Um programa de computador foi desenvolvido especificamente para a segmentaÃÃo e quantificaÃÃo de angiogÃnese corneana em imagens digitais capturadas in vivo. O propÃsito foi estabelecer um mÃtodo automÃtico para quantificar, de forma rÃpida, objetiva e acurada, a progressÃo temporal da resposta angiogÃnica. Desenvolveu-se ainda um modelo de angiogÃnese corneana inflamatÃria em coelhos, induzida por uma cauterizaÃÃo alcalina pontual, onde a resposta angiogÃnica foi avaliada, conforme cinco mÃtodos manuais, nos dias 3, 6, 9, 12, 15, 18 e 21 apÃs a cauterizaÃÃo, ocasiÃes em que tambÃm foram obtidas, de maneira padronizada, imagens digitais da cÃrnea. O software à composto de cinco mÃdulos, com funÃÃes especÃficas, que identificam e segmentam automaticamente os neovasos e quantificam a resposta angiogÃnica mediante a determinaÃÃo de trÃs parÃmetros principais: Ãrea de neovascularizaÃÃo, comprimento vascular total e nÃmero de vasos sangÃÃneos. Assim, o sistema dispensa a rotulaÃÃo prÃvia da neovascularizaÃÃo, propiciando, por conseguinte, o monitoramento espacial e temporal da resposta angiogÃnica in vivo. A avaliaÃÃo da validade do mÃtodo automÃtico proposto envolveu a determinaÃÃo do grau da correlaÃÃo entre cada um dos quantificadores automÃticos e os cinco parÃmetros manuais. Compreendeu ainda a comparaÃÃo do reconhecimento automÃtico dos vasos sangÃÃneos realizado pelo software em 50 subimagens com o reconhecimento manual efetuado, consensualmente, por trÃs examinadores (padrÃo-ouro), determinando-se entÃo a sensibilidade, especificidade e o coeficiente de concordÃncia kappa. Para avaliar a confiabilidade, trÃs examinadores utilizaram o mÃtodo automÃtico para analisar 50 imagens em dois momentos. A concordÃncia intra e interexaminadores foi medida pelo coeficiente de correlaÃÃo intraclasse. Para ilustrar a utilidade do mÃtodo automÃtico, delineou-se um ensaio que avaliou o efeito dos fÃrmacos prednisona, talidomida, Ãcido acetilsalicÃlico, etoricoxib e celecoxib no modelo de angiogÃnese corneana inflamatÃria. A anÃlise dos grÃficos dos quantificadores manuais e automÃticos revelou que a evoluÃÃo temporal da resposta angiogÃnica no modelo de angiogÃnese corneana inflamatÃria seguiu um padrÃo bifÃsico: crescimento exponencial atà o dia 12 (fase de proliferaÃÃo), seguido de crescimento linear atà o dia 21 (fase de maturaÃÃo). Constatou-se uma forte correlaÃÃo linear positiva estatisticamente significante entre os quantificadores automÃticos e manuais, denotando que o mÃtodo automÃtico mensurou a resposta angiogÃnica de forma anÃloga à realizada pelo mÃtodo manual. A sensibilidade do mÃtodo automÃtico foi 85,32%, enquanto sua especificidade foi 96,37%. A concordÃncia entre o reconhecimento manual e o reconhecimento automÃtico dos vasos sangÃÃneos foi classificada pela estatÃstica kappa como quase perfeita. A concordÃncia interexaminadores foi avaliada em seis situaÃÃes, sendo classificada como excelente em quatro delas e como boa nas outras duas. A concordÃncia intra-examinador foi mensurada em nove situaÃÃes, sendo classificada como boa em apenas uma e como excelente nas demais. AlÃm disso, o sistema automÃtico foi capaz de identificar diferenÃas na intensidade do efeito antiangiogÃnico dos diferentes fÃrmacos avaliados, possibilitando graduar a atividade inibitÃria em plena (prednisona), parcial (talidomida, Ãcido acetilsalicÃlico e etoricoxib) e insuficiente (celecoxib), demonstrando, assim, o seu valor como mÃtodo para anÃlise quantitativa de angiogÃnese. Portanto, tais dados demonstram que o sistema automÃtico proposto constitui um mÃtodo de quantificaÃÃo de angiogÃnese acurado e reprodutÃvel.<br>A software was developed specifically for segmentation and quantification of corneal angiogenesis in digital images acquired in vivo. The purpose was to establish an automatic method to quantify the corneal progression of the neovascular response in a rapid, objective and accurate manner. It was also developed a model of inflammatory corneal angiogenesis in rabbits induced by a punctual alkaline cauterization. Angiogenic response was evaluated at days 3, 6, 9, 12, 15, 18 and 21 after cauterization. At these occasions, digital images of cornea were also captured in a standardized fashion. The software is composed of five modules, each with specific functions, which automatically identify and segment the neovessels and quantify the neovascular response through the calculation of three main parameters: neovascularization area, total vascular length and blood vessels number. Thus, the system does not require previous enhancement of the neovascularization, so that it provides the temporal and spatial monitoring of the angiogenic response in vivo. To assess the validity of the automatic method, it was determined the correlation degree between each automatic parameters and the five manual variables. It was also evaluated by comparing automatic recognition of blood vessels performed by the software on 50 subimages with the manual recognition performed by three raters by consensus (gold-standard) and then calculating the sensitivity, specificity and kappa coefficient. To assess reliability, three raters used the automatic method for analysing 50 images at two moments. The intra and inter-raters agreement was assessed by calculating intraclass correlation coefficient. To illustrate the utility of the automatic method, it was designed an assay that evaluated the effect of prednisone, thalidomide, acetylsalicylic acid, etoricoxib and celecoxib in the model of inflammatory corneal angiogenesis. The analysis of the graphics of the manual and automatic parameters showed that the temporal progression of the neovascular response in this model followed a biphasic pattern: exponential growth until day 12 (proliferation phase), followed by linear growth until day 21 (maturation phase). It was found a statistically significant positive linear correlation between automatic and manual variables, denoting that both methods measured the angiogenic response in an analogous fashion. The sensitivity of the automatic method was 85.32% and the specificity was 96.37%. The agreement between manual and automatic recognition of blood vessels was classified as almost perfect, according to kappa statistics. The inter-raters agreement was measured in six situations and it was classified as good in two of them and as excellent in the others. Among the nine situations analysed, the intra-rater agreement was classified as good in only one of them and as excellent in the others. Furthermore, the automatic system was able to detect differences in the intensity of the antiangiogenic effect of tested drugs, allowing the inhibitory activity to be graduated as full (prednisone), partial (thalidomide, acetylsalicylic acid and etoricoxib) and insufficient (celecoxib), demonstrating, thus, its value as method for quantitative analysis of angiogenesis. Therefore, such results demonstrate that the proposed automatic system constitutes an accurate and reproducible method of angiogenesis quantification.
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Veiga, Paulo Jorge Silva. "A corneta de Chaves em Portugal séc. XIX: composições de Santos Pinto." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7395.
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Mestrado em Música para o Ensino Vocacional<br>Integrado no âmbito do Mestrado em Música para o Ensino Vocacional da Universidade de Aveiro, este trabalho de investigação pretende reflectir sobre a presença da corneta de chaves em Portugal na primeira metade do séc. XIX e qual o contexto histórico, estético e musical que contribuiu para a prática interpretativa, pedagógica e composicional de Francisco António Norberto dos Santos Pinto (1815-1860).
É realizada uma abordagem histórica do instrumento com referência a construtores, intérpretes e compositores. Também são apresentadas fichas de identificação técnica, reunindo, pela primeira vez, num só documento, informação de oito cornetas de chaves localizadas em território nacional. Sete exemplares deste espólio encontram-se localizados no Museu da Música em Lisboa e um pertence à colecção privada da Professora Elisa Lamas.
É discutida a actividade pedagógica, interpretativa e composicional de Francisco António Norberto dos Santos Pinto, onde é realizado um levantamento de toda a obra para corneta de chaves da sua autoria em depósito na Biblioteca Nacional de Portugal, bem como a sua acção para a consolidação técnica e divulgação artística do instrumento, dentro do contexto cultural e musical do séc. XIX.
A edição musical de quatro obras de Santos Pinto para corneta de chaves, a saber, 1º Concerto (1834), Tema e Variações (1834), Tema e Variações (1835) e Pequeno Solo (1849), a sua inserção no ensino fundamentada através de um projecto pedagógico e a transcrição das obras seleccionadas encerra este projecto.<br>Integrated within the Aveiro’s University Master’s in Music Education, this research work aims to reflect on the presence of the keyed bugle in Portugal in the first half of the 19th-century and what historical, aesthetic and musical contexts that contributed to the interpretive, educational and compositional practices of Francisco António Norberto dos Santos Pinto (1815-1860). It held a historical approach with reference to the instrument builders, performers and composers. Also featured are notes identifying technical meeting for the first time in a single document, information of eight keyed bugles located on national territory. Seven copies of this collection are located in the Museum of Music in Lisbon and another one belongs to private collection of Professor Elisa Lamas. We discuss the educational, interpretive and compositional activities of Francisco António Norberto dos Santos Pinto, where a survey of all his own work for keyed bugle on deposit in the National Library of Portugal, as well as its action on the consolidation technique and artistic promotion of the instrument, within the cultural context and musical of the 19th century. The musical edition of four works by Santos Pinto for keyed bugle, namely, 1st Concert (1834), Theme and Variations (1834), Theme and Variations (1835) and Little Solo (1849), their inclusion in education grounded through an educational project of selected works and the transcript terminates this project.
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Jamacaru, Francisco Vagnaldo Fechine. "Quantificação de angiogênese corneana in vivo através de processamento de imagens digitais." reponame:Repositório Institucional da UFC, 2006. http://www.repositorio.ufc.br/handle/riufc/7700.
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JAMACARU, Francisco Fechine Vagnaldo. Quantificação de angiogênese corneana in vivo através de processamento de imagens digitais. 2006. 243 f. Tese (Doutorado em Cirurgia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2006.<br>Submitted by denise santos (denise.santos@ufc.br) on 2014-03-17T15:54:20Z
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Previous issue date: 2006<br>A software was developed specifically for segmentation and quantification of corneal angiogenesis in digital images acquired in vivo. The purpose was to establish an automatic method to quantify the corneal progression of the neovascular response in a rapid, objective and accurate manner. It was also developed a model of inflammatory corneal angiogenesis in rabbits induced by a punctual alkaline cauterization. Angiogenic response was evaluated at days 3, 6, 9, 12, 15, 18 and 21 after cauterization. At these occasions, digital images of cornea were also captured in a standardized fashion. The software is composed of five modules, each with specific functions, which automatically identify and segment the neovessels and quantify the neovascular response through the calculation of three main parameters: neovascularization area, total vascular length and blood vessels number. Thus, the system does not require previous enhancement of the neovascularization, so that it provides the temporal and spatial monitoring of the angiogenic response in vivo. To assess the validity of the automatic method, it was determined the correlation degree between each automatic parameters and the five manual variables. It was also evaluated by comparing automatic recognition of blood vessels performed by the software on 50 subimages with the manual recognition performed by three raters by consensus (gold-standard) and then calculating the sensitivity, specificity and kappa coefficient. To assess reliability, three raters used the automatic method for analysing 50 images at two moments. The intra and inter-raters agreement was assessed by calculating intraclass correlation coefficient. To illustrate the utility of the automatic method, it was designed an assay that evaluated the effect of prednisone, thalidomide, acetylsalicylic acid, etoricoxib and celecoxib in the model of inflammatory corneal angiogenesis. The analysis of the graphics of the manual and automatic parameters showed that the temporal progression of the neovascular response in this model followed a biphasic pattern: exponential growth until day 12 (proliferation phase), followed by linear growth until day 21 (maturation phase). It was found a statistically significant positive linear correlation between automatic and manual variables, denoting that both methods measured the angiogenic response in an analogous fashion. The sensitivity of the automatic method was 85.32% and the specificity was 96.37%. The agreement between manual and automatic recognition of blood vessels was classified as almost perfect, according to kappa statistics. The inter-raters agreement was measured in six situations and it was classified as good in two of them and as excellent in the others. Among the nine situations analysed, the intra-rater agreement was classified as good in only one of them and as excellent in the others. Furthermore, the automatic system was able to detect differences in the intensity of the antiangiogenic effect of tested drugs, allowing the inhibitory activity to be graduated as full (prednisone), partial (thalidomide, acetylsalicylic acid and etoricoxib) and insufficient (celecoxib), demonstrating, thus, its value as method for quantitative analysis of angiogenesis. Therefore, such results demonstrate that the proposed automatic system constitutes an accurate and reproducible method of angiogenesis quantification.<br>Um programa de computador foi desenvolvido especificamente para a segmentação e quantificação de angiogênese corneana em imagens digitais capturadas in vivo. O propósito foi estabelecer um método automático para quantificar, de forma rápida, objetiva e acurada, a progressão temporal da resposta angiogênica. Desenvolveu-se ainda um modelo de angiogênese corneana inflamatória em coelhos, induzida por uma cauterização alcalina pontual, onde a resposta angiogênica foi avaliada, conforme cinco métodos manuais, nos dias 3, 6, 9, 12, 15, 18 e 21 após a cauterização, ocasiões em que também foram obtidas, de maneira padronizada, imagens digitais da córnea. O software é composto de cinco módulos, com funções específicas, que identificam e segmentam automaticamente os neovasos e quantificam a resposta angiogênica mediante a determinação de três parâmetros principais: área de neovascularização, comprimento vascular total e número de vasos sangüíneos. Assim, o sistema dispensa a rotulação prévia da neovascularização, propiciando, por conseguinte, o monitoramento espacial e temporal da resposta angiogênica in vivo. A avaliação da validade do método automático proposto envolveu a determinação do grau da correlação entre cada um dos quantificadores automáticos e os cinco parâmetros manuais. Compreendeu ainda a comparação do reconhecimento automático dos vasos sangüíneos realizado pelo software em 50 subimagens com o reconhecimento manual efetuado, consensualmente, por três examinadores (padrão-ouro), determinando-se então a sensibilidade, especificidade e o coeficiente de concordância kappa. Para avaliar a confiabilidade, três examinadores utilizaram o método automático para analisar 50 imagens em dois momentos. A concordância intra e interexaminadores foi medida pelo coeficiente de correlação intraclasse. Para ilustrar a utilidade do método automático, delineou-se um ensaio que avaliou o efeito dos fármacos prednisona, talidomida, ácido acetilsalicílico, etoricoxib e celecoxib no modelo de angiogênese corneana inflamatória. A análise dos gráficos dos quantificadores manuais e automáticos revelou que a evolução temporal da resposta angiogênica no modelo de angiogênese corneana inflamatória seguiu um padrão bifásico: crescimento exponencial até o dia 12 (fase de proliferação), seguido de crescimento linear até o dia 21 (fase de maturação). Constatou-se uma forte correlação linear positiva estatisticamente significante entre os quantificadores automáticos e manuais, denotando que o método automático mensurou a resposta angiogênica de forma análoga à realizada pelo método manual. A sensibilidade do método automático foi 85,32%, enquanto sua especificidade foi 96,37%. A concordância entre o reconhecimento manual e o reconhecimento automático dos vasos sangüíneos foi classificada pela estatística kappa como quase perfeita. A concordância interexaminadores foi avaliada em seis situações, sendo classificada como excelente em quatro delas e como boa nas outras duas. A concordância intra-examinador foi mensurada em nove situações, sendo classificada como boa em apenas uma e como excelente nas demais. Além disso, o sistema automático foi capaz de identificar diferenças na intensidade do efeito antiangiogênico dos diferentes fármacos avaliados, possibilitando graduar a atividade inibitória em plena (prednisona), parcial (talidomida, ácido acetilsalicílico e etoricoxib) e insuficiente (celecoxib), demonstrando, assim, o seu valor como método para análise quantitativa de angiogênese. Portanto, tais dados demonstram que o sistema automático proposto constitui um método de quantificação de angiogênese acurado e reprodutível.
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Lefebvre, Bertrand. "Stylophores (Cornuta, Mitrata) : situation au sein du phylum des échinodermes et phylogenèse." Lyon 1, 1999. http://www.theses.fr/1999LYO10018.
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Assiri, Abdullah A. M. "A clinical and ultrastructural investigation of the cornea in keratoconus." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/55421/.
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Keratoconus is a non-inflammatory corneal disease that progressively causes topographical alteration of the cornea as a result of thinning, and consequently leads to impaired vision. In this thesis, the clinical studies are showed that the incidence rate and severity of keratoconus in Asir province, Saudi Arabia is high with an early onset and more rapid progress to the severe disease stage at a young age compared to other countries. The result also showed that the disease required different contact lens designs to be available in the clinics and the selection of initial back optic zone radius for multiple contact lens designs should be based in the steepest keratometric reading in early stage, and on average keratometric reading on moderate and advanced stages. However, regardless of the stage of disease, tricurve contact lens design should be selected based on average keratometric reading. Ultrastructure investigation of the anterior surface of Bowman's layer using different microscopes revealed that the changes are not limited to the apical cone only, but extend to the periphery of the cornea especially in the advances stage of keratoconus. Also, although the topographical map is usually used in trephination, it was found that the topographical features alone failed to indicate the full extent of the progress of keratoconus towards the corneal periphery. Data from transmission electron microscopy and high-angle X-ray diffraction suggest that the structural abnormalities in the stromal fibrillar matrix might be influential underlying reasons for topographic changes in the keratoconic-like changes of SPARC-null and JKC mice.
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Wang, Defu. "Biomechanical simulation of the human cornea with applications in tonometry." Thesis, University of Dundee, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505612.
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Carrington, S. D. "Observations on the structure and function of the feline cornea." Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303837.
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Frida, Jonsson. "Underlying genetic mechanisms of hereditary dystrophies in retina and cornea." Doctoral thesis, Umeå universitet, Institutionen för medicinsk biovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-130538.
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Inherited retinal and corneal dystrophies represent a group of disorders with great genetic heterogeneity. Over 250 genes are associated with retinal diseases and 16 genes are causative of corneal dystrophies. This thesis is focused on finding the genetic causes of corneal dystrophy, Leber congenital amaurosis (LCA), Stargardt disease and retinitis pigmentosa in families from northern Sweden. By whole exome sequencing a novel mutation, c.2816C>T, p.Thr939Ile, in Collagen Type XVII, Alpha 1 chain, COL17A1, gene was identified in several families with epithelial recurrent erosion dystrophy (ERED). We showed that the COL17A1 protein is expressed in the basement membrane of the cornea, explaining the mutation involvement in the corneal symptoms. We could link all the families in this study to a couple born in the late 1700s confirming a founder mutation in northern Sweden. Our finding highlights role of COL17A1 in ERED and suggests screening of this gene in patients with similar phenotype worldwide. Furthermore the genetic causes in several retinal degenerations were identified. In one family with two recessive disorders, LCA and Stargardt disease, a novel stop mutation, c.2557C>T, p.Gln853Stop, was detected in all LCA patients. In the Stargardt patients two intronic variants, the novel c.4773+3A>G and c.5461-10T>C, were detected in the ABCA4 gene. One individual was homozygous for the known variant c.5461-10T>C and the other one was compound heterozygote with both variants present. Both variants, c.4773+3A>G and c.5461-10T>C caused exon skipping in HEK293T cells demonstrated by in vitro splice assay, proving their pathogenicity in Stargardt disease. Finally, in recessive retinitis pigmentosa, Bothnia Dystrophy (BD), we identified a second mutation in the RLBP1 gene, c.677T>A, p.Met226Lys. Thus, BD is caused not only by common c.700C>T variant but also by homozygosity of c.677T>A or compound heterozygosity. Notably, known variant, c.40C>T, p.R14W in the CAIV gene associated with a dominant retinal dystrophy RP17 was detected in one of the compound BD heterozygote and his unaffected mother. This variant appears to be a benign variant in the population of northern Sweden. In conclusion, novel genetic causes of retinal dystrophies in northern Sweden were found demonstrating the heterogeneity and complexity of retinal diseases. Identification of the genetic defect in COL17A1 in the corneal dystrophy contributes to understanding ERED pathogenesis and encourages refinement of IC3D classification. Our results provide valuable information for future molecular testing and genetic counselling of the families.
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Booysen, Dirk. "Tonometry and biomechanics of the cornea in contact lens wear." Thesis, Aston University, 2016. http://publications.aston.ac.uk/30151/.
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Aims: Research on use of contact lenses as drug delivery systems continues. Disposable lenses are often used to treat corneal injuries. Accurate intraocular pressure (IOP) measurements with lenses in situ will enhance patient care and save valuable chair time. Inter- and intraobserver reliability of rebound tonometer (RBT) and intraobserver reliability of ocular response analyser (ORA) with and without contact lenses of 50 (15 male, 35 female) healthy well adapted contact lens wearers between 18 – 55 years (M = 38.90, SD = 9.23) were examined. Clinical comparisons of IOP measurements with ORA and RBT were done. Accuracy of IOP measurements with four commonly prescribed disposable contact lenses (Acuvue Oasys, Frequency XC, Acuvue 1-Day Moist, and Pure Vision with powers -6.00 − +6.00 D) in situ was evaluated. Physiological and physical factors influencing IOP measurements with both instruments were determined. Findings: Intraobserver reliability of RBT without and with lenses was excellent (ICC > 0.88; > 0.92 respectively). Interobserver reliability of RBT was excellent without or with lenses (ICC 0.81; 0.88 respectively). Intraobserver reliability of ORA was good for all metrics measured except for corneal hysteresis (CH) (ICC: CH 0.63; corneal resistance factor (CRF) 0.79; corneal compensated IOP (IOPcc) 0.77; IOPg 0.87).RBT and ORA IOPg (Goldmann equivalent IOP) measurements were clinically and statistically comparable without or with lenses (differences < 0.6 mmHg). ORA IOPcc and RBT were less comparable (differences < 1.45 mmHg).Accurate RBT and ORA tonometry (within 2 mmHg) was possible with low minus power (range -0.50 to -6.00 D); moderate modulus of elasticity (< 0.75 MPa); thin silicone hydrogel (Acuvue Oasys) and hydrogel (Frequency XC; Acuvue 1-Day Moist) contact lenses in situ. Multiple regression analyses showed biomechanical metrics CRF and CH affected RBT and ORA (IOPcc and IOPg) measurements strongly (p < 0.0001). Therefore, cornea’s biomechanical properties had greater influence on accuracy of IOP measurements with these two instruments than other variables examined.
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Lee, Graham Andrew. "Advances in anterior segment disease / Graham A. Lee." [St. Lucia, Qld.], 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18442.pdf.
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Monteiro, Pedro Miguel Lourenço. "An investigation of tilt, decentration and defocusing errors in videokeratoscopy." Thesis, City University London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270579.
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