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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A prospective national survey of laser treatment for diabetic retinopathy

Bailey, Catherine Clare January 1998 (has links)
No description available.
2

Diagnóstico de glaucoma em retinografias utilizando funções geoestatística / Diagnosing Glaucoma in Retinopathy Using Geostatistical Functions

Sousa, Jefferson Alves de 26 January 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-30T20:52:23Z No. of bitstreams: 1 JeffersonSousa.pdf: 2049556 bytes, checksum: f9f7046416ba8b0f024d06906537417f (MD5) / Made available in DSpace on 2017-05-30T20:52:23Z (GMT). No. of bitstreams: 1 JeffersonSousa.pdf: 2049556 bytes, checksum: f9f7046416ba8b0f024d06906537417f (MD5) Previous issue date: 2017-01-26 / Glaucoma is one of the diseases that mopstly causes blindness, according to estimates by the World Health Organization (WHO). The Brazilian Council of Ophthalmology (CBO) estimates that in Brazil there are 985 thousand glaucoma patients with more than 40 years of age. The use of computer aided detection and diagnosis systems (CAD - Computer Aided Detection and CADx - Computer Aided Diagnosis) has contributed to increase the chances of detection and correct diagnoses. They provide a second opinion, assisting the experts in making decisions about the treatment of glaucoma. The main objective of this work is to present a method for automatic diagnosis of glaucoma in retinography images using texture characteristics. The Local Binary Pattern is used to generate a representation of the texture patterns of the image. The geostatistical functions, semivariogram, semimagram, covariogram and correlogram, are used as texture extractors. With the generated characteristics, a step is made to select the best classification model using the genetic algorithm. Then sorting is performed using the Support Vector Machine. The best result was an accuracy of 91%, sensitivity of 95% and specificity of 88%, proving that the characteristics generated by the geostatistical functions for texture extraction generate a satisfactory discriminant set. / O glaucoma e uma das doenças que mais causam cegueira em todo o mundo segundo estimativa da Organização Mundial da Saúde (OMS). O Conselho Brasileiro de Oftalmologia (CBO) estima que no Brasil existam 985 mil portadores de glaucoma com mais de 40 anos de idade. A utilização de sistemas de detecção e diagnóstico auxiliados por computador (CAD - Computer Aided Detection e CADx -Computer Aided Diagnosis) tem contribuído para aumentar as chances de detecção e diagnósticos corretos, que proporcionam, uma opinião preliminar, auxiliando os especialistas na tomada de decisões sobre o tratamento do glaucoma. O principal objetivo deste trabalho e apresentar um método para diagnóstico automático de glaucoma em imagens de retinografia utilizando características de textura. Neste trabalho, o Local Binary Pattern é usado para gerar uma representação do padrões de textura da imagem. As funções geoestatísticas, semivariograma, semimadograma, covariograma e correlograma, sao utilizadas como extratores de textura. Com as características geradas e realizada uma etapa para selecionar o melhor modelo de classificação utilizando o algoritmo genético. Em seguida é realizada a classificação usando a Maquina de Vetores de Suporte. O método apresentou como melhor resultado uma acurácia de 91%, sensibilidade de 95% e especificidade de 88%, comprovando que as características geradas pelas funções geoestatísticas para extração de textura geram um conjunto discriminante satisfatório.
3

Comparação entre as medidas lineares da relação escavação/disco óptico obtidas com o OCT RTVue e a retinografia digital

Ribeiro Junior, Valdenir 19 November 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-05-11T20:23:53Z No. of bitstreams: 3 Dissertação - Valdenir Ribeiro Júnior - 2014.pdf: 1448512 bytes, checksum: 318b3171b4b9dbe4d3d79bea1af6ca77 (MD5) PARECER CONSUBSTANCIADO.pdf: 29881 bytes, checksum: a11bf6a7fd5e3fd476da07a1a90abf93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-05-11T20:32:27Z (GMT) No. of bitstreams: 3 Dissertação - Valdenir Ribeiro Júnior - 2014.pdf: 1448512 bytes, checksum: 318b3171b4b9dbe4d3d79bea1af6ca77 (MD5) PARECER CONSUBSTANCIADO.pdf: 29881 bytes, checksum: a11bf6a7fd5e3fd476da07a1a90abf93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-11T20:32:27Z (GMT). No. of bitstreams: 3 Dissertação - Valdenir Ribeiro Júnior - 2014.pdf: 1448512 bytes, checksum: 318b3171b4b9dbe4d3d79bea1af6ca77 (MD5) PARECER CONSUBSTANCIADO.pdf: 29881 bytes, checksum: a11bf6a7fd5e3fd476da07a1a90abf93 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-11-19 / The purpose of this study was to compare the linear measurements of the optic disc cup, obtained by RTVue OCT with those obtained by Digital Retinography. It is a cross-sectional retrospective study, conducted at VER Hospital - Excellence in Ophthalmology. Was used images from digital retinography and OCT scans obtained by an RTVue device. In the color retinography, the greatest horizontal and vertical diameters of the optic disc from the inner edge of the Elschnig ring were obtained by a pachymeter with 0.01 mm. In OCT, the delineation of optic nerve was obtained automatically and from the results the horizontal and vertical diameters of the excavation were recorded. One hundred eyes of 100 subjects were included, with a mean age of 60.1 ± 15.7 years. Of these, 79 were of the right eye and 21 the left eye, 61 men and 39 women. It was found that the mean of the horizontal excavation obtained by the OCT was 0.91 ± 0.10, while that obtained by angiography was 0.79 ± 0.11 (p <0.01). It was concluded that there was no agreement between the evaluated methods to quantify the measurements of optic disc cup excavations. Measures obtained automatically by OCT RTVue of the OD were higher, but significantly correlated with measurements obtained manually by Digital Retinography. Poor agreement of the optic disc parameters between the two imaging devices was noted. / O objetivo deste estudo foi comparar as medidas lineares da escavação do disco óptico, obtidas com o OCT RTVue com as obtidas pela Retinografia Digital. Trata-se de um estudo transversal e retrospectivo, conduzido no Hospital VER - Excelência em Oftalmologia. Utilizou-se imagens de retinografia digital e exames de OCT obtidos pelo aparelho RTVue. Na retinografia colorida, foram obtidos os maiores diâmetros horizontal e vertical do disco óptico, a partir da borda interna do Anel de Elschnig através de paquímetro com graduação de 0,01 mm. No OCT, a delineação do nervo óptico foi obtida automaticamente e a partir dos resultados foi registrado o diâmetro horizontal e vertical da escavação. Foram incluídos 100 olhos de 100 indivíduos, com idade média de 60,1 ± 15,7 anos. Desses, 79 foram do olho direito e 21 do olho esquerdo, sendo 61 homens e 39 mulheres. Verificou-se que as médias das escavações horizontais obtidas com o OCT foram de 0,91 ± 0,10, enquanto que as obtidas pela retinografia foram 0,79 ± 0,11 (p < 0,01). Conclui-se que não houve concordância entre os métodos avaliados para quantificar as medidas das escavações do DO. As medidas obtidas automaticamente pelo OCT RTVue do DO foram maiores, porém correlacionadas com as medidas obtidas manualmente pela Retinografia Digital. Além disso, notou-se fraca concordância nos parâmetros do disco óptico entre os dois dispositivos de imagens.
4

La Hipertensió arterial a la pràctica: optimització de la mesura de la pressió arterial i de l'avaluació de l'afectació dels òrgans diana

Coll de Tuero, Gabriel 15 March 2010 (has links)
Objectius: a) avaluar la utilitat de la mesura de la pressió arterial a la consulta pel diplomat d'infermeria; b) establir quin és el punt de tall pel valor normal de l'automesura de la pressió arterial al domicili del propi malalt; c) determinar si l'exploració del fons d'ull als malalts hipertensos permet una millor estratificació del risc cardiovascular. Resultats: a) primer objectiu: els valors de la PAC de la infermera són molt similars a l'AMPA i les decisions s'han de prendre en funció d'aquesta mesura. b) segon objectiu: el risc de presentar alguna AOD en els hipertensos recent diagnosticats amb hipertensió clínica aïllada passa de forma progressiva d'una OR de 2.5 per un punt de tall de <125/80 mmHg a una OR de 4.0 pel punt de tall <135/85 mmHg. c) tercer objectiu: un nombre significatiu de pacients canvien de grup de risc quan es consideren els resultats de l'exploració del fons d'ull. / Goals: a) to evaluate the utility of BP measurement in the nurse office; b) to determine the normal 'cut-off' of HBPM at the moment of diagnosis; c) to determine if fundus eye examination permit a better cardiovascular risk stratification in hypertensive. Results: a) first goal: the values of the nurse measured blood pressure are very similar to AMPA and decisions should be based on this measure. b) second goal: the risk of target organ damage in some hypertensive patients newly diagnosed with isolated clinical hypertension occurs progressively from an OR of 2.5 for a cutoff of <125/80 mmHg OR of 4.0 for a cutoff <135/85 mmHg. The normal 'cut-off' is <130/80-85 mmHg. c) third goal: a significant number of patients change risk group when considering the results of the exploration of the fundus

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