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Made available in DSpace on 2014-06-11T19:23:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T18:51:14Z : No. of bitstreams: 1 cremonini_dn_me_botfmvz.pdf: 2146235 bytes, checksum: eee408e98c2b02c0eec4a23160355e60 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A superfície ocular normal é composta pelos epitélios da córnea, conjuntiva e limbo, cada qual com um distinto fenótipo celular; juntos, formam uma unidade funcional responsável pela manutenção da integridade desta superfície. O presente estudo visou avaliar as alterações relacionadas à deficiência das células precursoras do epitélio corneano, presentes no limbo, e o efeito do transplante de membrana amniótica, conservada em diferentes meios, sobre esta deficiência. A lesão foi induzida pelo contato do n-heptanol com a superfície da córnea e do limbo, associado à peritomia conjuntival em 360° em coelhos; em seguida, foi recoberta com membrana amniótica canina, suturada à episclera perilímbica, criopreservada em meio próprio para conservação ou em meio utilizado para conservação de embrião, ambos com glicerol a 50% e mantidos a -80°C, à exceção do grupo controle, não tratado com a membrana. Os animais foram submetidos à avaliação clínica diária e morfológica aos sete, 15 e 30 dias. Todos desenvolveram sinais de deficiência de células límbicas, denominada conjuntivalização, caracterizada pela presença de neovascularização, inflamação crônica e defeitos epiteliais recorrentes; ao exame histopatológico da córnea observou-se presença de neovasos, edema, leucócitos e células caliciformes. O transplante de membrana amniótica não foi eficiente para o tratamento da deficiência total de células germinativas límbicas, entretanto auxiliou o processo de cicatrização, sendo mais eficiente quando preservada em meio para conservação de embrião. Palavras-chave: coelho; córnea; criopreservação; histopatologia; membrana amniótica. / A normal ocular surface is composed by corneal, conjunctival and limbal epithelia, each having distinct cellular phenotypes; together, they form a functional unit, which is responsible for maintaining the integrity of the ocular surface. The following research was conducted with the intent of evaluating changes related to limbal stem-cell deficiency, as well as analyzing the results that canine amniotic membrane transplant, which was preserved in different solutions, had over this deficiency. The ulcer was induced by putting n-heptanol in contact with the corneal and limbal surface, associated to 360° conjunctival peritomy in rabbits; the following step was to cover the surface with canine amniotic membrane, secured to perilimbal episclera, cryopreserved in its own solution or embryo solution, both with 50% glycerol and stored at -80°C, with the exception of the control group, which was not treated with membrane. The animals were examined daily and morphologically at seven, 15 and 30 days. All of them developed signs of limbal stem-cell deficiency, entitled conjunctivalization, due to the occurrence of neovascularization, chronic inflammation and recurrent epithelial defects; during corneal histopathology it was observed the occurrence of neovascularization, edema, leukocytes and goblet cells. The amniotic membrane transplant was not efficient in the treatment of limbal stem-cell deficiency, however it did help in the process of cicatrisation, demonstrating to be more efficient when preserved in embryo solution. Key words: rabbits; cornea; cryopreservation; histopathology; amniotic membrane.

Orientador : José Joaquim Titton Ranzani / Resumo: A superfície ocular normal é composta pelos epitélios da córnea, conjuntiva e limbo, cada qual com um distinto fenótipo celular; juntos, formam uma unidade funcional responsável pela manutenção da integridade desta superfície. O presente estudo visou avaliar as alterações relacionadas à deficiência das células precursoras do epitélio corneano, presentes no limbo, e o efeito do transplante de membrana amniótica, conservada em diferentes meios, sobre esta deficiência. A lesão foi induzida pelo contato do n-heptanol com a superfície da córnea e do limbo, associado à peritomia conjuntival em 360° em coelhos; em seguida, foi recoberta com membrana amniótica canina, suturada à episclera perilímbica, criopreservada em meio próprio para conservação ou em meio utilizado para conservação de embrião, ambos com glicerol a 50% e mantidos a -80°C, à exceção do grupo controle, não tratado com a membrana. Os animais foram submetidos à avaliação clínica diária e morfológica aos sete, 15 e 30 dias. Todos desenvolveram sinais de deficiência de células límbicas, denominada conjuntivalização, caracterizada pela presença de neovascularização, inflamação crônica e defeitos epiteliais recorrentes; ao exame histopatológico da córnea observou-se presença de neovasos, edema, leucócitos e células caliciformes. O transplante de membrana amniótica não foi eficiente para o tratamento da deficiência total de células germinativas límbicas, entretanto auxiliou o processo de cicatrização, sendo mais eficiente quando preservada em meio para conservação de embrião. Palavras-chave: coelho; córnea; criopreservação; histopatologia; membrana amniótica. / Abstract: A normal ocular surface is composed by corneal, conjunctival and limbal epithelia, each having distinct cellular phenotypes; together, they form a functional unit, which is responsible for maintaining the integrity of the ocular surface. The following research was conducted with the intent of evaluating changes related to limbal stem-cell deficiency, as well as analyzing the results that canine amniotic membrane transplant, which was preserved in different solutions, had over this deficiency. The ulcer was induced by putting n-heptanol in contact with the corneal and limbal surface, associated to 360° conjunctival peritomy in rabbits; the following step was to cover the surface with canine amniotic membrane, secured to perilimbal episclera, cryopreserved in its own solution or embryo solution, both with 50% glycerol and stored at -80°C, with the exception of the control group, which was not treated with membrane. The animals were examined daily and morphologically at seven, 15 and 30 days. All of them developed signs of limbal stem-cell deficiency, entitled conjunctivalization, due to the occurrence of neovascularization, chronic inflammation and recurrent epithelial defects; during corneal histopathology it was observed the occurrence of neovascularization, edema, leukocytes and goblet cells. The amniotic membrane transplant was not efficient in the treatment of limbal stem-cell deficiency, however it did help in the process of cicatrisation, demonstrating to be more efficient when preserved in embryo solution. Key words: rabbits; cornea; cryopreservation; histopathology; amniotic membrane. / Mestre

M.Phil. / The anterior surface of the eye, especially the corneal curvature, is of importance in optometric and ophthalmic examinations. Pathological, surgical and contact lens induced changes to the cornea can have a significant influence on vision. It is therefore necessary to study the structure, curvature, and factors that influence the cornea. Each study contributes to a greater understanding about the nature of the anterior surface of the eye. Previous studies showed that physical exercise has an effect on the eye. These studies however looked at changes in intraocular pressure, visual acuity and other visual functions due to exercise. No study was found in the literature that investigated the effect of exercise on keratometric variation or on corneal curvature. A study done by Cronje-Dunn (1995) suggested the possibility of exercise influencing keratometric variation and the mean keratometric measurement. Due to little research in this area and the suggestions that exercise might influence keratometric variation, it was decided to investigate the influence of physical exercise on keratometric variation. In this study, 14 subjects took part in an experiment. The experiment consisted of three sets of keratometer readings obtained for each subject. The first set of readings was obtained before exercise. Directly after the first set of keratometer readings, the subject had to reach 85% of his predicted maximum heart rate on a stationary bicycle. Immediately after the cycling the second set of keratometric readings was obtained. After the second set of measurements the subject rested for an hour. The third set of keratometric readings was obtained after the hour of rest. The different sets of keratometric measurements were converted to h vectors. Transforming keratometric readings to h vectors and plotting the readings on threedimensional graphs representing symmetric dioptric power space make it possible to view the distribution or spread of the keratometric measurements and to define any variation in the measurements. The results from this dissertation indicate that keratometric variation and corneal curvature was influenced by physical exercise (cycling). Exercise increased variation in curvature around the vertical meridian and/or increased torsional variation in the horizontal and vertical meridians for most subjects. The increase in variation in curvature after exercise was greatest between the 80° and 120° meridian of the eye. This increase in keratometric variation after the cycling decreased after the rest period in most subjects. Little change in variation was noted in the curvital power around the horizontal meridian. Some subjects indicated a change in mean. The mean was greater around the vertical meridian either after the exercise and/or after the rest period.

Orientador: Luis Alberto Magna / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-19T01:43:50Z (GMT). No. of bitstreams: 1 Freitas_Edwalde_M.pdf: 3357657 bytes, checksum: 90c9ab9cf396e306bf1a2c8450928dfe (MD5) Previous issue date: 1994 / Mestrado / Biologia Celular / Mestre em Ciências

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