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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.
31

"Comparação entre a sensibilidade do hemicampo visual temporal e do hemicampo visual nasal em pacientes com estrabismo convergente de aparecimento precoce" / Comparative study between the visual temporal hemifield and the visual nasal hemifield sensitivity in patients with early onset convergent strabismus

Polati, Mariza Aparecida 12 April 2005 (has links)
Com o objetivo de avaliar a hipótese de redução da sensibilidade do hemicampo nasal do campo visual, o que aumentaria a assimetria temporal-nasal dos hemicampos, nos pacientes com estrabismo convergente de aparecimento precoce (antes de dois anos de idade) em comparação aos normais, foram estudados os dois olhos de 66 pacientes, 33 estrábicos e 33 normais, com idade que variou de 7 a 30 anos, com o método da perimetria estática, utilizando-se o programa SITA Standard, do perímetro Humphrey HFA-II Série 700. / With the objective of analysing the hypothesis that a reduction in sensitivity of the nasal hemifield, that in turn would lead to an increase in the nasotemporal asymmetry of the visual field, in patients with early onset convergent strabismus - before 2 years of age - if compared to normal patients, both eyes of 66 patients - 33 esotropes and 33 normal - were studied. Patient's age varied from 7 - 30 years. The method of examination was that of Static Perimetry utilizing the Sita Standard program, of the Humphrey perimeter HFA II 700 Series. The results depicted a clear accentuation of the nasotemporal asymmetry in esotropes if compared to normal patients. This asymmetry was due to the evident decrease of sensitivity in the most peripheral of the chosen points of study. The quantitative sum of values of sensitivity of these points exhibited an average reduction of -15,71% in relation to the normal patients. For both groups, normal and esotropes, there was no difference in values of sensitivity between the to eyes.
32

Short- and Long-Term Follow-Up of Ophthalmological Findings in Preterm Infants and Children

Larsson, Eva January 2004 (has links)
<p>In a prospective population-based study in Stockholm County, 1998-2000, the incidence of retinopathy of prematurity (ROP) was investigated and was found to be 36% in prematurely-born infants with a birth weight of ≤ 1500 grams. Compared to a study performed ten years ago, the overall incidence was unchanged, but was reduced in “mature” infants and increased in immature ones. The incidence of ROP was 25% in infants with a gestational age of ≤ 32 weeks at birth. The main risk factors for ROP were the gestational age at birth, followed by the birth weight. Current guidelines for ROP screening in Sweden were modified.</p><p>A 10-year follow-up study of the ophthalmological findings in prematurely-born children, previously included in a prospective population-based incidence study of ROP, was performed. The children were compared with full-term ones. </p><p>Prematurely-born children ran a four times higher risk of refractive errors than full-term ones. The cryotreated children had the highest risk, but those without ROP also had more refractive errors than the full-terms. Within the group of prematurely-born children, the cryotreated ones had the highest prevalence of myopia, astigmatism and anisometropia, but no difference was found regarding hypermetropia.</p><p>The visual acuity of prematurely-born children was poorer than that of the full-terms. The cryotreated children and those with neurological complications had the most marked reduction, but the children without ROP and neurological findings also had a poorer visual outcome than the full-terms. The prevalence of visual impairment was 1.8% among the prematurely-born children, and was due to ROP in half the cases and cerebral lesions in the others. </p><p>The cryotreated children had constricted peripheral visual fields compared to the untreated prematurely-born and full-term children. The central visual fields tended to be reduced in the prematurely-born children compared to the full-terms, but no difference was observed within the preterm group.</p>
33

Short- and Long-Term Follow-Up of Ophthalmological Findings in Preterm Infants and Children

Larsson, Eva January 2004 (has links)
In a prospective population-based study in Stockholm County, 1998-2000, the incidence of retinopathy of prematurity (ROP) was investigated and was found to be 36% in prematurely-born infants with a birth weight of ≤ 1500 grams. Compared to a study performed ten years ago, the overall incidence was unchanged, but was reduced in “mature” infants and increased in immature ones. The incidence of ROP was 25% in infants with a gestational age of ≤ 32 weeks at birth. The main risk factors for ROP were the gestational age at birth, followed by the birth weight. Current guidelines for ROP screening in Sweden were modified. A 10-year follow-up study of the ophthalmological findings in prematurely-born children, previously included in a prospective population-based incidence study of ROP, was performed. The children were compared with full-term ones. Prematurely-born children ran a four times higher risk of refractive errors than full-term ones. The cryotreated children had the highest risk, but those without ROP also had more refractive errors than the full-terms. Within the group of prematurely-born children, the cryotreated ones had the highest prevalence of myopia, astigmatism and anisometropia, but no difference was found regarding hypermetropia. The visual acuity of prematurely-born children was poorer than that of the full-terms. The cryotreated children and those with neurological complications had the most marked reduction, but the children without ROP and neurological findings also had a poorer visual outcome than the full-terms. The prevalence of visual impairment was 1.8% among the prematurely-born children, and was due to ROP in half the cases and cerebral lesions in the others. The cryotreated children had constricted peripheral visual fields compared to the untreated prematurely-born and full-term children. The central visual fields tended to be reduced in the prematurely-born children compared to the full-terms, but no difference was observed within the preterm group.
34

"Comparação entre a sensibilidade do hemicampo visual temporal e do hemicampo visual nasal em pacientes com estrabismo convergente de aparecimento precoce" / Comparative study between the visual temporal hemifield and the visual nasal hemifield sensitivity in patients with early onset convergent strabismus

Mariza Aparecida Polati 12 April 2005 (has links)
Com o objetivo de avaliar a hipótese de redução da sensibilidade do hemicampo nasal do campo visual, o que aumentaria a assimetria temporal-nasal dos hemicampos, nos pacientes com estrabismo convergente de aparecimento precoce (antes de dois anos de idade) em comparação aos normais, foram estudados os dois olhos de 66 pacientes, 33 estrábicos e 33 normais, com idade que variou de 7 a 30 anos, com o método da perimetria estática, utilizando-se o programa SITA Standard, do perímetro Humphrey HFA-II Série 700. / With the objective of analysing the hypothesis that a reduction in sensitivity of the nasal hemifield, that in turn would lead to an increase in the nasotemporal asymmetry of the visual field, in patients with early onset convergent strabismus - before 2 years of age - if compared to normal patients, both eyes of 66 patients - 33 esotropes and 33 normal - were studied. Patient's age varied from 7 - 30 years. The method of examination was that of Static Perimetry utilizing the Sita Standard program, of the Humphrey perimeter HFA II 700 Series. The results depicted a clear accentuation of the nasotemporal asymmetry in esotropes if compared to normal patients. This asymmetry was due to the evident decrease of sensitivity in the most peripheral of the chosen points of study. The quantitative sum of values of sensitivity of these points exhibited an average reduction of -15,71% in relation to the normal patients. For both groups, normal and esotropes, there was no difference in values of sensitivity between the to eyes.
35

Utilisation of the structure of the retinal nerve fiber layer and test strategy in visual field examination

Nevalainen, J. (Jukka) 08 June 2010 (has links)
Abstract The aim of this study was to create a mathematical model of the retinal nerve fiber layer and of the entire hill of vision, and to compare different perimetric methods and test grids in the detection of visual field loss in glaucoma and optic neuritis. A mathematical model of the retinal nerve fiber layer was developed, based on traced nerve fiber bundle trajectories extracted from 55 fundus photographs of 55 human subjects. The model resembled the typical retinal nerve fiber layer course within 20° eccentricity from the foveola. The standard deviation of the calculated corresponding angular location at the optic nerve head circumference ranged from less than 1° up to 18° (mean 8.8°). A smooth mathematical model of the hill of vision was created, based on 81 ophthalmologically healthy subjects. The model fit R2 was 0.72. Applying individually condensed test grids in 41 glaucomatous eyes of 41 patients enhanced remarkably the detection of progression. Seven out of 11 (64%) of the progressive scotomata detected by spatially condensed grids would have been missed by the conventional 6° × 6° grid. In 20 eyes of 20 patients with advanced glaucoma, the comparability of visual field areas obtained with semi-automated kinetic perimetry and automated static perimetry was satisfactory and within the range of the test-retest reliability of automated static perimetry. Using a standardized grid of 191 static targets within the central 30° visual field, the most common finding in 100 eyes of 99 patients with acute optic neuritis were central scotomas, accounting for 41% of all visual field defects in affected eyes. In conclusion, a model of the retinal nerve fiber layer was developed, which provided a detailed location specific estimate of the magnitude of the variability on the courses of retinal nerve fiber bundle trajectories in the human retina. A smooth mathematical model of the hill of vision with a satisfactory model fit was described for the 80° visual field. Individually condensed grids enabled the detection of a glaucomatous visual field progression more frequently and also earlier than conventional grids. Semi-automated kinetic perimetry was found to be a valuable alternative to automated static perimetry in monitoring advanced glaucomatous visual field loss. Using a grid with a higher spatial resolution may enhance the detection of small central visual field loss in optic neuritis.
36

Campo de Visão : Inventário de Procedimentos / Field of Vision : Inventory of Procedures

Gonçalves, Michelle Costa, 1980- 26 August 2018 (has links)
Orientador: Marcelo Ramos Lazzaratto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-08-26T18:38:33Z (GMT). No. of bitstreams: 5 Goncalves_MichelleCosta_M.pdf: 1421168 bytes, checksum: ac2ffb6364871c685e608e858c714245 (MD5) Goncalves_MichelleCosta_M_Arquivo2.zip: 686662621 bytes, checksum: 3bcd2fe31450507a68a05ecc2db845f6 (MD5) Goncalves_MichelleCosta_M_Arquivo3.zip: 2065791095 bytes, checksum: b936850242816b224c60c10d2fea6bfd (MD5) Goncalves_MichelleCosta_M_Arquivo4.zip: 1676352273 bytes, checksum: a2495e5a4a89abf2eb09facf709e72e8 (MD5) Goncalves_MichelleCosta_M_Arquivo1.zip: 658195522 bytes, checksum: 382b6f97a819a483bea46b41bc78717e (MD5) Previous issue date: 2015 / Resumo: Esta dissertação apresenta um inventário dos procedimentos utilizados na iniciação ao Campo de Visão ¿ sistema improvisacional coral, utilizado como prática do ator, formação de artistas da cena e criação poética de linguagem cênica ¿ investigado há 23 anos por Marcelo Lazzaratto e há 14 anos sistematizado com os atores da Cia. Elevador de Teatro Panorâmico. O inventário foi construído a partir do relato de uma experiência particular, no caso, os encontros iniciais de um curso ministrado em 2013 por Lazzaratto aos alunos do 2o ano do Curso de Graduação em Artes Cênicas da Unicamp. O trabalho se concentra nos aspectos formativos e voltados à prática do ator, mas em seus capítulos finais aborda a aplicação do Campo de Visão na construção poética da cena, através de uma breve análise do espetáculo Ifigênia / Abstract: This essay presents an inventory of the procedures applied in the Campo de Visão (Field of Vision) ¿ improvisational coral system, used as practice of actors, as artistic educational processes and as poetic creation of performing language ¿ a result of 23 years of research by Marcelo Lazzaratto and systematized for 14 years with the actors from Cia. Elevador de Teatro Panorâmico. The inventory has been made by a report of a specific experience, on this case, through the first meetings of a course ministered by Lazzaratto to the students of the 2nd grade from the Graduation Course in Performing Arts of Unicamp in 2013. This work focus on the Campo de Visão¿s (Field of Vision¿s) formative and directed to the actor¿s practice aspects, but discusses, its final chapters, the application of the system to poetic creation of scene, through a brief analysis of the play Ifigênia / Mestrado / Teatro, Dança e Performance / Mestra em Artes da Cena
37

The Visual Apparatus of Avian Dinosaurs and Other Diapsids: Anatomical Correlates of Behavior and Evolution

Cerio, Donald Greene 20 September 2019 (has links)
No description available.
38

Avaliação morfológica e funcional da retina de pacientes com esclerose múltipla e espectro da neuromielite óptica usando os eletrorretinogramas de campo total e multifocal e a tomografia de coerência óptica / Morphological and functional evaluation of the retina of patients with multiple sclerosis and neuromyelitis optica using full field electroretinogram, multifocal electroretinography and optical coherence tomography

Filgueiras, Thiago Gomes 25 March 2019 (has links)
Objetivos: avaliar as alterações morfofuncionais da retina de pacientes com esclerose múltipla (EM) e espectro da neuromielite óptica (ENMO), com ou sem histórico de neurite óptica (NO), por meio de eletrorretinografia de campo total e multifocal (ERGct / ERGmf) e a tomomografia de coerência óptica (TCO). Avaliar as correlações de tais achados entre si e com o potencial evocado visual (PEV), o campo visual (CV) e a sensibilidade ao contraste (SC). Métodos: Pacientes com EM (n = 30), ENMO (n = 30) e controles (n = 29) foram submetidos a avaliação oftalmológica completa incluindo CV, TCO, ERGct, ERGmf, PEV e medida da SC. Os olhos foram distribuídos em 5 grupos: EM com ou sem história de NO (EM + NO e EM - NO), ENMO com ou sem NO (ENMO + NO e ENMO - NO) e controles. Com a TCO foram medidas as espessuras das camadas de fibras nervosas da retina na região macular (CFNRm), camada de células ganglionares (CCG), camada plexiforme interna (CPI), camada nuclear interna (CNI), camada plexiforme externa (CPE), camada nuclear externa (CNE), complexo camada de fotorreceptores + epitélio pigmentário da retina(CFR+EPR) e da camada de fibras nervosas peripapilar (CFNRp). Dados das ondas a, b e potenciais oscilatórios (POs) do ERGct, medidas de amplitude e latência de N1 e P1 do ERGmf, ondas do PEV e medidas do desvio da normalidade do CV foram analisados. Os grupos foram comparados usando equações estimadas generalizadas. Correlações entre as medidas foram avaliadas. Resultados: Redução da sensibilidade do desvioda normalidade do CV, da SC e aumento da latência das ondas do PEV foram identificadas para ambos os grupos. Nos pacientes ENMO+NO apresentaram redução de amplitude ao PEV em relação aos controles, diferentemente aos demais grupos. As medidas de espessura da CCG e da CPI foram significativamente menores nos grupos de olhos dos pacientes em relação aos controles. A RNFLm foi menor em todos os grupos de olhos de pacientes, exceto o grupo ENMO-NO. Não foi observada diferença significativa entre os grupos de olhos estudados nas comparações referenetes às demais camadas da retina. Comparado aos controles, as amplitudes do POs foram maiores nos olhos de pacientes com ENMO, enquanto as latências de N1 e P1 do ERGmf foram menor nos olhos de pacientes com EM. Essas anormalidades foram fortemente correlacionadas com a espessura da camada retiniana intermediária e externa. Os achados do PEV, assim como do CV e SC, se correlacionaram fortemente com as camadas retinianas. Conclusões: as camadas retinianas internas se mostraram reduzidas à TCO tanto nos olhos de pacientes com EM quanto no naqueles com ENMO, mas os achados POs e ERGmf sugerem também envolvimento das outras camadas retinianas nessas afecções. O PEV apresentou alterações distintas para cada doença. O uso combinado da TCO, do ERG e PEV podem ajudar a entender como as duas condições diferem em relação aos danos retinianos / Objectives: To evaluate the morphofunctional alterations of the retina of patients with multiple sclerosis (MS) and spectrum of neuromyelitis optica spectrum disorder (NMOSD), with or without a history of optic neuritis (ON), using full field electroretinogram (ERG) and multifocal electroretinography (mf- ERG) and optical coherence tomography (OCT). To evaluate the correlations of such findings among themselves and with visual evoked potential (VEP), visual field (VF) and contrast sensitivity (CS). Methods: Patients with MS (n = 30), NMOSD (n = 30) and healthy controls (n = 29) were submitted to a complete ophthalmologic evaluation including VF, OCT, ERG, mf-ERG, VEP and SC measurement. The eyes were distributed in 5 groups: MS with or without history of ON (MS + ON and MS - ON), NMOSD with or without ON (NMOSD + ON and NMOSD - ON) and controls. With the OCT were measured the thickness of the retinal nerve fiber layers in the macular region (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor layer (PHOT) and peripapillary retinal nerve fiber layer (pRNFL). The data of the a- and b-waves and oscillatory potentials (OPs) of the ERG, amplitude and peak time of N1 and P1 of mf-ERG, waves of the VEP and VF deviation were analyzed. The groups were compared using generalized estimating equations. Correlations between measurements were evaluated. Results: Reduction of the oVF deviation, CS and increased VEP wave\'s peak times were identified for both groups. In the NMOSD + ON patients, an amplitude redeuction was found in the VEP in relation to the controls, unlike the other groups. The thickness of GCL and IPL was significantly lower in patients\' eyes than controls. mRNFL was lower in all patients, but NMOSD-ON. No significant difference was observed for the remaining layers. Compared to controls, the amplitudes of the POs were higher in the NMOSD group, whereas the mf-ERG\'s N1 and P1 peak time was lower in the MS patients. These abnormalities were strongly correlated with the thickness of the intermediate and outer retinal layers. The findings of the VEP, as well as the VF and SC, correlated strongly with the retinal layers. Conclusions: the inner retinal layers were reduced in both the MS and the NMOSD, but the findings OPs and mf-ERG suggest involvement of the other retinal layers. The VEP presented different alterations for each disease. The combination of OCT, ERG and VEP may help to understand how the two conditions differ in relation to retinal damage
39

Specialized and independent processing of orientation and shape in visual field maps LO1 and LO2

Silson, E.H., McKeefry, Declan J., Rodgers, J., Gouws, A.D., Hymers, M., Morland, A.B. January 2013 (has links)
We identified human visual field maps, LO1 and LO2, in object-selective lateral occipital cortex. Using transcranial magnetic stimulation (TMS), we assessed the functions of these maps in the perception of orientation and shape. TMS of LO1 disrupted orientation, but not shape, discrimination, whereas TMS of LO2 disrupted shape, but not orientation, discrimination. This double dissociation suggests that specialized and independent processing of different visual attributes occurs in LO1 and LO2.
40

Induced deficits in speed perception by transcranial magnetic stimulation of human cortical areas V5/MT+ and V3A

McKeefry, D. J., Burton, M. P., Vakrou, C., Barrett, B. T., Morland, A. B. January 2008 (has links)
In this report, we evaluate the role of visual areas responsive to motion in the human brain in the perception of stimulus speed. We first identified and localized V1, V3A, and V5/MT+ in individual participants on the basis of blood oxygenation level-dependent responses obtained in retinotopic mapping experiments and responses to moving gratings. Repetitive transcranial magnetic stimulation (rTMS) was then used to disrupt the normal functioning of the previously localized visual areas in each participant. During the rTMS application, participants were required to perform delayed discrimination of the speed of drifting or spatial frequency of static gratings. The application of rTMS to areas V5/MT and V3A induced a subjective slowing of visual stimuli and (often) caused increases in speed discrimination thresholds. Deficits in spatial frequency discrimination were not observed for applications of rTMS to V3A or V5/MT+. The induced deficits in speed perception were also specific to the cortical site of TMS delivery. The application of TMS to regions of the cortex adjacent to V5/MT and V3A, as well as to area V1, produced no deficits in speed perception. These results suggest that, in addition to area V5/MT+, V3A plays an important role in a cortical network that underpins the perception of stimulus speed in the human brain.

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