• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 10
  • 1
  • 1
  • 1
  • Tagged with
  • 33
  • 15
  • 15
  • 14
  • 12
  • 12
  • 12
  • 9
  • 9
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 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

"Análise comparativa das medidas de espessura da camada de fibras nervosas da retina de pacientes com atrofia em banda do nervo óptico e de indivíduos normais através da tomografia de coerência óptica e da polarimetria a laser" / A comparative analysis of the retinal nerve fiber layer thickness measurements in patients with band atrophy of the optic nerve and in normal controls using optical coherence tomography and scanning laser polarimetry

Bruno Campêlo Leal 07 July 2006 (has links)
As afecções que acometem a via óptica anterior podem acarretar perda de fibras das células ganglionares retinianas, gerando alterações na camada de fibras nervosas da retina (CFNR). O objetivo deste trabalho foi o de comparar a capacidade da tomografia de coerência óptica (OCT-1), do OCT 3 (Stratus OCT) e do polarímetro de varredura a laser (GDx) em diferenciar olhos normais de olhos com atrofia em banda do nervo óptico e hemianopsia temporal, assim como, comparar o desempenho de tais tecnologias entre si. Foram estudados 37 indivíduos num total de 46 olhos divididos igualmente em dois grupos. O Stratus OCT, o OCT 1 e o GDx se mostraram capazes de identificar corretamente a redução global (average) da espessura da CFNR dos indivíduos com AB comparados com uma população normal. Observamos uma melhora progressiva das sensibilidades/especificidades e das AROC, com o desempenho melhor do OCT1 sobre o GDx e do Stratus OCT sobre o OCT 1 / Most diseases that affect the optic pathways present clinically with loss of one or more visual functions.When optic pathway injuries involve the anterior visual pathways they may cause loss of the retinal nerve fiber layer (RNFL) and "band atrophy" (BA). The purpose of this study was therefore to compare the ability of the optical coherence tomography (OCT) 1, the OCT 3 (Stratus OCT) and the scanning laser polarimetry (GDx) to differentiate normal eyes from eyes with BA of the optic nerve and temporal hemianopsia. Thirty-seven individuals in a total of 46 eyes divided equally in two groups were studied. Each one of the parameters, except the values from the nasal quadrant measured by the GDx, showed statistically significant difference when we compare normal patients with the BA group. The study also showed a gradual improvement of the sensibilities/specificities and of the AROC, with a better performance of the OCT1 compared to GDx and of the Stratus OCT compared to the OCT 1
32

Sensor de frente de onda para uso oftalmológico / Wavefront sensor for ophthalmological use

Jesulino Bispo dos Santos 16 April 2004 (has links)
Este trabalho descreve os passos envolvidos no desenvolvimento de um protótipo de aberroscópio para uso oftalmológico. Este instrumento faz incidir no fundo do olho humano um feixe luminoso de baixa potência e amostra, por meio do método de Hartmann, as frentes de onda da luz espalhada. A partir dos dados coletados, a forma das frentes de onda são reconstituídas e as aberrações eventualmente existentes no olho são calculadas e representadas por intermédio dos polinômios de Zernike. Aqui são expostos os fundamentos deste método, algumas das suas propriedades e limitações. Também é mostrada a caracterização funcional do protótipo desenvolvido, testando-o com elementos ópticos de propriedades conhecidas / This work describes the steps involved in the aberroscope prototype development for ophthalmological use. This instrument injects inside the human eye a low power light beam and sample, by Hartmann method, the wavefronts produced by ocular fundus light scattering. From collected data, the wavefront shape is reconstructed and the eye aberrations that eventually existent are calculated and adjusted by Zernike polynomials. Are discussed the method foundations, some of properties and limitations. Also the functional characterization of the developed prototype is shown, by testing it with optical elements of known properties
33

Flow diversion for compressive unruptured internal carotid artery aneurysms with neuro-ophthalmological symptoms: a systematic review and meta-analysis

Kaiser, Daniel P. O., Cuberi, Ani, Linn, Jennifer, Gawlitza, Matthias 31 May 2024 (has links)
Background: Data on the safety and efficacy of flow diverters (FD) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms (NOS) are scarce and comprise mainly small case series. Methods: We performed a search of three databases and included series with ≥10 patients, with unruptured aneurysms of the ICA and NOS, treated with FD. Random-effects analysis of treatment results and safety was performed. Results: A total of 22 studies reporting on 594 patients were included. Pooled proportions of NOS recovery, improvement, transient and permanent worsening were: 47.4% (95% CI 35.0% to 60.1%); 74.5% (95% CI 67.9% to 80.2%); 7.1% (95% CI 3.3% to 14.7%); and 4.9% (95% CI 3.2% to 7.4%), respectively. Rates of complete recovery and improvement in patients with isolated visual symptoms were 30.6% (95% CI 12.5% to 57.7%) and 56.6% (95% CI 42.3% to 69.9%). Isolated oculomotor symptoms recovered completely in 47.8% (95% CI 29.9% to 66.3%) and improved in 78% (95% CI 69.2% to 84.9%). Morbidity occurred in 5% (95% CI 2.8% to 9%) and mortality in 3.9% (95% CI 2% to 7.5%) of patients. An increased likelihood of symptom improvement was observed when treatment was performed early (<1 month) after symptom onset (OR=11.22, 95% CI 3.9% to 32.5%). Conclusion: Flow diversion promotes recovery or improvement of compressive symptoms in a large proportion of patients but is associated with significant rates of morbidity and mortality. Transient and permanent NOS worsening is not uncommon. Early treatment is of utmost importance, as it increases the likelihood of symptom improvement more than 10-fold.

Page generated in 0.0475 seconds