Navegando por Assunto "Eletrorretinograma multifocal"

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Eletrorretinografia multifocal: desenvolvimento de método avaliativo e aplicação em pacientes com toxoplasmose ocular e investigação funcional da função retiniana em pacientes com malária, infectados pelo P. Vivax
(Universidade Federal do Pará, 2014-11-03) CARVALHO, Aline Correa de; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718; SILVEIRA, Luiz Carlos de Lima; http://lattes.cnpq.br/9383834641490219
The current thesis was composed by two studies performed in parallel. The first purpose was the development of a reliable method to classify the electroretinographic responses and to validate this method in ocular toxoplasmosis. The second purpose was to investigate the effect of the acute use of chloroquine in the retina of vivax malaria patients, which received the standard treatment of the Ministry of Health of Brazil. The experimental tool of both studies was the multifocal electroretinogram (mfERG). In the first study the Veris system was used to test 10 healthy subjects to calculate a signal to noise ratio analysis in order to find the best values to separate normal responses from impaired retinal responses. The final results of this analysis were applied in three patients with visual loss due ocular toxoplasmosis. The results showed an optimal signal to noise ratio of 0.47 to separate waveforms with and without signal. The signal to noise ratio of 0.47, 0.44, 0.48, 0.57, 0.78, 1.21 were optimal to separate normal responses from progressively attenuated responses. The application of the signal to noise ratio analysis into ocular toxoplasmosis patients was able to map the retinal area with no activity evoked by the light. The second study was performed using mfERG to evaluate 48 vivax malaria patients which received chloroquine-based treatment. Their data were compared to 37 healthy subjects. The results showed that number of infections ranged between from 01 to 18 times. During the treatment, the mean dosage of intaken chloroquine was 5429 ± 782.3 mg. The cumulative dosage normalized to the body mass ranged from 14.58 to 545.45 mg/kg. No difference was observed in the mfERG amplitude and implicit time obtained from malaria patients and control group at any concentric rings of the visual field. There was no significant correlation between the retinal activity with the chloroquine cumulative dosage. It was concluded that the signal to noise analysis developed in this thesis can be used as a reliable method to study impaired retinal function, including the mapping of ocular toxoplasmosis consequences; and the acute use of chloroquine for malaria treatment caused no impairments to retinal activity recorded by mfERG.