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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.
171

Kleur as hulpmiddel in die uitdrukking van emosie by die vyfjarige kind : 'n Gestalt-Terapeutiese benadering

De Vries, Renata 30 June 2003 (has links)
Text in Afrikaans with t.p. and summaries in Afrikaans and English / Limited research concerning a child's association between emotion and color is available, both in terms of the amount of research studies done as well as the generalization of the results for the purposes of the five year-old. This study's aim was to explore the individual, unique, symbolic meaning between the experiencing of emotion and color of the five year-old. Color was used as an expedient to facilitate the identification of emotion. The test sample consisted out of five, five year-old Afrikaans speaking children. The researcher developed a technique and used it to explore the above. The results of this study showed that the associations that five year-olds draw between emotions and color can't be generalized. The study further showed that color can be very helpful in the identification process of emotions when working with the five year-old child. The results of this study were compared to relevant previous research results and at the end the researcher made certain recommendations for further research concerning the subject. / Bestaande navorsing oor die assosiasie wat die kind vorm tussen emosie en kleur is beperk, beide in terme van die aantal navorsingstudies en in die veralgemeenbaarheid van die resultate ten opsigte van die vyfjarige kind. Hierdie studie het gepoog om die individuele, unieke, simboliese betekenis te ondersoek tussen die belewing van emosie en kleur by die vyfjarige kind. Dit het behels dat kleur as 'n hulpmiddel aangewend is, ten einde die identifisering van emosie te vergemaklik. Die steekproef het bestaan uit vyf, vyfjarige Afrikaans-sprekende kinders. 'n Tegniek, deur die navorser ontwikkel, is gebruik om die bogenoemde te ondersoek. Die resultate van hierdie studie het getoon dat kinders van vyfjarige ouderdom se assosiasies tussen emosies en kleur nie veralgemeen kan word nie. Die studie het verder getoon dat kleur 'n bruikbare hulpmiddel is in die identifisering van emosies by die vyfjarige kind. Die resultate van die studie is met vorige relevante navorsingsbevindinge vergelyk en bepaalde aanbevelings is gemaak vir toekomstige navorsing rakende hierdie onderwerp. / Psychology / M.Diac. (Play Therapy)
172

Avaliação oftalmológica e psicofísica do sistema visual de portadores de albinismo / Ophthalmologic and psychophysical evaluation of the visual system of individuals with albinism

Sano, Ronaldo Yuiti 21 September 2017 (has links)
O albinismo e uma alteracao genetica rara que compromete a producao de melanina. As alteracoes clinicas consistem na falta de pigmentacao da pele, cabelo e pelos. Apresenta alteracoes oftalmologicas importantes, que comprometem a acuidade visual de forma severa, na grande maioria dos casos. As alteracoes oftalmologicas sao, ametropias, nistagmo, rarefacao do epitelio pigmentado da iris e da retina, hipoplasia foveal e decussacao anomala do nervo optico. Este estudo foi dividido em tres diferentes partes com os seguintes objetivos principais: Parte 1: Analise comparativa entre o grau de transparencia da iris (GTI), o grau de transparencia da retina (GTR) e a espessura da regiao macular com a acuidade visual nos pacientes com albinismo. Parte 2: Teste de sensibilidade ao contraste espacial de luminancia e ofuscamento com lentes de contato filtrantes em ambientes claros e escuros. Parte 3: Avaliacao da visao de cores, utilizando\\se o teste de Pranchas de Ishihara e o Cambridge Color Test (CCT). Material\' e\' Métodos: Participaram do estudo 121 individuos albinos, com idade media de 31,18 (} 15,47) anos, o que totalizou 242 olhos. Os participantes foram divididos em diferentes grupos nas tres partes do estudo, alguns participaram de uma ou mais partes. Na primeira parte os participantes foram submetidos a consulta oftalmologica, classificacao do grau de transparencia da iris e da retina em uma nova classificacao baseada em quatro diferentes graus de transparencia, alem de avaliacao foveal pelo exame de Tomografia de Coerencia Optica (OCT). Na segunda parte, os participantes foram submetidos ao teste de contraste computadorizado, utilizando lentes de contato filtrante e transparentes, em ambientes claros e escuros. Nesta etapa foi avaliada a influencia da lente filtrante na sensibilidade de contraste visual dos individuos com albinismo. Na terceira parte, os participantes foram submetidos aos testes de Pranchas de Ishihara e de Cambridge Colour Test (CCT), para avaliacao da visao de cores nos pacientes albinos. Resultados: Os resultados foram os seguintes: Parte\'1: A correlacao entre AV logMAR e GTI foi positiva (+0,569) e significativa (p<0,001). A correlacao entre AV logMAR e GTR foi positiva (+0,531) e significativa (p<0,001). A correlacao entre AV logMAR e a espessura macular nao foi significativa (p=0,105). A correlacao entre GTI e GTR foi positiva (+ 0,627) e significativa (p<0,001). A correlacao entre espessura macular e GTI nao foi significativa (p=0,397). A correlacao entre espessura macular e GTR nao foi significativa (p=0,458). Parte 2: Houve melhora estatisticamente significante da sensibilidade ao contraste com as lentes filtrantes em relacao as lentes transparentes no ambiente de ofuscamento (claro), na frequencia de 0,3 cpg, 0,6 cpg e 1,0 cpg (ciclos por grau). Nao houve melhora significante nas frequencia 2,0 cpg e 4,0 cpg. Nao houve melhora estatisticamente significante da sensibilidade ao contraste de lentes filtrantes em relacao as lentes transparentes no ambiente escuro (penumbra) em nenhuma das frequencias espaciais estudadas. Parte\' 3: Todos os individuos com albinismo nao apresentaram nenhuma alteracao de visao de cores no teste de Pranchas de Ishihara. O CCT demonstrou piora no limiar de deteccao de cores significativa nos eixos protan (p=0,021) e deutan (p=0,017), mas nao houve diferenca no eixo tritan (p=0,212). Os testes estatisticos sugerem que uma amostra maior seja estudada para validacao dos resultados / Albinism is a rare genetic alteration that compromises the production of melanine in all body tissues. The clinical alterations are the lack of pigment in the skin and hair. It presents important ophthalmological changes that compromise the visual acuity, in most cases. The ophthalmological changes are: ametropia, nystagmus, iris pigmented epithelium rarefaction, retina pigmented epithelium rarefaction, foveal hipoplasia and abnormal optic nerve decussation. This study has been divided in three different parts and had the following main objectives: Part 1, comparative analysis of the iris transparency degree (ITD), the retina transparency degree (RTD) and macular thickness with the visual acuity in albino patients. Part 2: Spatial contrast sensitivity test of luminance and outshine wearing contact lenses with filters in light and dark environments. Part 3: color vision evaluation using the Ishihara Test and the Cambridge Color Test (CCT). For the study 121 individuals with albinism were included with an average of 31,18 years old } 15,47, a total of 242 eyes. The participants were divided in different groups in the three parts of the study, some participated in one or more parts. In the first part the participants have been through an ophthalmological exam, classification of the iris transparency degree (ITD) and the retinal transparency degree (RTD) by a new classification based in 4 different degrees of transparency. Foveal evaluation by the Optic Coherence Tomography exam (OCT) was made in the first part of this study. In the second part, the participants have been submitted to the computerized contrast test, using filtered and transparent contact lenses in light and dark environments. In this part the influence of the filtering lenses in the visual contrast sensitivity in the albinism patients has been evaluated. In the third part, the participants have been submitted to Ishihara Test and Cambridge Color Test in order to evaluate the color vision in albino patients. The results are as follows: Part\' 1: the correlation between visual acuity in Logarithm of the Minimum Angle of Resolution (logMAR) and ITD was positive (+0,569) and significant (p<0,001). The correlation between visual acuity in logMAR and RTD was positive (+0,531) and significant (p<0,001). The correlation between visual acuity in logMAR and the macular thickness was not significant (p=0,105). The correlation between ITD and RTD was positive (+ 0,627) and significant (p<0,001). The correlation between the macular thickness and the ITD was not significant (p=0,397). The correlation between the macular thickness and the RTD was not significant (p=0,458). Part\'2: There has been a statistically significant improvement of the contrast sensitivity wearing the filtering lenses in relation to the transparent ones in bright environment, in the frequencies of 0,3 cycles per degree (cpd), 0,6 cpd and 1,0 cpd. There has been no significant improvement in the frequencies 2,0 cpd and 4,0 cpd. There has been no statistically significant improvement in contrast sensitivity wearing the filtering lenses in relation to the transparent one in the dark environment (shadow) in any of the spatial frequencies studied. Part\' 3: all albinism patients did not present any color vision change in the Ishihara Test. The CCT has shown a worsening in the color detection threshold in the protan axis (p=0,021) and deutan axis (p=0,017), but there has been no difference in the tritan axis (p=0,212). The statistic tests show that a bigger sample is recommended to confirm part 3 results
173

Relação entre funções cognitivas e perdas adquiridas na visão de cores de pacientes com esclerose múltipla tipo remitente recorrente / Relationship between cognitive functions and acquired color vision loss in patients with relapsing-remitting type of multiple sclerosis

Teixeira, Rosaní Aparecida Antunes 12 September 2012 (has links)
A Esclerose Múltipla (EM) é uma doença inflamatória autoimune caracterizada por desmielinização e degeneração do sistema nervoso central (SNC) duas a três vezes mais frequente em mulheres. A etiologia da EM é dividida em dois subtipos principais: o tipo remitente-recorrente (EMRR) mais comum, caracterizado por dois ou mais episódios de agravamento dos sintomas que envolvem diferentes locais do SNC, separados por pelo menos 1 mês e remisão dos sintomas e o tipo progressivo é a forma menos comum, caracterizada por um contínuo agravamento dos sintomas desde o início geralmente sem recaídas claras ou remissões. A presente pesquisa teve por objetivo avaliar o comprometimento da visão de cores e de sua relação com perdas de atenção, memória visual imediata, memória visual tardia, memória operacional e funções executivas dos portadores de esclerose múltipla tipo remitente recorrente. Método: participaram 41 pacientes com esclerose múltipla de idades entre 20 e 58 anos (35,4±12,2) e 37 controles com idade (34,7±12,1) e escolaridade semelhante. A discriminação de cores foi avaliada com o Cambridge Colour Test (CCT) e a avaliação de funções neuropsicológicas foram utilizados subtestes da bateria Cambridge Neuropsychological Testing Automated Battery (CANTAB) - Pattern Recognition Memory, Spatial Span, Spatial Recognition Memory, Information Sampling Task, Stop Signal Task e Rapid Information Processing; Escalas de Depressão e Ansiedade de Beck e Escala de Determinação Funcional da Qualidade de vida (DEFU). Resultados: A visão de cores está prejudicada de forma difusa em 24% dos pacientes com esclerose múltipla, tanto em pacientes com histórico de neurite óptica quando em pacientes que não tiveram neurite óptica. Na parte cognitiva, os pacientes demonstraram lentidão em executar as tarefas, comprometimento na atenção, na memória visual de curto e longo prazo, na memória operacional, na memória visuoespacial, além de lentidão no processamento de informações. Há uma relação entre alterações na visão de cores e alterações de memória visual somente em testes em que os estímulos são complexos e com inúmeros detalhes / Multiple sclerosis (MS) is an autoimmune inflammatory disease characterized by demyelination and central nervous system (CNS) degeneration. It is two times more frequent in women. It can be presented in two subtypes: the relapsing-remitting (RR), most common type, characterized by two or more episodes of focal disorders in different sites of the CNS, and remission of the symptoms; and the progressive subtype, less common, characterized by a continuous worsening of the symptoms, since the beginning, usually with no remissions. The present research evaluated color vision impairment and its relationship to attention loss, short-term memory, long-term memory, working memory and executive function in patients with the relapsing-remitting MS type. Methods: 41 patients with multiple sclerosis (20 to 58 years, 35.4 ± 12.2 in average) and 37 controls matched to age (34.7 ± 12.1 in average) and years of education participated of the study. Color vision was tested using the Cambridge Colour Test (CCT) and the neuropsychological assessment was performed using tests of the Cambridge Neuropsychological Testing Automated Battery (CANTAB) - Pattern Recognition Memory, Spatial Span, Spatial Recognition Memory, Information Sampling Task, Stop Signal Task, Rapid Information Processing the Beck Depression and Anxiety Inventories and the Functional Assessment of Multiple Sclerosis quality of life instrument. Results: Color vision was diffusely impaired in 24% of the MS patients, with or with no history of optic neuritis. Patients also showed a delay during the tasks execution, impairment in attention, short and long-term visual memory and working memory, and slowness in the information processing. There was a relationship between color vision loss and visual memory impairment, but only in tests with complex and highly detailed stimuli
174

An fMRI study of chromatic processing in humans / Untersuchung der menschlichen Farbverarbeitung mittels fMRT

D'Souza, Dany Vijay 09 September 2009 (has links)
No description available.
175

Kleur as hulpmiddel in die uitdrukking van emosie by die vyfjarige kind : 'n Gestalt-Terapeutiese benadering

De Vries, Renata 30 June 2003 (has links)
Text in Afrikaans with t.p. and summaries in Afrikaans and English / Limited research concerning a child's association between emotion and color is available, both in terms of the amount of research studies done as well as the generalization of the results for the purposes of the five year-old. This study's aim was to explore the individual, unique, symbolic meaning between the experiencing of emotion and color of the five year-old. Color was used as an expedient to facilitate the identification of emotion. The test sample consisted out of five, five year-old Afrikaans speaking children. The researcher developed a technique and used it to explore the above. The results of this study showed that the associations that five year-olds draw between emotions and color can't be generalized. The study further showed that color can be very helpful in the identification process of emotions when working with the five year-old child. The results of this study were compared to relevant previous research results and at the end the researcher made certain recommendations for further research concerning the subject. / Bestaande navorsing oor die assosiasie wat die kind vorm tussen emosie en kleur is beperk, beide in terme van die aantal navorsingstudies en in die veralgemeenbaarheid van die resultate ten opsigte van die vyfjarige kind. Hierdie studie het gepoog om die individuele, unieke, simboliese betekenis te ondersoek tussen die belewing van emosie en kleur by die vyfjarige kind. Dit het behels dat kleur as 'n hulpmiddel aangewend is, ten einde die identifisering van emosie te vergemaklik. Die steekproef het bestaan uit vyf, vyfjarige Afrikaans-sprekende kinders. 'n Tegniek, deur die navorser ontwikkel, is gebruik om die bogenoemde te ondersoek. Die resultate van hierdie studie het getoon dat kinders van vyfjarige ouderdom se assosiasies tussen emosies en kleur nie veralgemeen kan word nie. Die studie het verder getoon dat kleur 'n bruikbare hulpmiddel is in die identifisering van emosies by die vyfjarige kind. Die resultate van die studie is met vorige relevante navorsingsbevindinge vergelyk en bepaalde aanbevelings is gemaak vir toekomstige navorsing rakende hierdie onderwerp. / Psychology / M.Diac. (Play Therapy)
176

Sinaliza??o crom?tica da condi??o reprodutiva de f?meas de segui comum (Callithrix jacchus) / Reproductive signaling in female common marmosets (Callithrix jacchus).

Moreira, La?s Alves Ant?nio 26 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:37:17Z (GMT). No. of bitstreams: 1 LaisAAM_DISSERT.pdf: 1507276 bytes, checksum: 23b9ddf330fd173132cb924ee0fb4b51 (MD5) Previous issue date: 2013-04-26 / As social animals, primates use different sensory modalities (acoustic, chemical, tactile and visual) to convey information about social and sexual status to conspecifics. Among these modalities, visual signals are widely used, especially color signals, since primates are the mammalian group that displays the greatest variety of colors in their skin and fur. Studies with Old World primate species suggest that hormonal variations are related to variations in the colors of individual faces and genitals. Therefore, chromatic cues can be used by conspecifics to identify the reproductive condition of an individual. To date, studies with the same approach are unknown for New World species. However, behavioral and physiological studies suggest that different New World primate species seem to perceive reproductive conditions such as the timing of female conception and gestation. Thus, in this study, our aim was to: i) identify whether there are chromatic cues on the skin of female common marmosets, (Callithrix jacchus) that indicate their reproductive condition; ii) define whether this chromatic variation can be perceived by all visual phenotypes known in this species; iii) identify if these chromatic cues can be perceived under different light intensity levels (dim, intermediate and high). For this, we selected 13 female common marmosets in four distinct reproductive conditions: pregnant female preceding parturition, postpartum mothers, noncycling and cycling females. The coloration of the skin in genital and thigh areas in females was measured using a spectrophotometer. Using mathematical models of visual perception, we calculated the values of quantum catch for each photoreceptor type known in this species, the visual opponency channels and color contrast between those body spots. Our results indicate the occurance of chromatic variations in the genital area during the weeks that precede and follow parturition, forming a U-pattern of variation perceptible to males and females in natural conditions of low and high luminosity. Furthermore, we observed distinct color patterns in the genital skin of pregnant and cycling females that indicate their reproductive conditions. Finally, we present evidence of color contrast in noncycling females that is higher than that of pregnant ones. This study suggests that there is a chromatic xii variation in the genital skin of females that can be perceived by conspecifics and that may be related to hormonal changes typical of pregnancy and the ovarian cycle / Como animais sociais, os primatas usam sinais de diferentes modalidades (ac?stico, qu?mico, t?til e visual) para transmitir informa??es sobre status social e sexual a membros da mesma esp?cie. Dentre essas modalidades, os sinais visuais s?o amplamente utilizados, especialmente os sinais de cor, uma vez que dentre os mam?feros, os primatas formam o grupo com maior variedade de cores em suas peles e pelos. Trabalhos com esp?cies de primatas do Velho Mundo sugerem que varia??es hormonais estejam relacionadas com varia??es crom?ticas vis?veis em ?reas genitais e faces de machos e f?meas. Desta forma, pistas crom?ticas podem ser usadas por coespec?ficos para identificar a condi??o reprodutiva de um indiv?duo. At? o momento, trabalhos com essa mesma abordagem em esp?cies do Novo Mundo s?o desconhecidos. Por?m, estudos comportamentais e fisiol?gicos sugerem que diferentes esp?cies de primatas do Novo Mundo parecem perceber caracter?sticas reprodutivas como o momento da concep??o e a fase da gesta??o em f?meas. Desta forma, neste trabalho buscamos: i) identificar se existem pistas crom?ticas na pele de f?meas de sagui comum (Callithrix jacchus) que indicam a condi??o reprodutiva; ii) determinar se essas pistas s?o percept?veis aos diferentes fen?tipos visuais encontrados na esp?cie; iii) identificar qual seria o efeito de diferentes condi??es de ilumina??o na detec??o dessa colora??o. Para isso, trabalhamos com 13 f?meas de sagui comum em quatro condi??es reprodutivas distintas: gestantes pr?-parto, gestantes p?s-parto, ovulat?rias e n?o ovulat?rias. A colora??o de ?reas da pele das f?meas foi mensurada utilizando um espectrofot?metro e, utilizando modelos matem?ticos de percep??o visual, calculamos os valores de capta??o qu?ntica para cada tipo de fotorreceptor presente na esp?cie, os canais de opon?ncia visual e o contraste crom?tico entre duas ?reas corp?reas. Esse trabalho mostra evid?ncias de varia??o no contraste crom?tico das peles da genit?lia e da coxa nas semanas que antecedem e sucedem o parto, formando um padr?o de varia??o em U percept?vel a machos e f?meas em condi??es naturais de baixa e alta luminosidade. Al?m disso, evidenciamos padr?es de colora??o distintos na regi?o da pele genital para f?meas gestantes que indicam uma sinaliza??o dessa condi??o reprodutiva. Por fim, apresentamos evid?ncias de que o contraste de cor em f?meas x ovulat?rias e n?o ovulat?rias ? superior ao de f?meas gestantes. Este estudo sugere que existe uma varia??o crom?tica na pele genital de f?meas, que essa varia??o ? percept?vel a coespec?ficos e que pode estar relacionada ?s altera??es hormonais acentuadas que ocorrem durante a gesta??o e o ciclo ovariano
177

Relação entre funções cognitivas e perdas adquiridas na visão de cores de pacientes com esclerose múltipla tipo remitente recorrente / Relationship between cognitive functions and acquired color vision loss in patients with relapsing-remitting type of multiple sclerosis

Rosaní Aparecida Antunes Teixeira 12 September 2012 (has links)
A Esclerose Múltipla (EM) é uma doença inflamatória autoimune caracterizada por desmielinização e degeneração do sistema nervoso central (SNC) duas a três vezes mais frequente em mulheres. A etiologia da EM é dividida em dois subtipos principais: o tipo remitente-recorrente (EMRR) mais comum, caracterizado por dois ou mais episódios de agravamento dos sintomas que envolvem diferentes locais do SNC, separados por pelo menos 1 mês e remisão dos sintomas e o tipo progressivo é a forma menos comum, caracterizada por um contínuo agravamento dos sintomas desde o início geralmente sem recaídas claras ou remissões. A presente pesquisa teve por objetivo avaliar o comprometimento da visão de cores e de sua relação com perdas de atenção, memória visual imediata, memória visual tardia, memória operacional e funções executivas dos portadores de esclerose múltipla tipo remitente recorrente. Método: participaram 41 pacientes com esclerose múltipla de idades entre 20 e 58 anos (35,4±12,2) e 37 controles com idade (34,7±12,1) e escolaridade semelhante. A discriminação de cores foi avaliada com o Cambridge Colour Test (CCT) e a avaliação de funções neuropsicológicas foram utilizados subtestes da bateria Cambridge Neuropsychological Testing Automated Battery (CANTAB) - Pattern Recognition Memory, Spatial Span, Spatial Recognition Memory, Information Sampling Task, Stop Signal Task e Rapid Information Processing; Escalas de Depressão e Ansiedade de Beck e Escala de Determinação Funcional da Qualidade de vida (DEFU). Resultados: A visão de cores está prejudicada de forma difusa em 24% dos pacientes com esclerose múltipla, tanto em pacientes com histórico de neurite óptica quando em pacientes que não tiveram neurite óptica. Na parte cognitiva, os pacientes demonstraram lentidão em executar as tarefas, comprometimento na atenção, na memória visual de curto e longo prazo, na memória operacional, na memória visuoespacial, além de lentidão no processamento de informações. Há uma relação entre alterações na visão de cores e alterações de memória visual somente em testes em que os estímulos são complexos e com inúmeros detalhes / Multiple sclerosis (MS) is an autoimmune inflammatory disease characterized by demyelination and central nervous system (CNS) degeneration. It is two times more frequent in women. It can be presented in two subtypes: the relapsing-remitting (RR), most common type, characterized by two or more episodes of focal disorders in different sites of the CNS, and remission of the symptoms; and the progressive subtype, less common, characterized by a continuous worsening of the symptoms, since the beginning, usually with no remissions. The present research evaluated color vision impairment and its relationship to attention loss, short-term memory, long-term memory, working memory and executive function in patients with the relapsing-remitting MS type. Methods: 41 patients with multiple sclerosis (20 to 58 years, 35.4 ± 12.2 in average) and 37 controls matched to age (34.7 ± 12.1 in average) and years of education participated of the study. Color vision was tested using the Cambridge Colour Test (CCT) and the neuropsychological assessment was performed using tests of the Cambridge Neuropsychological Testing Automated Battery (CANTAB) - Pattern Recognition Memory, Spatial Span, Spatial Recognition Memory, Information Sampling Task, Stop Signal Task, Rapid Information Processing the Beck Depression and Anxiety Inventories and the Functional Assessment of Multiple Sclerosis quality of life instrument. Results: Color vision was diffusely impaired in 24% of the MS patients, with or with no history of optic neuritis. Patients also showed a delay during the tasks execution, impairment in attention, short and long-term visual memory and working memory, and slowness in the information processing. There was a relationship between color vision loss and visual memory impairment, but only in tests with complex and highly detailed stimuli
178

Avaliação oftalmológica e psicofísica do sistema visual de portadores de albinismo / Ophthalmologic and psychophysical evaluation of the visual system of individuals with albinism

Ronaldo Yuiti Sano 21 September 2017 (has links)
O albinismo e uma alteracao genetica rara que compromete a producao de melanina. As alteracoes clinicas consistem na falta de pigmentacao da pele, cabelo e pelos. Apresenta alteracoes oftalmologicas importantes, que comprometem a acuidade visual de forma severa, na grande maioria dos casos. As alteracoes oftalmologicas sao, ametropias, nistagmo, rarefacao do epitelio pigmentado da iris e da retina, hipoplasia foveal e decussacao anomala do nervo optico. Este estudo foi dividido em tres diferentes partes com os seguintes objetivos principais: Parte 1: Analise comparativa entre o grau de transparencia da iris (GTI), o grau de transparencia da retina (GTR) e a espessura da regiao macular com a acuidade visual nos pacientes com albinismo. Parte 2: Teste de sensibilidade ao contraste espacial de luminancia e ofuscamento com lentes de contato filtrantes em ambientes claros e escuros. Parte 3: Avaliacao da visao de cores, utilizando\\se o teste de Pranchas de Ishihara e o Cambridge Color Test (CCT). Material\' e\' Métodos: Participaram do estudo 121 individuos albinos, com idade media de 31,18 (} 15,47) anos, o que totalizou 242 olhos. Os participantes foram divididos em diferentes grupos nas tres partes do estudo, alguns participaram de uma ou mais partes. Na primeira parte os participantes foram submetidos a consulta oftalmologica, classificacao do grau de transparencia da iris e da retina em uma nova classificacao baseada em quatro diferentes graus de transparencia, alem de avaliacao foveal pelo exame de Tomografia de Coerencia Optica (OCT). Na segunda parte, os participantes foram submetidos ao teste de contraste computadorizado, utilizando lentes de contato filtrante e transparentes, em ambientes claros e escuros. Nesta etapa foi avaliada a influencia da lente filtrante na sensibilidade de contraste visual dos individuos com albinismo. Na terceira parte, os participantes foram submetidos aos testes de Pranchas de Ishihara e de Cambridge Colour Test (CCT), para avaliacao da visao de cores nos pacientes albinos. Resultados: Os resultados foram os seguintes: Parte\'1: A correlacao entre AV logMAR e GTI foi positiva (+0,569) e significativa (p<0,001). A correlacao entre AV logMAR e GTR foi positiva (+0,531) e significativa (p<0,001). A correlacao entre AV logMAR e a espessura macular nao foi significativa (p=0,105). A correlacao entre GTI e GTR foi positiva (+ 0,627) e significativa (p<0,001). A correlacao entre espessura macular e GTI nao foi significativa (p=0,397). A correlacao entre espessura macular e GTR nao foi significativa (p=0,458). Parte 2: Houve melhora estatisticamente significante da sensibilidade ao contraste com as lentes filtrantes em relacao as lentes transparentes no ambiente de ofuscamento (claro), na frequencia de 0,3 cpg, 0,6 cpg e 1,0 cpg (ciclos por grau). Nao houve melhora significante nas frequencia 2,0 cpg e 4,0 cpg. Nao houve melhora estatisticamente significante da sensibilidade ao contraste de lentes filtrantes em relacao as lentes transparentes no ambiente escuro (penumbra) em nenhuma das frequencias espaciais estudadas. Parte\' 3: Todos os individuos com albinismo nao apresentaram nenhuma alteracao de visao de cores no teste de Pranchas de Ishihara. O CCT demonstrou piora no limiar de deteccao de cores significativa nos eixos protan (p=0,021) e deutan (p=0,017), mas nao houve diferenca no eixo tritan (p=0,212). Os testes estatisticos sugerem que uma amostra maior seja estudada para validacao dos resultados / Albinism is a rare genetic alteration that compromises the production of melanine in all body tissues. The clinical alterations are the lack of pigment in the skin and hair. It presents important ophthalmological changes that compromise the visual acuity, in most cases. The ophthalmological changes are: ametropia, nystagmus, iris pigmented epithelium rarefaction, retina pigmented epithelium rarefaction, foveal hipoplasia and abnormal optic nerve decussation. This study has been divided in three different parts and had the following main objectives: Part 1, comparative analysis of the iris transparency degree (ITD), the retina transparency degree (RTD) and macular thickness with the visual acuity in albino patients. Part 2: Spatial contrast sensitivity test of luminance and outshine wearing contact lenses with filters in light and dark environments. Part 3: color vision evaluation using the Ishihara Test and the Cambridge Color Test (CCT). For the study 121 individuals with albinism were included with an average of 31,18 years old } 15,47, a total of 242 eyes. The participants were divided in different groups in the three parts of the study, some participated in one or more parts. In the first part the participants have been through an ophthalmological exam, classification of the iris transparency degree (ITD) and the retinal transparency degree (RTD) by a new classification based in 4 different degrees of transparency. Foveal evaluation by the Optic Coherence Tomography exam (OCT) was made in the first part of this study. In the second part, the participants have been submitted to the computerized contrast test, using filtered and transparent contact lenses in light and dark environments. In this part the influence of the filtering lenses in the visual contrast sensitivity in the albinism patients has been evaluated. In the third part, the participants have been submitted to Ishihara Test and Cambridge Color Test in order to evaluate the color vision in albino patients. The results are as follows: Part\' 1: the correlation between visual acuity in Logarithm of the Minimum Angle of Resolution (logMAR) and ITD was positive (+0,569) and significant (p<0,001). The correlation between visual acuity in logMAR and RTD was positive (+0,531) and significant (p<0,001). The correlation between visual acuity in logMAR and the macular thickness was not significant (p=0,105). The correlation between ITD and RTD was positive (+ 0,627) and significant (p<0,001). The correlation between the macular thickness and the ITD was not significant (p=0,397). The correlation between the macular thickness and the RTD was not significant (p=0,458). Part\'2: There has been a statistically significant improvement of the contrast sensitivity wearing the filtering lenses in relation to the transparent ones in bright environment, in the frequencies of 0,3 cycles per degree (cpd), 0,6 cpd and 1,0 cpd. There has been no significant improvement in the frequencies 2,0 cpd and 4,0 cpd. There has been no statistically significant improvement in contrast sensitivity wearing the filtering lenses in relation to the transparent one in the dark environment (shadow) in any of the spatial frequencies studied. Part\' 3: all albinism patients did not present any color vision change in the Ishihara Test. The CCT has shown a worsening in the color detection threshold in the protan axis (p=0,021) and deutan axis (p=0,017), but there has been no difference in the tritan axis (p=0,212). The statistic tests show that a bigger sample is recommended to confirm part 3 results
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Structural Endeavors in the Retinoid (Visual) Cycle

Hofmann, Lukas 06 September 2017 (has links)
No description available.
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Estudo da resposta da melanopsina na neuropatia óptica e no distúrbio de sono através do reflexo pupilar à luz / Study of melanopsin responses in optic neuropathy and sleep disturbance by means of the pupillary light reflex

Duque-Chica, Gloria Liliana 24 September 2015 (has links)
Dentre as células ganglionares da retina existe uma pequena população de células que contem melanopsina e respondem diretamente à luz. Estas são as células ganglionares intrinsecamente fotossensíveis (ipRGCs), cujas funções são principalmente não visuais. Dentre as funções não visuais das ipRGCs sua influência na resposta pupilar dependente da luz foi o objeto central desta tese. Tanto a retina interna, através das ipRGCs, quanto a retina externa, através dos bastonetes e cones, fornecem uma informação neural que regula a resposta pupilar à luz (RPL). Este estudo avaliou a integridade das ipRGCs através do RPL em pacientes com glaucoma primário de ângulo aberto (GPAA), leve, moderado e avançado, e em pacientes com síndrome da apnéia obstrutiva do sono (SAOS), moderada e grave. Também foi avaliada a discriminação cromática e a sensibilidade ao contraste espacial de luminância (SC), a perimetria visual e a espessura da retina avaliada por tomografia de coerência óptica (OCT). Foram avaliados 98 participantes: 45 pacientes com GPAA ( 27, 18; idade média = 65,84 + 10,20), 28 pacientes com SAOS ( 14, 14; idade média = 52,93 + 7,13), e 25 controles ( 17, 8; idade média = 54,27 + 8,88). Após o exame oftalmológico foram avaliadas a SC de grades e a discriminação de cores através do Cambridge Colour Test (CCT). A avaliação do RPL foi feita apresentando-se flashes de 470 e 640 nm, de 1s de duração, em 7 luminâncias desde -3 até 2.4 log cd/m2 em um Ganzfeld Q450 SC (Roland Consult). O RPL foi registrado pelo sistema de eye tracker View Point System (Arrington Research Inc.). Os testes foram realizados em ambos os olhos, de forma monocular e no escuro. Para a comparação dos dados entre os grupos, utilizou-se um modelo de equações de estimação generalizada (GEE), para correção da dependência entre os dois olhos. O RPL dos pacientes com GPAA moderado e avançado apresentou redução significativa na amplitude do pico, dependente da severidade do glaucoma, nas diferentes luminâncias tanto para 470 nm quanto para 640 nm, evidenciando redução das contribuições dos cones e bastonetes ao RPL. As contribuições das ipRGCs ao RPL (avaliadas pela amplitude da resposta sustentada entre 6-8 s) foram também significativamente menores em GPAA moderado e avançado. No estado inicial do GPAA as contribuições das ipRGCs para o RPL encontram-se preservadas. No entanto, o GPAA parece afetar o processamento espacial desde o inicio da doença. Nos pacientes com GPAA leve foi observada uma perda acentuada nas faixas baixas de frequência espacial, compatível com prejuízo seletivo das células ganglionares do tipo M. A SC de pacientes com GPAA moderado e avançado mostrou perdas nas faixas baixas e altas de frequência espacial, apontando um prejuízo nas vias parvo- e margnocelulares. Uma perda significativa da discriminação de cores no eixo azul-amarelo foi observada em todos os estágios do GPAA. O RPL nos pacientes com SAOS está parcialmente preservado, não obstante, as respostas da amplitude do pico para o flash de 470 nm diminuem conforme aumenta a severidade da SAOS. As contribuições dos fotorreceptores da retina externa ao RPL, foram significativamente menores em algumas das luminâncias. Não foram observadas diferenças significativas de SC ou discriminação de cores nos pacientes com SAOS. Em conclusão, no estágio moderado e avançado do glaucoma tanto as contribuições das ipRGCs ao RPL quanto as vias M e P, se encontram mais afetadas do que no inicio do GPAA, quando a via parvocelular e as contribuições das ipRGCs ao RPL parecem estar mais preservadas / Among the retina ganglion cells there are a small population of cells containing melanopsin and which respond directly to light. They are the intrinsically photosensitive ganglion cells (ipRGCs), whose functions are mainly non-visual. Among these non-visual functions of the ipRGCs, their influence on the pupillary response as a function of light was the central subject of this thesis. Both the inner retina through the ipRGCs and the outer retina through the rods and cones, provide neural information that regulates the pupillary light response (PLR) to light. This study evaluated the integrity of ipRGCs through PLR in patients with Primary Open Angle Glaucoma (POAG), mild, moderate and advanced, and in patients with Obstructive Sleep Apnea Syndrome (OSAS), moderate and severe. We evaluated also the color discrimination and achromatic spatial contrast sensitivity (CS), visual perimetry and retinal thickness evaluated by Optical Coherence Tomography (OCT). 98 participants were evaluated, 45 patients with POAG ( 27 18; mean age = 65.84 + 10.20), 28 with OSAS ( 14 14; mean age = 52.93 + 7.13) and 25 controls ( 17 8; mean age = 54.27 + 8.88). After the ophthalmological exam it was evaluated the contrast sensitivity and color discrimination measures using the Cambridge Colour Test (CCT). Pupil responses were elicited by Ganzfeld (Q450 SC, Roland Consult) presentation of 1-sec flashes of 470- and 640-nm at 7 luminance from -3 to 2.4 log cd/m2. PLR was measured with the eye tracker system View Point (Arrington Research Inc.). The tests were performed monocularly, on both eyes, in a darkened room. In order to compare data across groups, we used a General Estimating Equations (GEE) to adjust for within subject inter-eye correlations. Patients with moderate and advanced POAG had a significantly decreased PLR that depends on the severity of the glaucoma, for both the 470- and 640-nm stimuli, making evident the reduction of the contributions of the cones and rods to the PLR. The contributions of ipRGCs to PLR (assessed by the amplitude of the sustained response between 6 8 sec) were also significantly lower in patients with moderate and advanced POAG. In the initial and mild stages of POAG the contribution of ipRGCs to the PLR is preserved. However, POAG appears to affect spatial processing from the early stages of the disease. Mild-POAG patients showed a marked loss in the low spatial frequency bands, compatible with selective loss of magnocellular ganglion cells. The CS of patients with moderate and advanced POAG showed losses at both low and high spatial frequencies, suggesting a loss in both parvo- and margnocellular channels. A significant loss of color discrimination along the blue-yellow axis was observed in all stages of POAG. The PLR in patients with OSAS is partially preserved, however the peak amplitude responses for the 470-nm flash decreased with increased severity of OSAS. The contributions of the photoreceptors of the outer retina to the PLR were significantly lower at some of the luminance. Significant differences in CS or color discrimination were not observed in patients with OSAS. In conclusion, in moderate and advanced stages of glaucoma, both the contributions of ipRGCs to PLR as well as the M- and P channels, were found more affected than at the beginning of POAG, in contrast the parvocellular channel and the contributions of ipRGCs on the PLR would be more preserved

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