Orientador: Newton Kara-José / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T15:02:59Z (GMT). No. of bitstreams: 1 Minguini_Nilza_D.pdf: 5086893 bytes, checksum: 39a18efb37934b146ddf768d9cae5161 (MD5) Previous issue date: 2011 / Resumo: Os objetivos do estudo foram pesquisar a existência de efeito coadjuvante da injeção de 5U de toxina botulínica A intraoperatória em cirurgia monocular de retrocesso-ressecção para a correção de estrabismos horizontais de ângulos grandes em adultos e descrever tipos e frequências de efeitos colaterais desse tratamento. Desenho do estudo: ensaio clínico controlado randomizado duplo-cego. Vinte e três portadores de desvios horizontais de ângulos grandes foram randomizados em dois grupos: cirurgia associada à injeção intraoperatória de Toxina Botulínica A (CG+TBA) ou apenas cirurgia (CG). Os procedimentos de retrocesso-ressecção foram conduzidos sob anestesia local no olho de pior visão. A injeção de toxina botulínica A foi aplicada no músculo submetido a procedimento de retrocesso após sua tenotomia. Para a avaliação de resultados, foram comparados entre os grupos: as características clínicas, as quantidades de desvio corrigido no último retorno (6 a 12 meses) e entre o primeiro e último retornos, as porcentagens de desvios corrigidos nos retornos de 1 dia, 7 a 15 dias, 1 mês, 3 meses e 6 a 12 meses e as porcentagens de resultados satisfatórios no último retorno. As médias e desvios-padrão dos ângulos de desvio pré-operatório para os grupos CG+TBA (12 pacientes) e CG (11 pacientes) foram, em dioptrias prismáticas (Dp), respectivamente: 65,8 ± 14,9 e 60,0 ± 16,8 (p=0,26) e as médias e desvios-padrão das quantidades de desvio corrigido em Dp no último retorno foram, respectivamente, 51,5 ± 14,8 e 41,3 ± 14,0 (p=0,18). As porcentagens de desvio corrigido foram significativamente maiores no grupo CG+TBA no retorno de 30 dias (p=0,05), nos demais retornos não houve diferenças significativas entre os grupos. As quantidades de desvio corrigido foram significativamente menores no último retorno em relação ao primeiro para ambos os grupos (p=0,006) e sem diferença entre eles (p=0,59). Não houve diferença significativa entre as porcentagens de resultados satisfatórios entre os grupos no último retorno (p=0,63). Os efeitos colaterais da toxina botulínica A mais frequentemente encontrados foram: ptose e desvio vertical transitórios (em 5 dos 12 pacientes tratados). Assim, a injeção intraoperatória de TBA não aumentou o efeito cirúrgico da correção de estrabismos horizontais de ângulos grandes nos pacientes estudados e provocou alta incidência de ptose palpebral e desvio vertical transitórios / Abstract: Objective: To investigate the existence of adjuvant effect of botulinum toxin A (5u intraoperative injection) in monocular recess-resection procedure for correction of large angle horizontal strabismus in adults under local anesthesia and to describe types and frequencies of side effects. Subjects and Methods: A randomized clinical trial. Twenty-three patients with large angle horizontal deviations were randomized into two groups: surgery associated with intraoperative injection of botulinum toxin A (CG+BTA) or surgery only (CG). The recess-resection procedures were performed under local anesthesia on the non-fixating eye. The clinical characteristics, amounts of corrections at the last visit (6 to 12 months) and between the first and last visits, the percentages of changes in the pre-operative deviations at 1 day, 7 to 15 days, 1 month, 3 months and 6 to 12 months, the amount of correction between the first and last post operative visits, and the percentages of satisfactory results were compared between groups at the last visit. Results: Means and standard deviations of the preoperative angles of deviation for the groups CG+BTA and CG were 65.8 Dp ± 14.9 and 60.0 Dp ± 16.8 (p=0.26) and the means and standard deviations of the amounts of corrections at the last visit were respectively: 51,5 Dp ± 14,8 and 41,3 Dp ± 14,0 (p=0.18). The percentages of changes in the pre-operative deviations were significantly higher in the CG + TBA group at 30 days (p=0.05), and did not differ between groups at others post operative visits. Amounts of corrections were significantly lower at the last post operative visit in relation to the first for both groups (p=0.006) with no difference between them (p=0.59). There was no difference between groups in the percentage of satisfactory results at the last visit (p=0,63). Side effects of botulinum toxin A more common were: transient ptosis and transient vertical deviation both in 5 of 12 patients treated. Conclusions: Intraoperative injection of TBA did not increase the effect of surgical correction of horizontal strabismus large angles in the patients studied and led to high incidence of ptosis and vertical deviation transitory / Doutorado / Oftalmologia / Doutor em Ciências Médicas

Yes / Adults with amblyopia ('lazy eye'), long-standing strabismus (ocular misalignment) or both typically do not experience visual symptoms because the signal from weaker eye is given less weight than the signal from its fellow. Here we examine the contribution of the weaker eye of individuals with strabismus and amblyopia with both eyes open and with the deviating eye in its anomalous motor position. The task consisted of a blue-on-yellow detection task along a horizontal line across the central 50 degrees of the visual field. We compare the results obtained in ten individuals with strabismic amblyopia with ten visual normals. At each field location in each participant, we examined how the sensitivity exhibited under binocular conditions compared with sensitivity from four predictions, (i) a model of binocular summation, (ii) the average of the monocular sensitivities, (iii) dominant-eye sensitivity or (iv) non-dominant-eye sensitivity. The proportion of field locations for which the binocular summation model provided the best description of binocular sensitivity was similar in normals (50.6%) and amblyopes (48.2%). Average monocular sensitivity matched binocular sensitivity in 14.1% of amblyopes' field locations compared to 8.8% of normals'. Dominant-eye sensitivity explained sensitivity at 27.1% of field locations in amblyopes but 21.2% in normals. Non-dominant-eye sensitivity explained sensitivity at 10.6% of field locations in amblyopes but 19.4% in normals. Binocular summation provided the best description of the sensitivity profile in 6/10 amblyopes compared to 7/10 of normals. In three amblyopes, dominant-eye sensitivity most closely reflected binocular sensitivity (compared to two normals) and in the remaining amblyope, binocular sensitivity approximated to an average of the monocular sensitivities. Our results suggest a strong positive contribution in habitual viewing from the non-dominant eye in strabismic amblyopes. This is consistent with evidence from other sources that binocular mechanisms are frequently intact in strabismic and amblyopic individuals.

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-04-17T11:42:26Z No. of bitstreams: 1 Thales Valente.pdf: 2116457 bytes, checksum: 1fe85262c104d5e919673a3d65e1fd56 (MD5) / Made available in DSpace on 2017-04-17T11:42:26Z (GMT). No. of bitstreams: 1 Thales Valente.pdf: 2116457 bytes, checksum: 1fe85262c104d5e919673a3d65e1fd56 (MD5) Previous issue date: 2017-02-03 / CNPQ, TeCGraf/PUC-Rio / Medical image processing can contribute to the detection and diagnosis of human body anomalies, as an important toll to minimizes the degree of uncertainty in diagnosis, and provides specialists with an additional source of information. Strabismus is one of these anomalies, which affects approximately 4% of the population. Strabismus modify the mechanism of vision, resulting in aesthetical and sensory problems. The first case is reversible at any age. Regarding sensory problems, late treatment may lead to an irreversible condition. The cover test is one of the types of exams used to diagnose this pathology. The use of low cost computational resources to aid in the diagnosis and treatment within the strabismus subspecialty is not yet a reality. Therefore, this work presents a computational methodology to automatically pre-diagnosis strabismus through digital videos featuring cover test. To do this, the methodology was divided in 8 stages: Acquisition (1), Detection of eyes region (2), Location of pupil (3), Location of limbus (4) , Tracking eyes (5), Detection of occluder (6) , Detection (7) and Diagnosis of strabismus (8). The effectiveness of the method in the indication of the diagnosis was evaluated by comparisons made with the diagnosis provided by the expert. For detection of strabismus, the method proposed achieved 100% specificity, sensitivity of 80% and 93.33% accuracy and was demonstrated to be 87% accurate in diagnosing strabismus, while acknowledging measures lower than 1 prismatic diopter, and an average error of 2.57 prismatic diopters in deviation measure. So, was demonstrated the feasibility of using computational resources based on images processing techniques to achieve diagnosing strabismus through cover test. / O processamento de imagens médicas vem contribuindo para a detecção e o diagnóstico de anomalias no corpo humano, sendo uma importante ferramenta na redução do grau de incerteza do diagnóstico, provendo uma fonte adicional de informação aos especialistas. Uma dessas anomalias é o estrabismo, que afeta aproximadamente 4% da população e modifica o mecanismo de visão, resultando em problemas estéticos e sensoriais. O primeiro caso é reversível a qualquer idade. Já em relação aos problemas sensoriais, o tratamento tardio pode levar á um quadro irreversível. O cover test é um dos tipos de exames realizados para diagnosticar tal patologia. A utilização de recursos computacionais de baixo custo no auxílio diagnóstico e terapêutico dentro da subespecialidade estrabismo ainda não é uma realidade. Portanto, este trabalho apresenta uma metodologia computacional para pré-diagnosticar automaticamente o estrabismo através de víıdeos digitais da aplicação do exame cover test. Para tanto, a metodologia foi dividida em 8 etapas: (1) Aquisição, (2) Redução da região dos olhos, (3) Localização da pupila, (4) Localização do limbo, (5) Rastreamento dos olhos, (6) Detecção do oclusor, (7) Detecção e (8) Diagnóstico do estrabismo. A eficácia do método na indicação do diagnóstico foi avaliada através de comparações realizadas com os diagnósticos fornecidos pelo especialista. Para a detecção de estrabismo, a metodologia proposta obteve 100% de especificidade, 80% de sensibilidade e 93,33% de acurácia e demonstrou 87% de acurácia no diagnóstico do estrabismo, mesmo considerando medidas menores que 1 dioptria prismática, apresentando erro médio de 2,57 dioptrias prismáticas na aferição do desvio. Assim, foi demonstrada a viabilidade da utilização de recursos computacionais baseados em técnicas de processamento de imagens para alcançar o diagnóstico de estrabismo através do cover test.

This work is dealing with design of the systém for measuring dynamics of the vergence and accommodation. Vergence accommodation synkinesis is a complex process controlled by various mechanisms in CNS. Deviations from physiological state of the vision process are projected to course of the vergence accommodation curves and is possible the quantitative and qualitative evaluation. For this purpose was designed the measuring system Ir.M.A. (Infrared Measurement of Accommodation). The system uses high-speed videometric device for determination of the relative vergence and relative accomodation of the eyes. Stimulation of the patient's eyes is performed by the standardized jump change of the fixation object distance. The object is reconstruted by holographic method. Measured videosequences are processed by the image analysis. Results of the image analysis are courses of the vergence and accommodation curves depending on time and characteristics of the curves. System is designed for using in clinical practice where it could be used as screening instrument for diagnostics of the oculomotor system disorders.

No description available.

Yes / Purpose: Two binocular sources of information serve motion-in-depth (MID) perception: changes in disparity over time (CD), and interocular velocity differences (IOVD). While CD requires the computation of small spatial disparities, IOVD could be computed from a much lower-resolution signal. IOVD signals therefore might still be available under conditions of binocular vision impairment (BVI) with limited or no stereopsis, e.g. amblyopia. Methods: Sensitivity to CD and IOVD was measured in adults who had undergone therapy to correct optical misalignment or amblyopia in childhood (n=16), as well as normal vision controls with good stereoacuity (n=8). Observers discriminated the interval containing a smoothly-oscillating MID “test” stimulus from a “control” stimulus in a two-interval forced choice (2IFC) paradigm. Results: Of the BVI observers with no static stereoacuity (n=9), one displayed evidence for sensitivity to IOVD only, while there was otherwise no sensitivity for either CD or IOVD in the group. Generally, BVI observers with measurable stereoacuity (n=7) displayed a pattern resembling the control group: showing a similar sensitivity for both cues. A neutral-density (ND) filter placed in front of the fixing eye in a subset of BVI observers did not improve performance. Conclusions: In one BVI observer there was preserved sensitivity to IOVD but not CD, though overall only those BVI observers with at least gross stereopsis were able to detect disparity-based or velocity-based cues to MID. The results imply that these logically distinct information sources are somehow coupled, and in some cases BVI observers with no stereopsis may still retain sensitivity to IOVD. / UK Biotechnology and Biological 498 Sciences Research Council (BBSRC): BB/M002543/1 (Alex R. Wade) BB/M001660/1 (Julie 499 M. Harris) and BB/M001210/1 (Marina Bloj)

PURPOSE: To evaluate whether the Amblyopia and Strabismus Questionnaire (A&SQ) is a suitable instrument for the assessment of vision-related quality-of life (VR-QoL) in individuals with strabismus and/or amblyopia. METHODS: The A&SQ was completed by 102 individuals, all of whom had amblyopia, strabismus, or both. Rasch analysis was used to evaluate the usefulness of individual questionnaire items (i.e., questions); the response-scale performance; how well the items targeted VR-QoL; whether individual items showed response bias, depending on factors such as whether strabismus was present; and dimensionality. RESULTS: Items relating to concerns about the appearance of the eyes were applicable only to those with strabismus, and many items showed large ceiling effects. The response scale showed disordered responses and underused response options, which improved after the number of response options was reduced from five to three. This change improved the discriminative ability of the questionnaire (person separation index increased from 1.98 to 2.11). Significant bias was found between strabismic and nonstrabismic respondents. Separate Rasch analyses conducted for subjects with and without strabismus indicated that all A&SQ items seemed appropriate for individuals with strabismus (Rasch infit values between 0.60 and 1.40), but several items fitted the model poorly in amblyopes without strabismus. The AS&Q was not found to be unidimensional. CONCLUSIONS: The findings highlight the limitations of the A&SQ instrument in the assessment of VR-QoL in subjects with strabismus and especially in those with amblyopia alone. The results suggest that separate instruments are needed to quantify VR-QoL in amblyopes with and without strabismus.

L’amblyopie est un trouble développemental de la vision binoculaire. Elle est typiquement caractérisée par des atteintes de l’acuité visuelle et de la stéréoscopie. Toutefois, de plus en plus d’études indiquent la présence d’atteintes plus étendues telles que les difficultés d’attention visuelle ou de lecture. L’amblyopie est généralement expliquée par une suppression interoculaire au niveau cortical, considérée comme chronique ou permanente à l’extérieur de la période développementale. Or, un nombre croissant d’études suggèrent que des interactions binoculaires normales seraient présentes chez les amblyopes adultes. Dans une première étude, nous avons tenté d’identifier un marqueur électrophysiologique de la vision binoculaire. Nous avons enregistré des potentiels évoqués visuels chez des observateurs normaux à qui l’on a induit une dysfonction binoculaire. Les interactions binoculaires étaient caractérisées à l’aide de patrons (facilitation, moyennage et suppression) en comparant les réponses monoculaires et binoculaires. De plus, ces interactions étaient quantifiées à partir d’index d’intégration continus en soustrayant la somme des réponses monoculaires de la réponse binoculaire. Les résultats indiquaient que les patrons d’interaction n’étaient pas optimaux pour estimer les performances stéréoscopiques. Ces dernières étaient, en revanche, mieux expliquées par notre index d’intégration binoculaire. Ainsi, cette étude suggère que l’électrophysiologie est un bon prédicteur de la vision binoculaire. Dans une deuxième étude, nous avons examiné les corrélats neuronaux et comportementaux de la suppression interoculaire chez des amblyopes adultes et des observateurs normaux. Des potentiels évoqués visuels stationnaires ont été enregistrés en utilisant un paradigme de suppression par flash. La suppression était modulée par un changement de contraste du stimulus flash (10, 20, 30, ou 100%), ou le suppresseur, qui était présenté soit dans l’œil dominant ou non-dominant (ou amblyope). Sur le plan comportemental, la suppression interoculaire était observée indépendamment de l’œil stimulé par le flash chez les contrôles. Au contraire, chez les amblyopes, la suppression était asymétrique (c’est-à-dire supérieure lorsqu’elle provenait de l’œil dominant), ce qui suggérait une suppression chronique. De manière intéressante, l’œil amblyope a supprimé l’œil dominant à haut niveau de contraste. Sur le plan électrophysiologique, l’effet de suppression interoculaire observé à la région occipitale était équivalent dans chaque groupe. Toutefois, les réponses électrophysiologiques à la région frontale chez les amblyopes n’étaient pas modulées comme celles des contrôles; la suppression de l’œil amblyope était manifeste même à bas contraste. Nous résultats supportent ainsi l’existence d’interaction binoculaire fonctionnelle chez les amblyopes adultes ainsi que l’implication d’un réseau cortical étendu dans la suppression interoculaire. En somme, l’amblyopie est une condition complexe dont les atteintes corticales et les déficits fonctionnels semblent globaux. L’amblyopie ne doit plus être considérée comme limitée à une dysfonction de l’aire visuelle primaire. La suppression interoculaire semble un point central de cette problématique, mais encore beaucoup d’études seront nécessaires afin de déterminer l’ensemble des mécanismes impliqués dans celle-ci. / Amblyopia is a developmental dysfunction of binocular vision. It is typically characterized by visual acuity and stereopsis deficits. However, presence of more spread deficits such as problems in visual attention and reading are beginning to be reported in literature. Amblyopia is generally explained by interocular suppression at cortical level, which is considered to be chronic or permanent outside the developmental period. Nevertheless, a growing body of evidence suggests that normal binocular interactions are still present in amblyopic adults. In the first study, we tried to establish an electrophysiological marker of binocular vision. Visual evoked potentials (VEPs) were recorded in normal observers for whom binocular dysfunction was induced. Patterns of binocular interaction were categorized (facilitation, averaging or suppression) by comparing monocular and binocular responses. Quantitative and continuous indexes of binocular integration were also calculated (binocular response minus the sum of monocular responses). Results indicated that patterns of interaction were not optimal to account for stereoscopic performance. The latter was, however, best explained by binocular integration indexes. This study shows evidence of predicting binocular vision based on a novel index that allows continuous quantification of binocular transient-VEP responses. In the second study, we examined the behavioural and neural correlates of interocular suppression in amblyopic adults and controls using a flash suppression paradigm while recording steady-state visual evoked potentials (ssVEP). The strength of suppression was manipulated by changing the contrast (10, 20, 30 or 100%) of the "flash", or the suppressor, and the stimulus was presented either in the dominant (or fellow) or non-dominant (or amblyopic) eye. At the behavioural level, interocular suppression was found regardless the eye origin of the flash for normal observers, but was asymmetric in the amblyopes, so that the suppression from the fellow eye was stronger, supporting a putative chronic suppression. Interestingly, the amblyopic eye suppressed the dominant eye at the highest contrast level. At the electrophysiology level, interocular suppression effects found over the occipital region were equivalent in both groups. However, ssVEP responses over the frontal region in the amblyopic observers were not modulated as those in controls; suppression of the amblyopic eye was manifest even at low contrast levels. Our findings support the existence of functional binocular interaction in adult amblyopia and the implication of a widespread cortical network in interocular suppression. To conclude, amblyopia is a complex condition with widespread cortical and functional deficits. It seems clear that it can’t be limited to a primary visual cortex dysfunction. Interocular suppression seems a core mechanism of the problematic, but more studies are necessary to determine more precise mechanisms implicated.

Submitted by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-09-19T15:20:57Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) COMPARAÇÃO ENTRE O PEVP E O PERG DE CRIANÇAS COM AMBLIOPIA ESTRÁBICA E ANISOMETROPICA 1_3 V5.pdf: 3334834 bytes, checksum: f21a6dfb6b0e7fbc0eb2ef6452f3f4c0 (MD5) / Approved for entry into archive by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-09-19T15:21:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) COMPARAÇÃO ENTRE O PEVP E O PERG DE CRIANÇAS COM AMBLIOPIA ESTRÁBICA E ANISOMETROPICA 1_3 V5.pdf: 3334834 bytes, checksum: f21a6dfb6b0e7fbc0eb2ef6452f3f4c0 (MD5) / Made available in DSpace on 2017-09-19T15:21:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) COMPARAÇÃO ENTRE O PEVP E O PERG DE CRIANÇAS COM AMBLIOPIA ESTRÁBICA E ANISOMETROPICA 1_3 V5.pdf: 3334834 bytes, checksum: f21a6dfb6b0e7fbc0eb2ef6452f3f4c0 (MD5) Previous issue date: 2017 / Universidade Federal Fluminense. Centro de Ciência Médicas / A ambliopia é uma desordem neurológica do desenvolvimento visual que se manifesta com a redução de capacidades sensoriais em ambos os olhos ou mais comumente de forma monocular, diante da total correção óptica e na ausência de anormalidades do exame clínico. Está associada ao estrabismo e a anisometropia e menos frequentemente à privação visual. As ambliopias estrábica e anisometrópicas apresentam diferenças nas suas fisiopatologias. Comparamos as respostas eletrofisiológicas das ambliopias estrábica e anisometrópicas com o eletroretinograma padrão (PERG) e o potencial evocado visual padrão (PVEP). Cinquenta e seis pacientes, 18 crianças amblíopes anisometrópicas hipermetrópicas (idade média e desviopadrão 9,7 ± 2,5); 19 crianças com ambliopia estrábica esotrópica (idade média e desvio padrão 10,3 ± 2,6) e 19 crianças emétropes normais (idade média e desvio-padrão 10,1 ± 2,2) foram divididos em três grupos. Após o exame oftalmológico de rotina, o eletroretinograma padrão (PERG) e o potencial evocação visual padrão (PVEP) foram registrados em respostas a um estímulo de padrão reverso à taxa de duas reversões/segundo. A diferença entre ambliopia anisometrópica hipermetrópica e ambliopia estrábica em relação às latências das ondas P100 / P50 / N95 (p = 0,055 / 0,855 / 0,132) e as amplitudes P100 / P50 / N95 (p = 0,980 / 0,095 / 0,045) não foi estatisticamente significante. No entanto, houve uma diferença estatística significante entre a ambliopia estrábica e os controles com relação às latências das ondas P100 / P50 / N95 (p = 0,000 / 0,006 / 0,004). Nossos achados indicam que, apesar das diferenças clínicas e fisiopatológicas entre pacientes amblíopes estrábicos esotrópicos e os pacientes com ambliopia anisometrópica hipermetrópica, não foram encontradas diferenças nas respostas de PVEP e PERG. Os componentes anormais do PVEP e PERG em crianças amblíopes podem refletir uma disfunção da retina e da via visual. / Amblyopia is a neurological disorder of visual development manifested by the reduction of sensory abilities in both eyes or more commonly monocular in the face of total optical correction and absence of clinical examination abnormalities. It is associated with strabismus and anisometropia, and less often with visual deprivation. Strabismus amblyopia and anisometropic amblyopia present clinical differences and their pathophysiology. We compared the electrophysiological responses of the strabismic and anisometropic amblyopia with the pattern electroretinogram (PERG) and the pattern visual evoked potential (PVEP). Fifty-six patients, 18 hypermetropic anisometropic amblyopic children (mean age and standard deviation 9.7 ± 2.5); 19 children with esotropic strabismus amblyopia (mean age and standard deviation 10.3 ± 2.6) and 19 normal emetopic children (mean age and standard deviation 10.1 ± 2.2) were divided into three groups. After routine ophthalmologic examination, the pattern electroretinogram (PERG) and standard visual evoked potential (PVEP) were recorded in responses to a reverse pattern stimulus at the rate of two reversions/second. The difference between hypermetropic anisometropic amblyopia and strabismus esotropic amblyopia in relation to P100 / P50 / N95 wave latencies (p = 0.055 / 0.855 / 0.132) and P100 / P50 / N95 amplitudes (p = 0.980 / 0.095 / 0.045) was not statistically significant. However, there was a statistically significant difference between strabismic amblyopia and controls with respect to P100 / P50 / N95 wave latencies (p = 0.000 / 0.006 / 0.004). Our findings indicate that, despite clinical and pathophysiological differences between esotropic strabismus-amblyopic patients and patients with hypermetropic anisometropic amblyopia, no differences in PVEP and PERG responses were found. Abnormal PVEP and PERG components in amblyopic children may reflect retinal and visual pathway dysfunction.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-14T17:54:04Z No. of bitstreams: 1 JoaoDallysonAlmeida.pdf: 4607146 bytes, checksum: 8e76d2b2ba34e77fcc3d20c8cfa92e17 (MD5) / Made available in DSpace on 2017-08-14T17:54:05Z (GMT). No. of bitstreams: 1 JoaoDallysonAlmeida.pdf: 4607146 bytes, checksum: 8e76d2b2ba34e77fcc3d20c8cfa92e17 (MD5) Previous issue date: 2010-02-12 / Strabismus is a pathology that affects about 4% of the population causing aesthetic problems, reversible at any age, and irreversible tensorial alterations, modifying the vision mechanism. Hirschberg's test is one of the available exams to detect such pathology. Computer Aided Diagnosis and Detection Systems have been used with relative success to help health professionals. Nevertheless, the increasingly application of high technology resources to help diagnosis and therapy in ophthalmology is not a reality in the Strabismus sub-specialty. This way, the present work has the objective of introduing a methodology for automatic detection Strabismus in digital images through Hirschberg's test. For such, it is organized in four stages: finding the region of the eyes, precise location of the eyes, limb and bright, and identi cation of Strabismus The methodology presents results of 100% of sensibility, 91,3% of specificity and 94% of match in the identification of Strabismus, comproving the eficiency of the geostatistical functions in the extraction of the texture of the eyes and of the calculations of the alignment between eyes in digital images acquired from Hirschberg's test. / O estrabismo é uma patologia que afeta cerca de 4% da população provocando problemas estéticos, reversíveis a qualquer idade, e alterações sensoriais irreversíveis, modificando o mecanismo da visão. O teste de Hirschberg é um dos tipos de exames existentes para detectar tal patologia. Sistemas de Detecção e Diagnóstico auxiliados por computador (Computer Aided Detection/Diagnosis) estão sendo usados com relativo sucesso no auxílio aos profissionais de saúde. No entanto, o emprego cada vez mais rotineiro de recursos de alta tecnologia, no auxílio diagnóstico e terapêutico em oftalmologia, não é uma realidade dentro da subespecialidade estrabismo. Sendo assim, o presente trabalho tem como objetivo apresentar uma metodologia para detectar automaticamente o estrabismo em imagens digitais através do teste de Hirschberg. Para tal, o estudo está organizado em quatro fases: localização da região dos olhos, localização precisa dos olhos, localização do limbo e do brilho, e identificação do estrabismo. A metodologia apresenta resultados de 100% de sensibilidade, 91,3% de especificidade e 94% de acerto na identificação do estrabismo comprovando a eficiência das funções geoestatísticas na extração de textura dos olhos e do cálculo da alinhamento entre os olhos em imagens digitais adquiridas a partir do teste de Hirschberg.