925 resultados para eye blink
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Purpose: To describe spontaneous blink kinematics in Graves' upper eyelid retraction (UER).Methods: The magnetic search coil technique was used to record spontaneous blinks of 15 healthy subjects (aged 23-56 years, 15 eyelids) and 15 patients with Graves' UER (aged 22-62 years, 15 eyelids) during a 5-min period of video observation, and the signals were digitized at 200 Hz (12 bits). Overall, a total of 2,798 blinks were recorded for the controls and 1,860 for the patients. The distance between pupil center and upper eyelid margin in the primary position of gaze (MRD) was measured with the Image J software.Results: The blinking rate of patients was lower than that of control subjects, with a mean (+/-SEM) blinking rate (blinks/min) of 13.0 +/- 1.7 for patients and of 20.0 +/- 2.1 for the controls (t = 2.58, P = 0.016). There were no statistically significant differences in blink amplitude between controls (22.7 +/- 3.1 degrees) and Graves' patients (24.7 +/- 3.3 degrees). However, while only 22% of the blinks performed by controls were smaller than MRD, this rate was 78% for patients. In addition, in blinks larger than 25, patients showed lower down-phase velocity than controls.Conclusions: Patients with Graves' UER show reduced blinks rates and abnormal blink kinematics, which might be related to the development of exposure keratitis in this disease.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Importance of the field: The use of topical agents poses unique and challenging hurdles for drug delivery. Topical steroids effectively control ocular inflammation, but are associated with the well-recognized dilemma of patient compliance. Although administration of topical antimicrobials as prophylaxis is acceptable among ophthalmologists, this common practice has no sound evidence base Developing a new antimicrobial agent or delivery strategy with enhanced penetration by considering the anatomical and physiological constraints exerted by the barriers of the eye is not a commonly perceived strategy. Exploiting the permeability of the sclera, subconjunctival routes may offer a promising alternative for enhanced drug delivery and tissue targeting.Area covered in this review: Ocular drug delivery strategies were reviewed for ocular inflammation and infections clinically adopted for newer class of antimicrobials, which use a multipronged approach to limit risks of endophthalmitis.What the reader will gain: The analysis substantiates a new transscleral drug delivery therapeutic approach for cataract surgery.Take home message: A new anti-inflammatory and anti-infective paradigm that frees the patient from the nuisance of topical therapeutics is introduced, opening a large investigative avenue for future improved therapies.
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This article aims to analyse the introduction of environmental issues in the context of the production function, which has been referred to as the organisational area to lead corporate environmental management. With that purpose, the theoretical references for corporate environmental management and the necessary alterations in production function have been organised to include environmental aspects, especially in terms of product and process development, quality management, and logistics. Considering that this research field still lacks empirical evidence for Brazilian companies, four case studies were conducted using companies located in the country. The environmental management maturity level of those companies tends to follow the rate with which the environmental issue is introduced in production sub-areas, especially in the product development process. However, in most cases we found that the companies had difficulties in structuring the insertion of the environmental dimension in logistics. The final notes point out the distance observed between what is recommended by international literature and the reality of Brazilian companies in the challenge of making the production function environmentally friendly.
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This study analyses the blink reflex in 20 adult male patients with terminal chronic renal failure undergoing hemodialysis. Abnormalities were found in ten patients (50%), eight of them with conduction studies showing axonal peripheral neuropathy. Dialysis time was longer for patients with blink reflex alterations (median 55.1 months) than for patients with normal blink reflex (median 36.3 months). Different types of early R1 and late R2 component abnormalities were recorded. The late response abnormalities may indicate subclinical functional or anatomical impairment of the low brainstem reticular formation in patients with chronic renal failure. (C) 2002 Elsevier B.V. Ltd. All rights reserved.
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Latências do reflexo trigêmino-facial e índices cefalométricos foram analisados em 30 voluntários adultos normais, de 3 diferentes raças, sendo 10 brancos, 10 negros e 10 orientais. Idades variaram de 15 a 59 anos, alturas de 1,6 a 1,8 m e pesos de 60 a 80 kg. Os reflexos trigêmino-faciais foram obtidos por estimulação elétrica unilateral do nervo supra-orbital e captação nos músculos orbicularis oculi, para análise quantitativa de 3 respostas, ipsolateral precoce (R1), ipsolateral tardia (R2i) e contralateral tardia (R2c). Índices cefalométricos foram obtidos multiplicando-se por 100 a razão entre maior diâmetro transverso e maior diâmetro sagital do crânio. As médias dos índices cefalométricos de cada grupo foram compatíveis com as respectivas características raciais. As respostas R1, R2i e R2c não mostraram diferenças de latências estatisticamente significativas entre as 3 diferentes raças analisadas neste estudo.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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OBJETIVO: Avaliar o ritmo de piscar de portadores de pterígio antes e depois da exérese. MÉTODOS: Foram avaliados os movimentos palpebrais de 41 pacientes antes e 60 dias depois da remoção cirúrgica da lesão. Os movimentos palpebrais foram capturados durante 1 minuto, usando filmadora Sony Digital 8 DCR - TRV110, sob iluminação artificial, com o indivíduo em posição primária do olhar, tendo como ponto de fixação a própria filmadora. As imagens obtidas foram processadas por computador, quantificando-se o total de movimentos de piscar, o número de piscar completo e incompleto, e as respectivas durações. Os dados foram submetidos à análise estatística. RESULTADOS: Antes da cirurgia 36,36% dos pacientes queixavam-se de sensação de corpo estranho e após a cirurgia, 61,02% estavam assintomáticos. A avaliação do ritmo de piscar revelou que a freqüência do piscar incompleto aumentou no pós-operatório. A duração do piscar não se alterou antes e após a cirurgia. CONCLUSÃO: A exérese do pterígio leva à diminuição dos sintomas irritativos. Após a remoção da lesão, houve discreto aumento da freqüência de piscar incompleto. Há a possibilidade da presença do pterígio não estar relacionada com alterações do filme lacrimal, considerando que a alteração do ritmo de piscar foi discreta. No entanto, outros estudos deverão ser realizados para afirmar ou contestar esta hipótese.
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We investigated the association of eye color with the dominant-subordinate relationship in the fish Nile tilapia, Oreochromis niloticus. Eye color pattern was also examined in relation to the intensity of attacks. We paired 20 size-matched fish (intruder: 73.69 ± 11.49 g; resident: 75.42 ± 8.83 g) and evaluated eye color and fights. These fish were isolated in individual aquaria for 10 days and then their eye color was measured 5 min before pairing (basal values). Twenty minutes after pairing, eye color and fights were quantified for 10 min. Clear establishment of social hierarchy was observed in 7 of 10 pairs of fish. Number of attacks ranged from 1 to 168 among pairs. The quartile was calculated for these data and the pairs were then divided into two classes: low-attack (1 to 111 attacks - 2 lower quartiles) or high-attack (112 to 168 attacks - 2 higher quartiles). Dominance decreased the eye-darkening patterns of the fish after pairing, while subordinance increased darkening compared to dominance. Subordinate fish in low-attack confrontations presented a darker eye compared to dominant fish and to the basal condition. We also observed a paler eye pattern in dominants that shared low-attack interactions after pairing compared to the subordinates and within the group. However, we found no differences in the darkening pattern between dominants and subordinates from the high-attack groups. We conclude that eye color is associated with social rank in this species. Moreover, the association between eye color and social rank in the low-attack pairs may function to reduce aggression.
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We have been developing a computational code to project optical lenses, with low aberration effects. Our main interest is model the human eye, particularly, project special corrective lenses. As the lens shape is the focus of the optimization, we have coupled a ray tracing method with Monte Carlo techniques. The initial results indicated that the algorithm must be improved in terms of resolution and reliability.
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Purpose. To trace the eye components involved in proteoglycan synthesis and to characterize the sulfated glycosaminoglycans which are associated to these macromolecules.Methods. Sodium [S-35]-sulfate was injected intravitreally and the rabbits were killed at different time intervals after the injection. The glycosaminoglycans of choroid, ciliary body, cornea, iris, lens capsule, retina and sclera were extracted and processed for estimations of their specific activities, and for electrophoresis plus autoradiography with or without previous treatment with specific enzymes. In addition, methacrylate sections of the eyes were analysed by autoradiography.Results. The peak of specific activities of the glycosaminoglycans of all eye components occurred at 2 days after the intravitreal injection of [S-35]-sulfate. The autoradiography of the agarose gels revealed three types of glycosaminoglycans, namely, heparan-, chondroitin- and dermatan sulfate, only in the retina. The other eye components contained heparan sulfate and either chondroitin or dermatan sulfate. Tissue autoradiography together with the biochemical techniques contributed to unravel the origin of the glycosaminoglycans in the eye components.Conclusions. The results of the present investigation have shown that heparan sulfate, contrasting to chondroitin sulfate and dermatan sulfate, is synthesized in all eye components studied and that the glycosaminoglycan composition differs according to the tissue of origin.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)