Many factors determine the individual intraocular pressure in a given eye and the mean level in a given population. When it is estimated by indentation tonometry, such variables as the corneal curvature and rigidity, the scleral rigidity, and the initial ocular volume, have all been found to influence the readings (Friedenwald, I937; Phillips and Quick, I960), but these are much less important when applanation tonometry is used because of the small volumetric displacement (Goldmann, 1957; Schmidt, I959). Friedman (I966) showed that differences in the initial volume of the eye affect the stressstrain relationship in the ocular coats, and this may cause variations in tonometric readings, even when the applanation method is used.Direct determination of the volume of the living eye is difficult but, as there is known to be a correlation between the refraction of the eye and its axial length (and therefore its voluime) (Sorsby, Benjarmin, Davey, Sheridan, and Tanner, 1957), errors of refraction may influence applanation readings.The aim of this paper is to report the results of a comparison of applanation tonometric readings in 760 emmetropic and myopic eyes examined at Ain Shams University Hospitals during the year I967. Material and methodsSubjects were selected from patients attending the ophthalmic out-patients clinic for refraction and from normal persons accompanying their sick relatives. They were all above the age of Io years, and their eyes were healthy with no corneo-scleral damage past or present that might have interfered with the measurement of the intraocular pressure.After the visual acuity had been assessed, the ocular tension was measured with the Goldmann applanation tonometer mounted on the Haag-Streit goo slit lamp. Homatropine 2 per cent. was then instilled into each eye and one hour later a refraction was done and the results recorded. All eyes with an applanation reading above 20 mm. Hg or below I0 mm. Hg were excluded fiom the study.All those examined were divided into five age gIroups and these were subdivided according to the state of refraction (Table I,
Beh §et (I937) drew attention to a syndrome characterized by a triad of symptoms: iritis, aphthous ulceration of the mouth, and ulcerationofthegenitalia. Although this diseasewas originally considered to be a rarity, recent reports show that it is more common and widespread than was previously thought, especially in the Middle East, the Mediterranean countries, and Japan. During the last few years, 26 patients seen in the departments of rheumatology, ophthalmology, dermatology, and neurology in our university hospital (Abdel-Fattah, Abdallah, and Fadly, I969) reflect the relatively high incidence of the disease in Egypt.
A WELL-KNOWN anatomical feature of the orbit is its rich fatty content, distributed both inside and outside the muscle cone. The literature contains numerous reports of a variety of orbital tumours, and although angiolipomas and fibrolipomas appear quite frequently, the occurrence of a true lipoma is extremely rare. Strauss (1911) based his diagnosis of primary liposarcoma of the orbit on the predominance of fat in the tumour. In 1960, Enterline, Culberson, Rochlin, and Brady, in their review of 53 cases of liposarcoma, included one case of metastatic orbital liposarcoma. Fourteen of their cases metastasized, and only two of their patients were still alive at the time of review, and one of these two had metastasis in the lung six years after the original diagnosis. In the other case metastatic liposarcoma of the orbit was diagnosed sixteen years after the original diagnosis of liposarcoma of the thigh had been made. This patient also developed multiple secondaries with eventual invasion of the pelvis. The interesting case here presented is one of primary liposarcoma of the thigh with distant metastases.
INTRODUÇÃOO eletrorretinograma multifocal (ERGmf) é obtido por meio de registro simultâneo das respostas de múltiplas áreas da retina central, utilizando-se estímulos de alta e baixa luminância, apresentados na seqüência denominada seqüência-m (seqüência de extensão ou alcance máximo) em monitor de vídeo. Seu registro gráfico é formado por um conjunto de ondas, obtido por extração matemática de sinais, com picos negativo (N 1 ) e positivo (P 1 ), semelhantes ao do eletrorretinograma (ERG) de campo total. A análise da Fatores técnicos intervenientes na realização do exame de eletrorretinograma multifocal (ERGmf) Descritores: Doenças retinianas/diagnóstico; Eletrorretinografia/métodos; Retina/fisiologia; Potenciais evocados visuais; Erros de diagnóstico Objetivo: Descrever os principais fatores intervenientes observados durante a aquisição e análise do exame de eletrorretinograma multifocal (ERGmf), que afetam o registro gráfico das ondas obtidas e portanto sua análise. Métodos: Análise dos fatores de erro observados durante a aquisição de 100 exames seqüenciais de eletrorretinograma multifocal, realizados com o Reti System da Roland Consult, no período de maio a julho de 2005. Os exames de eletrorretinograma multifocal foram realizados conforme recomendações internacionais, respeitando-se os parâmetros preestabelecidos do equipamento, com 61 elementos, e ângulo visual de 30º. Todos os pacientes foram submetidos à avaliação oftalmológica completa, excluindo-se aqueles com transparência inadequada de meios, córneas planas e os incapazes de visualizar as linhas de fixação. Resultados: Os fatores intervenientes, que poderiam causar erros na interpretação dos resultados obtidos, observados e corrigidos durante a realização dos exames foram: fixação excêntrica, movimentação dos olhos, contração do orbicular, contração da musculatura cervical, não-correção adequada, não-transparência adequada do eletrodo corneano, deslocamento do eletrodo em geral para baixo, descentralização do suporte da lente corretora, distância inadequada paciente-monitor em pacientes com alta ametropia, altura inadequada dos olhos em relação ao centro da tela, ruído na freqüência de 60 HZ (rede elétrica) e de campo eletromagnético, impedân-cias elevadas. No processamento das ondas, a utilização excessiva de filtros para remoção de ruídos dos registros obtidos, pode interferir na análise dos resultados obtidos. Conclusões: Cuidados simplesmente observacionais durante a aquisição dos sinais são de importância significativa para a obtenção de registros com boa morfologia e baixo nível de ruído. Permitindo, por meio de sua pronta correção, a análise correta e adequada da amplitude e do tempo implícito dos picos N1 e P1, fundamentais para a corroboração diagnóstica de lesões ou afecções retinianas. RESUMOATUALIZAÇÃO CONTINUADA
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