The effect of Müllerectomy on Kocher sign.

PURPOSE: To measure the magnitude of the effect of attention on upper eyelid retraction in patients with thyroid orbitopathy (Kocher sign) and to determine if Müllerectomy can abolish this effect. METHODS: The study design was prospective with two phases: The first one was observational and the second interventional. Two groups of eyes were studied. The control group consisted of 30 eyes of 30 healthy subjects. The second group included 34 eyes of 17 patients with thyroid orbitopathy and hyperthyroidism. The mid-pupil to eyelid margin distance of both groups was measured when the subjects were relaxed and during attentive gaze. The same measurements were performed for the patients with thyroid orbitopathy after Müllerectomy. All measurements were performed on digitalized images of the palpebral fissure with software on a Macintosh computer. RESULTS: Attention induced a mean increment of 1.33 mm in the mid-pupil eyelid margin distance of patients with thyroid orbitopathy. For the control subjects, attention did not modify the position of the upper eyelid. After Müllerectomy, the effect of attention was abolished. CONCLUSIONS: Müllerectomy abolishes the variability of upper eyelid retraction induced by attentive gaze in patients with thyroid orbitopathy.

Quantitative study of the effect of dacryocystorhinostomy on lacrimal drainage.

Using scintigraphy, we have studied the lacrimal drainage from the conjunctival sac of normal subjects and patients who have undergone dacryocystorhinostomy. A mathematical model of drainage was constructed that accurately described the complete activity curves for both groups. The initial rate of drainage was shown to be a relevant parameter to characterize drainage, and it was found to be different from normals to patients, indicating that the lacrimal pump mechanism is affected by dacryocystorhinostomy.

Simplifying scleral fixation of posterior chamber intraocular lenses.

We describe a surgical modification for primary scleral fixation of posterior chamber intraocular lenses. The technique keeps intraocular surgical manipulation at a minimum and allows fixation of the lens during accidental rupture of the posterior lens capsule.

Measurement of visual acuity with logarithmic charts: comparison between methods of threshold estimation.

The variability of the repetition of visual acuity measurements with a log MAR acuity chart with five optotypes in each row of acuity was studied in four groups of subjects. In three groups the threshold was calculated by probability of seeing curves, but the optotypes were read in different orders. For the fourth group the acuity was taken as the smallest row discriminated. Estimating the threshold by a probability of seeing curve did not improve the threshold's stability. Poorer acuity was detected when the optotypes were read vertically. It is suggested that clinical visual acuity charts are not suitable tools for generating data points to be fitted by probability of seeing curves.

Transplante autologo homotopico de musculo ocular extrinseco. / Homotopic autologous transplantation of extrinsic ocular muscle

Com a finalidade de contribuir para a resolucao de problemas relacionados aos desequilibrios oculo-motores, realizamos, no presente trabalho, o estudo de transplantes autologos e homotopicos do musculo reto superior do bulbo ocular de coelhos.Utilizamos seis coelhos albinos, femeas.Cada transplante era realizado com a permuta hemotopica de segmentos de 7 mm do musculo reto superior de ambos os olhos de um mesmo animal. Nossos resultados permitiram as seguintes conclusoes: a) Em todos os casos ocorreu revascularizacao do enxerto e regeneracao macica das fibras musculares; b) na regiao de uniao musculo-muscular ocorreram aderencias entre esta e a esclera subiacente; c) As fibras musculares do coto distal e enxerto tendem a se organizar e migrar sobre a area de uniao musculo-muscular

Consideracoes a respeito da utilizacao, em estatistica de tabelas de acuidade visual. / Use of visual acuity tables in statistics

O autor discute algumas caracteristicas matematicas das tabelas de acuidade visual e faz consideracoes a respeito do tratamento estatistico de dados obtidos com tais tabelas

O metodo do gradiente e a medida clinica da relacao CA/A. / The gradient method and the clinical measure of AC/A relation.

A metodologia utilizada para a quantificacao da relacao CA/A nao foi ainda padronizada. Com o fito de se verificar, para o emprego na clinica, o melhor procedimento de calculo, aplicou-se, em quarenta pessoas normais, o metodo do gradiente com sete niveis acomodativos (0,1,2,3,4,5,6 dioptrias). Nossos resultados mostram que a variancia das heteroforias de cada nivel acomodativo aumenta segundo uma parabola com o estimulo acomodativo. Essa constatacao, aliada ao fato de que as modificacoes heteroforicas nao sao independentes, nos levou a concluir que o modelo de regressao linear simples, nao e, do ponto de vista estatistico, adequado para o ajuste da reta cuja inclinacao representa a relacao CA/A. Contudo, verificamos que, quando a medida da relacao CA/A representa a inclinacao de uma reta, ela apresenta uma estabilidade compativel com o uso clinico. A extensao otima de tal reta e de cinco dioptrias de estimulacao acomodativa, niveis 1 a 5 dioptrias, podendo esta reta ser, porem sem validade estatistica, tracada pelo metodo dos minimos quadrados ou, mais simplesmente, atraves dos pontos extemos.