Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3 cases of cyclical convergent strabismus (48 hour rhythm) were investigated. In contrast to intermittant strabismus, cyclical strabismus is not fatigue dependant. An alteration in the rhythm of the cyclical esotropia was produced by wearing prisms, red glasses or occlusion for several days. This observation indicates that centrally inaugurated rhythm processes can be altered by peripheral sensory influcences. In the case of our third patient, who was not operated upon, there was a cyclical strabismus which persisted from the age of 4 to 19 years, before changing to a constant convergent strabismus. The other two patients, following strabismus surgery, had a small angle esophoria with good fusion and stereopsis.
 ...
PMID:[Alternate day squint (author's transl)]. 122 20

Tait described four categories of binocular disorders including convergence excess, convergence insufficiency, divergence excess, and divergence insufficiency. These disorders are defined by the distance where the largest heterophoria occurs (distance or near), and the amplitude of the accommodative vergence ratio (AC/A). Insufficiency corresponds to a low AC/A ratio, whereas excess corresponds to a high AC/A. The magnitude of the AC/A ratio, which may be influenced by the adaptability of the accommodation and vergence systems, has been shown to be reciprocally related to adaptability of accommodation. Likewise, the degree of vergence accommodation has been shown to be related reciprocally to adaptability of vergence to prism. An imbalance of adaptability of accommodation and vergence systems produces abnormal cross-coupling between the two motor systems. When accommodation is more adaptable than vergence, the AC/A ratio is low and the CA/C ratio is high. Conversely, when vergence is more adaptable than accommodation, the AC/A ratio is high and the CA/C ratio is low. A method is reported for temporarily restoring moderate amplitudes of abnormal AC/A and CA/C ratios by reducing excessive adaptation with fatigue. Finally, new clinical procedures for measuring adaptation of accommodation and the CA/C ratio are presented. Taken together with current measures of vergence adaptation and AC/A ratio these procedures will permit a more complete evaluation of mutual interactions between accommodation and vergence in patients diagnosed as having excessive and insufficient vergence.
 ...
PMID:Influence of accommodative and vergence adaptation on binocular motor disorders. 304 65

The investigation of the role of visual and ocular characteristics of visual display unit (VDU) operators in the causation of subjective visual fatigue has not been reported previously. A retrospective study in which the visual and ocular characteristics of symptomatic and asymptomatic VDU operators was carried out in order to determine whether such a relation could be demonstrated. Three groups totaling 1013 VDU operators from two semigovernment organizations were assessed using either a full eye examination or a modified clinical screening technique. Before examination, the operators completed a short questionnaire on the symptoms they experienced when using VDU's. Significant differences between the symptomatic and asymptomatic operators in some groups were found for over-refraction (spherical equivalent and cylindrical) and near horizontal heterophoria. Despite the existence of this relation, no basis for valid visual standards could be established. In particular, no basis was found for the automatic prescribing of low plus corrections and, in the absence of clearly definable visual standards, the involvement of clinical judgment in the assessment of operators was found to be necessary.
 ...
PMID:Symptoms in VDU operators. 336 24

Composite sheets obtained reinforcing PHEMA with a tricot PET net have been implanted in rabbits to test their potential applications for cross-eye surgical correction. The mechanical characterization of the composites has been carried out both in static tension and fatigue. The clinical evaluation was performed on twelve adult New Zealand white Rabbits implanting the sheets on the rectus dorsalis muscle of the eye. The material seems to be highly compatible with the surrounding tissue, mechanical satisfying and clinically helpful in correcting many of the pathological conditions connected with strabismus. The long term behaviour of the implanted prosthesis in still under investigation.
 ...
PMID:[Biological and surgical aspects of the use of polymers in experimental surgery. 1: implants on the oculo-extrinsic musculature]. 622 97

A new method for the detection and recording of the oculocardiac reflex (OCR) is described and applied to 49 healthy infants and children (six months to nine years old) undergoing strabismus surgery under halothane anaesthesia with spontaneous ventilation. Eighty-one extraocular muscles were studied. Square wave stimuli (abrupt and sustained tractions) were definitely more reflexogenic than slow slope stimuli (very gradual, progressive and gentle tractions). Vagal escape, as well as fatigue of the OCR, are graphically documented and analysed. In this series, using well-defined and controlled tractions, the medial rectus was not more reflexogenic than the other extraocular muscles. Hypercapnia was an important adjuvant factor of the OCR. Controlled ventilation is recommended. The routine use of intravenous anticholinergic drugs is briefly discussed. Prevention of the OCR, and prophylaxis of cardiac arrhythmias during strabismus surgery, now seem to be placed on a more rational basis.
 ...
PMID:The oculocardiac reflex: a graphic and statistical analysis in infants and children. 687 77

With the help of this chart, the image incongruity of simultaneous perception, fusion and stereoscopic vision can be precisely determined. It can objectively evaluate the binocular visual function and possesses important significance for the diagnosis and treatment of anisometropia, amblyopia, strabismus and visual fatigue.
 ...
PMID:[Study and application of "binocular aniseikonia test chart"]. 780 36

Paroxysmal tonic upgaze of childhood is a rare, distinctive, childhood syndrome that may be associated with ataxia and sometimes strabismus or amblyopia. Neurological examination as well as metabolic studies, electroencephalogram and neuroradiological investigations are normal in these patients. Although it has been considered as an age-related, dopa-sensitive dystonia, the exact pathogenetic mechanism is still unknown. Aggravation of attacks by fatigue, intercurrent infection or vaccination, and possible corticomesencephalic dysmaturation may underlie this abnormality. We report on a sporadic case of paroxysmal tonic upgaze with ataxia in which there was prompt aggravation of symptoms with sleep without response to levodopa treatment. This case suggests a different underlying pathogenetic mechanism from dopaminergic pathways for this syndrome.
 ...
PMID:A case of paroxysmal tonic upgaze of childhood with ataxia. 1046 69

We report a family in which the mother and her three sons suffered sick sinus syndrome and strabismus. Two members had a persistent left superior vena cava with drainage into coronary sinus. The illness in all members of this family was oligosymptomatic, and well tolerated with mild symptoms like dizziness, fatigue and exercise dyspnea associated with nodal rhythm. Three of them, had episodes of paroxysmal atrial fibrillation. All patients remain asymptomatic after pacemaker implantation.
 ...
PMID:[Familial sick sinus syndrome associated to strabismus and persistent left superior vena cava]. 1097 40

Studies of external eye muscle morphology and physiology are reviewed, with respect to both motor and sensory functions in concomitant strabismus. The eye muscles have a more complex fibre composition than other striated muscle, and they are among the fastest and most fatigue-resistant muscles in the body. However, it is not generally believed that concomitant strabismus is due to a primary abnormality of the eye muscles or the ocular motor system. The gross anatomy of eye muscles, including the shape and position of the eye muscle pulleys, was not changed in strabismus. The histology of the eye muscle fibres was also basically the same, but changes have been observed in the cellular and biochemical machinery of the fibres, most notably in the singly innervated orbital fibres. Functionally, this was seen as slower contractions and reduced fatigue resistance of eye muscles in animals with strabismus and defects of binocular vision. Most likely the changes represented an adaptation to modified visual demands on the ocular motor control, because of the defects of binocular vision in strabismus from an early age. Adaptation of eye muscle function to visual demands could be seen also in the adult human ocular motor system, but here the effects could be reversed with treatment in some conditions. External eye muscles in the human have sensory organs, muscle spindles and tendon organs, responding to changes in muscle force and length. It is not known how these proprioceptors are used more specifically in ocular motor control, and there is no stretch reflex in the external eye muscles. However, a clear influence on space localization and eye position can be demonstrated with vibratory stimulation of the eye muscles, presumably activating muscle spindles. Different effects were observed in normal subjects and in adult patients with strabismus, which would indicate that the proprioceptive input from one eye of strabismic patients could be suppressed by the other eye, similar to visual suppression in concomitant strabismus. Such an interaction would most likely occur in the visual cortex, and not in the ocular motor system. Further studies of proprioceptive mechanisms, during the postnatal developmental stage and in adult concomitant strabismus may shed light on the mechanisms of childhood strabismus and may, in this respect, be a more fruitful avenue for further research than eye motor studies.
 ...
PMID:Strabismus and eye muscle function. 1794 25

A 10-year-old boy with unilateral ophthalmoplegia, ptosis, and proptosis underwent diagnostic examination. Symptoms of headache, nausea, dyspnea, fatigue, weakness, and loss of appetite began 14 days after the onset of ocular manifestations and 7 days before he was examined. Complete blood count showed an increased white blood cell count with 64% blast cells, anemia, and thrombocytopenia. The patient was transferred to a pediatric hematology unit, where he underwent bone marrow aspiration biopsy. Bilateral ocular inflammatory findings and left-sided mild proptosis became evident. He was diagnosed as having B-cell non-Hodgkin lymphoma infiltrating the bilateral cavernous and sphenoid sinuses.
J Pediatr Ophthalmol Strabismus
PMID:Cavernous sinus syndrome as the initial presentation of childhood non-hodgkin lymphoma. 1964 4


1 2 Next >>