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Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was prompted by the observation that after horizontal muscle surgery a large number of cases of non-paralytic squint ended up with no binocular vision and an appreciable residual vertical deviation with a "V" or "A" pattern. It has become clear to us that the associated vertical deviation is usually present from the onset, and may play a major part in the mechanism of the squint. In less marked cases the vertical deviation is noticed only when the eye movements are fully examined, and is missed unless the extremes of elevation and depression are evoked. We have been largely influenced by the work and experience of Dr. M.H. Gobin (1964, 1968a, b, c), who feels that cyclotropia is an important factor in the aetiology of convergent squint. Gobin regards torsion as a third dimension in ocular motility, and thinks that for images to fall on corresponding retinal points it is reasonable to try to make the visual axes parallel horizontally and vertically, and that the retinal meridians should coincide.
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PMID:Role of the vertical muscles in horizontal deviations. 27 94

Fifteen patients with diplopia associated with prior scleral buckling, prior penetrating keratoplasty, severe corneal scarring, monocular aphakia, long-standing strabismus, or prior vertical offsets of the horizontal recti were thought to have disruption of fusion because diplopia could not be eliminated with prisms. They were each found to have a substantial symptomatic cyclotropia unassociated with an obvious dysfunction of an oblique muscle. In 13 patients, diplopia resolved after the cyclotropia was corrected surgically.
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PMID:Unexpected cyclotropia simulating disruption of fusion. 141 41

The practical aspects of this work may be summarized as follows: The absence of subjective cyclotropia in patients with cyclovertical muscle paralysis is frequently associated with a congenital or infantile onset of the palsy. The Maddox double rod test provides quantitative information about the degree of cyclotropia but, due to its disassociating characteristics, may easily be misinterpreted. For instance, a positive Maddox test may be found in a cyclotropic patient with adequate cyclofusion who is asymptomatic. The Bagolini striate lenses are introduced as a superior test for cyclotropia since they provide information under more natural conditions of seeing. The Bagolini lenses not only permit us to measure the degree of cyclotropia but also tell us how a patient copes with it. The phase difference haploscope of Aulhorn provides similar information but is not readily available in clinical practice. The occurrence of cyclotropia in the non-paretic eye emphasizes that the diagnosis of a cyclovertical paralysis must not be made exclusively on the basis of subjective tests for cyclotropia. These tests are helpful only in the context of other clinical information of which the laterality of fixation preference of the patient has gained special significance. An apparent over-response to surgery for cyclotropia as evidenced, for example, by complaints of image tilting to the opposite side during the postoperative period after surgery for superior oblique paralysis may be caused by persistence of abnormal spatial localization. As a rule, this problem is only temporary and will disappear as normal egocentric localization re-establishes itself and the anatomical vertical and horizontal retinal meridians of the formerly cyclotropic eye assume their physiological spatial response.(ABSTRACT TRUNCATED AT 250 WORDS)
J Pediatr Ophthalmol Strabismus
PMID:Clinical and theoretical aspects of cyclotropia. 647 Sep 8

1. A convergent or divergent strabismus was induced surgically in eight kittens and a cyclotropia of about 90 deg in two additional kittens. 2. Behavioural measurements were made of the visual acuity of each eye for square-wave gratings. All eight animals that were so tested displayed a reduction of acuity in one eye relative to the other of 1.3-2.5 octaves. 3. The activity of retinal ganglion cells was recorded within the amblyopic eye of six cats, three with a convergent strabismus, two with a divergent strabismus and one with a cyclotropia. Measurements were made of the spatial resolution with 215 on-centre cells for horizontal and vertical gratings. 4. In contrast to other reports, we found the spatial resolution of ganglion cells in the amblyopic eye of the strabismic animals to be comparable to those of normal cats at all retinal eccentricities. In particular there was no evidence for a loss of resolution in the vicinity of the area centralis. 5. Measurement of the cross-sectional area of cells in the lateral geniculate nucleus (l.g.n.) revealed no evidence of cell shrinkage in laminae receiving a projection from the amblyopic eye. 6. Together, these findings lead to the conclusion that the neural deficit responsible for the strabismic amblyopia in these animals did not lie in the retina but rather at more central levels of the visual pathway.
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PMID:Normality of spatial resolution of retinal ganglion cells in cats with strabismic amblyopia. 710 89

In most instances, a head tilt to either shoulder is caused by hypertropia or cyclotropia and responds well to conventional surgical strengthening or weakening operations on the cyclovertical muscles. Occasionally, an ocular head tilt occurs in the absence of cyclovertical strabismus, in association with congenital nystagmus or without an apparent cause. We have successfully treated four of five such patients by surgically rotating the eye(s) around the sagittal axis. This was accomplished by horizontal transposition of the vertical rectus muscles. No complications were encountered. We present this method as a viable alternative to other surgical approaches to rotate the eyes around their sagittal axis.
J Pediatr Ophthalmol Strabismus
PMID:Horizontal transposition of the vertical rectus muscles for treatment of ocular torticollis. 845 32

The paper for the first time presents statistically processed data on the cyclofusion reserves of subjects with normal binocular vision (25) for different age groups: adolescents aged 12-14 and adults aged 18-35 years. Two types of tests for evaluating cyclofusion under conditions of haploscopy (sinoptophore) are offered. The results can be used as a criterion for evaluating cyclofusion in various oculomotor abnormalities: squint, diplopia, and cyclotropia.
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PMID:[State of cyclofusion reserves in subjects with normal binocular vision]. 1156 73

The horizontal and vertical components of strabismus are measured routinely and relatively easily in the clinical setting using prism-and-cover and/or corneal light reflex tests. The third dimension of ocular alignment, ocular torsion, is more difficult to assess. Objective torsional deviation (cyclotropia) is evaluated qualitatively with fundus examination. For quantitative assessment, however, fundus photography is needed, which may not always be available during a strabismus examination and typically requires pupil dilation. We present a simple, inexpensive photographic technique to assess changes in iris torsion and evaluate its accuracy by comparison with fundus photography. Using a consumer-grade digital camera, basic photographic editing software, and a data worksheet, this technique assesses changes in objective torsion with accuracy and retest variability of both approximately 1 degrees.
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PMID:Photographic assessment of changes in torsional strabismus. 2000 24

In general an A-or V-symptom is an additional sign of an oblique muscle dysfunction and is treated by surgery of oblique muscles. The vertical transposition of horizontal rectus muscles is a suitable treatment only in those cases with no coexistent vertical deviation. The mechanical particularities of this vertical displacement are summarized. Possible side effects of this surgical method, including cyclotropia are reported.
Strabismus 1995
PMID:Cycloduction as a possible side-effect of vertical transposition of horizontal eye muscles in A- and V-pattern. 2131 9