[Cyclotorsions].
Cyclotorsions are movements of cyclorotation of the eyes (in- or ex-cycloversions or vergences) and positions of cyclotorsion (in- or ex-cyclotorsion or cyclodeviation). Torsion is absent when the vertical meridian 0 traversing the cornea center is parallel to a plumbline. In a state of intorsion, the nasal end of the horizontal meridian is higher than the temporal part: the optic disk is lower than the fovea. Conversely the optic disk is higher in cases of excyclotorsion. Fundus observation is the only objective test in cases of torsion. Cyclodeviations are peripheral in nature (ex: SO palsy orbital strabismus) or linked to fixation (ex: congenital nystagmus, incyclo, and DTDs in infantile strabismus). All the facias and the orbits play a role in cyclorotations. The anterior fibers of the oblique muscles are responsible for torsion. Dissociated surgery and shift of the insertion follow. In a situation of cyclotorsion, the recti act differently (Weiss): the medial rectus becomes an elevator and is less an adducto, the superior rectus is less an elevator, etc. The consequences are alphabetic deviations, tilt of the coordimeter and synoptometer charts, displacement surgery of the recti insertions. Surgery of the facias must not be ignored. The study of torsions is currently evoluing.
Spielmann
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D001251:Astigmatism / Q000209:etiology; D004172:Diplopia / Q000209:etiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000502:physiology / Q000503:physiopathology* / Q000601:surgery*; D013285:Strabismus / Q000503:physiopathology / Q000601:surgery; D014102:Torsion Abnormality / Q000503:physiopathology / Q000601:surgery