extorsion

(redirected from excyclotorsion)

extorsion

 [eks-tor´shun]
tilting of the upper part of the vertical meridian of the eye away from the midline of the face.

ex·tor·sion

(eks-tōr'shŭn),
1. Conjugate rotation of the upper poles of each cornea outward. Synonym(s): excyclotorsion
2. Outward rotation of a limb or of an organ.
[L. extorsio, fr. ex- torqueo, to twist out]

ex·tor·sion

(eks-tōr'shŭn)
1. Outward rotation of a limb or of an organ.
2. Conjugate rotation of the upper poles of each cornea outward.
[L. extorsio, fr. ex-torqueo, to twist out]

torsion 

Rotation of an eye about an anteroposterior axis. If the upper pole of the vertical meridian of the cornea appears to rotate inward, it is called intorsion, and outward, extorsion. If the eye rotates to the right it may be called dextrotorsion and if it rotates to the left it may be called laevotorsion. It may occur as a result of a head tilt, extraocular muscle weakness or rotation of the eye to a tertiary position. Syn. cycloductin; cyclorotation; torsional movement. See Donder's law; tertiary position; incongruous hemianopia.
References in periodicals archive ?
The Harada-Ito (HI) procedure is a strabismus surgical technique developed to treat torsional diplopia caused by excyclotorsion resulting from superior oblique (SO) muscle palsy.
Diagnosis of SO palsy was made based on limited depression on adduction, IO hyperfunction, V-pattern, hypertropia, abnormal head position, excyclotorsion findings, and medical history.
Acquired trochlear nerve palsy may cause symptomatic excyclotorsion, also referred to as torsional diplopia, which is rarely seen in congenital cases.
Patients with more than 10 degrees of excyclotorsion are usually symptomatic, as in our other 2 cases.
Pure cyclotropia is also generally compensated by a head tilt toward the side of the incyclodeviated eye or the opposite side in case of excyclotorsion of one eye.
SO palsy causes a vertical deviation in the field of action of the underacting SO and overacting inferior oblique with excyclotorsion of the affected eye.
In recently acquired palsies, there is a characteristic motility pattern with hyperdeviation and excyclotorsion of the affected eye in down gaze [2].
The torsional vestibulo-ocular reflex (VOR) generates conjugate torsional eye movements which consist of excyclotorsion of one eye and incyclotorsion of the other that compensate for head tilt.
Superior oblique palsy causes an ipsilateral hypertropia and excyclotorsion. Frequently, the patient will compensate with a contralateral head tilt.
Surgical correction of subjective excyclotorsion by tucking the anterior part of the superior oblique muscle tendon.