cyclotorsion
Rotational movement of the eye around its visual axis, measured in degrees of intorsion or extorsion.
Full Definition
Cyclotorsion refers to the rotational movement of the eye around the anterior-posterior axis, causing the vertical meridians to tilt. Intorsion rotates the superior pole nasally, while extorsion rotates it temporally. Cyclotorsional movements are produced primarily by the superior and inferior oblique muscles, with secondary contributions from the superior and inferior rectus muscles. Excessive cyclotorsion can cause diplopia and is often associated with superior oblique weakness, Brown syndrome, or skew deviation. Measurement can be performed using fundus photography, double Maddox rods, or synoptophore testing. Surgical correction may involve oblique muscle procedures or transposition surgeries.
Usage
Usage note: Specify whether intorsion or extorsion and quantify in degrees when measured. Note associated vertical or horizontal deviations.
In Context
- "Fundus photography revealed 15 degrees of excyclotorsion secondary to superior oblique palsy." — Cranial nerve assessment
- "The patient's diplopia was attributed to significant cyclotorsion following orbital trauma." — Post-traumatic evaluation