Skew deviation is an acquired vertical strabismus that can mimic superior or inferior oblique palsy. The deviation is due to peripheral or central asymmetric disruption of supranuclear input from the otolith organs. Intorsion of the hypertropic eye on fundus examination—rather than the expected extorsion in superior oblique palsy—suggests skew deviation, particularly when there are associated neurologic findings. In addition, if the patient is placed in a supine position, the vertical tropia is more likely to decrease with skew deviation than with superior oblique palsy. Similarly, if there is extorsion of the hypotropic eye on fundus examination—instead of the expected intorsion in inferior oblique palsy—then skew deviation is the likely diagnosis. See BCSC Section 5, Neuro-Ophthalmology, for additional discussion.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.