Agnes M F Wong1, Linda Colpa, Manokaraananthan Chandrakumar. 1. Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario M5G 1X8, Canada. agnes.wong@utoronto.ca
Abstract
OBJECTIVE: To determine the sensitivity and specificity of a new upright-supine test to differentiate skew deviation from trochlear nerve palsy and other causes of vertical strabismus in a large number of patients. METHODS: The study consisted of 125 consecutive patients who sought treatment from January 1, 2008, through December 31, 2010, for vertical strabismus of various causes: skew deviation (25 patients), trochlear nerve palsy (58 patients), restrictive causes (14 patients), and other causes (eg, myasthenia gravis and childhood strabismus) (28 patients). Twenty healthy participants served as controls. The deviation was measured by the prism and alternate cover test using a near target at ⅓ m in both the upright and supine positions. A vertical strabismus that decreased by 50% or more from the upright to supine position constituted a positive test result. RESULTS: The upright-supine test result was positive in 20 of 25 patients with skew deviation (sensitivity, 80%) but negative in all patients with trochlear nerve palsy, restrictive, or other causes (specificity, 100%). CONCLUSIONS: The upright-supine test is highly specific for differentiating skew deviation from other causes of vertical strabismus. This test could be added as a fourth step after the 3-step test, and if the result is positive, neuroimaging should be considered if indicated clinically.
OBJECTIVE: To determine the sensitivity and specificity of a new upright-supine test to differentiate skew deviation from trochlear nerve palsy and other causes of vertical strabismus in a large number of patients. METHODS: The study consisted of 125 consecutive patients who sought treatment from January 1, 2008, through December 31, 2010, for vertical strabismus of various causes: skew deviation (25 patients), trochlear nerve palsy (58 patients), restrictive causes (14 patients), and other causes (eg, myasthenia gravis and childhood strabismus) (28 patients). Twenty healthy participants served as controls. The deviation was measured by the prism and alternate cover test using a near target at ⅓ m in both the upright and supine positions. A vertical strabismus that decreased by 50% or more from the upright to supine position constituted a positive test result. RESULTS: The upright-supine test result was positive in 20 of 25 patients with skew deviation (sensitivity, 80%) but negative in all patients with trochlear nerve palsy, restrictive, or other causes (specificity, 100%). CONCLUSIONS: The upright-supine test is highly specific for differentiating skew deviation from other causes of vertical strabismus. This test could be added as a fourth step after the 3-step test, and if the result is positive, neuroimaging should be considered if indicated clinically.
Authors: Matthew Ryan Tan; Jorge Serrador; Jamie Perin; Yoav Gimmon; Jennifer Millar; Kelly Brewer; Dan Gold; Michael C Schubert Journal: J Assoc Res Otolaryngol Date: 2022-03-22
Authors: Michael C Schubert; Yoav Gimmon; Jennifer Millar; Kelly J Brewer; Dale Roberts; Mark Shelhamer; Charles Rohde; Jorge M Serrador Journal: PLoS One Date: 2018-12-26 Impact factor: 3.240