The antielevation syndrome may occur after there is anterior transposition (anteriorization) of the inferior oblique muscle.
Rationale for anterior transposition of the inferior oblique muscle:
(1) the normal insertion of the inferior oblique muscle results in elevation on muscle contraction
(2) overaction of the inferior oblique muscle can result in dissociative vertical deviation (DVD)
(3) moving the insertion of the inferior oblique muscle anterior to the equation converts action of the inferior oblique muscle from elevation to depression
The procedure may be unilateral or bilateral.
Pathophysiology for the antielevation syndrome: if the new position of the muscle is not quite right then it can interfere with elevation of the globe in abduction. Moving the insertion of the muscle may also cause overaction of the inferior oblique muscle of the contralateral eye (in adduction).
Clinical signs and symptoms:
(1) diplopia
(2) inability to elevated the eye in abduction
(3) correction by a targeted intervention (denervation of inferior oblique muscle, moving the inferior oblique muscle, inferior oblique myectomy, moving the superior rectus muscle)
Differential diagnosis:
(1) inferior oblique muscle adherence syndrome
Mims and Wood report that the syndrome may be avoided by attaching the posterior fibers of the inferior oblique muscle no more than 2 mm lateral to the inferior rectus muscle insertion site.
