Succinylcholine alteration of the forced duction test.

Prior to strabismus surgery, succinylcholine produces a sustained contraction of the extraocular muscles that interferes with an accurate interpretation of the forced duction test (FDT) for up to 20 minutes. Pancuronium, a nondepolarizing muscle relaxant, does not alter the FDT. Suggestions are given for management of anesthetic induction with or without muscle relaxants to facilitate intubation.