The Relationship of the Succinylcholine-Induced Ocular Position to the Postoperative Alignment: A Preliminary Report

Abstract

A video-data system was developed to record the response of the extraocular muscles to a 2 mg/kg intravenous bolus of succinylcholine, under anesthesia, pre and postsurgically. The ocular position was expressed in terms of an interlimbal distance in millimeters.

The first phase of the study addressed the ability of succinylcholine to reproduce the preoperative awake alignment under anesthesia, prior to the planned surgery. In 20 consecutive tropias, of varied etiology, the succinylcholine-induced ocular position agreed with the preoperative awake alignment in the range of 97+/-9.5% in 20 patients. The second phase of the study evaluated the ability of succinylcholine to predict the postoperative alignment at one week, when introduced postsurgically. A defined subgroup consisting of nonaccommodative esotropes, nonfibrotic or paralytic, with no history of cerebral palsy or hydrocephalus, were analyzed. The intraoperative, postsurgical succinylcholine-induced ocular position, agreed with the postoperative awake alignment at one week in the range of 106+/-2.56% in all ten patients. The average interlimbal distance was 36 mm, and, therefore, the standard deviation from the predicted position was 0.92 mm.

Further evaluation of the succinylcholine-induced ocular position postsurgically, within each subgroup of strabismus patients, may lead to an ability to predict the postoperative alignment intraoperatively.