Electromyographic Study of the Optomotor Effect in Exotropia Under General Anesthesia

Abstract

In cases of exotropia, prolonged administration of prifinium bromide caused firing from both lateral recti under general anesthesia. This firing disappeared in two to three minutes when the room was kept completely dark. When one eye was spot-lighted after the period of darkness, firing re-appeared from the contralateral lateral rectus. This reaction was strictly limited to the contralateral eye and the lag time until firing re-appeared was considerably shorter when the master eye was spot-lighted than when the slave eye was spot-lighted. The firing of both lateral recti disappeared when retrobulbar anesthesia was applied to the master eye. It is supposed that firing from the lateral recti of cases of exotropia under general anesthesia after treatment with prifinium is the result of interaction between the proprioceptive afferent and visual inputs, the former being the signal and the latter facilitating transmission of this signal.

Key Words:

• electromyography
• optomotor effect
• proprioception
• exotropia
• general anesthesia
• retrobulbar anesthesia