Pupillary constriction and ptosis following caudal epidural analgesia.

This study reports pupillary changes occurring in seventeen of twenty pregnant women at term who received caudal analgesia for the relief of pain in the first and second stages of labour. It is suggested that 10 ml or more of analgesic solution, injected into the sacral epidural space, reaches high enough (probably to T1) to cause meiosis and/or ptosis.