Rectus displacement

When the contractility of an extraocular muscle is completely lost, general strengthening techniques, such as amputation, advancing, or folding, cannot restore the muscle's rotational force. Hummelshein (1970) designed a surgical method to transfer part of the functions of the superior and inferior rectus muscles to the external rectus muscle for the treatment of the iliac cranial nerve anesthesia. Since then, there have been many improved methods, but the basic principle remains the same, that is, when the zygomatic cranial nerve is paralyzed, part of the function of the superior and inferior rectus muscle is transferred to the external rectus muscle; The upper and lower rectus muscles (normally functioning) are transferred to the medial rectus muscle. Similarly, in the case of paralysis of the double upper or lower inferior muscles, the horizontal muscle is shifted. It is emphasized that there may be mechanical traction at the same time when one or more extraocular muscles are paralyzed. This traction must be confirmed by a traction test before surgery and released after the operation. Otherwise, muscle displacement cannot improve the eyeball. motion.