What Is the Inferior Rectus Muscle?

That is, the striated muscle originated below the total tendon ring and attached to the sclera at 6.5 mm behind the lower edge of the cornea. The muscle length is about 40 mm, the tendon length is 5.5 mm, the tendon width at the attachment is 9.8 mm, and the muscle width is 10 mm. This muscle extends forward and outward from the total tendon ring between the orbital floor and the eyeball, at an angle of 23 ° to the visual axis of the eyeball, over the inferior oblique muscle, and advances to the scleral surface 6.5 mm behind the limbus. It is innervated by the oculomotor nerve, and its inferior branch is 26 mm away from the muscle stop, which is the innervation point. When in the first eye position, the inferior rectus muscle travels at an angle of 23 ° to the visual axis. Its main actions are downturn, and its secondary actions are inward and external rotation. When it is 23 ° outward, only the main downward effect , The secondary effect disappears; when the line of sight is at an angle of 67 ° with the first eye position, the primary effect disappears, only inward and external rotation.

That is, the striated muscle originated below the total tendon ring and attached to the sclera at 6.5 mm behind the lower edge of the cornea. The muscle length is about 40 mm, the tendon length is 5.5 mm, the tendon width at the attachment is 9.8 mm, and the muscle width is 10 mm. This muscle extends forward and outward from the total tendon ring between the orbital floor and the eyeball, at an angle of 23 ° to the visual axis of the eyeball, over the inferior oblique muscle, and advances to the scleral surface 6.5 mm behind the limbus. It is innervated by the oculomotor nerve, and its inferior branch is 26 mm away from the muscle stop, which is the innervation point. When in the first eye position, the inferior rectus muscle travels at an angle of 23 ° to the visual axis. Its main actions are downturn, and its secondary actions are inward and external rotation. When it is 23 ° outward, only the main downward effect , The secondary effect disappears; when the line of sight is at an angle of 67 ° with the first eye position, the primary effect disappears, only inward and external rotation.

Chinese name

Lower rectus muscle

Foreign name

inferior rectus muscle

Inferior rectus clinically related diseases:

Inferior rectus unilateral congenital inferior rectus absent:

1. Clinical manifestations:

For patients with upslope, the number of upslopes can be greater than 45 °. As the age increases and the rectus muscle contractures, the upslope increases. Combined horizontal strabismus is more common in exotropia, which can manifest as exotropia A sign. Patients with high suspicion of this disease are feasible with CT or MRI. If the patient has concomitant congenital superior oblique insufficiency paralysis, the contralateral inferior oblique muscle is hyperactive, the original in-situ inclination number is not large, R / L30 , although the rectus muscle function in the right eye is found to be insufficient before surgery, but can pass the midline The reason may be related to the ectopic end of the inferior oblique muscle. The inferior oblique muscle is ectopic at 7:30. The inferior oblique muscle may play a part of the downward turning effect, and the inferior oblique muscle was found by the patient's preoperative eye movement examination. Hyperfunction, preoperative imaging examination was ignored. This disease needs to be distinguished from right eye double lower muscle paralysis and contralateral superior oblique hypertrophy, and the diagnosis requires intraoperative exploration.

2. Treatment method:

Surgery is a way to improve appearance and eye movement. Partial displacement of the medial and lateral rectus muscles can also be selected, as well as inferior oblique muscle transposition. The former can significantly improve the function of the inferior rectus muscle, but has the risk of causing anterior segment ischemia. If the inferior rectus abscess is accompanied by significant oblique oblique hyperplasia, the right inferior oblique is selected. The end of the inferior oblique muscle is shifted to the temporal attachment point of the inferior rectus muscle, so that the angle of inclination of the inferior oblique muscle from the first eye position to the visual axis 51 ° becomes 23 °, and the original external rotation and external rotation are weakened. , The upper muscle becomes the lower muscle. It strengthens the downward function of the eyeball. The inferior oblique muscle was used for transposition, and the postoperative appearance was satisfactory. Part of the downward function was restored. Although there was a small amount of upward strabismus, the downward function of the right eye was still insufficient.

Inferior rectus rupture:

1. Diagnosis:

For trauma, especially cuts and lacerations with eyelid and bulbar conjunctival wounds, special attention should be paid to checking the position of the eye and eye movements, and to timely detect any muscle rupture. When performing eyelid and conjunctival wound repair, the depth of the wound and the presence of muscle tissue should also be carefully examined in order to make a correct diagnosis and treatment.

2. Treatment:

Regardless of whether it is fresh or obsolete, the reduction of the inferior rectus should be preferred. After fresh rupture of the inferior rectus muscle is restored, eye movement improves immediately, but due to muscle strain, it is impossible to restore all its functions immediately. Therefore, a part of the vertical slope still remains. It should be noted that muscles cannot be easily removed. After a period of recovery after surgery, good results are often obtained. Old inferior rectus rupture, especially those with severe paralysis. Those who have a simple muscle reduction and still have a part of the vertical slope can be partially excised and then reset. If the effect is still not satisfactory, external rectus muscle transplantation is feasible. Those with mild and secondary superior rectus muscles who are obviously too strong can perform satisfactory surgery by performing supine rectus weakening.