What is superior oblique Overaction?
Definition. An ocular motility abnormality characterized by an overacting superior oblique muscle resulting to vertical incomitance of the eyes in lateral gaze.
What is the main action of the superior rectus muscle?
The superior rectus has a primary action of elevating the eye, causing the cornea to move superiorly. The superior rectus originates from the annulus of Zinn and courses anteriorly and superiorly over the globe, making an angle of 23 degrees with the visual axis.
What Innervates the superior rectus muscle?
The superior rectus is innervated by the superior division of the oculomotor nerve, which enters the muscle on its inferior face. Branches pass either through the muscle or around it to innervate the levator.
What causes inferior rectus palsy?
Isolated inferior rectus (IR) muscle palsy may occur after orbital trauma. Various mechanisms have been proposed, including muscle contusion, longitudinal splitting of the muscle, transection or destruction of the muscle, posterior muscle slippage within its sheath, and nerve injury (damage to the oculomotor nerve).
Where is the superior rectus muscle?
eye
Superior rectus is one of the extrinsic muscles of the eye. Being located outside the eyeball but within the orbit, it belongs to a group called the extraocular muscles. This group of muscles serves to move the eyes within the orbit.
What is V pattern exotropia?
V-pattern exotropia is a form of strabismus in which the exodeviation is larger in upgaze than in downgaze. 1-5 Although the pathophysiology of V-pattern exotropia is not certain, it is generally attributed to overaction of the inferior oblique muscles.
What direction does the superior rectus move the eye?
upward
The superior rectus is an extraocular muscle that attaches to the top of the eye. It moves the eye upward. The inferior rectus is an extraocular muscle that attaches to the bottom of the eye. It moves the eye downward.
What is the insertion of the superior rectus?
Superior rectus muscle
| Origin | Common tendinous ring (Annulus of Zinn) |
|---|---|
| Insertion | Anterior half of eyeball (posterior to corneoscleral junction) |
| Action | Elevates, adducts, internally rotates eyeball |
| Innervation | Oculomotor nerve (CN III) |
| Blood supply | Ophthalmic artery, supraorbital branch of ophthalmic artery |
Does the superior rectus adduct or abduct?
Function. The superior rectus muscle elevates, adducts, and helps intort (rotate medially) the eye.
What is Intorsion and extorsion of eye?
Incycloduction (intorsion) is nasal rotation of the vertical meridian; excycloduction (extorsion) is temporal rotation of the vertical meridian.
What is the function of the superior rectus?
Respectively, the recti muscles insert onto the superior, inferior, medial and lateral sides of the eyeball. Based on their global attachments, these muscles serve to move the eyes in the four cardinal directions, with superior rectus producing elevation, adduction and internal rotation of the eyeball.
Where does the superior rectus muscle parallel the orbit?
The superior rectus muscle parallels the roof of the orbit until it passes through a connective tissue pulley just posterior to the equator of the globe; at this point it follows the curve of the globe to its insertion. 34,35
What are the different types of recti muscles?
It includes the superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique and inferior oblique muscles. Notice how these muscles can be divided into four recti and two oblique muscles. The four recti muscles all arise from a connective tissue ring called the common tendinous ring (annulus of Zin).
Where are the recti muscles located in the eye?
This is located at the apex of orbit, surrounding the optic canal. Respectively, the recti muscles insert onto the superior, inferior, medial and lateral sides of the eyeball.
