How does superior and inferior oblique move the eye?
The two obliques prevent the eye from rotating about its long axis (retina to pupil) when the superior and inferior rectus muscles contract. For this reason, these two rectus muscles work in conjunction with the two obliques. When acting alone, superior oblique causes intorsion, inferior oblique, extorsion.
What does the superior oblique of the eye do?
These muscles are unique in that they do not originate from the common tendinous ring, have an angular attachment to the eyeball, and they attach to the posterior aspect of the eyeball. The superior oblique functions explicitly to move the eye in the down-and-out position and intort the eye.
What way does the superior oblique move the eye?
When the eyeball is in a neutral position, superior oblique is responsible for abduction (directed laterally from the nose), depression (inferiorly) and internal rotation (movement of the superior pole of the eye medially) of the eyeball.
How does the inferior oblique move the eye?
Due to its oblique course and attachment on the posterolateral side of the eyeball, contraction of the inferior oblique muscle pulls the eyeball in a direction posterior to its vertical axis, and therefore rotates the eye laterally around this axis.
What movement does the inferior oblique do?
[2] The inferior oblique is responsible for extorsion, elevation, and abduction. Because of their course, the superior and inferior oblique muscles are the only muscles that can depress or elevate the eye, respectively when the eye moves in adduction.
What is the action of the inferior oblique?
The inferior oblique muscle externally rotates, elevates, and abducts the eye.
Where does the inferior oblique insert?
At the orbital groove, the muscle is described in terms of its anterior and posterior border. The inferior oblique tendon inserts in the sclera, under the lateral rectus. The anterior border is about 10mm from the lateral rectus insertion point, and its posterior border is 1 to 2 mm in front of the macula.
What causes superior oblique Myokymia?
Superior oblique myokymia is an unusual eye movement disorder where an eye muscle, the superior oblique, twitches periodically causing jumping of a single eye (Thurston and Saul 1991). It is probably caused by blood vessel compression of the trochlear (4th) nerve, at the root entry zone.
Can Brown syndrome cured?
Brown syndrome due to other conditions is more likely to go away without surgery. Treating the underlying health condition may help reduce symptoms. For example, someone with Brown syndrome due to lupus might find it helpful to be treated with corticosteroids.