What is inferior oblique Overaction?
What is inferior oblique Overaction?
1. Introduction. Inferior oblique muscle overaction (IOOA) manifests by overelevation of the eye in adduction and is frequently associated with horizontal deviations. It is reported in 70% of patients with esotropia and 30% of patients with exotropia. There are two types of IOOA: primary and secondary.
What does the inferior oblique muscle of the eye do?
The inferior oblique muscle externally rotates, elevates, and abducts the eye.
How do you test for inferior oblique?
To test superior rectus from the inferior oblique, the clinician asks the patient to first look out (or lateral) to orient the visual gaze axis perpendicular to the inferior oblique muscle fiber direction, then up. After the inferior oblique is trapped, the only muscle that can mediate elevation is the superior rectus.
What is inferior oblique Anteriorization?
A recognized risk of anteriorization of the inferior oblique muscle is the potential for postoperative limitation of elevation during abduction, resulting in an apparent inferior oblique overaction in the contralateral eye, often accompanied with Y-pattern exodeviation, or AES.
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 causes a pattern esotropia?
Oblique muscle dysfunction The tertiary abduction effect of the superior oblique muscle is believed to produce the A-pattern. The abducting force is greatest in downgaze, the superior oblique’s primary field of action, causing an increased relative divergence of the eyes in downgaze.
What is the action of the inferior rectus?
The inferior rectus has a primary action of depressing the eye, causing the cornea and pupil to move inferiorly. The inferior rectus originates from the Annulus of Zinn and courses anteriorly and laterally along the orbital floor, making an angle of 23 degrees with the visual axis.
Where is the inferior oblique muscle located?
anterior orbit
The inferior oblique is the only extraocular muscle to have its anatomic origin in the anterior orbit. The muscle runs from the medial corner of the orbit to the lateral aspect of the globe, its length approximately paralleling the tendon of insertion of the superior oblique muscle.
What is oblique muscle?
The oblique muscles consist of external oblique muscle and internal oblique muscle. The oblique muscles consist of external oblique muscle and internal oblique muscle. They are a group of muscles of the abdomen (belly) acting together forming a firm wall.
Which way does the inferior rectus move the eye?
downward
The inferior rectus is an extraocular muscle that attaches to the bottom of the eye. It moves the eye downward. The medial rectus is an extraocular muscle that attaches to the side of the eye near the nose. It moves the eye inward toward the nose.
What are the signs of primary inferior oblique overaction?
Primary inferior oblique overaction is usually bilateral; however, it can be very asymmetric. Clinical signs of primary inferior oblique overaction include an upshoot of the adducting eye on versions, a V-pattern, and extorsion on indirect ophthalmoscopy. If the overaction is symmetric, there will be no significant hypertropia in primary position.
Is there hypertropia in primary oblique muscle overaction?
If the overaction is symmetric, there will be no significant hypertropia in primary position. Children with primary inferior oblique overaction do not experience subjective extorsion because they have learned to sensorially adapt at a young age.
What does possible inferior infarct, age undetermined mean on an EKG?
What Does “possible Inferior Infarct, Age Undetermined” Mean on an EKG? An EKG/ECG that finds dead tissue of undetermined age in the inferior heart wall is called an “inferior infarct, age undetermined.”
What are the criteria for an inferior infarct?
The criteria for inferior infarct are Q waves in the inferior leads of 0.04 sec. or greater. But the computer algorithm accepts any size Q wave. Small q waves are often present normally; so “inferior infarcts” are over diagnosed. If the EKG is read by a trained cardiologist, a more accurate reading is likely.