Orbital muscles
arterial supply
ophthalmic artery
innervation
CN 3, SO4, LR6
- Superior rectus
- Medial rectus
- Inferior rectus
- Superior oblique
- Lateral rectus
- Inferior oblique
Blend into a common tendinous ring on the body of the sphenoid bone
This is the basis of "extraconal" regional anaesthesia
actions of extraocular muscles
| Muscle | Action | Palsy |
|---|---|---|
| Superior rectus | elevation, adduction, and internal rotation | |
| Medial rectus | Abduction of eyeball | |
| Inferior rectus | Adduction of eyeball | |
| Superior oblique | Elevation, abduction, lateral rotation | failure of intortion - "The patient may walk around with his or her head tilted away from the lesion – that is, to the opposite shoulder" |
| Lateral rectus | Depression, abduction, medial rotation | - convergent strabismus - diplopia - signs are maximal on looking to the affected side, and the images are horizontal and parallel to each other (LITFL) |
| Inferior oblique | Lateral rotation (extorsion), elevation |
NB - actions have now been checked with Grays