muscles of eye

1. Extra ocular muscles &
ophthalmic artery

3. Orbit
• Made by 7 Bones
• Frontal
• Lacrimal
• Ethmoidal
• Sphenoid
• Zygomatic
• Maxillary
• Palatine

4. Superior orbital fissure
• Retort shaped
• Between posterior part of lateral wall
& roof
• Connects
• Orbit with middle cranial fossa
• Boundaries
• Superior – lesser wing of sphenoid
• Inferior – greater wing of sphenoid
• Medial – body of sphenoid

5. Compartments of superior
orbital fissure
• Divided into 3 compartments
by
• Common tendinous ring
• Lies at apex of orbit
• Enclosing optic foramen &
middle part of superior orbital
fissure
• Attachment
• Medially to apex of orbit
• Laterally to tubercle on lower
border of superior orbital
fissure
• Superolateral
• Intermediate
• Inferomedial

6. Extraocular muscles
• 4 Recti
• Superior rectus (SR)
• Inferior Rectus (IR)
• Medial rectus (MR)
• Lateral Rectus (LR)
• 2 Obliques
• Superior Oblique(SO)
• Inferior oblique (IO)

7. Levator palpebrae superioris
• Origin
• Roof of orbit in front of optic
canal
• In undersurface of lesser wing
above common tendinous ring
• Insertion
• By 3 lamella
• Upper – skin of upper eyelid
• Middle – upper tarsal plate
• Lower – superior fornix

8. • Action
• Elevation of upper eyelid
• Nerve supply
• Oculomotor
• Paralysis
• Ptosis (Drooping of eyelid)

9. Superior oblique
• O: Body of sphenoid
• Tendon passes through
trochlea
• I: Sclera behind equator of
eyeball
• Between superior & lateral
recti

10. Superior oblique
A: Directs cornea downwards and
laterally
N.S.: Trochlear n.

11. Trochlear nerve palsy
• Affected eye rotated up and in
• To compensate
• Patient tilts head to the contralateral side.

12. Inferior oblique
• Origin
• Orbital surfaceof maxilla
• Passes backward and
laterally
• Below inferior rectus
• Insertion
• Behind equator parallel
to superior oblique
• Postero‐superior
quadrant
• Action
• Extorsion

13. Recti muscles
• Common Origin
• Common tendinous ring
• Insertion
• Into sclera
• Infront of equator of eyeball
• Posterior to limbus
• MR – 5 mm
• IR – 6 mm
• LR – 7 mm
• SR – 8 mm
• Spiral line of Tillaux

14. Eye movements

15. Eye movements
• No movement is done by a single muscle

16. Eye movements
And the RULEis…..(for recti andoblique)
Any muscleinserting
Medial to vertical axis –
Adduction
Lateral to vertical axis -
Abduction
Superior to A-Paxis -
Intorsion
Inferior to A-Paxis –
Extorsion
Formuscleinserting in front of equator i.e
RECTI abovetransverse axis – Elevation
below transverse axis -Depression

17. Nerve supply
• All muscles are supplied by
Oculomotor nerve
• Except lateral rectus and
superior oblique
• Lateral rectus is innervated by
Abducent nerve
• Superior oblique is innervated
by Trochlear nerve

18. Extraocular muscle palsy
• Injury to III, IV, VI cranial nerve
• Unilateral paralysis produces
• Strabismus /Squint, Diplopia
• Abducent palsy
• Internal squint the right eye unable to
abduct
• External squint-
• Medial rectus paralysis
• Right eye unable to adduct
• Trochlear nerve palsy
• Eyeball turned upwards and inwards

19. Opthalmic artery
• Arises from internal carotid
• On medial side of anterior clinoid
process

20. • Course
• Passes forward through optic canal
• Inferolateral to optic nerve
• In the orbit
• Crosses above optic nerve
• Obliquely from lateral to medial
accompanied by nasocilliary nerve
• Passes between
• Superior oblique & medial rectus
• Reaches medial end of upper eyelid
• Terminates by dividing into
• Supratrochlear
• Dorsal nasal

21. • Central artery of retina
• Supplies optic nerve & retina
• Long & short ciliary arteries
• Pierce sclera to supply eyeball
• Lacrimal
• Lacrimal gland & palpebra

22. • Supraorbital
• Passes through supraorbital foramen
• Supplies forehead & scalp
• Posterior ethmoidal
• Passes through posterior ethmoidal
foramen
• Supplies posterior ethmoidal air cells
• Anterior ethmoidal
• Passes through anterior ethmoidal
foramen
• Supplies anterior & middle ethmoidal air
cells, frontal sinus & nasal cavity & external
nose