This document provides information about the extraocular muscles. It describes the seven voluntary extraocular muscles - the four rectus muscles (superior, inferior, medial, lateral), and two oblique muscles (superior, inferior). It also describes the levator palpebrae superioris muscle. For each muscle, it details their origin, course, innervation, and actions. Clinical testing techniques for each muscle are also outlined. The summary focuses on identifying the seven voluntary extraocular muscles and briefly mentioning their attachments and functions.

1. Extraocular muscles
All the information, including the images and pics
collected from various sources is strictly for
teaching and helping the students in learning.
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Dr. G. RAVINDRANATH MBBS; MS
PROFESSOR OF ANATOMY,
NRI INSTITUTE OF MEDICAL SCIENCES

2. Learning objectives
1. Describe the attachments, nerve supply, actions of
muscles of the orbit
2. Explain the applied anatomy of muscles of the orbit
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3. Monocular eye movements- Ductions
• Monocular eye movements are called ductions
• Movement of the eyeball nasally/medially is adduction;
temporal/lateral movement is- abduction.
• Elevation of the eye is termed as sursumduction (supraduction)&
depression of the eye- deorsumduction (infraduction)
• Incycloduction(intorsion) is nasal rotation of the vertical meridian;
excycloduction (extorsion) - temporal rotation of the vertical
meridian.
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4. G R N 4

5. G R N 5

6. Binocular eye movements(BOM)
• Binocular eye movements are either conjugate
(versions) or disconjugate (vergences).
• conjugate movements (Versions)- are movements
of both eyes in the same direction(E.g. right gaze in
which both eyes move to the right- dextroversion and
levoversion is movement of both eyes to the left).
- Similarly sursumversion(supraversion) and
deorsumversion(infraversion) are elevation and
depression of both eyes, respectively.
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7. Conjugate binocular movements -
(versions)
1. Dextroversion / right gaze
2. Laevoversion / left gaze
3. Sursumversion / elevation / up gaze
4. Deorsumversion / depression / down gaze
5. Dextroelevation / gaze up and right
6. Dextrodepression / gaze down and right
7. Laevoelevation / gaze up and left
8. Laevodepression / gaze down and left
9. Dextrocycloversion – top of the eye rotates to the right
10. Laevocycloversion – top of the eye rotates to the left
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8. CONJUGATE BINOCULAR MOVEMENTS- VERSIONS
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9. DISCONJUGATE BINOCULAR MOVEMENTS
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10. ? ?
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11. Voluntary(skeletal) Muscles:7
1. Four Recti – Superior,
inferior, medial and lateral.
2. Two Oblique – Superior &
inferior.
3. Elevator of upper eyelid –
Levator palpebrae
superioris.
Involuntary(smooth) Muscles:3
1. Superior tarsal muscle –
Deeper part of levator
palpebrae superioris
2. Inferior tarsal muscle
3. Orbitalis muscle
Extra ocular Muscles
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12. VOLUNTARY EXTRAOCULAR MUSCLES
7 in number
These include:
• Four recti (superior,
inferior, medial and
lateral), and
• Two oblique
(superior and inferior)
muscles.
• Levator palpebrae
superioris (LPS) ,
LEFT EYE
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13. Diagram to show/remember the action of
individual extraocular muscles
irrespective of the right or left eye G R N 13

14. The four recti muscles
originate posteriorly from the
common tendinous ring(CTR)
The recti muscles(4)
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15. CTR encircles the superior,
medial and inferior margins of
the optic canal, but laterally
continues across the superior
orbital fissure, and includes
part of it within.
The tendinous ring is closely
adherent to the dural sheath of
the optic nerve medially and to
the surrounding periosteum.
Common tendinous ring(CTR)
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16. 1.Superior rectus
Origin- upper part of the common tendinous ring, immediately above the
optic canal and also from the dural sheath of the optic nerve.
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17. Superior rectus
The fibres pass forwards and laterally at
an angle of ~ 25° to the median plane of
the eye in the primary position to
insert into the upper part of the sclera,
approximately 8 mm from the limbus.
The insertion is slightly oblique, the
medial margin being more anterior.
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18. G R N 18

19. G R N 19

20. • Need to isolate the action
of each muscle
• For superior and inferior
recti you need to abduct
the eye first
• For superior and inferior
obliques you first adduct
the eye
Clinical examination of the
individual extraocular muscles
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21. Clinical testing of the superior rectus
Clinical Examination
Adduct
1st
Abduct
1st
Remember the
axis of the eye!
For checking SR or IR muscle, during
clinical examination You ask the patient
or individual to look laterally (abduct
the eye first) then ask to look up or
down. Only in abducted eye, the
muscle axis and optic/eye axis coincide. G R N 21

22. G R N 22

23. Muscles involved/responsible in conjugate binocular movements (Versions)
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24. 2.Inferior rectus
Arises from the common tendinous
ring, below the optic canal.
It runs along the orbital floor in a similar
direction to superior rectus (i.e., forwards
and laterally) and
inserts obliquely into the sclera ~ 6.5
mm from the limbus
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25. Inferior rectus
Innervation : by a
branch of the inferior
division of the
oculomotor nerve
which enters the
superior surface of
the muscle.
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26. Inferior rectus actions
In primary position
of eyeball
In adducted eyeball In abducted eyeball
(axis of the muscle
coincides with the
median axis of the eye
ball)
1. Adduction
2. Extorsion
3. Depression
Extorsion
( Excycloduction)
only!
Depression only!
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27. Clinical testing of the inferior rectus
Clinical Examination
Adduct
1st
Abduct
1st
Remember the
axis of the eye!
For checking SR or IR muscle, You
should ask to look laterally (abduct the
eye first) then to ask look up or down.
Only in abducted eye muscle axis and
optic axis coinside.
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28. G R N 28

29. 3.Medial rectus
• slightly shorter but strongest
of the group.
• It arises from the medial part
of the common tendinous
ring and passes forwards
along the medial wall of the
orbit, below superior oblique
.
• It inserts into the medial
surface of the sclera,
approximately 5.5 mm from
the limbus (slightly anterior
than other recti).
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30. Medial rectus
• Innervation: branch from
the inferior division of the
oculomotor nerve which
enters the lateral surface of
the muscle.
• Actions :moves the eye
so that it is directed
medially (adducted). The
two medial recti acting
together are responsible
for convergence of
eyes(part of near reflex)
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31. Medial rectus action- adducts the eye so that it is directed
medially/nasally.
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32. 4.Lateral rectus
Origin: from the lateral part
of the common tendinous
ring and bridges
the superior orbital fissure;
some fibres arise from a
spine on the greater wing of
the sphenoid.
The muscle passes
horizontally forward along
the lateral wall of the orbit to
insert into the lateral surface of
the sclera, approximately 7 mm
from the limbus
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33. Lateral rectus
Innervation: Abducens nerve(VI
CN) whose branches enter the
medial surface of the muscle.
Action- moves the eye ball
laterally (abduction).
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34. 5.Superior oblique
Fusiform in shape
Origin: from the body of the Sphenoid,
superomedial to the optic canal and
the tendinous attachment of the superior
rectus.
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35. Superior oblique
It passes forwards to end in a round
tendon which plays through a
fibrocartilaginous loop, the trochlea,
attached to the trochlear fossa of
the frontal bone .
Tendon and trochlea are separated
by a synovial sheath.
The tendon subsequently continues
posterolaterally and inferior to the
superior rectus, for attachment to
the sclera in the posterior part of
the superolateral quadrant(ppslq)
behind the equator, between the
superior and lateral recti.
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36. Superior oblique
Innervation :
trochlear nerve which
enters the superior
surface of the muscle.
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37. Superior oblique muscle Actions
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38. Superior oblique muscle Actions
In primary position
of eyeball
In adducted eyeball
(axis of the muscle coincides
with the median axis of the
eyeball)
In abducted
eyeball
1. Abduction
2. Depression
3. Intorsion
Depression only (when it
contracts, the back of the eyeball
is elevated, and the front of
the eyeball is depressed)
Intorsion
only
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39. Clinical testing of the Superior oblique
Clinical Examination
Adduct
1st
Abduct
1st
Remember the
axis of the eye!
For checking SO or IO muscle, during
clinical examination You should ask to
look medially (adduct the eye first)
then to ask look down or up. Only in
adducted eye, the muscle axis and optic
axis coinside. G R N 39

40. G R N 40

41. 6.Inferior oblique
Thin , narrow muscle that lies
near the anterior margin of the
floor of the orbit.
It arises from the orbital surface
of the maxilla(floor of the orbit)
lateral to the nasolacrimal fossa
and
ascends posterolaterally, at first
inferior to the inferior rectus (i.e
between it and the orbital floor)
and then between the eyeball
and lateral rectus.
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42. Inferior oblique
Insertion: into the sclera
behind the equator to the
posterior part of the inferolateral
quadrant(ppilq) between the
inferior and lateral recti.
In contrast to the other
extraocular muscles its
tendon is barely discernible at
its scleral attachment.
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43. Inferior oblique
Innervation : branch of the
inferior division of the
oculomotor nerve which
enters the orbital surface of
the muscle.
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44. Inferior oblique muscle Actions
In primary position
of eyeball
In adducted eyeball
(axis of the muscle coincides
with the median axis of the
eyeball)
In abducted
eyeball
Abduction
Elevation
Extorsion
Elevation
Only(when it contracts, the back
of the eyeball is depressed, and
the front of the eyeball is
elevated).
Extorsion only
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45. Clinical testing of the Inferior oblique
Clinical Examination
Adduct
1st
Abduct
1st
Remember the
axis of the eye!
For checking SO or IO muscle, during
clinical examination You should ask to
look medially (adduct the eye first)
then to ask look down(SO) or up(IO).
Only in adducted eye, the muscle axis
and optic axis coinside. G R N 45

46. Extra ocular muscles insertion: into the sclera
Recti – In front of equator; distance from cornea –
SR = 7.5mm, LR = 7 mm IR = 6.5mm; MR = 5.5mm,.
Superior Oblique – Behind the equator in superolateral posterior
quadrant, between the recti superior and lateralis.
Inferior Oblique: - Behind the equator in inferolateral posterior
quadrant, between the recti superior and lateralis.
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47. 7.LEVATOR PALPEBRAE SUPERIORIS
Thin , triangular muscle which arises by a short narrow tendon from the inferior
aspect of the lesser wing of the sphenoid, above the optic canal(OC), and
separated from OC by the attachment of superior rectus.
The muscle broadens as it passes anteriorly above the eyeball and splits in two
laminae, ending in a wide aponeurosis.
The Superior lamina consisting of skeletal muscle (voluntary) passes straight into
the upper eyelid and some fibres of it attach to the anterior surface of the tarsus,
and the rest pierce the orbicularis Oculi for insertion to the skin of the upper eyelid.
A thin Inferior lamina of smooth (involuntary) muscle -superior tarsal or Muller’s
muscle , lying the underside of the superior lamina of LPS runs to upper/superior
margin of superior tarsal plate & superior conjunctival fornix.
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49. LEVATOR PALPEBRAE SUPERIORIS
Actions:
Elevation of the upper eyelid. During this process the lateral and
medial parts of its aponeurosis are stretched and thus limit its action.
Elevation is opposed by the palpebral part of orbicularis oculi.
The upper eyelid also elevates whenever the gaze of the eye is
directed upwards as Levator palpebrae superioris is linked to superior
rectus by a check ligament.
In states of fear or excitement widening of the palpebral apertures
seen due to contraction of the smooth muscle of the superior and
inferior tarsal muscles as a result of increased sympathetic activity.
Lesions of the sympathetic supply result in drooping of the upper eyelid
(ptosis), as seen in Horner's syndrome.
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50. LEVATOR PALPEBRAE SUPERIORIS
The connective tissue sheaths of the adjoining surfaces of levator
palpebrae superioris and superior rectus are fused.
Where the two muscles separate to reach their anterior attachments,
the fascia between them forms a thick mass to which the superior
conjunctival fornix is attached( usually described as an additional
attachment of LPS).
Traced laterally, the aponeurosis of the levator passes between the
orbital and palpebral parts of the lacrimal gland to attach to the orbital
tubercle of the zygomatic bone(Whitnall’s tubercle).
Traced medially, it loses its tendinous nature as it passes closely over
the reflected tendon of superior oblique, and continues on to the medial
palpebral ligament as loose strands of connective tissue.
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51. G R N 51

52. LEVATOR PALPEBRAE SUPERIORIS
Innervation : branch of the superior
division of the oculomotor nerve
which enters the inferior surface of the
muscle.
The smooth muscle component of LPS
(superior tarsal muscle/Muller’s
muscle) innervated by sympathetic
fibres derived from the plexus
surrounding the internal carotid artery;
these nerve fibres join the oculomotor
nerve in the cavernous sinus and pass
forward in its superior branch.
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53. • Causes: interruption of sympathetic pathway in multiple sclerosis,
syringomyelia, traction of stellate ganglion by cervical rib, Pancoast’s tumor and
ganglion metastatic lesions.
• Signs: are ipsilateral
• Constriction of pupil (miosis) due to paralysis of dilator pupillae
• Slight drooping of eyelid (ptosis) due to paralysis of Muller’s muscle (Part
of Levator palpebrae superioris)
• Enophthalmos (Retraction of eyeball) due to paralysis of Orbitalis muscle
which support the eyeball
• Loss of sweating (anhydrosis) damage of sympathetic fibers to sweat
glands
• Loss of ciliospinal reflex
Horner’s syndrome
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54. Horner's syndrome-Which side?
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55. Bringing the binocular conjugate movements or
versions
• Yoke muscles are the primary
muscles in each eye that
accomplish a given version
(eg, for right gaze, the right
lateral rectus and left medial
rectus muscles).
• Each extraocular muscle has a
yoke muscle in the opposite
eye to accomplish versions
into each gaze position. By the
Herring law, yoke muscles
receive equal and
simultaneous innervation.
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56. Extraocular muscles
involved in various
binocular movements
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57. Few clinical Terms
1. Exotropia: eye deviated outward
2. Esotropia: eye deviated inward
3. Exophthalmos: eye bulging outward
4. Enophthalmos: relative recession (backward or downward
displacement) of the eye into the bony orbit.
5. Ptosis: dropping of the eyelid
6. Miosis: constriction of the pupils
7. Mydriasis: dilitation of the pupils
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58. Exotropia Esotropia Exophthalmos
Enophthalmos Miosis
ptosis
Mydriasis
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59. STRABISMUS(Squint)
Why?
• Muscle weakness
CN (III,IV or VI) palsies
• Poor vision in one eye
• Eye physically stuck
Post-traumatic
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60. Long way to go!
THANK YOU
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