:)

1. ANATOMY
AND
PHYSIOLOGY
OF EYELID
Dr. Najara Thapa
1st year Resident
LEI, NAMS

2. OBJECTIVES
• To know the process of development of lid
structures and the associated developmental
defects.
• To understand the anatomical features and related
clinical aspects of eyelid.
• To have the overview of the physiological aspect of
lid structures.

3. CONTENTS
Introduction
Embryology
Gross Anatomy
Structure
Glands of Eyelids
Vessels and Nerve supply
Physiology of Eyelid movements

4. Introduction
• The eyelids are the mobile tissue in front of the
eyeballs. (ocular appendages)
• Upper and lower eyelid
Functions:
Act as shutters protecting eyes from injuries and
excessive light
Spread the tear film over the cornea and conjunctiva
Contribute to the facial feature
Information regarding the state of wakefulness and attention

5. EMBRYOLOGY OF EYELID
 Develops from folds of surface ectoderm above and below
the developing cornea.
• The folds enlarge and fuse with each other by 3rd month
• A closed space, conjunctival sac is formed in front of the
cornea
• The lid separation starts by 5th month and completes by
7th month of intrauterine life

6. 7th week
8th week
5-7th month

7.  Connective tissue and tarsal plate : from mesenchymal
core.
 Orbicularis oculi muscle:
From mesenchyme of 2nd
Pharyngeal arch.
(12wks)

8.  Eyelashes develop as epithelial buds from surface
ectoderm. [ 1st arise in upper lid]
 Glands of Moll and Zeis : from ciliary follicles.
 Meibomian glands : from columns of ectodermal cells in
lid margin.

9. Gross Anatomy
• Extent
• Position of eyelids
• Parts of eyelids
• Canthi
• Eyelids Margin
• Eyelashes
• Palpebral Aperture

10. Extent:
Upper lid: eyebrows to the free margin
Lower lid: merges to skin of the cheek below
Position of the eyelids:
Upper lid covers about
1/6th of the cornea (1.5-2
mm below superior
corneal limbus)
Lower lid margin just
touches the cornea

11. Parts of eyelids:
Orbital part
horizontal sulcus(or forrow).
Tarsal part
• Additional folds in
lower lid- nasojugal
fold medially and the
malar fold laterally.
These folds limit the spread
of blood downward from
eyelids to cheek.

12. Canthi (sing. canthus)
• The upper and lower lids meet at an angle of about 60˚
medially and laterally forming canthus.
• lateral canthus: 5-7 mm medial to the orbit

13. • Medial canthus: separated from globe by lacus
lacrimalis.
In the center is small pinkish elevation – caruncula
lacrimalis.
Lateral to it is semilunar fold called plica
semilunaris.
Racial variation- Mongoloid slant and antimongoloid
slant

14. Eyelid Margin:
• 2 mm wide
• Covered by cutaneous epithelium
• Lacrimal papillae (at the center of which is lacrimal
punctum) divides the margin into medial 1/6th and lateral
5/6th part

15. Eyelid margin contd..
Lacrimal part: medial to punctum
rounded
devoid of lashes and glands
contains lacrimal canaliculi
 Ciliary part: lateral to punctum
rounded anterior and sharp posterior border

16. Grey line:
Represents the line of demarcation
between the anterior portion of the
eyelid formed by the skin and
orbicularis muscle (ant. lamina) and
the posterior formed by the tarsus and
conjunctiva (post lamina).
Histologically corresponds to most
superficial portion of orbicularis
oculi , muscle of Riolan , and to the
avascular plane of lid.
Surgically Important: For splitting of
eyelid with minimal scarring.

17. Palpebral fissure or aperture
• Space between upper and
lower eyelid margin
Birth (mm) Adult (mm)
horizontal 18-21 28-30
vertical 8 9-11

18. Eyelashes:
2-3 rows
Upper lid: 100-150 (forward,
upward and backward)
Lower lid 50-75 (forward,
downward and backward)
Lifespan: 3-4 months

19. • Trichiasis: Acquired misdirection
of eyelashes
• Pseudotrichiasis: Seen in
entropion
• Madarosis: Decrease in number
of eyelashes.
• Lash Poliosis: Premature graying
of the lashes
• Trichomegaly: Excessive eyelash
growth

20. CONGENITAL /DEVELOPMENTAL
ANOMALIES
• Coloboma of lid: notch
in the edge of eyelid
Cryptophthalmos: partial
or complete loss of
brows, palpebral
fissure, lashes,
conjuctiva

21. • Ectropion: eversion of
eyelid margin
Entropion: eyelid margin
inversion

22. • Euryblepharon: vertical
shortening and
horizontal lengthening
of eyelids.
• Epiblepharon: lower lid
pretarsal muscle and
skin ride above the
lower lid margin to form
a horizontal fold of
tissue

23. • Ankyloblepharon:
partial or complete
fusion of eyelids by
webs of skin.
Symblepharon: adhesion
of lid to the gobe.

24. • Distichiasis : extra rows
of eyelashes
• Epicanthus: medial
canthal fold

25. Blepherophimosis: condition in which palpebral fissure
appear to be smaller.
Ptosis : drooping of upper lid.

26. LAYERS OF EYELIDS
Skin and subcutaneous tissue
Muscles of protraction
Orbital septum
Orbital fat
Muscles of retraction
Tarsus
Conjunctiva

28. Skin
• Thinnest in the body
• contains the usual adnexal structures: fine hairs,
sebaceous & sweat glands
• Microscopically epidermis and dermis

29. Subcutaneous Tissue
Loose connective tissue arrangement
Rich in elastic fibres
No fat
Applied anatomy - fluid from oedema or haemorrhage
rapidly engorges the loose subcutaneous eyelid tissue.

30. Protractors
ORBICULARIS OCULI
Striated muscle,
concentrically arranged
Divided anatomically into 2
contiguous parts –
Orbital
Palpebral

31. Orbicularis oculi
Origin Insertion
Orbital part Anterior limb of medial canthal
tendon
Orbital process of frontal bone.
Frontal process of maxillary
bone infront of anterior lacrimal
crest
Forms continuous
eclipse and inserts just
below the point of
origin.
Pretarsal part Deep origin : medially posterior
lacrimal crest (forms Horners
muscle.)
Superficial origin : anterior limb
of medial canthal tendon
Lateral canthal tendon
Preseptal part Upper and lower border of medial
canthal tendon
Lateral palpebral raphe

32. Palpebral portion
 Pretarsal part
Preseptal part
Functions for both involuntary and voluntary eyelid
movements (blink).
Deep heads of pretarsal orbicularis muscle fuse to form a
prominent bundle of fibres, near the common canaliculus
known as Horner muscle
Play a role in drainage of tears (pumping mechanism).

33. Orbital portion
Primarily involved in forced eyelid
closure
Orbicularis fiber extends to lid margin
, where there is a small bundle of
straited muscle called muscle of
Riolan. (forms gray line, play role in
meiomian gland discharge, blinking
and position of eyelashes).

34. Nerve supply :
 Temporal and zygomatic branch of facial nerve.
APPLIED :
Paralysis of the orbicularis oculi muscle leads to :
Lagopthalmous - inadequate closure of lids.

35. Orbital Septum
• thin, fibrous framework,
membranous sheet
• begins anatomically at the
arcus marginalis along the
orbital rim
• Separates the eyelid from
the contents of orbital cavity

36. Perforated by:
Nerves and vessels that exit form the orbital cavity
Aponeurosis of levator muscle in upper lid
Expansion of the inferior rectus in the lower lid

37. Functions:
Holds the orbital fat in position
Barrier function- prevent the transmission of infection
from lids to orbital cavity and viceversa
During the normal ageing process the thining of the
septum and the laxity of the orbicularis muscle causes
the anterior herniation of the orbital fat.

38. Orbital Fat
• Upper lid : 2 fat pockets
• Lower lid : 3 fat pockets
• Landmark for elective eyelid surgery and lid
laceration surgery

39. Retractors
• Upper lid: Levator palpebrae superioris along with
Mullers muscle
• Lower lid: Capsulopalpebral fascia

40. Levator Palpebrae Superioris
Origin: apex of the orbit, just above the annulus of
Zinn.
Extends as aponeurosis, in upper lid posterior to
orbital septum and inserts into anterior surface of
tarsus.
Muscle = 40mm, Aponeurosis = 14-20mm.
Medial and lateral expansion of aponeurosis forms
horns.
Thin sheet of smooth muscle arise from its inferior
surface – superior tarsal muscle / Muller muscle.

41. Insertion :
Lateral horn: lateral orbital tubercle.
Medial horn : posterior lacrimal crest.
In center, aponeurosis continues towards the tarsus
and divides into an anterior and posterior portion.
(Anterior portion inserts into septa between pretarsal
orbicularis and skin – forming upper lid crease.)

42. Whitnall’s ligament (superior transverse
ligament)
• Sleeve of elastic fibers around the LPS muscle
located in the area of transition from levator muscle
to levator aponeurosis.
Functions of whitnall’s ligament:
• Primarily as a suspensory support for the upper
eyelid and the superior orbital tissues.
• Also act as a fulcrum for the levator

43. Muller muscle :
• Originates from under-surface of LPS aponeurosis
approx. at the level of Whitnall ligament.
• 12-14mm
• Inserts in superior tarsal margin of upper eyelid.
• Provides 2mm elevation of upper eye lid.

44.  Action of LPS: raises upper lid
 Nerve supply :
LPS : superior branch of oculomotor
Superior tarsal : sympathetic nerves from cervical
ganglion
APPLIED:
• Fear and excitement causes contraction of superior
tarsal leading to further elevation of eyelid.

45. Applied anatomy
• Disinsertion of lower lid retractors from
tarsus may lead to spastic entropion.
• Paralysis of LPS [ 3rd nerve palsy,
myasthenia]:
 Ptosis
Loss of superior palpebral fold and
Horizontal furrows

46. contd…
• Paralysis of superior tarsal muscle [ lesion of
cervical sympathetic ganglion]:
Mild ptosis
When associated with miosis , anhydrosis –
Horner’s syndrome.

47. RETRACTORS OF LOWER
EYELID
• Capsulopalpebral fascia :
• Originates from terminal
muscle fiber of inferior
rectus muscle.
• Forms lockwood
ligament.

48. Tarsal plate:
Dense fibrous tissue.
Gives shape and firmness
to eyelid.
In upper lid – larger
-- crescentic
--11mm in center
--Orbital septum and smooth muscle
fiber of LPS attached to its upper edge.

49. In lower lid –smaller
--4mm at centre
--Orbital septum
attached to its lower edge.
Medially , MPL attaches it to
lacrimal crest and frontal
process of maxilla.
Laterally , LPL attaches it to
marginal tubercle on orbital
margin formed by zygomatic
bone.

50. Conjunctiva
Thin mucous membrane lining the eyelids(posterior
layer of lids).
Composed of non keratinizing squamous epithelium
• Contains - 1. goblet cells
2. accessary lacrimal glands ( Wolfring
and Krause )
At the margin of eyelid – continues into skin along
posterior margin of tarsal gland.

51. Subtarsal sulcus : shallow
groove on the back of the
lid, 2mm from posterior
edge of lid margin.
• APPLIED : site for FB impaction.

52. GLANDS
1. Tarsal or meibomian
glands
2. Ciliary glands of Moll
3. Sebaceous glands of
Zeis

53. Tarsal ( meibomian ) gland
 modified holocrine sebaceous glands.
 lies within the tarsal plates; single row
 Upper eyelid (30-40); Lower eyelid (20-
30).
 Vertically parallel to each other.
The orifice lies just infront of the posterior
edge of the lid margin---marks the junction
between the skin and conjunctiva.

54. Applied anatomy:
a)Meibomian gland dysfunction: dry eye.
b)Chalazion or tarsal cyst:
-chronic non infectious inflammatory
granuloma of meibomian gland.
c)Internal hordeolum:
-suppurative inflammation of meibomian gland
secondary to infection of chalazion

55. Glands of moll
 modified sweat glands
lie in the lid margin between the cilia.
more numerous in lower lid.
the duct opens between cilia
into ciliary follicles or into the
glands of Zeis.

56. Gland of zeis
 modified sebaceous gland.
 Consists 2-3 lobules.
 discharge directly into the eyelash follicles.
 Its secretion (sebum) prevents the lashes from becoming
dry and brittle.
Applied anatomy:
 External hordeolum / Stye:
Suppurative inflammation of Zeis gland
or lash follicle.

57. Accessory glands of wolfring
Present along upper border of superior tarsus
and lower border of inferior tarsus.
2-5 in upper lid
2-3 in lower lid

58. FASCIAL SPACES
1. Subcutaneous space
2. Submuscular space
3. Pretarsal space
4. Preseptal space

59. BLOOD SUPPLY
1. Internal carotid artery:
By ophthalmic artery and its branches (supraorbital and
lacrimal)
2. External carotid artery:
By arteries of the face (angular and temporal)

60. • LATERAL PALPREBRL ARTERY (branch of
lacrimal artery)
• MEDIAL PALPREBRAL ARTERY (direct branch of
ophthalmic artery)
• Each artery divides into 2 branch --- forming 2
arches in upper eyelid:
• Peripheral arterial arcade
• Marginal arterial arcade.
• In lower eyelid :
• Only single arterial arch

62. Venous Drainage
Preseptal
Medially: angular vein Internal Jugular Vein
Laterally: superficial temporal vein External
Jugular Vein
Postseptal
Orbital veins and facial veins Pterygoid
plexus

64. Lymphatic Drainage
• Lower lid and medial portion
drains into submandibular lymph
node.
• Upper lid and lateral portion
drains into superficial
preauricular lymph node
Deeper cervical nodes.

66. Nerve Supply of Eyelids
 Motor Nerve Supply:
• Orbicularis oculi muscle - facial nerve (temporal &
zygomatic branches)
• Levator palpebrae superioris - superior division of
oculomotor nerve
 Autonomic Nerve Supply:
• Superior and inferior tarsal muscle - sympathetic
nerve fibers from superior cervical ganglion.

67. upper eyelid -
supraorbital,
supratrochlear &
lacrimal nerves
(ophthalmic division)
lateral portion of
upper eyelid &
temple -
zygomaticotempor
al branch of the
maxillary nerve
extreme
medial
portion of
both upper &
lower eyelid -
infratrochlea
r nerve
lower eyelid -
infraorbital nerve
(maxillary
division)
lateral portion
of lower eyelid -
zygomaticofacia
l branch of the
maxillary nerve
 Sensory supply:

69. PHYSIOLOGY OF EYELID
MOVEMENTS

70. OPENING
MOVEMENTS:
 In upper lid:
1. LPS : primary
elevator
2. Frontalis : accessory
elevator
3. Superior palpebral
muscle of Muller’s :
long term adjustment
of upper lid in
position.
 In lower lid :
1. Elastic recoil of lower
eyelid tissue
2. Traction exerted by
attachment of inferior
rectus to inferior
tarsus.
3. Inferior palpebral
muscle.

71. CLOSING MOVEMENTS:
 Orbicularis oculi
1. Pretarsal fibres : spontaneous blinking and tactile
corneal reflex.
2. Preseptal fibres : voluntary blinking and sustained
activity.
3. Orbital fibres : forceful closure of eyelid in
association with all other fibres.
• Blepherospasm: involuntary sustained and forcible
eyelid closure.

72. PEERING :
Act of looking at some object with great interest.
Can be voluntarily inhibited.
Upper lid moves 2.5mm down and lower lid moves
2.5mm down and 1mm medially.

73. BLINKING :
Co – ordinated closing and opening movements of
eyelids.
2 types :
i. Voluntary
ii. Involuntary
spontaneous
Reflex blink

74. 1. Voluntary Blinking
Coordinated closure and opening of eyelids, carried out
as a willed act in both eyes.
- Produced by simultaneous contraction of palpebral
and orbital part of orbicularis muscle.

75. 2. Spontaneous blinking:
Occurs without any obvious stimulus.
Occurs at frequent interval
Infrequent during first few months of life.
Rate: 12-20 /minute, duration: 130 msec

76. • Events :
Relaxation of levator.
Contraction of preseptal fibers of orbicularis against minimal
resistance.
Synchronous activity occurs in pretarsal and upper lid
reaches the limit of its downward excursion.
Electrical activity ceases in orbicularis and the concomitant
action starts in levator.

77. As the upper lid move vertically
downward, the lower lid moves
medially in horizontal direction.
When upper lid touches the lower lid,
the downward movement of upper lid
is transmitted to lower lid.
After contact, the lower lid moves
downward with upper lid.
Pupil moves upward just before the
upper lid reaches the center of pupil {
Bell’s phenomenon}.

78. 3. Reflex blinking:
Co –ordinated closing and opening movements of
eyelid in response to some direct stimulus.
Types :
1. Tactile
2. Optic
3. Auditory
4. Stretch reflex blinking.

79. Hering’s law
• Law of equal innervation.
• States “ levator of two eyes act as yoke muscle i. e.
get equal innevation during contraction” .
• Causes symmetric opening movements.

80. Sherrington’s law
• Law of reciprocal innervation.
• Levator and orbicularis oculi get reciprocal
innervation during eyelid movement.
• i. e. opening movement of levator gets maximum
innervation while orbicularis is inhibited and gets
minimum innervation and vice versa.

81. Bell’s phenomenon
Co ordinated reflex between facial and oculomotor
nuclei , thus on closure of eyelids , eyeball rotates
upward and outward.
Inverse Bell’s phenomenon – when eyeball rotates
downward and outward on eyelid closure.

82. During sleep
• Tonic muscular activity in the orbicularis
combined with a simultaneous inhibition of
tonus in the levator

84. References
• Fundamentals and principals of ophthalmology, AAO, 2016-2017
• Clinical anatomy of eye , Richard S. Snell , Michaell A. Lemp [2nd edition]
• Wolff’s Anatomy of eye and orbit , eighth edition
• Clinical Opthalmology – Jack J Kanski and Brad bowling , seventh
edition
• Anatomy and Physiology of Eye, A. K. Khurana, 3rd edition
• Parson’s Diseases of the Eye ,22nd edition
• Internet sources