Anatomy of the eyelids

1. Anatomy Of The Eyelids
Dr. Sameeksha Agrawal

2. Introduction
• Eyelids are the mobile curtains placed in front of the eyeballs
• Protect the eyes from injuries & excessive light
• Help in spreading of the tear film over the eyeball & its drainage
• Important contribution to the facial features of an individual
• Gives an idea about the state of wakefulness & attention

3. Extent
• The upper eyelid extends from the eyebrow downward to
end in a free margin, which forms the superior boundary
of palpebral fissure
• The lower eyelids below merge into the skin of the cheek

4. Lid Folds
1) Superior Lid Fold:
 Lies 4 mm above the edge of the eyelid
 Formed by the fibrous slips arising from the LPS tendon which
pass forwards between the muscle bundles of orbicularis
muscle to insert into the skin (it is less developed in Mongols)
2) Inferior Lid Fold:
 Less distinct
 Formed by the slips arising from the fascia surrounding the
inferior rectus muscle & are inserted into the skin

5. Lid Folds
3) Nasojugal Fold (medially)
4) Malar Fold (laterally)
 Note: These folds limit the spread of blood or fluid
downwards from the eyelids into cheek

6. Position Of The Eyelids
• In primary position of gaze, the upper eyelid covers about
1/6th of the cornea & the lower eyelid just touches the
cornea

7. Canthi
• The two eyelids meet at lateral & medial
end to form the Lateral & the Medial
Canthi
• Lateral canthus lies in contact with the
eyeball & it is 5-7 mm away from the
lateral orbital margin
• Medial canthus is rounded,and is
separated from the globe by tear lake
(lacus lacrimalis). In this area, there is
caruncle & plica semilunaris

8. Canthi
• Normally the lateral & the medial canthi lie at the same
horizontal level. Sometimes the lateral canthus is slightly
elevated (about 2mm) than the medial one.
• Greater elevation of the lateral canthus results in a
mongoloid slant to the fissure, and the opposite results
into an antimongoloid slant

9. • Mongoloid slant in trisomy 21 • Anti mongoloid slant in
treacher collin syndrome

10. Caruncle and Plica-semilunaris
• Caruncle is a small, fleshy, ovoid structure attached to the
inferomedial side of plica semilunaris. It is a modified skin, and
it contains sebaceous glands and fine, colorless hairs
• Plica semilunaris is a narrow, highly vascular, crescent-shaped
fold of the conjunctiva located lateral to & partly under the
caruncle
 Its lateral border is free & separated from the bulbar conjunctiva,
which it resembles histologically
 It is a vestigial structure analogous to the nictitating membrane
(3rd eyelid) seen in other animals

11. Palpebral Fissure
• It is the exposed zone between the
upper & lower eyelids
• Elliptical in shape
• In adults, it is about 27-30mm long &
8-11 mm wide
• The upper eyelid is more mobile than
the lower, and can be raised 15 mm by
the action of the LPS muscle alone. If
frontalis is also used, then an
additional 2 mm elevation can be
achieved

12. Eyelid Margins
• Nearly flat, 2mm wide
• Each lid margin is divided into two parts
(lacrimal & ciliary) by the lacrimal papilla,
which is a small elevation present on the medial
side, containing an opening, the lacrimal
punctum in its centre
• Lacrimal portion (medial part) is rounded &
devoid of lashes or glands
• Ciliary portion (lateral part) consists of a
round anterior border & a sharp posterior
border. The capillarity induced by this sharp
angle of contact is important for proper
moistening of the surface of eye

13. Eyelid Margins
• The part lying in between the two borders
is known as the Inter-marginal strip
• Along the entire length of the free margin
of the eyelid is the delicate Grey Line (or
the Inter-marginal Sulcus),
corresponding histologically to the most
superficial portion of the orbicularis
muscle, the muscle of Riolan, & to the
avascular plane of the lid. Anterior to this
line, the eyelashes (cilia) arise, & behind it
are the openings of the tarsal
(meibomian) glands just anterior to the
mucocutaneous junction.

14. Eyelashes
• Are arranged in 2 or 3 irregular rows along the anterior part of the inter-
marginal strip
• They are usually longer & more numerous on the upper eyelid than on
the lower one
• They are darker than the scalp hair & tend to remain so throughout the
life
• Each cilium has a life-span of 3-4 months
• The margins contain the glands of Zeis, which are modified sebaceous
glands associated with the cilia, & the glands of Moll, apocrine sweat
glands of skin

15. Layers of eyelid
• From superficial to deep, each eyelid
consists of the following structures:
a) Skin
b) Layer of subcutaneous areolar
tissue
c) Layer of striated muscles
d) Submuscular areolar tissue
e) Fibrous layer
f) Layer of non-striated muscle fibres
g) Conjunctiva

16. Skin
• The skin covering the eyelids is elastic, having a fine
texture, is thinnest in the body & folds easily thereby,
contributing to the ease & speed of mobility of the upper
eyelid.
• Nasal part of the skin is smooth, shining & greasy in
comparison to the temporal part. Fine hair are seen on the
temporal part of the skin.

17. Skin
• Microscopic structure: The epidermis is stratified
squamous epithelium & composed of 6-7 layers of cells.
The basal layer of epidermis shows unicellular sebaceous
glands & numerous typical eccrine sweat glands.
• The dermis or corium is composed of a thin layer of dense
connective tissue, with rich network of elastic fibers, blood
vessels, lymphatics & nerves. A variable number of
melanocytes are also present, which may increase their
pigment production in response to chronic oedema or
inflammation.

18. Subcutaneous Areolar Tissue
• It lies beneath the skin.
• It is loose & fat less. It is thus readily distended by blood &
oedema.
• The overlying skin may be easily mobilized during plastic
surgery.
• This layer is non-existent near the ciliary margin, at the lid
folds, & at medial & lateral angles where the skin is
attached to the underlying ligaments.

19. Layer Of Striated Muscles
• This layer consists of two muscles:
1) Orbicularis oculi
2) Levator palpebrae superioris

20. The Orbicularis oculi Muscle
• It is arranged in several concentric bands around the palpebral fissure.
Of all the facial muscles, the orbicularis has fibres with the smallest
diameter.
• It can be divided into two parts:
a) Orbital part
b) Palpebral part
• The Orbital part forms the most peripheral fibres of the
orbicularis, which arise from the anterior part of the medial
palpebral ligament & the adjacent bones. The fibres run covering
the orbital margin in the form of a large ellipse & meet at the lateral
palpebral raphe.

21. The Orbicularis oculi Muscle

22. The Orbicularis oculi Muscle
• Superiorly, deep to the eyebrow the orbicularis fibres
intermingle with those of the frontalis & thereby gain
insertion into the skin of eyebrow
• The upper medial fibres of the orbital part which pass to
the skin of the medial part of the eyebrow are termed as
“musculus superciliaris”.
• Inferiorly, the medial & lateral peripheral fibres of the
orbital part which are attached to the skin of cheek are
called “musculus malaris”.

23. The Orbicularis oculi Muscle
• The orbital part acts like a sphincter & functions solely as a
voluntary muscle. It helps in forced closure of the eyelids
& thus pull the eyebrows downward.
• The Palpebral Part of orbicularis is subdivided into
preseptal & pretarsal portions.

24. The Orbicularis oculi Muscle
• The preseptal fibres arise from the lacrimal fascia,
posterior lacrimal crest (deep head) & the anterior part of
the medial palpebral ligament (superficial head).
• The fibres pass superiorly & inferiorly in front of the
orbital septum & unite at the lateral palpebral raphe.

25. The Orbicularis oculi Muscle
• The pretarsal fibres also arise by a deep head (from the
lacrimal fascia & posterior lacrimal crest) & a superficial
head (from the medial palpebral ligament).
• The fibres pass laterally above & below, overlying the
upper tarsus & lower tarsus, respectively; & join laterally to
form a lateral canthal tendon which is inserted over the
lateral orbital tubercle of Whitnall.

26. The Orbicularis oculi Muscle
The fibres of pretarsal portion which
arise from the lacrimal fascia & upper
part of posterior lacrimal crest help in
the drainage of tears by lacrimal sac &
are known as Pars lacrimalis
(Horner’s Muscle).
The fibres of the pretarsal portion
which run along the lid margin behind
the ciliary follicles form the Pars
ciliaris (muscle of Riolan); these
fibres keep the lids in close apposition
to the globe.

27. The Orbicularis oculi Muscle
• Disinsertion of the lower eyelid retractors from the tarsus
may result in lower lid laxity, followed by spastic
entropion, an inward turning of the eyelid margin.
• In general, the palpebral part of the orbicularis helps in
gentle closing of the eyelids during blinking, sleep & soft
voluntary closure.
• The entire orbicularis is supplied by the branches of
Facial nerve.

28. The Levator palpebrae superioris Muscle
• Origin: it takes origin at the apex of
the orbit from the undersurface of
lesser wing of sphenoid above the
annulus of Zinn, by a short tendon
which is blended with the
underlying origin of superior rectus
muscle.
• Course & Attachments: LPS has a
flat ribbon like belly. It overlies the
superior rectus as it travels
anteriorly towards the eyelid.

29. The Levator palpebrae superioris Muscle
• The Whitnall ligament (also known as the Check
ligament of LPS) results from a condensation of tissue
surrounding the superior rectus & levator muscle. Actually
it is a thickened band of orbital fascia which extends from
the trochlear pulley to the capsule of the orbital lobe of
lacrimal gland
• “Recognition of this ligament during ptosis surgery is
important, as severing of Whitnall’s ligament can lead to
failure of LPS function.”

30. The Levator palpebrae superioris Muscle
• Near the WL, the LPS changes direction from horizontal
to more vertical, and it divides anteriorly into the
aponeurosis and posteriorly into the Superior Tarsal
muscle (also known as Muller’s muscle)
• The aponeurosis inserts into the anterior surface of the
tarsus & passes by the medial & lateral horns into the
canthal tendons

31. The Levator palpebrae superioris Muscle
• The fibrous elements of the aponeurosis pass through the
orbicularis muscle & insert subcutaneously to produce the
superior eyelid fold
• The aponeurosis also inserts into the trochlea of the
superior oblique muscle & into the fibrous tissue bridging
the supraorbital notch. Attacments also exist with the
conjunctiva of the upper fornix & with the orbital septum.

32. The Levator palpebrae superioris Muscle
• Fleshy / horizontal part of LPS is 40mm long, while
tendinous / vertical part is 15mm long & 30mm wide.
• Nerve supply & action: LPS is supplied by a branch of
superior division of the oculomotor nerve and it acts as an
elevator of the upper eyelid. Its action is antagonised by
the palpebral portion of the orbicularis muscle.

33. Submuscular Areolar Tissue
• It consists of a layer of loose connective tissue present
between the orbicularis muscle & fibrous layer.
• The nerves & vessels of the lids lie in this layer, & so to
anaesthetize the lid, injection is made in this plane.
• This layer also splits the eyelid into two -the anterior
lamina & posterior lamina – which are easily approached
through the gray line.

34. Submuscular Areolar Tissue
• In the upper eyelid, superiorly this layer communicates
with the subaponeurotic stratum of the scalp. Hence, the
pus or blood can make its way into the upper eyelid from
the dangerous area of the scalp.
• In the lower eyelid, the submuscular tissue lies in a single
space behind the orbicularis. In the upper eyelid, this
space is traversed by the LPS muscle, which divides it into
two – the pretarsal space & the preseptal space.

35. Submuscular Areolar Tissue
• The Pretarsal Space is small area which appears fusiform
in a vertical section. The peripheral arterial arcade is
present in this space. Its anterior boundary is levator
aponeurosis and posterior boundary is tarsal plates.
• The Preseptal Space appears triangular in vertical section.
It is bounded in front by the orbicularis, behind by the
septum orbitale, and above by the preseptal cushion of fat.

36. Submuscular Areolar Tissue
• Preseptal cushion of fat is a crescent-shaped pad of fat
which lies in front of the septum and behind the
orbicularis muscle to which it is firmly adherent. Its upper
border lies along the superior orbital margin, to which it
may overlap at times, & its lower border corresponds to
the upper palpebral furrow.

37. Fibrous Layer
• It is the framework of the lid & consists of:
1) Tarsal plates (thick central part)
2) Septum orbitale (thin peripheral part)
3) Medial palpebral ligament
4) Lateral palpebral liigament

38. Tarsal Plates
• Tarsi are firm plates of dense
fibrous tissue that forms the
skeleton of the eyelids, giving
them shape & firmness. They are
attached to the orbital margin by
the medial & the lateral palpebral
ligaments.
• The tarsi are about 29mm long &
1mm thick. The upper tarsus is
about 10-11mm in height & lower
tarsus is 4-5mm in height.

39. Tarsal Plates
• Septum orbitale & Muller’s muscle are attached at the
superior border of the upper tarsus.
• The orbital septum, capsulopalpebral fascia & inferior
palpebral muscle are attached to the inferior border of the
lower tarsus

40. Tarsal Plates
• Anterior surface of each tarsus is convex and seperated
from the orbicularis muscle by loose areolar tissue, so that
muscle moves freely on the tarsus.
• Posterior surface of the tarsal plates is concave coinciding
with the curvature of globe, and is lined by conjunctiva
which is firmly adherent to the tarsal plates.
• Tarsal / meibomian glands are embedded in the substance
of the tarsal plates.

41. Septum orbitale / Palpebral Fascia
• It is a thin floating membrane, that takes part in all the
movements of eyelids.
• It is comparatively thick & strong on the lateral side than
the medial side, & in the upper eyelid than the lower
eyelid.
• It encircles the orbit as an extension of the periosteum of
the roof & floor of the orbit.

42. Septum orbitale / Palpebral Fascia
• Posterior to the orbital septum lies the orbital fat. In both
upper & lower eyelids, the orbital septum attaches to the
aponeurosis. Thus it acts as a barrier to anterior &
posterior extravasation of blood or the spread of
inflammation. It also delimits the lateral spread of edema,
inflammation, & blood as it is tightly adherent to the
orbital margins.

43. Septum orbitale / Palpebral Fascia
• Structures piercing through the septum orbitale:
1) Lacrimal vessels & nerves
2) Supraorbital vessels & nerves
3) Supratrochlear artery & nerve
4) Infratrochlear nerve
5) Anastomosing vein between the angular & ophthalmic vein
6) Superior & inferior palpebral arteries
7) Aponeurosis of LPS in the upper eyelid
8) Expansion of the inferior rectus in the lowerlid

44. Layer Of Non-striated Muscle Fibres
• Muller’s Muscle: It is a smooth (non-striated),
sympathetically innervated muscle that originates from
the undersurface of the LPS in the upper eyelid.
• A similar smooth muscle arises from the capsulopalpebral
head of inferior rectus in the lower eyelid.

45. Layer Of Non-striated Muscle Fibres
• The Muller muscle attaches to the upper border of the
upper tarsus & to the conjunctiva of the upper fornix.
• The capsulopalpebral muscle, which is a much weaker
muscle than the Muller muscle, attaches to the lower
border of the lower tarsus.

46. Layer Of Non-striated Muscle Fibres
• They are supplied by the sympathetic nerve fibres. Thus,
sympathetic irritation leads to the retraction of the lids &
paralysis leads to Horner’s Syndrome.

47. Conjunctiva
• It is the posterior most layer of eyelid.
• It extends from the mucocutaneous junction at the lid
margin to the conjunctival fornix.
• It is firmly adherent to the poosterior surface of tarsal
plates & Muller’s muscle.

48. Conjunctiva
• Palpebral conjunctiva can be
subdivided into three parts:
1) Marginal conjunctiva
2) Tarsal conjunctiva
3) Orbital conjunctiva

49. Conjunctiva
• Marginal conjunctiva: it extends from the lid margin to about 2
mm on the back of the lid up to a shallow groove – the sulcus
subtarsalis.
• It is actually a transition zone b/w the skin & the conjunctiva proper.
• At the sulcus subtarsalis, the perforating vessels pass through the
tarsus to supply the conjunctiva.
• This sulcus is a common site for lodgement of a conjunctival foreign
body.

50. Conjunctiva
• Tarsal Conjunctiva: is thin, transparent, & highly
vascular.
• It is firmly adherent to the whole tarsal plate in the upper
eyelid. In the lower eyelid, it is adherent only to half width
of the tarsus.
• The tarsal glands are seen through it as yellow streaks.
• Tarsal conjunctiva is a common site for follicular &
papillary reactions.

51. Conjunctiva
• Orbital conjunctiva: it lies loose b/w the tarsal plate &
fornix.
• Orbital conjunctiva of the upper eyelid is loose & lies over
the Muller’s muscle.

52. Glands Of The Eyelids
• These include:
1) Tarsal / Meibomian glands
2) Glands of Zeis
3) Glands of Moll
4) Accessory lacrimal glands of Wolfring

53. Tarsal / Meibomian Glands
• These are modified holocrine sebaceous glands
that are arranged vertically in parallel rows
through the tarsus.
• Their distribution & number within the eyelid
can be observed by infra-red transillumination
of the eyelid.
• A single row of 30-40 meibomian orifices is
present in the upper eyelid (b/w the gray line &
the posterior border of the lid), but there are
only 20-30 orifices in the lower eyelid.

54. Tarsal / Meibomian Glands
• Secretions from the tarsal glands are oily in nature &
perform the following functions:
1) The oily marginal tear strip prevents the overflow of
tears across the lid margin.
2) The oily layer prevents evaporation of tears & allows
smooth movements of the eyelids over the globe.
3) It ensures air-tight closure of the eyelids.

55. Glands Of Zeis
• These are also modified sebaceous glands, attached
directly to the eyelash follicle.
• Usually, two glands are associated with each cilium.
• Secretions from these glands prevent the eyelashes from
becoming dry & brittle.
• It also contributes to the oily layer of the tear film.

56. Glands Of Moll
• These are modified apocrine sweat glands, which lie b/w
the cilia.
• These are more numerous in the lower eyelid than the
upper.

57. Accessory Larimal Glands Of Wolfring
• These are microscopic accessory lacrimal glands present
along the upper border of superior tarsus & along the
lower border of the inferior tarsus.
• These are about 2-5 in the upper lid & 2-3 in the lower lid.

58. Arterial Supply
• The eyelids are mainly supplied by the medial & lateral
palpebral arteries, which are branches of the dorsal nasal
& lacrimal arteries.
• The superior & inferior arteries enter the upper & lower
eyelids, by piercing through the septum orbitale above &
below the medial palpebral ligament, respectively.

59. Arterial Supply
• Each medial palpebral artery then anastomoses with the
corresponding lateral palpebral artery to form marginal
arterial arcades which lie in the sub-muscular plane in
front of the tarsal plate some 2-3mm away from the lid
margin, in each eyelid.
• In the upper eyelid another arcade (superior or peripheral
arterial arcade) is formed from the superior branches of
medial palpebral artery, which lies near the upper border
of the tarsal plate.

60. Arterial Supply
• The tarsal arcades of the eyelids also receive anastomosing
twigs from the superficial temporal artery, transverse facial
artery & infraorbital artery.
• Branches from the arterial arcades go forward to supply
orbicularis & skin, & backward to supply the tarsal glands
& conjunctiva.

61. Arterial Supply

62. Venous Drainage
• Veins are larger & more numerous than the arteries of
eyelids. These are arranged in two sets of venous plexuses
in each eyelid:
1) Pre-tarsal Venous Plexus: It drains structures
superficial to the tarsus, mainly into the angular vein on
the medial side, which ultimately drains into the
internal jugular vein; & superficial temporal & lacrimal
veins on the lateral side, which ultimately drain into the
external jugular vein.

63. Venous Drainage
2) Post-tarsal Venous Plexus: it drains structures posterior
to the tarsal plates into the ophthalmic veins.

64. Lymphatic Drainage
• Lymphatic plexuses are two in each eyelid:
1) Superficial or Pre-tarsal plexus drains lymph from the
skin & the orbicularis muscle.
2) Deep or Post-tarsal plexus drains lymph from the tarsal
plate region & conjunctiva.

65. Lymphatic Drainage
• Lymph vessels are arranged in 2 groups:
1) Medial Group:
 The two superficial medial channels drain the medial
half of the lower lid, medial quarter of the upper lid &
medial commissure into the superficial submandibular
lymph nodes.
 The two deep medial channels drain the conjunctiva of
the medial 2/3rds of the lower lid & caruncle into the
deep submandibular lymph nodes.

66. Lymphatic Drainage
2) Lateral Group:
 The superficial lateral trunk drains the superficial
structures of the lateral 3/4th of the upper lid & of the
lateral part of the lower lid, into the superficial parotid
lymph nodes & preauricular lymph nodes.
 The deep lateral trunk drains the entire conjunctiva of
the upper lid & the conjunctiva of the lateral 1/3rd of the
lower lid into deep parotid lymph node.

67. Nerve Supply
 Motor nerves:
1) Facial nerve (orbicularis)
2) Oculomotor nerve (LPS)
 Sensory nerves are derived from branches of the 2nd & 1st division of
Trigeminal nerve
 Sympathetic nerves supply the non-striated muscles , the vessels & the
glands of the skin.
 Most of the nerves lie in the submuscular plane b/w the orbicularis & the
tarsal plate. Therefore to anaesthetize the lid, injection should be made in
this compartment.

68. Thank You