anatomy of eyelid

1. ANATOMY OF
EYELID
Dr.occulist

2. Development of eyelid
 Formed by reduplication of surface ectoderm
above and below the cornea during 2nd month
of gestation
 The folds enlarge and their margins meet and
fuse with each other
 Lids cut off a space called conjunctival sac
 The folds thus formed contain some mesoderm
which would form muscles of lid and tarsal plate
 Lids separate after 7th month of intrauterine life
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3. Gross anatomy
. Extent
 The upper eyelid extends from the eyebrow
downward to end in a free margin which
forms the superior boundary of palpebral
fissure
 Lower eyelids below merge into the skin of
the cheek
Position
 In primary position of gaze upper eyelid
covers 1/6th of cornea while lower eyelid
just touches the cornea
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4. Lid folds
Superior lid fold :
 4mm above the edge of eyelid
 Formed by attatchment of LPS aponeurosis to skin
 Divide upper eyelid into an orbital portion (above) and a
tarsal portion (below)
Inferior lid fold
 On skin of lower eyelid
 Less distinct
 Formed by fibrous slips arising from fascia surrounding
inferior rectus muscle and are inserted into skin
Nasojungal fold and malar fold
 On lower lid medially and laterally respectively
 Mark junction between skin and denser tissue of the cheeks
– limit spread of blood/fluid downwards from lids to cheek
 By skin being tethered to underlying periosteum
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5. Palpebral aperture or fissure
 Elliptical space
 Between upper and lower eyelid margin
 At birth 18-21 mm horizontally and 8 mm
vertically in the centre
 In adults its 28-30 mm and 9-11 mm
 Upper eyelid is more mobile than lower eyelid
and can be raised 15 mm by the action of the
LPS muscle alone. If frontalis is used, then an
additional 2 mm elevation can be achieved
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6. Canthi
 2 eyelids meet each other at medial
and lateral canthi
 Lateral canthus lies directly in contact
with eyeball
 Medial canthus is rounded and
separated from globe by a small
triangular area, the lacus lacrimalis, in
the centre of which is a small, pinkish
elevation, the caruncula lacrimalis.
 A semilunar fold – plica semilunaris
lies on lateral side of the caruncle.
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7.  Normally lateral and medial canthi lie at
the same level. Sometimes lateral
canthus is slightly elevated (about 2
mm) than medial canthus
 Mongoloid slant – greater elevation of
lateral canthus
 Antimongoloid slant – lateral canthus
placed lower than medial canthus
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8. Eyelid margins
 Nearly flat, 2 mm wide
 Each eyelid margin divided into two parts by
lacrimal papilla – lacrimal portion and ciliary
portion
 Lacrimal papilla is a small elevation present on
medial side ,containing an opening called lacrimal
punctum in its centre
 Lacrimal portion – extending from punctum
medially to the medial canthal angle
 Rounded and devoid of lashes or glands
 Ciliary portion – lateral part
 Rounded anterior border and sharp posterior
border and an intermarginal strip between the
two
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9.  Grey line represents line of
demarcation between the anterior
portion of the eyelid formed by the
skin and orbicularis muscle and
posterior formed by the tarsus and
conjunctiva
 It divides intermarginal strip into
anterior strip bearing lashes and a
posterior strip containing meibomian
glands arranged in a row and a lipid
strip
 Surgically important for splitting of
eyelid with minimal scarring
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10. Eyelashes
 Arranged in 2 or 3 rows along anterior part of intermarginal strip
 Longer and more numerous on the upper eyelid(100-150) than on lower one(50-
75)
 On upper eyelid- forward, upward and backward while on lower eyelid- forward,
downward and backward
 Vary in size ranging from 20-120 mm in diameter and 6-12 mm in length
 Lifespan – 3 to 4 months
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11.  Lash follicles pass obliquely in the lids, lack errectores and are embedded in the fibrous
tissue that binds the ciliary margin of the tarsus to the underlying skin
 The sebaceous gland of Zeis and glands of Moll empty into the infundibulum of each
ciliary canal.
 Each lash follicle is surrounded by a dense plexus of vessels and nerves.
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12. Layers of eyelid
From superficial to deep
 Skin
 Layer of subcutaneous areolar tissue
 Layer of striated muscles
 Submuscular areolar tissue
 Fibrous layer
 Layer of non striated muscle fibres
 Conjunctiva
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13. Skin
 Elastic having a fine texture
 Thinnest in the body and folds easily thereby
 Nasal part of the skin is smooth, shining and greasy in comparison to the
temporal part
 Fine hair are seen on temporal part of the skin
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14. Microscopic structure
 The epidermis is composed of 6-7 layers of stratified squamous epithelium and
have stratum corneum, stratum granulosum, stratum mucosum and stratum
germinatum resting on a basement membrane
 The basal layer of epidermis shows unicellular sebaceous glands and numerous
typical eccrine sweat glands
 At the lid margin epithelium is modified as we go from anterior to posterior
and becomes continuous with that of conjunctiva
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15.  The dermis or corium is composed of thin layer of dense connective tissue, with
rich network of elastic fibres, blood vessels, lymphatics and nerves
 A variable amount of melanocytes are also present which may increase their
pigment production in response to chronic oedema or inflammation
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16. Subcutaneous areolar tissue
 Lies beneath the skin
 Loose areolar connective tissue with no fat – readily distended by edema and
blood
 Overlying skin may be easily mobilized during plastic surgery
 Non existent near ciliary margin, at the lid folds and at the medial and lateral
angles where the skin is attached to the underlying ligaments
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17. Layer of striated muscles
This layer consists of two muscles:
1. Orbicularis oculi (forms a thin oval sheet
across eyelids)
2. Levator palpebrae superioris
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18. The orbicularis oculi muscle
It can be divided into 2 parts
 Orbital part
 Palpebral part (pretarsal and preseptal part)
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19. The orbital part
 Forms most peripheral fibres of orbicularis
 Arise from anterior part of the medial
palpebral ligament and adjacent bones (
upper orbital margin medial to the
supraorbital notch, the maxillary process of
frontal bone, frontal process of maxilla and
the lower orbital margin medial to
infraorbital foramen
 From orgin muscle fibres sweep superiorly
and inferiorly, covering orbital margin in
form of large ellipse and meet at the lateral
palpebral raphe
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20.  Superiorly deep to the eyebrow the orbicularis fibres intermingle with those of the
frontalis and thus gain insertion into skin of eyebrow
 Musculus superciliaris – upper medial fibres which passs to skin of the medial part of
eyebrow
 Musculus malaris – inferior medial and lateral fibres attatched to skin of cheek
 They help in forced closure of eyelids and thus pull eyebrows downwards
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21. The palpebral part- overlies mobile eyelid from orbital rim to eyelid margins
 Subdivided into preseptal and pretarsal portions
 Preseptal fibres – arise from lacrimal fascia, posterior lacrimal crest (deep
head) and the anterior part of medial palpebral ligament (superficial head)
 Fibres pass superiorly and inferiorly in front of orbital septum and unite at the
lateral palpebral raphe
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22.  Pretarsal fibres – arise from deep head (lacrimal fascia and posterior lacrimal crest) and
superficial head (medial palpebral ligament)
 Fibres pass laterally above and below, overlying the upper tarsus and lower tarsus
respectively and join laterally to form a lateral canthal tendon (inserted over lateral
orbital tubercle of Whitnall)
 The fibres of pretarsal portion which arise from lacrimal fascia and upper part of
posterior lacrimal crest help in drainage of tears by lacrimal sac and are known as Pars
lacrimalis (horner’s muscle)
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23.  Fibres which run along the lid margin behind the ciliary follicles form the Pars
ciliaris (muscle of Riolan) and these fibres keep lids in close apposition to globe
 In general the palpebral part helps in gentle closing of eyelids during blinking
,sleep and soft voluntary closure.
 Supplied by branches of facial nerve
 Antagonist is LPS
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24. The levator palpebrae
superioris muscle
Orgin
 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 orgin of superior rectus muscle
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25. Course and Attachments
 Has a flat ribbon like belly. It overlies
superior rectus as it travels anteriorly
towards the eyelid and numerous fascial
bands connect the two
 Widens as it courses forward and then
descends vertically posterior to orbital fat
wedge
 At orbital septum it fans out into
aponeurosis of LPS and forms medial and
lateral horn
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26.  Lateral horn divides lacrimal gland into orbital and palpebral parts and inserts
into superior edge of lacrimal canthal tendon
 Medial horn passes over reflected tendon of superior oblique and fuses with
medial canthal tendon
 Together the two horns serve to distribute the forces of levator muscle along the
aponeurosis and the tarsal plate
 Fleshy part of LPS muscle runs horizontally while tendinous aponeurosis runs
vertically
 This change of direction occurs at superior transverse ligament of whitnall
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27.  The Whitnall ligament (also known as check ligament of LPS) is a thickened
band of orbital fascia which extends from trochlear pulley to the capsule of
the orbital lobe of lacrimal gland
 Formed by condensation of superior sheath of levator muscle joined medially
by sheath of reflected tendon of superior oblique muscle
 Cutting of whitnall ligament in ptosis surgery can lead to failure of LPS
 LPS supplied by superior division of occulomotor nerve
 Acts elevator of upper lid and is antagonised by palpebral portion of
orbicularis oculi muscle
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28. Submuscular areolar tissue
 Layer of loose connective tissue between orbicularis muscle and fibrous layer
 Consists of tarsal plate and septum orbitale
 Contains nerves and vessels of the lids – injection is made here to anaesthetise
the lid
 This layer splits the eyelid into two – anterior lamina and posterior lamina
(approached through grey line)
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29.  In upper eyelid this layer communicates with dangerous area of scalp
(subaponeurotic stratum of scalp) – pus or blood can make its way here
 In lower eyelid submuscular tissue lies in a single space behind the orbicularis
 In the upper eyelid ,this space is traversed by levator muscle which divides it into
pretarsal space and preseptal space
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30.  Pretarsal space
 Small fusiform area in vertical section
 Peripheral arterial arcade present
 Bounded anteriorly by levator aponeurosis and posteriorly by tarsal plate
 Preseptal space
 Triangular in vertical section
 Bounded in front by orbicularis ,behind by septum orbitale and above by
preseptal cushion of fat
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31. Fibrous layer
Framework of lid and consists of
 Central thick part of tarsal plate
 Peripheral thin part of septum orbitale (palpebral fascia)
 Medial palpebral ligament
 Lateral palpebral ligaments
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32. Tarsal plates
 Firm plates of dense fibrous tissue that form skeleton of eyelids giving shape and
firmness
 About 29 mm long and 1 mm thick
 Upper tarsus 10-11 mm in height and lower tarsus 4-5 mm in height
 Free borders of tarsi are more or less straight whereas opposite attatched borders are
convex
 Septum orbitale and Mullers muscle are attatced to superior border of upper tarsus
 The orbital septum, capsulopalpebral fascia and inferior palpebral muscle are attatched
to inferior border of lower tarsus
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33.  Firm plates of dense fibrous tissue that form skeleton of eyelids giving shape and
firmness
 About 29 mm long and 1 mm thick
 Upper tarsus 10-11 mm in height and lower tarsus 4-5 mm in height
 Free borders of tarsi are more or less straight whereas opposite attatched borders are
convex
 Septum orbitale and Mullers muscle are attatced to superior border of upper tarsus
 The orbital septum, capsulopalpebral fascia and inferior palpebral muscle are attatched
to inferior border of lower tarsus
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34. Septum orbitale/ Palpebral fascia
 Firm plates of dense fibrous tissue that form skeleton of eyelids giving shape and firmness
 About 29 mm long and 1 mm thick
 Upper tarsus 10-11 mm in height and lower tarsus 4-5 mm in height
 Free borders of tarsi are more or less straight whereas opposite attatched borders are convex
 Septum orbitale and Mullers muscle are attatced to superior border of upper tarsus
 The orbital septum, capsulopalpebral fascia and inferior palpebral muscle are attatched to
inferior border of lower tarsus
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35. Structures piercing through septum orbitale
1. Lacrimal vessels and nerves
2. Supraorbital vessels and nerves
3. Supratrochlear artery and nerve
4. Infratrochlear nerve
5. Anastomosing vein between the angular and ophthalmic vein
6. Superior and inferior palpebral arteries
7. Aponeurosis of LPS in the upper eyelid
8. Expansion of inferior rectus in the lower eyelid
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36. Medial palpebral ligament
 Triangular band of connective tissue, attached to the frontal process of maxilla from
anterior lacrimal crest to suture line of frontal process with the nasal bone
 It can be divided into 2 parts : anterior and posterior
 Anterior part fans out laterally from anterior lacrimal crest and at medial canthus splits
into upper and lower band that are attached to medial ends of upper and lower tarsal
plates respectively
 Posterior part passes behind lacrimal sac from anterior lacrimal crest to posterior
lacrimal crest
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37. Lateral palpebral ligament
 Thin band of fibrous tissue
 Laterally attactched to Whitnall’s tubercle on lateral orbital margin
 Medially attached to lateral ends of upper and lower tarsal plate
 Upper border of LPL merges with lateral expansion of aponeurosis of levator
muscle and the lower border with the lateral expansions of inferior oblique and
inferior rectus muscles
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38. Layer of non striated muscle fibres
 Consists of smooth muscle fibres of Muller which lie deep to septum orbitale in
upper and lower lid
 Orgin : from inferior terminal striated fibres of LPS in upper eyelid and expansion
of inferior rectus in lower eyelid
 Runs vertically and gets inserted in the orbital margin of the tarsal plate
 Supplied by sympathetic nerves
 Thus sympathetic irritation leads to retraction of lids and paralysis leads to
Horners syndrome
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39. Conjuctiva
 Posterior most layer of eyelid
 Extends from mucocutaneous junction at the lid margin to the conjunctival fornix
 It is firmly adherent to the posterior surface of tarsal plates and Muller’s muscle
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40. Glands of the eyelids
These include
 Tarsal / Meibomian glands
 Gland of Zeis
 Glands of Moll
 Accessory lacrimal glands of Wolfring
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41. Tarsal / Meibomian Glands
 Modified sebaceous glands present in posterior part
of stroma of tarsal plates
 They are arranged in single row vertically parallel to
each other numbering about 20-30 in each lid
 Each gland contains central duct which runs straight
perpendicular to the lid margin and occupies the
entire thickness of tarsal plate
 Opening of meimobian glands are arranged in a
single row on the lid margin between grey line and
posterior border of lid
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42. Secretions
 Secretions are oily in nature
 The oily marginal tear strip prevents overflow of tears across lid margin
 Prevents evaporation of tears and allow smooth movements of eyelids over the
globe
 Ensure airtight closure of eyelids
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43. Gland of Zeis
 Modified sebaceous glands
 Attached to eyelash follicles (usually 2 glands with each cilium)
 Unilobar
 Sebum secretion prevents eyelashes from becoming dry and brittle
 Also contributes towards oily layer of tear film
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44. Gland of Moll
 Modified sweat gland
 Lies between cilia
 More numerous in lower lid than in upper lid
 Has unbranched spiral shape
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45. Accessory gland of Wolfring
 Microscopic accessory lacrimal glands
 Present along upper border of superior tarsus and along lower border of inferior
tarsus
 About 2-5 in upper eyelid and 2-3 in lower eyelid
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46. Arterial supply
 Each eyelid mainly supplied by medial and lateral palpebral arteries (branches of
dorsal, nasal and lacrimal arteries
 Anastomoses of medial and lateral palpebral arteries toform Marginal and
peripheral arterial arcades
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47. Venous drainage
2 sets of venous plexus on each eyelid
 Pretarsal venous plexus – drains structures superficial to tarsus. It drains into
subcutaneous veins
 Angular vein on medial side which ultimately drain into internal jugular vein
 The superficial temporal and lacrimal veins on lateral side ultimately drain into
external jugular vein
 Post tarsal venous plexus – drains structures posterior to tarsal plate and in turn
drains into ophthalmic vein
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48. Lymphatic drainage
 Superficial or pretarsal plexus – drains lymph from skin and orbicularis muscle
 Deep or post-tarsal plexus – drains lymph from tarsal plate region and
conjunctiva
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49. Nerve supply
 Motor nerves – facial and occulomotor
 Sensory nerves – branches of 1st and 2nd division of trigeminal nerve
 Upper lid- supraorbital, suptratrochlear, infratrochlear and lacrimal nerves
 Lower lid – infraorbital, lacrimal and infratrochlear nerves
 Sympathetic nerves supply the vessels , glands and mullers muscle
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50. Clinical correlations of eyelid
 Hordeolum Externum (Stye) – localized suppurative inflammation of gland of zeis
at lid margin at ciliary follicle
 Hordeolum Internum – inflammation of meibomian gland associated with
blockage of duct
 Chalazion – chronic inflammatory granuloma of meibomian gland
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51. Blepharitis
 Chronic inflammation of lid margin occurring as true inflammation
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52. Meibomitis (posterior Blepharitis)
 Inflammation and obstruction of meibomian glands. Characterized by diffuse
thickening of posterior border of eyelid margin which becomes rounded
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53.  Inward rolling and rotation of lid
margin towards globe
Entropion
 Out rolling of eyelid margin
Ectropion
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54.  Incomplete closure of the palpebral
aperture when attempt is made to
close the eyes
Lagophthalmos
 Drooping of upper eyelid usually due
to paralysis or defective development
of LPS
Ptosis
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Central thick part of tarsal plate
Peripheral thin part of septum orbitale (palpebral fascia)
Medial palpebral ligament
Lateral palpebral ligaments

55. Blepharospasm
 Involuntary , sustained and forceful closure of the eyelids
55

56.  Partial or complete adhesion of the
palpebral conjunctiva of the eyelid to
the bulbar conjunctiva of the eyeball
Symblepharon
 Adhesion of ciliary edges of the
eyelid to each other
Ankyloblepharon
56

57.  Extra row of cilia occupies position of
meibomian glands
Distichiasis
 Inward misdirection of cilia
Trichiasis 57

58. Coloboma of lid
 Notch in edge of the lid
 Usually situated to the inner side of midline, generally affecting upper lid
 Sometimes a bridge of skin links coloboma to the globe
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59.  Rare condition where skin passes
continously from brow over the eye
to the cheek
Cryptophthalmos
 Lids are abnormally small
Microblepharon 59

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