2. EYELID ANATOMY
Embryology:-
Eyelids- reduplication of surface ectoderm above & below cornea
during 2nd month of IUL.
Folds enlarge & their margins meet & fuse with each other to enclose a
space - conjunctival sac.
Folds thus formed contain some mesoderm which gives muscles of
eyelid & tarsal plates.
Lids seperates after 7th mon of IUL.
Tarsal glands developes from ingrowth of solid columns of ectodermal
cells from the lid margins.
Ciliary glands are outgrowths
from ciliary follicles.
Cilia developes as epithelial buds from lid margines.
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3. Gross anatomy:-
• Eyelids are mobile tissues curtains placed in front of the
eyeballs.
• Extent:-upper lid extends form eyebrows above to free lid
margins bellow & lower lid merges bellow into skin of cheek.
• Lid folds:-
A. Superior lid fold - 4mm above lid margins
-formed by fibrous slip arrising from levator tendon
-divides upper lid into orbital and tarsal parts
B. Inferior lid fold – formed by fibrous slip arising from fascia
around IR
C. Nasojugular (medial) fold Both marks the line betn skin &
D. Malar (lateral) fold denser tissue of cheek –limits the .
spread blood downwards from
. lid to cheek.
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4. • Position- in primary gaze upper lid covers 1/6 of cornea & lower
lid just touches cornea.
• Canthi -
Lateral canthus -5-7mm from lateral orbital margines
-forms 30-40 degree when eyes are normally open
Madial canthus- seperated from globe by tear lake (lacus
lacrimalis).
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5. • Lid margins – 2 mm in width
-divided by lacrimal papilla into
Medial portion Lateral portion
(lacrimal portion) (Cilliary portion )
-devoid of lashes & -rounded anterior & sharp post
glands border
-Intermarginal strip- divided by grey line into
Anterior strip posterior strip
-bears eye lashes -bears opening of mebomian glands &
lipid strip.
• Eye lashes-2-3 rows
UL - (100-150) directed forward ,upward & backward
LL – (50-75) directed forward , downward & backward
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6. • Cilia-
20-129 µm in diameter.
6-12mm in length.
lifespan 3-4 months shed off goes in dormant phase or
weeks new hair grows.
Lacks errector muscles
Glands off Zies & Moll empties into infundibulum of these cilia.
• Palpabral apperture /fissure-
Elliptical space betn upper & lower lid margins
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At birth In adults
At birth In adults
In caucation race fissure is either horizontal or lateral
canthus is slightly <2mm higher than medial canthus..
18-20mm
8mm
28-30mm
9-11mm
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7. Mongoloid slant Lateral canthus is >2mm higher than medial.
Antimongoloid slant Lateral canthus is lower than medial.
Structure :-
i. Skin
ii. Subcutaneus areolar tissue (pic)
iii. Layer of striated muscle
iv. Submuscular areolar tissue
v. Fibrous layer
vi. Layer of non striated muscle
vii. conjunctiva
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8. i. Skin :- Elastic & folds easily
Thinnest in body
Epidermis *is stratified squamous epithelium 6-7
layered,
* Basal layer contain numerous unicellular
sebacious glands & typical eccrine sweat glands..
* At margins , get modified & continues with
conjunctiva.
Dermis *Rich network of elastic fibers, blood
vessels, nerves, lymphatics with variable no. of
MELANOCYTES * es their production in
response chronic edema or inflamation.
ii. Subcutaneous areolar tissue :-
Loose connective tissue
Contains no fat
*Radially distended by blood or fluids .
**easily mobilized during plastic sx .
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9. iii. Layer of striated muscle:- 2 muscles orbicullaries oculi & levator
1.Orbicularis oculi palpabrae
Orbital part (peripheral) Palpebral part
Origin- Ant part of MPL &
adj bone fibers sweep
superiorly & inferiorly to a . Preseptal part b.Pretarsal part
meet at lateral palpebral raphe.
Musculus Supercilliaries – Origin- both parts originates through
Upper Medial fibers of orbital superficial head (MPL) & deep head
part which passes to skin of (Lacrimal fascia & crest)
eyebrow. Fibers then sweep superiorly & inferiorly
Musulus malaries-Inferiorly to meet laterally to form Lateral canthal
medial& lateral fibers attached tendon inserted over lat orbital tubercle
to skin of cheek of whitnall
*causes forceful closure of *causes gentle clossing of eyelid
eyelid during blinking & sleeping.
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11. Horner’s muscle (pars lacrimalis) - Fibers of pretarsal portion arising from
lacrimal fascia & upper part of post lacrimal crest .
*helps in draining tears by lacrimal sac
Muscle of Riolan (pars ciliaries) – Fibers of pretarsal portion which run along
lid margins behind ciliary follicles
*keeps lid in close opposition to globe.
Nerve supply:- facial nerve
2.Levator palpabrae superioris..
Origin:- at appex of orbit from under
surface of lesser wing of sphinoid above
annulus of zinn.
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12. Course:-
Fleshy part - Horizontal , approx. 40mm
passes forward & nasally , below
roof of orbit & above SR muscle.
Tendinous part – Vertical , 15mm long &
30 mm wide. Forms an
aponeurosis occupying whole lid.
Madial horn – fuses with medial canthal tendon
Lateral horn – is thicker & divides lacrimal
gland into orbital &
palpebral part.
Insertion:- on superior edge of lateral canthal tendon, anterior
surface & upper border of tarsus & some fibers to skin &
sup conjunctival fornix.
Nerve supply :- superior division of occulomotor nerve.
Action:- Elevator of lid (its action is antagonised by palpabral part
of orbicularis oculi)
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13. Superior transverse ligament of Whitnall
Thickened band of orbital fascia
which extends trochlear pulley (PIc)
(medially) to capsule of orbital lobe
of lacrimal gland (laterally).
It’s a condensation of fibers of SR & LPS .
*Recognition of ligament during
ptosis sx is imp as severing of lig
can leads to failure of LPS function.
iv. Submuscular areolar tissue:-
Its tissue betn orbicularis oculi & fibrous layer.
contains nerves & vessels of lid.
*to anaesthetize the lid injection is made in this plane.
**in upper lid, this layer communicates with dangerous area of
scalp giving way to extravasseted blood & pus.
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14. Spaces:-
a. Pretarsal space- bounded ant- Levator aponeurosis & post – tarsal
plate. Fusiform in vertical section. Contains arterial
arcade.
b. Preseptal space- bounded ant – orbicularis oculi , post – septum
orbitale & above by preseptal fat cushion..
a.Tarsal plate
v. Fibrous layer:- b.Septum orbitale
c. Medial palpebral lig.
d.Lateral palpebral lig.
a.Tarsal plate-
• Plates of dense fibrous tissue.
• Size – 29 mm long , 1mm thick, ht – upper 10-11mm & lower 4-5mm.
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15. 14
Parts Attachments
Sup border of upper tarsus Septum orbitale ,
Muller’s muscle
Inf border of lower tarsus Septum orbitale,
Capsulopalpebral fascia,
Inferior palpebral muscle
Ant surface of upper tarsus Levator aponeurosis
Post surface of both Conjunctiva
Lateral ends Whitnall’s tubercle by LPL
Medial end Ant lacrimal crest & frontal process of
maxilla by MPL.
Containts Mebomian glands.
16. b. Septum orbitale( palpebral fascia):-
Thin floating membrane of connec-
tive tissue.
Attachments peripherally to
orbital margins at thickening
called arcus marginale. & centrally to
convex borders of tarsal plates.
Relations:-
Ant-Orbicularis oculi , LPS
Post- Orbital fat , LPS, SO tendon
*On the upper medial angle ,There is tendency for fat to Herniate
through gap left by non attachment of septum to orbital margin
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17. Structures piercing :-
• Lacrimal nerves & vessels
• Supraorbital nerves & vessels
• Supratrochlear artery & nerve
• Infratrochlear nerve
• Anastomosing vein betn angular
& ophthalmic vein.
• Sup & Inf palpebral arteries
• Aponeurosis of LPS
• Expansion of LR
c. Medial palpabral lig – Triangular in shape.
Has anterior part-Attached to ant lacrimal crest & fans out laterally.
Angular artery & vein passes over medial part of ant surface..
Posterior part – passes behind lacrimal sac from ant to post lacrimal
crest..
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18. d.Lateral palpabral lig.- about 7 mm in length &2.5 mm in ht.
Attachments- laterally-whitnall’s tubercle
medially –lateral ends of tarsal plates
Relations - Ant surface- Lateral palpebral raphe
Post surface-check lig of lateral rectus.
Upper border – merges with aponeurosis of LPS
Lower border – merges with expansions of IO &
IR
vi. Layer of non striated muscle fibers:-
Contains Muller muscle k/a Sup & Inf palpebral muscles.
Origin:- terminal fibers of LPS in upper lid & IR in lower lid.
Insetion:- orbital parts of tarsal plates.
Nerve supply:- Sympathetic nerves
Action:- Retraction of lids
*paralysis leads to Horner syndrome.
vii. Conjunctiva.
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19. Glands of eyelid
Mebomian Zeis Moll Krause & wolfring
*modified sweat *modified seba *modified sweat *accessory lacrimal
Glands ceous glands glands glands
*+nt in sroma of *opens in eye *lie betn cilia *+nt along superior
tarsal plates lash follicle *numerous in border of upper
*20-30 in each lid *secretes sebum LL tarsus & inf border
*opens at post *prevents eye *r unbranched of lower tarsus
Part of intermarg- lashes to beco- spiral shape *2-5 in upper lid
Inal strip me dry & 2-3 in lower lid.
*Secretes sebum *contributes to
lipid layer of
tear film. Cont…..
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20. Mebomian glands:-
Functions:-
-Oily marginal tear strips prevent the
overflow of tears across lid margins.
-Oily layer of tear film prevents
evaporation of tears & allows free
movement of lid over globe.
-Ensures the airtight closure of eyelids
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21. • Arterial supply-
-Medial & lateral palpebral arteries
Br.of Dorsal nasal & Lacrimal artery
-Each medial artery anastomose
with Lateral artery to form
marginal arterial arcade.
• Venous drainage:- through 2 plexuses
i. Pretarsal plexus-drains structures superficial to tarsus.
medial side drains into angular vein Int jugular vein.
lateral side drains into superficial temporal & lacrimal vein
Exrtnal jugular vein.
ii. Posttarsal plexus- drains structures posterior to tarsus.
drains into Ophthalmic vein.
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22. • lymphatic drainage:
• Medial group Lateral group
Superficial trunk Deep trunk Superficial trunk Deep trunk
*Drains-
Structures of conjunctiva of Structure of
Medial ½ of LL medial 2/3 of LL Lateral ¾ of UL UL & conjunctiva
Medial ¼ of UL & caruncle Lateral part of LL of lateral 1/3 of LL
Medial cummisure
Superficial Deep Superficial parotid & Deep parotid
submandibular LN submandibular LN preauricular LN LN
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23. • Nerve supply:-
Motor supply –facial nerve (orbicularis), oculomotor N. (LPS)
Sensory –Trigeminal nerve
upper lidsupraorbital , supratrochlear, infra trochlear & lacrimal
lower lidinfraorbital , infratrochlear & lacrimal.
Sympathetic supply to muller’s muscle, skin & glands.
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24. Congenital anomalies of eyelid
A. Eyelid coloboma:-
-eyelid defect due to either due to failure of migration of lid
ectoderm to fuse the lid folds or mechanical forces such as
amniotic band.
*Upper lid coloboma-
Middle & inner 1/3
Associated with criptophthalmos,
Facial anamolies & Goldenhar syndrome.
i.e (Oculo-auriculo-vertebral syndrome)
*Lower lid coloboma-
N At junction of Outer & middle 1/3
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25. *Treacher collins syndrome –(mandibulofacial dysostosis)-
Malformation of derivatives of 1st & 2nd brachial arch…
B. Cryptophthalmos:-
-Eyelids absent
- Freaser syndrome: Syndactyly,
urogenatal & craniofacial abnormalities.
C. Euryblepharon:-
-Horizontal enlargement of palpabral fissure
+ lateral canthus ectropion
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26. D. Microphthalmos:-
-small eyelids , sometimes
associated with anophthalmos
E. Ablepharon:-
-deficiency of anterior lamellae of eyelid
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27. F. Ankyloblepharon:-
-upper & lowerlids are joined by thin tags..
G. Epicanthic folds:-
- Bilateral vertical folds of skin that extend
from upper & lower lids towards the medial canthus.
- pseudoexotropia
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28. H. Telecanthus:-
-Increased distance between the medial
canthi d/t abnormally long medial canthal
Tendon
- In contrast hypertelorism is wide bony
separation of orbits.
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30. Tear film –
• Consist of 3 layers-
i. Superficial lipid layer secreted by mebomian glands
ii. Middle layer of aqueous secreted by accessory lacrimal
glands & minimally by main lacrimal gland.
iii. Deeper layer of mucus secreted by goblet in conjunctiva..
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32. Tear film dynamics
Main role of lacrimal passage is to
establishe & maintain a contineous tear film over
preocular surface. Tear film dynamics include,
i. Secretion of tear film
ii. Formation of tear film
iii. Retaintion & redistribution of tear film
iv. Displacement phenomenon
v. Evaporation of tear film
vi. Drying & breakup of tear film
vii.Dynamic events during blinking
viii.Elimination of tears.
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33. i. Secretion of tear film
Tears are continuously secreted by
-Main lacrimal galnd (Reflex secetion) responsible for
hypersecretion.
-Acceessory lacrimal gland(basal secretion)secondary to light or
temp stimulation through propreoceptors
Supplied by afferent pathway through Trigeminal nerve &
efferent through parasympathetic .
Normal tear production @ about 1.2 µl/min , of volume approx.
7 µl, turnover rate 5-7 min .
* newborn babies secrete tears within 24 hrs but abnormal tearing
(hyper lacrimation) starts after the age of 4 mon.
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34. ii. Formation of tear film
Wettability of surface depends on angle Ø .
If angle θ=90 degree –surface is hydrophobic
If angle θ < 90 degree - surface is relatively hydrophobic
If angle θ = 0 degree – surface is hydrophilic
Corneal epithelium is relatively hydrophobic.
*During blinking lids spread conjunctival mucus over cornea &
converts it into hydrophilic surface
*On this aqueous layer spreads spontaneously.
*F/b lipid layer spreads contributing to its stability & reducing
evaporation .
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35. iii. Retention & redistribution of film
Tear film is retained at uniform thickness over corneal surface
against gravitational force due to outermost layer of corneal
epithelium long with mucopolysaccharide layer.
Redistribution occures in the form of bringing new tear fluid by
the way of marginal strip where there is constant flow of tears.
iv . Displacement phenomenon
When lower lid is displaced upward over the eye ball there occurs
displacement of monomolecular layer of tear film..
This phenomenon is attributed to Stability , compressibility &
elasticity of tear film.
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36. v. Evaporation of tear film
Evaporation is decreased by superficial lipid layer, specially
in arid &windy climate.
Rate of evaporation estimated to be 10% of production rate.
i.e approx. 0.12μl/min.
vi. Stability ,drying & rupture of tear film.
Tears can function properly only if it covers preocular surface &
redistributed quickly & completely after blink..
.When blinkiny is prevented for 15-40 secs , tear film ruptures
& dry spot appers..
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37. Holly & Lemp’s mechanism-
Tear film thins uniformly by evaporation
To some critical level , significant no of lipid
molecules begin atracting towards mucin layer
when mucin layer is sufficiently coated contaminated
by lipid migrating down to mucin layer.
it becomes hydrophobic
Tear film ruptures. Dry spot formation occurs
*twice more common temporally than nasally bcz nasal areas
are more protected against air current
.
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39. vii. Dynamic events during blinking
As upper lid moves downwards , superficial layer is
compressed.
Whole of lipid layer together with associated biopolymers gets
compressed betn lid edges.
When eyelid opens ,first the monomolecular lipid layer spreads
followed by multi molecular layer of lipids formed.
Thus removing the lipid contaminants from mucus layer &
removing the breaks.
Drainage of lacrimal fluid from lacus lacrimalis into
nasolacrimal duct. 20% -upper punctum
80%-lower punctum.
Lacrimal fluid from preocular surface reaches marginal strip
tears collects at Lacrimal lake in medial canthus lacrimal
canaliculi lacrimal sac NLD Inferior meatus
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40. Horner’s muscle constitute lacrimal pump.
Fibers of preseptal portion of orbicularis oculi that arises from
post lacrimal crest & lacrimal fascia.
A) Events occurring during closure of eyelid:-
i. Contraction of pretarsal fibers compresses ampulla &
shorten lacrimal canaliculi Propels tears from ampulla &
canaliculi towards sac
ii. Contraction of preseptal fibers pulls lacrimal fascia &
lateral wall of lacrimal sac laterally creates –ve pressure in
sac & opens sac draws fluid from canaliculi to sac
iii. Increased tension along lacrimal fascia inferior end of NLD
closes
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42. B) Events occurring during closure of lid:-
i. Relaxation of pretarsal fibers of orbicularis allows
canaliculi to open & expand draws tears from
lacrimal lake to canaliculi.
ii. Relaxation of preseptal fibers (Horner’s muscle)
causes lacrimal sac to collapse Expels fluid
downwards to open in meatus.
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44. Drainage of lacrimal fluid by NLD.
• Gravity
• Air current movement in nose- induces –ve pressure in
nose
• Hasner’s valve – Mucus membrane fold forming a valve
at lower end of NLD.
-remains open as long as pressure within nose is less
than NLD & allows tears to drain into nose.
- when intranasal pressure increase as in Blowing the
nose , Hasner’s valve closes there by preventing the
reflux upward.
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