ANATOMY OFANATOMY OFE Y E L I D SE Y E L I D S

FEIRUZ HAMID FEIRUZ HAMID UMAR BAHASYWEN UMAR BAHASYWEN

(A126670)(A126670)

EyelidsEyelids

Act to protect the anterior surface and Act to protect the anterior surface and cover the globe from local injurycover the globe from local injury

Spread tear film across the cornea with Spread tear film across the cornea with blinkingblinking

Aid in regulation of light reaching the eye Aid in regulation of light reaching the eye

Aid in tear flow regulation by their pumping Aid in tear flow regulation by their pumping actionaction

6 Structural Layers of Eyelid6 Structural Layers of Eyelid

1.1. Skin and subcutaneous tissueSkin and subcutaneous tissue

2.2. Striated Muscle ( Orbicularis Occuli & Striated Muscle ( Orbicularis Occuli & Levator Palpebral Superiosis ) Levator Palpebral Superiosis )

3.3. Muller’s MuscleMuller’s Muscle

4.4. Fibrous Layer ( Tarsal Plates & Orbital Fibrous Layer ( Tarsal Plates & Orbital Septum )Septum )

5.5. ConjunctivaConjunctiva

1. Skin and Subcutaneous Tissue 1. Skin and Subcutaneous Tissue

Skin :Skin : thinnest of the bodythinnest of the body2 layers :2 layers :

- Epidermis Epidermis - superficial keratinising stratified squamous epithelium- superficial keratinising stratified squamous epithelium- keratonocyte developed from basal cell layer- keratonocyte developed from basal cell layer

- DermisDermis- located below epidermis- located below epidermis- vascular connective tissue- vascular connective tissue- hair follicles, sebum gland and sweat gland- hair follicles, sebum gland and sweat glandUpper eyelid crease :Upper eyelid crease : caused by attachment of caused by attachment of levator aponeurosis to pretarsal orbicularis bundle and levator aponeurosis to pretarsal orbicularis bundle and skinskin

2. Striated Muscle2. Striated Musclea. Orbiccularis Occulia. Orbiccularis Occuli

Superficial muscles of facial expression Superficial muscles of facial expression Close the eyelids by moving down the upper lid to meet Close the eyelids by moving down the upper lid to meet the lower lid and palpebral fissure tighten up from the the lower lid and palpebral fissure tighten up from the outer to the inner canthusouter to the inner canthus300 msec to complete ; 1 blink / 3 sec300 msec to complete ; 1 blink / 3 secForms the thickess of the eyelidForms the thickess of the eyelidThe muscle divided into the The muscle divided into the orbitalorbital and and palpebralpalpebral parts, parts, with the latter being divided further into the with the latter being divided further into the preseptalpreseptal and and pretarsalpretarsal portions. portions. Palpebral :Palpebral : blinking, winking ( spontaneous )blinking, winking ( spontaneous )Pretarsal :Pretarsal : forced closureforced closureBoth of the palpebral and orbital portion is innervated by Both of the palpebral and orbital portion is innervated by facial nervefacial nerve

cont..cont..

b. Levator Palpebral Superiosisb. Levator Palpebral Superiosis

Originates at the inferior aspect of lesser Originates at the inferior aspect of lesser wing of sphenoid bone, just above the wing of sphenoid bone, just above the optic foramenoptic foramen

It is a skeletal muscle that aided by tarsal It is a skeletal muscle that aided by tarsal musclemuscle

Maintain the position of the upper eyelidMaintain the position of the upper eyelid

Innervated by oculomotor nerveInnervated by oculomotor nerve

the anatomy of of orbicularis occuli musclethe anatomy of of orbicularis occuli muscle

A : FrontalisA : FrontalisB : Corrugator B : Corrugator superciliarissuperciliarisC : ProcerusC : ProcerusD : Orbital D : Orbital orbicularisorbicularisE : Preseptal E : Preseptal orbicularisorbicularisF : Pretarsal F : Pretarsal orbicularis. orbicularis.

3. Muller’s Muscle3. Muller’s Muscle

Originate from the undersurface of the Originate from the undersurface of the levator in the region of the aponeurotic-levator in the region of the aponeurotic-muscle junction, and insert into the muscle junction, and insert into the superior margin of the tarsus. superior margin of the tarsus. To assist levator palpebral superiosis and To assist levator palpebral superiosis and raise the upper lidraise the upper lidInnervated by sympathetic nervous systemInnervated by sympathetic nervous systemFatty infiltration may occur, giving the Fatty infiltration may occur, giving the muscle a yellowish color, due to agingmuscle a yellowish color, due to aging

4. Fibrous Layer4. Fibrous Layer

a. Orbital Septuma. Orbital SeptumFibrous tissue, arises from periosteum of the Fibrous tissue, arises from periosteum of the orbital margin to the edge of tarsal platesorbital margin to the edge of tarsal platesLaterally attached to the orbital marginLaterally attached to the orbital marginHollowed by blood vassels, nerves, and Hollowed by blood vassels, nerves, and aponeurosis of the levatoraponeurosis of the levatorFuse with :Fuse with : - levator aponeurosis ( to cover - levator aponeurosis ( to cover the tarsal plate )the tarsal plate )

- capsulopalpebral orbital - capsulopalpebral orbital septum complexseptum complex

Weak and thin with ageWeak and thin with age

cont..cont..

b. Tarsal Platesb. Tarsal Plates

Dense connective tissue that responsible Dense connective tissue that responsible for the integrity of the lidsfor the integrity of the lids

Skeleton of eyelidSkeleton of eyelid

Each tarsus approximately 25 - 29 mm Each tarsus approximately 25 - 29 mm long and 1 mm thicklong and 1 mm thick

Upper plate ~ 10 – 12 mm highUpper plate ~ 10 – 12 mm high

Lower eyelid ~ 4 mm highLower eyelid ~ 4 mm high

5. Conjunctiva5. Conjunctiva

A clear mucous membraneA clear mucous membrane

Non-keratinizing squamous epithelium and Non-keratinizing squamous epithelium and goblet cellgoblet cell

Posterior layer of the eyelidsPosterior layer of the eyelids

Goblet cell – producing mucous Goblet cell – producing mucous component of tear filmcomponent of tear film

Other Anatomical ConsiderationOther Anatomical Consideration

1.1. Lid MarginLid Margin• Mucocutaneous junction (grey line)Mucocutaneous junction (grey line)• 2mm wide ; 30 mm long2mm wide ; 30 mm long

2.2. EyelashesEyelashes• One of the hairs that grow at the edge of the eyelidOne of the hairs that grow at the edge of the eyelid• Protect the eyeProtect the eye• Upper lid : 100 – 150 eyelashesUpper lid : 100 – 150 eyelashes• Lower lid : 50 – 75 eyelashesLower lid : 50 – 75 eyelashes• Eyelashes take about 7 – 8 weeks to grow back if pulled outEyelashes take about 7 – 8 weeks to grow back if pulled out

3.3. Meibomian GlandsMeibomian Glands• Also known as tarsal gland. Originated in tarsusAlso known as tarsal gland. Originated in tarsus• Located at the rim of the eyelids inside the tarsal plateLocated at the rim of the eyelids inside the tarsal plate• Responsible for the supply of meibum, and oily substance that Responsible for the supply of meibum, and oily substance that

prevents evaporation of the eye’s tear film.prevents evaporation of the eye’s tear film.• Upper : 25 glandsUpper : 25 glands• Lower : 20 glandsLower : 20 glands

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