EYELID-1 ANATOMY, PHYSIOLOGY AND CONGENITAL

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Transcript EYELID-1 ANATOMY, PHYSIOLOGY AND CONGENITAL

The Eyelids
DR. NAILA ALI
ASSISTANT PROFESSOR
OPHTHALMOLOGY
The eyelids are movable folds which act
as a shutter protecting eye from injury or
excessive light.
 Both the upper and
lower eyelids meet at
medial and lateral
canthi with the opening
the papebral fissure
between them.
SURFACE ANATOMY
 Superior
Palpebral Sulcus
 Lateral Canthus
 Medial Canthus
 Palpebral Fissure
ON THE MEDIAL SIDE
 Lacus lacrimalis
 Caruncula lacrimalis
 Plica semilunaris
The medial 1/6th is distinct and it
contains
 papilla lacrimalis
 punctum lacrimalis
 canaliculus lacrimalis.
THE STRUCTURE
The margin of each eyelid is 2mm thick and 30mm long
It contains eyelashes and just posterior to it are the
meibomian glands orifices.
The tissues of the lids from anterior (cutancous) to posterior
conjunctival aspects as follows:-
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skin
subcutaneous areolar tissue
layer of striated muscle (orbicularis oculi)
sub muscular areolar tissue
layer of non striated muscle
the fibrous layer—including tarsal plate
conjunctiva
THE SKIN
 It is thinnest and marked
by sulci.
 The superior sulci is due
to aponeurosis of levalor
palpebrae superior
inserted into the skin.
 The less obvious lower
sulci is due to the skin
being tethered to the
underlying periosteum.
 Histologically it consist of
epidermis, sebaceous
and sweat gland and
melanocytes.
EYE LASHES
 100 in upper lid
 50 in lower lid
 Originate from anterior lamella in two or
three irregular rows.
 The upper lid lashes are directed upward,
and outwards
 The lower lid lashed are directed downward
and outwards
THE SUBCUTANEOUS
AREOLAR TISSUE
 It is a loose connective tissue containing
no fat.
 It is absent at medial and lateral angles,
ciliary margin and at sulci.
THE ORIBICULARIS OCULI
Part
Position
 Orbital
Surrounds the orbital
rim
 Preseptal In front of the orbital
Septum
 Pretarsal in front of the tarsal
Plate
Function
Forced lid closure
pull lacrimal fascia
laterally and
create a relative
vacuum in lacrimal
sac.
Close lid and pull
lacrimal puncta
medially
THE FIBROUS LAYER---ORBITAL
SEPTUM AND TARSAL PLATE
 Attached to the orbital
margin.
 Lies post to the medial
palpebral ligament and
lateral palpebral raphe
medially and laterally.
 With in the lids it is
thickened to form tarsal
plates—embedded in it
are tarsal glands.
THE LIGAMENTS
 The medial palpebral ligament attaches the
medial end of tarsi to lacrimal crest and
frontal process of maxilla.
 The lateral palpebral ligament attach the
lateral end of tarsi to margin tubercle on
marginal tubercle of zygomatic bone.
LEVATOR PALPEBRAE
SUPERIOR
 Originate from lesser wing
of sphenoid bone and is
inserted an aponeurosis
on the ant surface of
superior tarsal plate, skin,
lat palpebral ligament,
medial palpebral ligament
 From its inferior surface
arises the superior tarsal
muscle.
CONJUNCTIVA
 Thin mucous membrane lined by non
keratinized stratified squamous
epithelium.
 It has a richly vascularized Substantia
propria
 At the margin of the eyelids it is
continuous with the skin.
ARTERIAL SUPPLY
 The lateral palpebral
Artery---lacrimal artery.
 medial palpebral
artery---Ophthalmic
Artery.
 Marginal and
Peripheral arcades.
VENOUS DRANAGE
 Medially – Ophthalmic and angular vein
 Laterally-superficial temporal vein
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NERVE SUPPLY
Upper eyelid
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Supra orbital nerve
Supra trochlear nerve
Infra trochlear nerve
Lacrimal nerve
Lower eyelid
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Infra trochlear nerve
Infra orbital nerve
LYMPHATIC DRAINAGE
SECRETION OF THE EYELIDS
Glands
Tear Film Layer
 Meibomian gland
Oily layer
 Glands of Zei’s
 Glands of Wolfring
 Glands of Krause
Oily layer
Aqueous layer
Aqueous layer
Location
of glands
Tarsal
plate
Eyelashes
Tarsal plate
Fornix
Blinking
There are two main types of blinking
 Reflex blinking
 Spontaneous Blinking
Reflex Blinking
Tactile
 Corneal Touch
 Cortical Connection
 Dimunation of sensitivity in contact lens
wearer
Dazzle
 Bright light
 Optic nerve--- Superior colliculus
 Associated fiber to facial nuclei
Menace
 Sudden presence of near object
 Optic nerve--- Cortical Connection
 Predominantly cortical in nature
Spontaneous Blinking
– Occurs at regular basis without an apparent
external stimuli.
– Mechanics facilitates the drainage of tear film.
– Present in blind as no retinal stimuli are
required.
Blephrospasm
 Simultaneous forcible contraction of
orbiculars oculi.
 Forcible closure of the lids.
 Its role in surgical procedures.
 Anterior segment injury.
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