EYELIDS: REVIEW OF CLINICAL ANATOMY AND PHYSIOLOGY · Anatomy Mobile tissue curtains placed in...
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Transcript of EYELIDS: REVIEW OF CLINICAL ANATOMY AND PHYSIOLOGY · Anatomy Mobile tissue curtains placed in...
EYELIDS: REVIEW OF CLINICAL
ANATOMY AND PHYSIOLOGY05.09.2014
Ayesha S. Abdullah
Learning outcomes
Correlate the structure of the eyelids with their functions
Identify the anatomical landmarks and histological
structures on photographs and microphotographs of the
eyelids.
Important superficial anatomical
landmarks
Lid margin
Upper lid creasePalpebral fissure height
(max)
Palpebral fissure length (max)
Anatomy
Mobile tissue curtains placed in front of the eyeballs
1. Cutaneous layer
Delicate, elastic with fine downy hair
Loose areolar layer beneath it
Gross oedema
2. Muscular layer
i. Orbicularis oculi
ii. Levator palpabrae superioris
iii. Muller’s muscle
3. Fibrous layer
i. Septum orbitale
ii. Tarsal plate with meibomian glands.
4. Mucous membrane Conjunctiva
CMFM
The eyelid margin
Glands of the eyelids
1. Mebomian glands:
Modified sebaceous glands,
30-40 in upper lid, 20-30 in lower lid.
2. Glands of Zeis:
Sebaceous glands along the hair follicles of lashes
3. Glands of Moll:
Modified sweat glands, lies between the lashes, opens
directly on lid margin or into the glands of Zeis.
Blood Supply
Lacrimal and palpebral branches of ophthalmic
Facial artery
Superficial temporal artery
Infraorbital artery
Upper lid has two arterial arcades
Lower lid has one arterial arcade
Nerve Supply
Supratrochlear, supraorbital and lacrimal are branches
of ophthalmic division of V. nerve.
Infraorbital, a branch of the maxillary division of V.
nerve
Venous & Lymphatic Drainage
Ophthalmic Vein
Temporal vein
Facial vein
Outer portion drains to preauricular L.nodes.
Inner portion to submandibular nodes.
Physiology
Protective
Reflex blinking—protects from air-born particles and intense light.
Optical—spreads tear, oily layer
Supportive– stabilizes globe
Lacrimal- pump mechanism in drainage of tears down the canaliculi
Cosmetic
Facial Expressions
Opening movements
LPS muscle – primary elevator
Fronatalis muscle – Accessory elevator
Muller’s muscle
Lower lid retractors
Closing movements
Orbicularis muscle – 3 diff functional units
Spontaneous blinking & tactile corneal reflex Pretarsal
Voluntary blinking and sustained activity - Preseptal and Pretarsal
Forceful closure – pretarsal, preseptal and orbitral fibres
Congenital anomalies
Coloboma
Epicanthus
Distichiasis
Blephrophimosis syndrome
Anchyloblephron
Congenital ectropion
Telecanthus
Anomalies of Eyelashes
Trichiasis
Congenital or acquired
Trachoma, chronic blephritis, membranous
conjunctivitis
Madarosis (Scanty eyelashes)
chronic blepharitis, skin disorders and leprosy
Poliosis (Whitening of eyelashes)
chronic blepharitis and trachoma
HW
What is the significance of Gray Line at the lid margin?
One line answer
Due date: Friday 12th Sep
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