Occular Anatomy: Eyelids

Functions of the eyelid

Physical Barrier

Protective Reflexes

Regulate the amount of light entering the eye

produce components of tears

help spread an drain tears

Eyelid protractors

closing

orbicularis oculi

corrugator supercilli

procesrus

Eyelid retractors

opening

levator palpebrae superioris

superior tarsal (muller) muscle

frontralis

lubcrication of the eye

glands of eyelids produce components of tears

lipids, mucin, aqueous

Spontaneous and voluntary blinks help to

spread the tears and drain tears

Eyebrows

loose areolar tissue from the scalp is continuouis with the submusclar layer of the eyelids

danger zone

loose areolar tissue where the scalp connects with the eyelids!!!!!!

Main boundaries of the eyelid

Sulci

eyebrow

malar sulcus

nasojugal sulcus

Sucli

superior palpebral sulcus

inferioir palpebral sulcus

superior palpebral sulcus

attatchment of LPS aponeurosis to skin

inferior palpebral sulcus

fascia around inferior rectus M attaching to skin

the position of the eyelids is determined by

Orbicularis oculi CN VII

Levator Palpebrae Superioris CN III

Superior Tarsal (Muller) Muscle Sympathetic

form palpebral fissure

Canthi

where the upper and lower eyelids meet

medial canthus

modified skin in the form of caruncle

and fold of the conjunctiva 0- plicae semilunaris

lid margins

eyelashes

muscle of reiolans (gray line)

meibimian glands

mucocutaneous junction

Eyelashes contain

sebaceous and sweat glands

richly innervated

Mucocutaneous junction

posterior border of the meibomian gland orifices

junction between conjunctiva and skin

Lid wiper

most of the posterior surface of the eyelid does not contact the eye during a blink

only a thin band of thickened palpebral conjunctiva contacts the eye

held against the eye bu the muscle of riolan

lid wuoer skims debris and spreads a thin uniform layer of tears

Layers of the eyelids

1. skin

1. Skin

very thin and more transparent than other facial skin

thinnest skin in the body - furrowed, no subcutaneous fat

elastic tissue is finer and less than elsewhere

- prine to wrinkle, depper fusures

- easukly disteneded

- elasticity decreases w age

skin glands

Glands of Moll

Glands of Zeis

Glands of Moll

sweat glands between the hair follicles. (apocrine)

Glands of Zeis

sebaceous glands (usually two) attached to hair follicles

same as meibomian glands

2. Muscular layer

orbicular oculi

orbicular oculi portions

Orbital Portion

Palpebral Portion

Orbital portion origin

Medial Palpebral Ligament

Depp orbital rim from supraorbital notch to infraorbital foramen

Orbital portion insertion

skin around the eye

Action of Orbital portion

Voluntary (forceful) closure of eyelids

Palpebral portion action

involuntary (gentle) closure of the eyelids - blink

Palpebral portion parts

Pre-septal

Pre-tarsal

Pre-septal origin

deep: posterioir MPL, lacrimal fascia, upper part of the posterior lacrimal crest

fibers from the preesptal orginin meet outside

lateral canthus forming the lateral pelpebral raphe

Pre-tarsal origin

deep: behind the upper half of the posterior lacrimal crest

superficial: lateral end of the antior limb of the MPL in front of the lacrimal foassa

Pars lacrimalis (Horner's muscle)

part of the deep origin of pretarsal portion of orbicularis muscle

splits in two and surrounds upper and lower canaliculi

helps with drainage of tears

Pars Ciliaris (muscle of riolan)

continuous medially with horner's muscle

continuation of Horner's muscle onto the upper and lower eyelids

Pars Ciliaris (muscle of riolan) function

Keeps margin of lid against the eye

Helps expel Meibomian gland content during blinking

Lacrimal Pump

contraction and relaxation of the Orbicularis Oculi helps drain the tears

Lids open

Orbicularis oculi relaxes

canaliculi fill

upper lacrimal sac empties

lower lacrimal sac and nasolacrimal duct fill

Lid closed

Orbicularis oculi contract

canaliculi empty

upper lacrimal sac fills

lower lacrimal sac and nasolacrimal duct empty

5. Fibrous Layer

muscle and connective tissue

Muscle in the fibrous layer

Levator Palpebrae Superioris

Superior Tarsal Muscle (muller)

Levator Palpebrae Superioris

elevates and retracts eyelid

Levator Palpebrae Superioris innervation

CN III

Levator Palpebrae Superioris origin

Whitnalls Ligament

Insertions of aponeurosis of Levator Palpebrae Superioris

Superior fornix of conjunctiva

tarsal plate

Skin of eyelid

MPL and medial rim of orbit

Lateral oribtal tubercle

Superior tarsal muscle (of Muller) origin

from inferioir surface of the aponeurosis of the levator

Superior tarsal muscle (of Muller) insertion

superior fornix and upper margin of the tarsal plate

Superior tarsal muscle (of Muller) innvervation

sympathetic

Superior tarsal muscle (of Muller) function

helps keep the lid raised after Levator PS has raised it

Orbital septum

extensin of periorbita

separates eyelid from the orbit

attaches to the tarsal plate

fuses withe levator

Tarsal plate

dense connective tissue

Protective barrier

NO cartilage

contains meibomian glands

tarsal plate attachement anterior

separated from Orbicularis Oculi M by the levator M

tarsal plate attachement posterior

attached to palpebral conjunctiva

tarsal plate attachement superior

attached to orbital septum and superior tarsal muscle

tarsal plate attachement laterally

medal palpebral ligament

lateral palpebral ligament

medial palpebral ligaments

very superficial

junst under skin

lateral palpebral ligament

inserts deeper

inside orbital rim

medial palpebral ligaments is anterior to

orbital septum

lateral palpebral ligaments are behind

the orbital septum

inside orbit!!

Glands of the tarsal plate

Meibomian glands

meibomian glands

sebaceous holocrine glands within the tarsal plates - secrete meibum

more in upper lid than lower lid

open on lid margin

contributes to the lipid layer of tears

Secretino of the muscle or riolan helps

expel secretion from meiobiom glands

Conjunctiva accessory glands

krause (fornix)

Wolfring (upper tarsal plate)

basal tear secretion - aqueous

Blood supply SEE SLIDES and lymph