At the lid fissures, the skin is tied to the ______.
Periosteum of the underlying facial bones by CT
What do the lid fissures limit?
Hemorrhage, edema, and herniated fat to the lower eyelid
What occurs when the attachments weaken with age?
Dermatochalasis - aka droopy lid
What are the 4 lid muscles?
Frontalis
Procerus
Corrugator
Obicularis Oculi
What are the 2 regions of the obicularis oculi?
Orbital region
Palpebral region
What three things make up the palpebral region?
Preseptal, pretarsal, ciliary regions
What are the functions of the lid?
Protection of the eye
Limits light entering eye
Contributes to tear production
Spreads tears across the cornea
Drainage of tears
What are the 6 layers of the lid?
1. Skin
2. Subcutaneous Areolar Tissue
3. Muscles
4. Submuscular Areolar Tissue
5. Fibrous tarsal plate
6. Conjunctiva
What are Dermal Glands?
Sweat glands (look like finger prints in H&E stain)
An everted upper eyelid would show what?
Stieda's grooves at the attached border of the tarsal plate
The outermost skin of the lid is how thick?
Thin - less than 1mm
The outermost skin of the lid is formed by what?
Multilaminar keratinocytes
Where do the multilaminar keratinocytes disappear at?
Mucocutaneous junction
What divides the upper lid into a pre-orbital portion and a lower pre-tarsal portion?
The superior palpebral furrow - aka orbital palpebral sulcus
What does blepharochalasis or dermatochalasis mean?
Baggy lids
What layer can be easily distended by edema? What type of tissue is it and what does it NOT contain?
Layer of subcutaneous aerolar tissue- loose connective tissue that contains NO fat
What muscle is most prominent in the muscular layer? What does it do?
The orbicularis oculi muscle- closes the eye lids
In the muscle layer what what two portions does it include adn what is it called at the lid margin?
Orbital and palpebral portion and at lid margin called "muscle of riolan
What is the muscle layer supplied by? (CN and two muscles)
Supplied by facial nerve (CN VII) and levator and tarsal muscle
What layer contains most of the nerves, vessels, and lymphatic?
Submuscular aerolar tissue
What layer is the orbital septum found in
Fibrous layer peripherally
What glands are found in the fibrous layer?
Tarsal glands (meibomian) found in the tarsal plate
What gives the lid their firmness?
Fibrous layer that includes the original septum and tarsal plate
What is the last layer? What does it contain?
Palpebral conjunctiva and contains sero mucous
What inervates the orbicularis oculi, what's its function, and type of muscle is it? Voluntary or involuntary?
It's striated, voluntary, CN7, and closes eyelid
What inervates the levator, what's its function, and type of muscle is it? Voluntary or involuntary?
Levator- striated, voluntary,
superior division of CN 3, raises
eyelid
What is another name for the tarsal muscle, what type of muscle is it, is it sympathetic or parasympathetic, and voluntary or involuntary?
Tarsal muscle (Mullers muscle)
- smooth muscle, sympathetic,
involuntary
How many cilia are found in the upper and lower lids?
150 upper
75 lower
How long does it take cilia to grow - how long do they last?
Grow - 10 weeks
Last - 5 months rach
What does the gray line do
Divides the lid anteriorly and posterior;y
What does the anterior portion of the gray line contain
Skin. Subcutaneous aerolar tissue and orbicularis
What does the posterior portion of the gray line include
Tarsal plate, smooth muscle, and conjuctiva
Why is the gray line gray
Avascular
What is the junction between the dry and moist portion of the eyelids
Mucocutaneous junction
What is important about the skin at the mucocutaneous junction
Skin changes from keratinized to non-keratinixed
Where is the subtarsal fold found?
Near the posterior border of the eyelid margin
What is important about the subtarsal fold in regards to the epidermis
Where the epidermis changes to palpebral conuctiva
What is the secretion of the tarsal glands
Meibum or sebum
How many tarsal glands are in the upper and lower lid
Upper 30-40
Lower 20-30
What is the purpose of the tarsal glands
Secretions prevent overflow of tears
Helps prevent evaporation
How do the tarsal glands run
Vertically
What is meibomitis
Infection of the meibomian glands
Tarsal plate is what kind of tissue
Dense connective tissue
Is the tarsal gland orifice found on the wet or dry side of the epidermis
Wet - past the mucocutaneous junction
Orbicularis muscle has what CN
7
What is the purpose / function of the orbicularis muscle
Closes the eyelid
What is the function of the Levator muscle? What cranial Nerve?
Raises the eyelid
CN 3
What is the innervation of the marshal muscle
Sympathetic involuntary (smooth muscle)
What drug stimulates the muller muscle?
Phenylephrine
The Levator muscle originates where
At the sphenoid bone - lesser wing
Does the Levator muscle run above or below the superior rectus
Above
The Levator muscle receives its blood supply from
The lateral branch of the ophthalmic artery
If the Levator muscle is affected due to CN 3 palsy - what happens
Ptosis - droopy eyelid
Is ptosis seen unilateral or bilateral?
Unilateral
What does the tarsal muscle do
Elevates the eyelid
Where is the tarsal muscle more developed
In the upper fornix
Where is the muller muscle located
Lies underneath the aponeurosis of the Levator
The tarsal muscle will interdigitate with what other muscle
The levator
Why is orbital cellulitis an emergency
It can easily progress to the brain (has already infiltrated past the orbital septum) - will affect the CNS
Is pre-septum cellulitis more dangerous or less dangerous
Less dangerous because it hasn't gone into the orbit yet
What is the gland of Zeiss?
Modified sebaceous gland
What does the zeiss gland secrete
Sebum
Where are the zeiss glands found
Attached to a hair follicle - 2 per follicle
What infection is associated with a zeiss gland
External hordeolum or a stye
What kind of secretion is associated with zeiss
Holocrine secetion
Ciliary glands are also called?
Moll glands
What kind of glands are moll glands
Modified sweat gland
How is the lumen of a moll gland compared to a zeiss gland
Moll have larger lumens
What is the mode of secretion of moll / ciliary glands
Apocrine
What gland provides the baseline of tears
Wolfring
What control - para or sym - is the Wolfring gland under
Sympathetic
How many Wolfring glands are there per lid
3-4 per lid
Are the Krause glands smaller or larger
Smaller
Where are the Krause glands found
Towards the fornix
How many Krause glands are there per lid
40-50 per lid
What is chronic chalazion
Inflammation of the tarsal gland
Are chalazions painful and red
No
Is a chalazion an infection
No
Is an acute chalazia - internal hordeolim - what is the infection in and how does it present
Infection of the tarsal gland
Red painful with discharge
What Is the lacus lacrimalis
Medial accumulation of tears
What is a yellowish modified skin with sweat glands and hair
Caruncle
What is the remnants of the third eyelid
Plica semilunaris
What is found in the plica semilunaris
Goblet cells and melanophores
What arteries supply the lid
Medial and lateral palpebral arteries
Branches of the ophthalmic and lacrimal arteries anastomoses to form what
The tarsal arcades at the lid margin
Stieda's grooves are attached where
To the border of the tarsal plate
How can you see steida's grooves
Evert the upper eyelid
The medial palpebral Arch is a branch of what artery
Ophthalmic artery
The lateral palpebral arch is a branch of what artery
Lacrimal artery
The lacrimal artery is a branch of what artery
Ophthalmic artery
What two veins make up the pre-tarsal venous system
The anterior facial and superior temporal veins
The anterior facial vein and superior temporal veins drain into
Internal and external jugular systems
What veins make up the post-tarsal region
The opthalmic / orbital veins
The opthalmic veins drain into what two things
Cavernous sinus and pterygoid plexus
The lateral portion of the upper and lower lids drain into the
Parotid lymph nodes
The medial portion of the upper and lower lids drain into
Submandibular nodes and submental
What nerve provides sensory innervation to the lid
5
The upper lid sensory is served mainly by
The supraorbital nerve
The upper lid sensory is served medially by
The Supra and infra trochlear nerve
The upper lid sensory is served laterally by
Lacrimal branches of the opthalmic nerve
The lower lid sensory is served by the
Infraorbital nerve
The infraorbital Nerve is a branch of what nerve
V2
What conjuctiva is found over the lid
Palpebral conjuctiva
What conjuctiva covers the sclera
Bulbar
What conjuctiva is adherent to the aerolar tissue
Fornix conjuctiva
The conjuctiva epithelium is how many cells thick
2-4 cells thick
The conjuctiva epithelium is what kind of cells
Non-keratinized straitifed squamous - all cells are nucleated
Where does the conjuctiva begin
Near the mucocutaneous junction
The conjunctival epithelium is continuous with what
The corneal epithelium
Where are goblet cells highly numerous
In the fornix conjuctiva
Where are goblet cells absent
At the mucocutaneous junction and limbus
Where are goblet cells very prevalent
Beyond the subtarsal fold
What produces the inner layer of the tear film
Mucin glands - MUC5AC
Review glands associated with each portion of the tear film.
Slide 54
Goblet cells are what kind of secretion - Holocrine or apocrine?
Both - normally Holocrine though
What layer is the outermost layer of tears?
Lipid layer
What glands help make the lipid layer?
Tarsal Glands
Zeis
Moll glands
What is the middle layer of the tears?
Aqueous Layer
What glands help make the aqueous layer?
Lacrimal Gland
Accessory Lacrimal Gland (Wolfring)
Fornix Accessory Lacrimal Gland (Krause)
What is the innermost layer of the tears?
Mucous layer
What glands help make the mucous layer?
Goblet cells
Lacrimal gland cells
What layer of the tear film has defense mechanisms?
Middle layer - Aqueous
What layer of the tear film wets the microvilli of the corneal epithelium?
Mucous layer
The lacrimal gland is separated into what two glands by what?
Orbital portion and palpebral portion by the aponeurosis of the levator muscle
The lacrimal gland receives blood by what artery?
Lacrimal artery
The lacrimal gland is drained by ______ into ______ vein.
Lacrimal vein into the opthalmic vein
The lacrimal gland is essentially ...
Acinus
The lacrimal gland may resemble what other gland (non-tear related)?
Parotid gland
The lacrimal gland is composed of two different cell types that secrete ....
Mucin and serous product
What are found in the tubules of the lacrimal gland?
Myoepithelial cells
The final product of the lacrimal gland has what kind of content?
Proteineous content that is bacteriocidial
What is a small orifice on the medial upper and lower lid margin?
Punctum lacrimalis
What is the papilla lacrimalis?
The raised tissue surrounding the punctum
Each canaliculi has a vertical and horizontal component of what dimensions?
Vertical 2mm
Horizontal 8mm
Where do canaliculi enter the lacrimal sac?
2mm below its apex
During blinking, the canaliculi are pulled _________, and _________.
Medially
Shortened and compressed
What compresses the canaliculi?
The lacrimal part of the orbicularis
The lacrimal sac measures how many mm long?
12mm
The nasolacrimal duct measures how many mm long?
18mm long
What does the nasolacrimal duct connect?
The inferior meatus of the nose with the lacrimal sac
What serves as a valve preventing air from entering the lacrimal sac when you blow your nose?
Plica lacrimalis
What is trachoma?
Where the eye-lid turns in
What is lagophthalmos?
The lid rolls out - can cause dry eye
What are pinguecula and ptyergiums caused by?
Overgrowths due to UV exposure