Ocular Adnexa PDF

Ocular Adnexa Karen Gil MD, MHSN Ocular Adnexa Development • Eyelids – 2nd month – form from the folds of surface ectoderm filled with mesenchyme • Eyebrows and Eyelashes • Surface ectoderm 4.5 months Eyebrows • Thick skin covered by characteristic short, prominent hairs extending across the s...

Ocular Adnexa Karen Gil MD, MHSN Ocular Adnexa Development • Eyelids – 2nd month – form from the folds of surface ectoderm filled with mesenchyme • Eyebrows and Eyelashes • Surface ectoderm 4.5 months Eyebrows • Thick skin covered by characteristic short, prominent hairs extending across the superior orbital margin • Important element for: – Protection – Facial expression • The cilia of the eyebrows and eyelashes are highly sensitive and are able to elicit a blink reflex when necessary Eyebrows • The forehead muscles produce eyebrow movements for facial expression C • Each is innervated by CN VII (Facial) • Muscles: & – – – – Frontalis charge of Corrugator eyebrow Procerus Orbicularis Oculi in : elevation movement of eye medially Tarsal plates brows a forehead Eyebrows • Frontalis – The main elevator of the eyebrows and forehead – Rises eyebrow for a look of surprise • Corrugator – Medial depressor of eyebrow – Moves brow medially for look of concentration Eyebrows • Procerus: – Medial depressor of the eyebrow – Pulls medial portion of brow inferiorly for appearance of menace or aggression • Orbicularis Oculi – Primary lateral depressor of the eyebrow - Closes eyelid Eyelids • Also called palpebrae • Are folds of skin and tissue • When close cover the globe • Four major functions: 1. Cover the globe for protection 2. Move the tears toward drainage at the medial canthus on closure 3. Spread the tear film over the anterior surface of the eye on opening 4. Contain glands that produce the tear film Eyelids • Palpebral fissure - – Area between the open eyelids – Upper eyelid margin is positioned 1-2 mm below Superior limbus should not the superior limbus – Lower eyelid margin is usually lying at the inferior limbus or 1mm below (variable) be seem 27-30mm Eyelid Creases • Superior palpebral crease • Inferior palpebral crease • Malar crease • Nasojugular crease Eyelids • Upper and lower eyelids meet at the corners of the palpebral fissure in the lateral and medial canthus – Lateral canthus • Approximately 5 to 7 mm medial to the bony orbital margin and lies directly on the globe – Medial canthus • Is a medial orbital marginal but is separated from the globe by a reservoir for the pooling of tears, the lacrimal lake Eyelids • Plica semilunaris (semilunar fold) – Is the floor of the lacrimal lake – Is a narrow, crescent-shaped fold of conjunctiva – Allow lateral movement of the eye • Caruncle – Small pink mass of modified skin just medial to the plica – Covered with epithelium, contains goblet cells and fine hairs Caruncle Lacrimal Punctum Eyelid topography • Upper eyelid: – Tarsal • • • • Lies close to the lid margin Rest on the globe Contains the tarsal plate Skin is thin – Orbital • Extends form the tarsus to the eyebrow • Superior palpebral sulcus – separates the tarsal and the orbital portion – Fibers of the superior palpebral levator muscle pass through the fibers of orbicularis oculi and get inserted into the skin Eyelids Topography Lower eyelids • Inferior palpebral sulcus – Separates the lower lid into • Tarsal – rest against the globe • Orbital – extends from the lower border of the tarsus onto the cheek, extending just past the inferior orbital margin to the nasojugal and malar sulci Eyelid Margin • Rest against the globe and contains – Eyelashes (cilia) – Pores of the meibomian glands • Eyelashes – Arranged at the lid margin in a double or triple row – Approximately 150 upper lid and 75 in the lower lid – Supplied with nerves, causing sensitiveness that will elicit a protective response (blink) Eyelid Margin • Meibomian glands – Located posterior to the cilia, and the transition from skin to conjunctiva (mucocutaneous junction) – Gray line • Runs between the cilia insertions and the pores of the meibomian glands Eyelid Margin • Eyelid margin divided into: – Lacrimal portion • The medial one sixth – Ciliary portion • The lateral five sixths • The division is at the lacrimal papilla – Small elevation containing the lacrimal punctum Ciliary Lacrimal portion portion Layers of the Eyelids 1. Skin layer 2. Subcutaneous layer 3. Orbicularis layer – – Orbital portion Palpebral portion 4. Orbital septum 5. Posterior muscular system 6. Tarsal plate 7. Palpebral conjunctiva Layers of the Eyelids Layers of the Eyelids • Skin Layer & – Thin layer of skin that contains fine hairs, sweat and sebaceous glands – The skin layer of the eyelid is unique because is the thinnest in the body and contains no fat - Regenerates very fast (24-48 urs) • Subcutaneous areolar layer – Thin layer of loose connective tissue – Lies between the outer skin and underlying orbicularis Orbicularis Layer • Contains the palpebral portion of the orbicularis oculi (facial expression –CN VII) • Orbicularis oculi portions: – Orbital portion – Palpebral portion • Pre-septal • Pre-tarsal Orbicularis Layer 1. Orbital portion – – Attaches to orbital margins, extends outward Used for forced closure of the eyelids Orbicularis Layer 2. Palpebral portion – Used for spontaneous and reflex blinking – Two specialized areas: • Muscle of Riolan – Most superficial portion – Keeps lid margin tightly applied to globe during eye movements – May contribute to rotating the eyelashes toward the eye during eye closure • Muscle of Horner – Fibers of the orbicularis which help drain tears into the lacrimal sac Orbital Septum Layer • Dense irregular connective tissue (in upper and lower lids) • Serves as a barrier • Restricts fat from falling down onto the lids margins • Keeps infections localized to the anterior portion of the eyelid, away form the orbit Posterior Muscular System • Consist of: – Superior levator palpebrae muscle – Superior and inferior tarsal muscle of Muller Posterior Muscular System Posterior Muscular System Superior palpebral levator muscle • Originates from lesser wing of sphenoid • The main retractor of the upper eyelid (15mm) • Whitnall’s ligament (superior transverse ligament) – serves as a fulcrum and changes the course of the muscle from anterior-posterior direction to superior-inferior Posterior Muscular System Superior Palpebral levator Muscle • Levator aponeurosis: – As the levator enters the eyelid become a fan-shaped tendon – Sends fibers anteriorly through the orbital septum to attach to the skin and superior surface of the tarsal plate (creates the palpebral sulcus) Posterior Muscular System Muscle of Muller (Tarsal muscle) • Smooth muscle • Innervated by the sympathetic nervous system • Originates on the levator and extends into the tarsal plate • Widens the palpebral fissure by providing 2-3 mm of upper eyelid lift (minor retractor) Tarsal Plate • Dense irregular connective tissue that provides rigidity to the eyelids • Consist of collagen fibrils that run horizontally and vertically to surround meibomian glands (sebaceous glands) Tarsal Plate Palpebral ligaments • Bands of dense connective tissue connecting the tarsal plates to the orbital rim and holding the tarsal plates in position – Medial palpebral ligament – Lateral palpebral ligament Tarsal Plate Palpebral ligaments • Medial palpebral ligaments – Divides into two limbs – One attaches to the posterior lacrimal crest – One to the anterior lacrimal crest – Both limbs lie anterior to the orbital septum Tarsal Plate Tarsal Plate Lateral Palpebral Ligament • Posterior to the orbital septum • Attaches the lateral edges of the tarsal plates to the lateral orbit margin at the lateral orbital tubercle Inferior Eyelid • • • • • • Skin Orbicularis Muscle Orbital septum Capsulopalpebral fascia Tarsal Plate (tarsus) Inferior tarsal muscle – Retractor of the inferior lid • Lockwood’s suspensory ligament Palpebral Conjunctiva • Inner lining of eyelids • Two layers: – Stratified Squamous epithelial layer (outer) – Submucosa (inner) Palpebral conjunctiva Fornix Bulbar conjunctiva Palpebral Conjunctiva Stratified epithelial layer • Outer protective layer that extends into the fonices and onto the bulbar conjunctiva • Contain goblet cells (produce innermost mucous layer of the tear film) • Crypts of Henleinvaginations of conjunctival epithelium Palpebral Conjunctiva Submucosa • Loose vascularized connective tissue • Two layers: – Outer lymphoid layer: • Immunologically active layer • IgA, macrophages, mast cells, PMN’s and eosinophils – Deep fibrous layer: • Contain accessory lacrimal glands, nerves, blood vessels • Continues with the dense connective tissue of the tarsal plate Glands of the Eyelid • • • • • Meibomian Glands Glands of Zeis Glands of Moll Glands of Krause Glands of Wolfring Glands of the Eyelid Meibomian Glands Clipid layer of fear film) • Large sebaceous glands • Located posterior to the eyelashes (inside tarsal plates) • Occupying the length of the tarsal plate • The opening duct is located in the eyelid margin - Obstructed fluid to can form accumulate Nowdeolum/stye C arronia) not ↑ Chalazion is Chronic # disease X A Glands of the Eyelid Glands of Zeis • Modified sebaceous glands associates with eyelash follicles (usually two Zeis glands per follicle) • Lubricate the eyelashes to prevent them form becoming brittle Glands of the Eyelids Glands of Moll • Modified sweat glands • Associated with eyelash follicles Glands of the Eyelids Glands of Krause smore superior the Working aqueous / Produce sucretion C • Accessory lacrimal glands • Located in the fornices • Are merocrine glands – the cell remains intact and secrets a product • Secrete fluids same as the main lacrimal gland Glands of the Eyelids Glands of Wolfring • Accessory lacrimal glands • Larger than glands of Krause • Predominate near the tarsal conjunctiva Innervation of the Eyelids • The trigeminal nerve (ophthalmic and maxillary divisions) provide sensory innervation • Upper eyelid – – Supraorbital – Supratrochlear – Infratrochlear – Lacrimal nerves (branches of the ophthalmic division) • Lower eyelid – – Infratrochlear (branch of the ophthalmic division) – Infraorbital nerve (branch of the maxillary division) Innervation of the Eyelids • Voluntary motor: – Temporal and zygomatic branch of the facial nerve – Supplies orbicularis muscle • Involuntary motor: – Sympathetic nervous system – Supplies the tarsal smooth muscles Blood Supply of the Eyelids Blood Supply of the Eyelids • Internal Carotid Artery Ophthalmic Artery Medial Palpebral Artery Lacrimal Artery Lateral Palpebral Artery anastomose Peripheral Arcades Blood Supply to Eyelids Peripheral Arcades • Two arcades each in the upper and lower eyelids – Marginal palpebral arcade (near lid margin) • Superior and Inferior – Peripheral palpebral arcade (near orbital edge of the tarsal plate) • Superior and Inferior • Main blood supply to the deeper eyelid structures Eyelids Physiology • Types of blinking 1. Spontaneous blinking 2. Reflex blinking 3. Forced blinking Eyelids Physiology • Spontaneous blinking – Most common – Maintains optics and comfort – Blink rate: 15/minute – Due to contraction of the palpebral portion of the orbicularis oculi Eyelid Physiology • Reflex Blinking: – Blink caused by sensory stimuli • Auditory: detection of loud noises (CN VII) can elicit a blink reflex • Touch or Irritation: CN V senses, CN VII causes the blink • Dazzle: bright light, received by CN II, stimulates reflex blink • Menace: an unexpected object threatens the eyes, received by CN II, causing a blink reflex Eyelid Physiology • Forced blinking – Voluntary closure that requires palpebral and orbital portions of the orbicularis Eyelid Physiology • During a blink, the globe is retracted approximately 1mm back into its socket • Voluntary closure of the lids produces an up an outward rotation of the globe • For protective reasons • Known as Bell’s Phenomenon Eyelid Physiology Role of Eyelids in Tear Processes • Distribution – The upper lid blanks laterally to medially – Wiping a thin film of tears over the corneal epithelium and bulbar conjunctiva – Each blink spreads the mucous layer evenly over the corneal epithelium to aid in proper tear film development 1). The distribution of these tears over the surface of the eye is achieved by movements of the eyelids (2) that spread the marginal tear bead (inset) shown here in optical cross section by a slit lamp beam. The passage of tears into the nose occurs via the lacrimal drainage system. (From Zide BM, Jelkes G. Surgical Anatomy of the Orbit. New York: Raven Press, 1985.) Eyelid Physiology Role in Eyelids in Tear process • Production – Blinking stimulates the secretion of lipid from the Meibomian glands to the tears – Also Zeiss glands (as sebaceous glands in the tarsal plate) contribute to the lipid layer – Accessory lacrimal glands: • Krause (fornices) • Wolfring (tarsal conjunctiva) Eyelid Physiology Role of Eyelids in Tear Processes • Drainage (lacrimal pump theory) – The muscle of Horner (part of the orbicularis) surrounds the canaliculi, contracts upon eyelid closure and shortens the length of the canaliculi by moving it medially – This action aids in pumping the tears into the lacrimal sac Eyelid Physiology • Eyelashes – Screen and sense the environment – Protect the eyes by inducing blink reflexes when necessary • Glandular secretion – The secretions and blinking, assist in proper hydratation of the cornea and movement of debris away the cornea Clinical Applications Lagophthalmos • Inability to oppose the eyelids on attempted lid closure • Cause: physiological, mechanical or paralytic (VII CN palsy) • More evident during sleep • Orbicularis oculi affected Clinical Applications • Xanthelasma – Yellow plaques of lipid – Commonly near the inner canthus – Common in patients with hyperlipidemia Clinical Applications • Madarosis – loss of eyelashes • Trichiasis – misdirected growth of eyelashes Clinical Applications • Poliosis – Depigmentation of the hair • Sarcoidosis • Thrichomegaly – Thick and longer eyelashes • Cancer tx • AIDS tx • Glaucoma tx Clinical Applications ~ • Pediculosis of the Eyelashes – Lice infestation ~ overcrowded sexual rooms abuse in children Clinical Applications • Ectropion – – eversion of the eyelid margin – loss of muscle tone – Part of normal aging process • Entropion – – Inversion of the lid margin – Spasm of the orbicularis oculi muscle Clinical Applications • Epicanthus – Vertical fold of skin at the nasal canthus – Common in newborn – Appearance of esotropia – As bridge of the nose develops, gradually disappears Clinical Applications • Ptosis – Upper eyelid droops or sags – Cause: • Multiple causes – Congenital » Myopathic ptosis » Blefarophimosis syndrome » Marcus- Gunn jawwrinkling syndrome – Acquired » Third nerve palsy » Horner’s syndrome » Myasthenia gravis » Aponeurotic ptosis » Mechanical ptosis Clinical Applications • External Hordeolum – Acute inflammation of an eye gland – Usually caused by staphylococci – Infected Zeis or Moll gland • Internal Hordeolum – Infection of a meibomian gland Clinical Applications • Chalazion – Localized, noninfectious, and sometimes painless swelling of a meibomian gland – Often caused of an obstructed duct Clinical Applications • Meibomitis – Dysfunction and inflammation of the Meibomian glands