Functional anatomy of the periorbital region Olga Lukts

Functional anatomy of the periorbital region Olga Lukáts 26. 02. 18.

Skin, subcutaneous tissue • Eyelid skin is the thinnest of the body - no subcutaneous fat tissue, the pretarsal tissues are normally firmly attached to the underlying tissue, the preseptal tissues are more loosely attached • Eyelid crease – attachments of the levator aponeurosis to the pretarsal orbicularis bundles and skin – at the level of the superior border of the tarsus • The lower eyelid crease is less well defined

Protractors Orbicularis oculi muscle – innervated by VII. facial nerve Divided into pretarsal, preseptal ( palpebral blinking) and orbital parts - forced eyelid closure

Gold weight loading – appropriated weight can be selected (0. 8 -1. 6 g)

Retractors Upper eyelid– levator muscle + its aponeurosis + superior tarsal muscle (Müller) - originates at the apex of the orbit – muscular portion is apprex 40 mm, Whitnall ligament – aponeurosis 14 -20 mm in length – anterior and posterior part – anterior lid creaseposterior inserts onto the anterior surface of the tarsus – innervation III. cranial nerve ( oculomotorius) + superior rectus muscle Lower eyelid – capsuloplapebral fascia – fuses with the orbital septum – attach to the inferior tarsal border

Eyelid anatomy • Upper eyelid retractors

Eyelid anatomy • Lower eyelid retractors • - Capsulopalpebral fascia – Lockwood’s ligament – M. palpebralis Inferior

Orbital septum Thin fibrous tissue Upper lid -superior orbital rim periosteum – fuses with the levator aponeurosis 2 -5 mm above the superior tarsal border Lower lid – inferior orbital rim periosteum – capsulopalpebral fascia – together attach to the inferior border of the tarsal plate

Tarsus • Firm, dense plates of connective tissue – skeleton of the eyelid • Upper eyelid tarsal plate measure 8 -12 mm vertically in the center, the lower eyelid - 4 mm • Thickness is approx 1 mm

Eyelid anatomy • Tarsus – length 25 mm – thickness 1 mm • Height: • Upper 8 - 12 mm • lower 4 mm

Conjunctiva • Nonkeratinizing squamous epithelium – posterior surface of the eyelids • Goblet cells – mucin secretion • Krause és Wolfring glands – subconjunctival accessory lacrimal glands

Canthal tendon • Important for the configuration of the palpebral fissure – medial and lateral – attach the tarsal plate to the orbital rim periosteum • Medial canthal tendon – origins from the anterior and posterior lacrimal crest just temporal to the lacrimal sac, split into upper and lower limb - tarsus • Anterior part attachment is diffuse and strong to the periosteum, the posterior part is more delicat –but important in maintaining apposition of the eyelids to the globe, and allowing the puncta in the tear lake

ØLateral canthal tendon attaches at the lateral orbital tubercl – inner aspect of the orbital rim Ø upper and lower limb – tarsus – the lateral cantal area acute-angled then the medial

Eyelid anatomy • Medial canthal tendon

Eyelid anatomy • Lateral canthal tendon

Eyelid margin • Mucocutan junction = gray line avascular zone border between the anterior and posterior part of the eyelid (isolated section of pretarsal orbicularis muscle (Riolan) just anterior to the tarsus) • Eyelashes and glands ( Meibomian gland orifices)

Healthy eyelid margin

Eyelashes • In the upper eyelid approx 100 • In the lower eyelid approx 50 • 2 -3 rows just anterior to the tarsal plate

Meibomian glands • • Originate in the tarsus Oil-producting sebaceous glands In the upper tarsus 25 , in the lower tarsus 20 (lipid layer of the tear film )

MEIBOMIAN GLAND DISFUNCTION MGD BLEPHARITIS

SEMMELWEIS EGYETEM SZEMÉSZETI KLINIKA

chalazion Hordeolum – internal or external

Blood supply • Eyelids have extensive vascularity • Two main systems – 1. internal carotid artery by way of the ophthalmic artery ( supraorbital and lacrimal branches) , 2. external carotid artery by the way of the face arteries ( angular and temporal ) extensive collateral circulation • forming the marginal and peripheral arcades

ØVenaous drainage divided into pretarsal and posttarsal Pretarsal drain into the angular vein medially and into superficial temporal vein laterally ØPosttarsal drainage is into the orbital veins and the deeper branches of the anterior facial vein and pterygoid plexus Ø Lymphatic vessels – medial portion of the eyelids drain into the submandibular lymph nodes ØLateral portion of the eyelids drain into the superficial preauricular nodes and into the deeper cervical nodes

Innervation • Sensory – V. cranial nerve ( nervus trigeminus) first branch ophthalmic nerve and second branch maxillary nerve • Motor – III. , VII. cranila nerve and sympathetic nerves