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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
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Functionalanatomy of theperiorbitalregion Olga Lukáts 26.02.18.
Skin, subcutaneoustissue • 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 crease- posterior 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
Eyelidanatomy • Upper eyelid retractors
Eyelidanatomy • Lower eyelid retractors • - Capsulopalpebral fascia • Lockwood’s ligament • M. palpebralis Inferior
Orbitalseptum 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, denseplates of connectivetissue – skeleton of theeyelid • Uppereyelidtarsalplatemeasure 8-12 mm vertically in the center, thelowereyelid - 4 mm • Thickness is approx 1 mm
Eyelidanatomy • Tarsus • length 25mm • thickness 1mm • Height: • Upper 8- 12 mm • lower 4mm
Conjunctiva • Nonkeratinizing squamous epithelium – posterior surface of the eyelids • Goblet cells – mucin secretion • Krause és Wolfring glands – subconjunctival accessory lacrimal glands
Canthaltendon • 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
Lateral canthal tendon attaches at the lateral orbital tubercl – inner aspect of the orbital rim • upper and lower limb – tarsus – the lateral cantal area acute-angled then the medial
Eyelidanatomy • Medial canthal tendon
Eyelidanatomy • 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)
Eyelashes • In the upper eyelid approx 100 • In the lower eyelid approx 50 • 2-3 rows just anterior to the tarsal plate
Meibomianglands • 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
chalazion Hordeolum – internal or external
Bloodsupply • 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
Venaous drainage divided into pretarsal and posttarsal Pretarsal drain into the angular vein medially and into superficial temporal vein laterally • Posttarsal drainage is into the orbital veins and the deeper branches of the anterior facial vein and pterygoid plexus • Lymphatic vessels – medial portion of the eyelids drain into the submandibular lymph nodes • Lateral 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