Anatomy of Eyelid كامل PDF

Anatomy and Physiology of the Eyelids Reem Shahin, M.optom Outline INTRODUCTION EMBRYOLOGY GROSS ANATOMY LAYERS OF EYELID GLANDS OF EYELID NERVE, VASCULAR SUPPLY AND LYMPHATIC DRAINAGE CLINICAL CORRELATION PHYSIOLOGY OF EYELID MOVEMENTS Importance of Eyeli...

Anatomy and Physiology of the Eyelids Reem Shahin, M.optom Outline INTRODUCTION EMBRYOLOGY GROSS ANATOMY LAYERS OF EYELID GLANDS OF EYELID NERVE, VASCULAR SUPPLY AND LYMPHATIC DRAINAGE CLINICAL CORRELATION PHYSIOLOGY OF EYELID MOVEMENTS Importance of Eyelids in Eye Health Lubrication: Eyelids play a key Protective Barrier: The eyelids role in spreading tears across Blink Reflex: Blinking helps are flexible, multilayered the eye surface, maintaining clear debris from the eyes and structures that shield the eyes, moisture, and preventing refreshes the tear film, acting as the first defence dryness. They are also essential contributing to overall eye against foreign objects, dust, for the distribution and drainage protection. and harmful substances. of tears. Aesthetic and Functional Role: Regulate Light: The eyelids Eyelids influence facial control the amount of light appearance and emotional entering the eye, helping expression while contributing to protect the retina from essential vision-related excessive light exposure. functions. Embryology Derived from surface ectoderm The upper eyelids are formed from the frontonasal process The lower eyelids are formed from the maxillary process Embryology Structure developed Time of gestation Appearance of the eyelid fold marks 6 or 7 week of gestation the beginning Eyelid fusion 8 to 10 weeks gestation. Development of eyelid structures 3 to 4 months gestation. Eyelid dysjunction (Reopening) 5 to 6 months gestation  Congenital Ectropion Ankyloblepheron Lid Coloboma Clinical correlation Cryptophthalmos Congenital Entropion Clinical correlation Blepherophimosis Epiblepheron Epicanthus Anatomy Upper eyelid extension Extension: From the eyebrow downward to end in a free margin Anatomical Portions: The upper eyelid consists of three sections: Orbital portion (upper part closer to the eyebrow) Tarsal portion (central part supported by the tarsal plate) Marginal portion (lower edge near the lashes) Note: Superior Palpebral Sulcus: A natural groove or fold that separates the orbital portion from the tarsal portion of the upper eyelid. This fold helps define the eyelid contour and is more pronounced in some individuals. Lower eyelid extension Extension: The lower eyelid transitions smoothly into the cheek, where the nasojugal and malar sulci mark the boundaries. Anatomical Portions: The lower eyelid is also divided into: Orbital portion (upper part closer to the eye socket) Tarsal portion (middle region supported by the tarsal plate) Ciliary margin (lower part near the eyelashes) Notee: Inferior Palpebral Sulcus: A faint groove that separates the orbital portion from the tarsal portion of the lower eyelid. It is less prominent than the superior sulcus and helps delineate the lower eyelid’s structure. Anatomy Eyelid Position - review Medial Canthus parts PALPEBRAL APERTURE OR FISSURE Diameter At birth Adult Horizontal 18-21mm 28-30mm Vertical 8mm 9-11mm Lid Margin What Gland Open at Lid Margine What Gland Open at Lid Margine Clinical Correlation Cyst of Moll Cyst of Zeiss Anatomy Clinical Correlation Distichiasis Trichiasis - Abnormal growth of lashes - Eyelashes are misdirected from Layers Of The Eyelids Skin & Muscles of Orbital subcutaneous protraction septum areolar tissue Muscles of Orbital fat Tarsus retraction Conjunctiva Layers Of The Eyelids Conjunctiva: Innermost layer of eyelid Posterior and innermost layer of the eyelid Transparent vascularized membrane covered by a non-keratinized epithelium that lines the posterior surface of the eyelids (palpebral conjunctiva)and the anterior surface of the globe (bulbar conjunctiva). Firmly adherent to the tarsus, for free mobility. Small accessory lacrimal glands (Glands of Krause & Wolfring) are located within the submucous connective tissue Let's Review https://www.youtube.com/watch?v=P0iHsYy4klA Nerve Supply of the Eyelid Motor Nerve Supply Motor nerves to the orbicularis oculi muscle - facial nerve (temporal & zygomatic branches) Motor nerve to the levator palpebrae superioris - Superior division of oculomotor nerve Motor nerve to the Müller muscle - sympathetic nervous system Sensory Nerve Supply Ophthalmic & maxillary divisions of the trigeminal nerve Upper eyelid - supraorbital, supratrochlear & lacrimal nerves (ophthalmic division) lateral portion of upper eyelid – zygomatico-temporal branch of the maxillary nerve extreme medial portion of both upper & lower eyelid - infratrochlear nerve lower eyelid - infraorbital nerve (maxillary division) Nerve Supply Nerve Supply Arterial Supply Marginal Arcade o Submuscular plane o In front of tarsal plate o 3-4 mm from lid margin o Lacrimal Artery ▪ Lateral Palpebral Artery o Dorsal Nasal Artery ▪ Medial Palpebral Artery Peripheral Arcade o Superior branch of Medial Palpebral Artery o Upper border of Tarsus Venous Drainage Venous Drainage Divided into pretarsal and postarsal Pretarsal which opens into subcutaneous veins and further drains into angular vein medially and superficial temporal vein laterally. Postarsal drainage is into orbital veins, then to ophthalmic vein and to cavernous sinus. To understand watch this video https://www.youtube.com/watch?v=0-9d5rb66Ek&t=270s Let's summarize The Eyelid Retractors Gland of the eyelid Clinical Correlation External Hordeolum (Common Stye) Localized suppurative inflammation of gland of Zeis and glands of Moll’s at lid margin at ciliary follicle. Internal Hordeolum( Meibomian stye) Internal Hordeolum is a suppurative inflammation of meibomian gland associated with the blockage of the duct. Chalazion Chronic granulomatous inflammation of meibomian gland or sometimes Zeis glands caused by retained sebaceous secretions Ocurrs secondary to obstruction of the gland duct. More common in upper eyelid appearing as hard, immobile, painless, roundish lump. Blepharitis Blepharitis is subacute or chronic inflammation of lid margin occurring as true inflammation. Bilateral and often misdiagnosed as conjunctivitis Types: Anterior Blepharitis: Affects the base of eyelashes and may be Staphylococcal, Seborrhoeic or parasitic. Staphylococcal: In case of Staphylococcal – Red eyes and peripheral corneal infiltrates (more common in atopic dermatitis) Common cause of ocular discomfort and irritation Posterior Blepharitis Yellow crusts are seen at the root of cilia Small ulcers which bleed easily on removal of clusters Seborrheic Blepharitis Primary anterior blepharitis with some posterior spill over Usually associated with seborrhea of scalp(dandruff) Accumulation of white dandruff like scales on lid margin Parasitic Blepharitis Due to crab louse very rarely to head louse Presence of nits at the lid margin and at roots of eyelashes Conjunctival congestion may be seen on long standing Meibomitis ( Posterior Blepharitis) Inflammation and obstruction of meibomian glands. Characterized by diffuse thickening of posterior border of lid margin which becomes rounded. Entropion Involutional entropion: Age related inward rolling of eyelashes mainly affecting lower lid Constant rubbing on the cornea cause irritation, corneal punctate epithelial erosions and sometimes ulceration Cicatricial Entropion Scarring of the palpebral conjunctiva can rotate the upper or lower lid margin towards the globe Causes include cicatricial conjunctivitis, trachoma, trauma and chemical injuries Involutional ectropion Age related outward rolling of eyelid margin mainly affecting lower lid Causes epiphora and on long standing become chronically inflamed and keratinized Lagophthalmos Incomplete closure of the palpebral aperture when attempt is made to close the eyes voluntarily. Occurs due to paralysis of orbicularis oculi muscle, cicatricial contraction, symblepharon, severe ectropion, proptosis etc. Blepharospasm It is the involuntary, sustained and forceful closure of the eyelids. Occurs in 2 forms: 1.Essential (Spontaneous) blepharospasm 2.Reflex blepharospasm. Thank you