Eyelis

• Globe


  Not a Sphere, Ablate Spheroid
• Globe


  • Cornea anterior sphere (7.8mm)
  • Sclera posterior sphere(12mm)
• Geometric equator


  Lies mid plane between the 2 poles
• Anatomical Equator


  Tilted slightly backward on the temporal side (due to bulge of sclera on this side) & slightly forward on the nasal side
• Surgical Equator


  Greatest circumference of the globe approx. in the coronal plane
• Axes of the Eye

  • Optical Axis
  • Visual Axis
  • Fixation Axis
• Glabella


  Hairless prominent area where the two eyebrows are separated from each other
• Hair of eyebrows


  Comma-shaped appearance
• Synophrys


  Condition where two eyebrows meet in the center above the root of the nose
• Types of hair in the eyebrows

  • Fine vellus hair
  • Medium Size hair
  • Supercilia
• Eyebrows


  • Consist of thick skin covered by characteristic short, prominent hairs extending across the superior orbital margin
  • In men the brows run along the orbital margin, whereas in women the brows run above the margin
  • The muscles located in the forehead—the frontalis, procerus, corrugator superciliaris, and orbicularis oculi—produce eyebrow movements, an important element in facial expression
• Structure of the eyebrow

  • Skin (thick & contains glands)
  • Subcutaneous Tissue (less fat & fibrous in nature)
  • Layers of striated muscles (Frontalis, Orbicularis Oculi, Corrugator Supercilii & pyramidalis muscle)
  • Submuscular areolar Tissue (straited muscle)
  • Aponeurosis (covers entire scalp area & at eyebrow forms deepest layer)
• Frontalis muscle


  Originates high on the scalp and inserts into connective tissue near the superior orbital rim, fibers are oriented vertically and raise the eyebrow, causing a look of surprise or attention
• Corrugator Supraciliary


  Originates on the frontal bone and inserts into skin superior to the medial eyebrow, characterized as the muscle of trouble or concentration, fibers are oriented obliquely, it moves the brow medially, toward the nose, creating vertical furrows between the brows
• Procerus/pyramidalis


  The muscle of menace or aggression, originates on the nasal bone and inserts into the medial side of the frontalis, pulls the medial portion of the eyebrow inferiorly and produces horizontal furrows over the bridge of the nose
• Orbicularis oculi


  Lowers the entire brow, fibers of these muscles blend with one another and are difficult to separate
• Vessels & Nerves to Eyebrows

  • Blood supply: supraorbital & superficial temporal artery
  • Venous drainage: supraorbital, frontal, angular & superficial temporal veins
  • Lymphatics: medial-submaxillary lymph nodes, lateral- drain into the parotid lymph nodes
  • Sensory nerve supply: 1st division of trigeminal nerve
  • Motor nerve supply: temporal branch & buccal branch of CN VII
• Functions of the eyebrow

  • Facial configuration
  • Facial Expression
  • Protective function
  • Aid in eyelid movement
• Eyelids


  Folds of skin and tissue that, when closed, cover the globe
• Functions of the eyelids

  • Cover the globe for protection
  • Move the tears toward drainage at the medial canthus on closure
  • Spread the tear film over the anterior surface of the eye on opening
  • Contain structures that produce the tear film
• Palpebral fissure


  The area between the open eyelids
• Lateral canthus


  Located approximately 5 to 7 mm medial to the bony orbital margin and lies directly on the globe
• Medial canthus


  At the medial orbital margin but is separated from the globe by a reservoir for the pooling of tears, the lacrimal lake
• Plica semilunaris


  The floor of the lacrimal lake, a narrow, crescent-shaped fold of conjunctiva, located in the medial canthus, allows for lateral movement of the eye without stretching the bulbar conjunctiva
• Caruncle


  A small, pink mass of modified skin located just medial to the plica, covered with epithelium that contains goblet cells and fine hairs and their associated sweat and sebaceous glands
• Layers of the eyelids

  • Skin elastic, fine texture, thinnest
  • Layer of subcutaneous areolar tissue
  • Layer of striated muscle
  • Submuscular aerolar
  • Fibrous layer (tarsal plate, septum orbitale)
  • Layer of non-striated muscle fiber
  • Conjunctiva
• Orbicularis Oculi muscle


  Palpebral part helps in closing eyelids during blinking, sleep & voluntary closure, Orbital part help forced closure, pulling the eyebrow downward
• Levator palpebrae superioris muscle (LPSM)


  Originates on the lesser wing of the sphenoid bone above and in front of the optic foramen, and its sheath blends with the sheath of the superior rectus muscle
• Fibrous layer of eyelids

  • Medial & lateral Palpebral ligament
• Upper eyelid


  Divided into the tarsal and the orbital (or preseptal) parts, the tarsal portion lies closest to the lid margin, rests on the globe, and contains the tarsal plate, the orbital portion extends from the tarsus to the eyebrow, and a furrow—the superior palpebral sulcus —separates the tarsal portion from the orbital portion
• Lower eyelid


  The inferior palpebral sulcus, which separates the lower lid into tarsal and orbital parts, is often not very distinct, the tarsal portion rests against the globe, and the orbital portion extends from the lower border of the tarsus onto the cheek, extending just past the inferior orbital margin to the naso jugal and malar sulci
• Eyelid margin


  Rests against the globe and contains the eyelashes and the pores of the meibomian glands
• Cilia (eyelashes)


  Arranged at the lid margin in a double or triple row, with approximately 150 in the upper eyelid and 75 in the lower lid, curl upward on the upper and downward on the lower lid, replaced approximately every 5 months
• Gray line


  Groove that runs along the eyelid margin between the cilia insertions and the pores of the meibomian glands, the location of a surgical plane that divides the lid into anterior and posterior portions
• Lacrimal portion


  Medial one sixth of the eyelid margin
• Ciliary portion


  Lateral five sixths of the eyelid margin
• Lacrimal papilla


  Small elevation containing the lacrimal punctum, the opening that carries the tears into the nasolacrimal drainage system
• Palpebral portion of orbicularis oculi

  Occupies the area of the eyelid that rests on the globe and is closest to the eyelid margin, sometimes divided into pretarsal and preseptal parts, composed of semicircles of muscle fibers that run from the medial orbital margin and the medial palpebral ligament to the lateral palpebral raphe
• Muscle of Horner or lacrimal part (pars lacrimalis)


  Encircles the lacrimal canaliculi, contraction assists in moving tears through the canaliculi into the nasolacrimal drainage system
• Muscle of Riolan or ciliary part (pars ciliaris)


  Lies near the lid margin on both sides of the meibomian gland openings, maintains the lid margins close to the globe