• 65 Mario Capecchi Drive
  • 175N 400W
  • 2255N 1700W
  • 617 E. Riverside Drive
  • 552 N. Dixie Drive
  • Harley Street
  • 1025 E. 3300 S.

Orbital Tumors - Anatomy



  • thinnest in body, no subcutaneous fat
  • upper lid crease (fold) = levator . attachment to pretarsal orbicularis and skin; located at level of sup border of tarsus
  • upper puntca is more medial
  • mucocutaneous border is post to meibomian gland level
  • gray line = muscle of Riolan (superficial orbicularis)
  • Zeis, sebaceous glands (holocrine) with cilia
  • Moll glands (only apocrine gland on lid) with skin
  • 100 lashes on upper lid, 50 on lower


    • extensive anastamosis between supraorbital, lacrimal branches of ophthalmic a. (from internal carotid) and angular and temporal a. (from ext carotid)
    • venous drainage: pretarsal, poatarsal
    • NO lymphatics for the orbit except in conjunctiva
    • eyelid medial lymphatics drain to submandibular nodes and laterally to preauricular nodes
  • Subcutaneous tissue
    • no fat, loose connective tissue holds fluid in preseptal > pretarsal area b/c less firmly attached
    • main protractor
    • supplied by Cranial Nerve VII, narrows PF, helps lacrimal pumporbital
    • voluntary sphincter (wink, blepharospasm)
    • origin at medial canthal tendon and corrugator supercilius muscle
    • palpebral (pretarsal & preseptal)
    • reflex blink and involuntary
    • pretarsal origin at post lacrimal crest (most important to keep lid apposed to globe to let punctum lie in tear lake ) & ant limb of med canthal tendon; deep head of pretarsal m. (Horner’s tensor tarsi) encircles canaliculi to facilitate tear drainage
    • upper & lower segments of pretarsal orb m. fuse to become lateral canthal tendon
    • pretarsal muscle firmly adherent
    • pretarsal muscle of Riolan = gray line = superficial orbicularis
    • extension of periosteum
    • in non-Asians, upper lid septum fuses w/levator aponeurosis. 2-5 mm above sup tarsal border; in lower lid it fuses w/capsulopalpebral fascia at or just below inf tarsal border
    • passes medially in front of trochlea
    • barrier to hemorrhage and infection between lid and orbit
    • orb fat can herniate through septum into lids causing bags
    • central orb fat pad lies behind septum, in front of levator aponeurosis.
    • dense connective tissue, attach med & lat to periosteum
    • 1 x 29 x 11 mm upper lids, 4 mm vertical height in lower lids
    • meibomian glands are modified holocrine glands
    • in upper lid marginal arcade lies 2 mm sup to lid margin, ant to tarsus
    • peripheral art arcade is sup to tarsus, between levator aponeurosis, Muller’s

Lacrimal Anatomy

  • Lacrimal Gland
    • separated from orbit by fibroadipose tissue
    • divided by LPS aponeurosis, smaller palpebral portion visible, larger orbital half hidden
    • blood vessels, lymph, nerve, and excretory ducts pass from orbital part through palpebral section
      • don’t biopsy or remove palpebral lobe which might significantly reduce tearing
    • ducts empty 5mm above superior tarsal border
    • reflex tear arc: afferent from V stimulates tear production from lacrimal gland; efferent complicated (with parasympathetics from VII, sympathetics not understood)
    • exocrine gland, acinar and myoepithelial cells, lacrimal artery
  • Accessory Glands of Krause and Wolfring
    • no neural control, basal tear production (BST)
    • located in sup fornix & above sup border of tarsus
  • Canalicular System
    • puncta sit in tear lake, approx 6mm from canthus, then 2 mm ampulla, then canaliculi extend medially 8-10 mm to common canaliculus (in 90% of population), then to lat wall of tear sac
    • dilation prior to sac: sinus of Maier, enters sac superior and posterior
    • valve of Rosenmuller prevents reflux from sac into common canaliculus during tear pump
    • sac lies btw ant and post crura of med canthal tendon in lacrimal sac fossa
    • puncta/lids move medially with lid closure
    • deep heads of preseptal orbicularis (Horner’s muscle) inserts on post lacrimal crest, lateral half of superior lacrimal sac, encircles canaliculi to help pump
  • Bony System
    • interosseos direction of Nasolacrimal Duct = inferior and slightly. lateral, posterior
    • Nasolacrimal Duct is approx 12 mm long, intranasal ostium high up in inf turbinate, covered by valve of Hasner, approx 2.5 cm post to naris on lat wall
    • lacrimal bone very thin, therefore aim posteriorly in DCR
    • ethmoid air cells are at superior and deeper parts of fossa, but may possibly extend under entire fossa
    • mucosa of ethmoid cells gray, thin, and friable
  • Lacrimal Pump Model
    • orbicularis actively pumps tears from lake
    • Rosengren-Doane model: orb m contraction > pressure in lacrimal sac > tears forced into nose > lids open, move laterally > - pressure in sac helped by closed valve of Hasner > lids open fully and puncta pop open, with - pressure drawing tears into ampulla and canaliculi
    • Jones model: closure--lateral move = negative pressure
    • Becker model: closure--upper half lateral move = lower pressure, lower half medial move with higher pressure
    • fistulas develop inferior to medial canthal tendon b/c tendon itself is tough