Eye
Orbit and optic nerve
General


Topic Completed: 1 February 2014

Revised: 3 April 2019

Copyright: 2004-2019, PathologyOutlines.com, Inc.

PubMed Search: Orbit [title] optic nerve

Nat Pernick, M.D.
Page views in 2018: 314
Page views in 2019 to date: 351
Cite this page: Pernick N. Orbit and optic nerve: general. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/eyeorbitgeneral.html. Accessed October 17th, 2019.
Definition / general
  • Orbit contains globe and its fibrous covering (Tenon capsule), lacrimal gland, optic nerve and its meningeal covering, extraocular muscles, cartilaginous trochlea, blood vessels and delicate fibroadipose connective tissue
  • Floor of orbit is roof of maxillary sinus
  • Medial wall of orbit (lamina papyracea) separates orbit from ethmoidal sinuses
  • Proptosis: forward displacement of eyeball (or other organs), due to any disease that increases orbital contents, since orbit is closed medially, laterally and posteriorly
  • Exophthalmos: abnormal protrusion of eyeball
    • Common symptom of orbital disease, although often due to thyroid disease and not biopsied
    • Other common causes of exophthalmos are mucocele from paranasal sinus, hemangioma, inflammatory pseudotumor
  • Optic nerve:
    • Surrounded by meninges; part of central nervous system
    • Not usually biopsied
    • Often has psammoma bodies or drusen (calcified acellular globular concretions of nerve fibers)
    • Site of convergence of one million axons from retinal nerve fiber layer
    • Nerve head accounts for physiologic blind spot in normal visual field
    • Receives blood supply from branches of ophthalmic artery
    • Surrounded on both sides by short posterior ciliary arteries
  • Lamina cribrosa:
    • Site of myelination of optic nerve axons
    • Highlighted with Luxol fast blue or other myelin stains
  • Trochlea:
    • Arc shaped structure through which tendon of superior oblique muscle passes before insertion upon eyeball
    • The only cartilaginous structure in normal orbit
  • Tumors should be reported using formats published for their counterparts elsewhere in body
  • Drainage through submandibular, parotid and cervical lymph nodes through vascular anastomosis
Radiology images

AFIP images

Normal eye and orbital contents
Missing Image

MR #1 (T1 weighted)

Missing Image

MR #2 (T2 weighted)

Missing Image

MR #3 (T1 weighted) shows coronal section
of orbital contents posterior to globe

Drawings

Images hosted on other servers:
Missing Image

Optic nerve

Missing Image

Orbit

Missing Image

Extraocular muscles in orbit

Microscopic (histologic) images

AFIP images
Missing Image

Intraocular and orbital portions of optic nerve

Missing Image

Cross section of optic nerve parenchyma and meninges



Images hosted on other servers:
Missing Image Missing Image Missing Image

Optic nerve and fovea centralis

Back to top