Topics

Topic

design image
Medial wall of orbit

The medial wall of the orbit is a thin, vertically oriented bony wall forming the medial boundary of the orbital cavity. It separates the orbit from the nasal cavity and ethmoid air cells and is the thinnest orbital wall, making it particularly important in trauma, infection spread, and surgical planning.

It is a key anatomical region in ophthalmology, otolaryngology, maxillofacial surgery, and radiologic evaluation of orbital and sinonasal disease.

Synonyms

  • Medial orbital wall

  • Ethmoidal wall of the orbit

Location

  • Forms the medial boundary of the orbital cavity

  • Extends from the orbital apex posteriorly to the anterior lacrimal crest anteriorly

  • Separates the orbit from the ethmoid air cells and nasal cavity

  • Medial to the orbital contents

  • Lateral to the nasal cavity

Anatomical components

  • Frontal process of the maxilla (anterior portion)

  • Lacrimal bone

  • Ethmoid bone (lamina papyracea) – largest and thinnest component

  • Body of the sphenoid bone (posterior portion, near orbital apex)

Relations

Laterally:

  • Orbital contents (globe, extraocular muscles, orbital fat)

Medially:

  • Ethmoid air cells

  • Nasal cavity

Anteriorly:

  • Lacrimal sac and nasolacrimal duct

  • Anterior lacrimal crest

Posteriorly:

  • Orbital apex

  • Optic canal (posterolateral relation)

Superiorly:

  • Frontal bone

  • Anterior cranial fossa (indirect relation)

Inferiorly:

  • Orbital floor

  • Maxillary sinus (anteroinferior relation)

Structures related to the medial wall

  • Lamina papyracea

  • Ethmoidal air cells

  • Anterior and posterior ethmoidal arteries and nerves

  • Lacrimal sac and nasolacrimal duct

  • Periorbita

X-ray appearance

Orbit and skull radiographs:

  • Medial wall: Thin bony outline, often poorly visualized due to superimposition

  • Ethmoid region: Radiolucent air cells medial to the orbit

  • Limitation: Low sensitivity for detailed medial wall assessment

CT appearance

Non-contrast CT:

  • Medial wall: Very thin bony plate, best seen on axial and coronal views

  • Lamina papyracea: Smooth, paper-thin cortical bone

  • Ethmoid air cells: Well-aerated, separated from orbit by medial wall

  • Preferred modality for evaluation of the medial orbital wall

Post-contrast CT:

  • Bone: No enhancement

  • Adjacent soft tissues: Normal enhancement of mucosa and orbital structures

3D CT VRT appearance

Volume-rendered technique (VRT):

  • Medial wall: Subtle or partially visualized due to extreme thinness

  • Orbital contour: Medial orbital margin appreciated

  • Utility: Helpful for overall orbital shape rather than fine medial wall detail

MRI appearance

T1-weighted images:

  • Medial wall bone: Low signal intensity

  • Orbital fat: High signal

  • Ethmoid air cells: Signal void

T2-weighted images:

  • Bone: Low signal

  • Ethmoid sinuses: High signal if fluid-filled; low signal if aerated

  • Orbital soft tissues: Normal intermediate signal

X ray image

Medial wall of orbit x ray

CT VRT 3D image

Medial wall of orbit 3d