Normal anatomy of orbit with diagram and Orbital masses — classification

Anatomy

• Roof:

  • Orbital process of frontal bone (anterior).

  • Lesser wing of sphenoid (posterior).

• Lateral wall:

  • Greater wing of sphenoid (posterior).

  • Zygomatic process of frontal bone.

  • Frontal process of zygomatic bone.

• Medial wall:

  • Lamina papyracea of ethmoid bone (posterior).

  • Lacrimal bone (anterior).

• Floor:

  • Orbital plate of maxilla.

  • Inferior orbital fissure (posterolateral).

ORBITAL COMPARTMENTS AXIAL DIAGRAM

1) Globe space

Anterior chamber

• Rupture of globe.

• Hyphema

• Cataract.

• Periorbital cellulitis.

Posterior chamber

• Glaucoma.

• Uveitis.

• Ciliary melanoma.

Vitreous

• Rupture.

• Hemorrhage.

• PHPV.

Retina

• Retinoblastoma.

• Hemangioblastoma.

• RD.

Choroid

• Melanoma.

• Mets.

• Detachment.

2) Intraconal space

Bounded by the extraocular muscles.

• Venous vascular malformation.

• Capillary hemangioma.

• Optic nerve:

  • Optic neuritis.

  • Optic nerve glioma.

  • Meningioma.

  • Pseudotumor.

• CCF -Caroticocavernous fistula

• Varices.

• Schwannoma of 3rd, 4th, 6th nerves.

• Lymphoma / metastasis.

3) Conal space / Tenon’s space

Formed by the ocular muscles and the envelope of fascia.

• Thyroid ophthalmopathy.

• Pseudotumors.

• Glycogen storage disease.

• Lymphoma.

4) Extraconal space / Peripheral orbital area outside the muscle cone

• Abscesses from adjacent sinuses

• Schwannoma of trigeminal nerves.

• Lacrimal gland lesions

• Bone:

  • Fibrous dysplasia of sphenoid.

  • Metastases

  • Multiple myeloma.