Eye Anatomy

Exophthalmus vs proptosis

proptosis

• Abnormal protrusion of the eyeball

Exophthalmus

• may refer specifically related to endocrinopathies or to very severe proptosis > 18mm
• Causes
  • Thyroid orbitopathy (most common)
  • Infection – orbital cellulitis, mucocele, sinusitis
  • Tumor – orbital lymphoma, brain Ca, orbital metastasis
  • Trauma
  • Vascular lesions – fistula, haemangiogma, orbital varix, AVM
  • Orbital inflammatory syndrome
  • pseudo proptosis

Enophthalmos

Posterior displacement of the globe in the orbit – implies that the eye is normal

• Due to either
  • Structural alterations in bony orbit
  • Orbital fat atrophy
  • Retraction
• Causes
  • Orbital blowout fracture
  • Silent sinus syndrome – collapse of maxillary sinus/orbital floor
  • Orbital metastasis – e.g. Breast cancer causes retraction of tissue
  • Maxillary sinus mucocele
  • Orbital varix when it empties
  • Congenital
  • Horner syndrome