Exophthalmos: Causes

Pathogenesis (development of disease)

For the pathogenesis of exophthalmos, see under the particular disease that is the cause of exophthalmos.

The most common cause of exophthalmos is endocrine orbitopathy (EO; hormonally induced disease of the agenic cavity(s) tissue), which occurs only in the setting of immunothyreopathies. In this case, exophthalmos is an extrathyroidal manifestation of immunothyreopathy.

Exophthalmos results from immigration of autoreactive T lymphocytes into the orbit or retroorbital tissue (as well as the thyroid and praetibial regions). The immunologic inflammatory response causes an increase in volume and pressure in a bony confined retroorbital space in the target tissue. As a result, there is protrusion of the eyeballs (protrusio bulbi) and prolapse (prolapse) of the swollen connective and fatty tissues in the upper and lower eyelids (periorbital edema).

Exophthalmos due to endocrine orbitopathy usually manifests in a very close temporal relation to hyperthyroidism (hyperthyroidism; ± 6-12 months).

Etiology (causes)

Disease-related causes

Eyes and ocular appendages (H00-H59).

• Orbital hematoma (blue eye) – contusion with blood pooling in the orbit and surrounding skin area.
• Orbitaphlegmon – rare, dangerous disease of the eye socket (orbit) associated with infection of the eyelids and surrounding skin in front of the septum orbitale

Endocrine, nutritional and metabolic diseases (E00-E90).

• Endocrine orbitopathy (hormonally related disease of the agenic cavity(s) tissue) in Graves’ disease (form of hyperthyroidism (hyperthyroidism) caused by autoimmune disease) or other autoimmune thyroiditis (thyroiditis due to autoimmune disease).

Cardiovascular system (I00-I99).

• Vascular abnormalities (pulsatile exophthalmos).
• Sinus cavernosus thrombosis – occurrence of blood clots (thrombosis) in the large collecting veins of the brain (venous sinus).

Neoplasms – tumor diseases (C00-D48).

• Orbital tumor (space-occupying processes in the eye socket (orbit)).
  • Benign (benign) orbital tumors:
    • Children: papillary hemangioma (benign growth of the blood system), lymphangioma (benign growth of the lymphatic system).
    • Adults: cavernous hemangioma, meningioma (meningeal tumors, which are usually benign), mucocele (accumulation (-cele) of mucus (Latin mucus) in a cavity (usually sinuses)).
  • Malignant (malignant) orbital tumors:
    • Children: rhabdomyosarcoma, neuroblastoma.
    • Adults: lymphomas (usually B-cell lymphomas), squamous cell carcinomas and metastases (daughter tumors).