Proptosis

    • Forward displacement of one eye or both eyes
    • Orbital causes: tumor, infection, non-infectious inflammation, orbital bone-expanding tumors
    • Cavernous sinus causes: direct carotid-cavernous fistula, indirect (dural) carotid-cavernous fistula, cavernous sinus thrombosis
    • Core clinical features
      • Eye protrudes more than expected
      • Tip: there is great variability even among normal subjects in ocular prominence, so look for findings to support pathologic forward displacement of the eye(s)
    • Possible accompanying clinical features
      • Periocular pain
      • Diplopia
      • Increased resistance to retropulsion of the eye
      • Upper lid retraction
      • Swollen, red, or tender lids, lacrimal gland, conjunctiva
      • Upward or downward displacement of the eye
      • Reduced ocular ductions
      • Eye misalignment
      • Elevated intraocular pressure
      • Reduced visual acuity or visual field
      • Lid lag
      • Upper lid ptosis
    • False appearance of proptosis caused by upper lid retraction, large eyes (myopia, buphthalmos), or congenitally shallow orbits (“exorbitism”)
    • Distinguish orbital from retro-orbital (cavernous sinus) disorders, which may be difficult
    • Push on (retropulse) the eyes with your hands, grading resistance as
      • Mild: orbitocavernous venous congestion
      • Moderate: orbital tumors or inflammation
      • Marked: orbital wall thickening or very firm and large orbital tumors
    • Measure intraocular pressure, which you must lower if it is extremely high
    • Apply the “suction duction” (“forced duction”) test if the eye has markedly reduced movement and you suspect restriction
    • Order orbitocranial imaging, with the following ideas in mind
      • Thin-section CT can disclose most orbital tumors and inflammations, an enlarged superior ophthalmic vein,
        and sometimes a dilated cavernous sinus of carotid-cavernous fistula
      • MRI provides better views of the cavernous sinus, and can suggest cavernous sinus pathology, but may not show the early venous filling of carotid-cavernous fistula, even with MRA and MRV
      • Special dynamic sequences may disclose the early venous filling of the carotid-cavernous fistula, but digital catheter angiography will be necessary for definitive diagnosis and characterization of supplying and draining channels
      • Diffusion-weighted MRI may disclose the restricted diffusion typical of cavernous sinus or orbital venous thrombosis
      • Tip: pay attention to the appearance of the paranasal sinuses, as important orbital and cavernous sinus lesions originate there and are accessible to biopsy
    • Tip: prompt diagnosis of orbital infection--especially aspergillosis, mucormycosis, and cavernous sinus thrombosis--can be life-saving!
    • Orbital wall removal for Graves disease is indicated only if the patient exhibits signs of an optic neuropathy and imaging discloses apical extraocular compression of the optic nerve
    • Orbital biopsy is indicated only if the mass is readily accessible and surveillance of other—more accessible—sites has been negative
    • Endovascular treatment usually closes a carotid-cavernous fistula with acceptable risks, but more than one treatment may be necessary (See Carotid-cavernous Fistula )
    • Tip: treatment of indirect (dural) fistulas should be undertaken only if the patient meets at least one of the following clinical criteria
      • Intractable pain
      • Intractable diplopia
      • Reduced vision from optic neuropathy
      • Marked cosmetic blemish
      • Intractably elevated intraocular pressure
      • Retinal vein occlusion
      • Non-resolving congestive signs after at least one year of follow-up

    Proptosis

    Proptosis