This section provides a framework to evaluate a variety of orbital disorders.

Eyelid swelling, bulging eye(s), and double vision are common. Pain, decreased visual acuity, decreased color vision, and changes in facial sensation can occur.

Critical

Globe dystopia (e.g., proptosis/exophthalmos, hypoglobus, and hyperglobus) and restriction of ocular motility, which can be confirmed by forced duction testing (see Appendix 6, Forced Duction Test and Active Force Generation Test). Resistance to retropulsion of the globe is common.

Differential Diagnosis of Proptosis

• Mass effect (e.g., infiltration or displacement of soft tissues by inflammatory, neoplastic, vascular, or infectious etiologies) either within the orbit or from structures surrounding the orbit (e.g., paranasal sinus, brain).

• Enlarged globe (e.g., myopia). Large, myopic eyes frequently have tilted discs and peripapillary crescents, and A-scan ultrasound (US) reveals a long axial length. Asymmetric myopia may result in unilateral pseudoproptosis.

• Enophthalmos of the fellow eye (e.g., after an orbital floor fracture).

• Asymmetric eyelid position: Unilateral upper and/or lower eyelid retraction, or contralateral upper eyelid ptosis.

• Physiologically shallow orbits.

Specific signs of orbital disease may not be diagnostic. Orbital disease can be grouped into six broad categories to help tailor the necessary workup:

1. Inflammatory: Thyroid eye disease (TED), idiopathic orbital inflammatory syndrome (IOIS), sarcoidosis, granulomatosis with polyangiitis (GPA, formerly Wegener granulomatosis), reactive inflammation from paranasal sinusitis, IgG4-related disease, etc.

2. Infectious: Orbital cellulitis, subperiosteal abscess (SPA), mucormycosis, etc.

3. Neoplastic (discrete, infiltrative, or hematologic): Typically categorized as primary (e.g., solitary fibrous tumor [SFT]), secondary (e.g., extension of sinus mucocele or intracranial meningioma, etc.), or metastatic. May be benign or malignant.

4. Trauma: Orbital fracture, retrobulbar hemorrhage, orbital foreign body with or without secondary infection, carotid–cavernous fistula (CCF), etc.

5. Malformation: Skeletal abnormalities, congenital/genetic syndromes, etc.

6. Vascular: Usually either congenital or acquired and categorized as primary arterial (e.g., CCF) or venous (e.g., varix). Venolymphatic malformations (e.g., lymphangioma) may also cause proptosis from intralesional hemorrhage.

NOTE As a general rule, any patient with a history of cancer and a new orbital process should be assumed to have metastatic disease unless proven otherwise.

1. History: Rapid or slow onset? Pain? Ocular bruit and/or pulsation? Fever, chills, systemic symptoms, skin rash, weight change? History of malignancy, diabetes, pulmonary disease, or renal disease? Trauma? History of sinonasal  congestion, epistaxis? Smoking? Up to date with health maintenance and age-appropriate screenings (e.g., mammography, prostate gland examination/screening)? Presence of systemic symptoms—weight loss/gain, fever, chills, night sweats, change in bowel habits, heat/cold intolerance?

2. Examination:

   • Review vital signs, particularly temperature.

   • Check visual acuity, size and reactivity of pupils, visual fields, color vision, and intraocular pressure. Check for excessive pulsatility of semicircles on Goldmann tonometry.

   • Check extraocular movements. Measure any ocular misalignment ([prisms or Maddox rod], see Appendix 3, Cover/Uncover and Alternate Cover Tests and 10.7, Isolated Fourth Cranial Nerve Palsy). Consider forced duction and force generation testing in select cases (see Appendix 6, Forced Duction Test and Active Force Generation Test).

   • Check for globe dystopia. Tilt the patient’s head back and look from below (“ant’s-eye view”). Measure with a Hertel exophthalmometer. Position the exophthalmometer against the lateral orbital rims, not the lateral canthi. The average value is 17 mm with the upper limit of normal about 22 to 24 mm. A difference between the two eyes of more than 2 mm is considered abnormal. Can be used in conjunction with a Valsalva maneuver if a venous malformation is suspected. In addition to classic axial exophthalmos, also look for nonaxial displacement of the globe (e.g., hypoglobus and hyperglobus).

   • Test resistance to retropulsion by gently pushing each globe into the orbit with your thumbs. Feel along the orbital rim for a mass. Check the conjunctival cul-de-sacs carefully and evert the upper eyelid.

   • Check trigeminal and facial nerve function. Check for preauricular and cervical adenopathy.

   • Perform a dilated examination to evaluate the optic nerves (pallor and swelling), posterior pole (especially for chorioretinal folds), and peripheral retina.

3. Consider automated perimetry if compressive optic neuropathy is suspected.

4. Imaging studies: Orbital computed tomography (CT, axial, coronal, and parasagittal views) or magnetic resonance imaging (MRI) with gadolinium and fat suppression, depending on suspected etiology. Orbital B-scan US with or without color Doppler imaging is useful if the diagnosis is uncertain or when a cystic or vascular lesion is suspected. Consider optical coherence tomography (OCT) to assess optic nerve contour and nerve fiber/ganglion cell layer loss. See Chapter 14, Imaging Modalities in Ophthalmology.

5. Laboratory tests when appropriate: Triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), antithyroid autoantibodies (thyroid-stimulating immunoglobulin [TSI] and antithyroid peroxidase antibody [TPO]), angiotensin-converting enzyme (ACE), cytoplasmic staining and perinuclear staining antineutrophil cytoplasmic antibody (cANCA and pANCA), lactate dehydrogenase (LDH), IgG/IgG4 levels, antinuclear antibody (ANA), serum protein electrophoresis (SPEP), complete blood count (CBC) with differential, blood urea nitrogen (BUN)/creatinine (especially if CT contrast or gadolinium is indicated), fasting blood sugar/hemoglobin A1c, prostate-specific antigen (PSA) level, blood cultures, etc.

6. Consider further systemic workup and additional systemic imaging, depending on clinical suspicion and radiologic findings (e.g., metastasis, lymphoma, etc.).

7. Consider an excisional or incisional biopsy, as dictated by the working diagnosis. Fine-needle aspiration biopsy has a limited role in orbital diagnosis.

Additional workup, treatment, and follow-up vary according to the suspected diagnosis. See individual sections.