lepharoptosis, lagophthalmos (incomplete lid closure), and interpalpebral fissure distance are additional signs to be considered during the examination.
Palpation of the anterior orbit can assess the level of tenderness, texture, and mobility of the mass.
Tenderness may denote an inflammatory process or neural invasion by a neoplasm.
Attention should be paid to regional lymph nodes.
Tactile inspection of the globe may reveal pulsations secondary to arteriovenous communications or physiological intracranially pulsations transmitted through a bony defect of the orbit, such as an encephalocele.
Protrusion of the eye is an important clinical manifestation of orbital disease. In addition to proptosis, one should note the displacement of the eye in planes other than the anteroposterior dimension (eg, downward, lateral).
Hertel exophthalmometry is a well-accepted tool to quantitate proptosis. The base is determined by the interlateral canthal space. The transection of the central cornea by the premarked millimeter ruler records the amount of anterior displacement of the globe. Its use requires intact lateral orbital rims. If the rim is not intact, a Luedde exophthalmometer.
Relative protrusion can be observed by simply standing behind a seated patient and gazing downward toward the chin from the forehead to assess the displacement of one globe as compared to the contralateral side.
Auscultation of the orbit may detect a high flow state in the orbit or intracranially. The bell is useful for this examination. If a high-flow lesion is suspected (eg, carotid cavernous fistula), arteriography should be sought to further qualify these lesions. It is important to have the contralateral eye remain fixated on a target while auscultating the orbit.
Decreased visual acuity, change of refraction, and pupillary abnormalities should be noted.
Extraocular motility dysfunction and diplopia should be carefully assessed and documented.
Forced duction testing may qualify the dysfunction as restrictive or neurogenic in nature. Intraocular pressure may be elevated, and slit lamp examination can discern chemosis and engorged or sentinel vessels.
Dilated funduscopic examination may reveal optic disc edema or pallor, retinal detachment, choroidal folds, vascular engorgement or shunt vessels, or indentation of the posterior pole.
Proptosis can be the result of a myriad of disease processes resulting from primary orbital pathology or systemic disease processes. The list below is not comprehensive but can help in forming a differential diagnosis. The list only consists of adult causes since a fair amount of overlap exists in the differential diagnosis of exophthalmos in adults and children.
Proptosis in adults
Concurrent sinus disease
Orbital inflammatory syndrome (orbital pseudotumor, benign orbital inflammation)
Metastatic (breast in women, lung and prostate in men, gastrointestinal, kidney)
Orbital vascular disease
Orbital varix (venous malformation)
Orbital arteriovenous malformation (carotid-cavernous sinus fistula, arteriovenous malformation)
Patients with thyroidopathy should undergo the appropriate thyroid function studies, even though some patients are euthyroid at the time of presentation with exophthalmos. Approximately 80% of those with Graves disease manifest orbital signs within 18 months, supporting the need for ophthalmic evaluation.
Any patient suspected of having a neoplasm as the cause of the proptosis should undergo imaging studies (see Imaging Studies). The imaging results should direct further laboratory studies. For example, in a patient with proptosis due to lymphoma, hematologic studies, further body imaging, and a bone marrow biopsy may be indicated.
In patients with proptosis due to orbital cellulitis, complete blood counts, blood and nasal cultures, and sinus imaging studies may be warranted.
CT scan, first used in the 1970s, is the product of tissue density calculations. X-rays with different vectors are emitted, penetrating through target tissues with resulting radioabsorbencies. These differences in radioabsorbencies are as