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 assigned value-specific gray shades to create the 2-dimensional image. CT scan can produce detailed axial and coronal views of soft tissue and bony structures. Image windows from 1.0-3.0 mm in thickness allow for detailed evaluation of orbital masses. Contrast-enhanced images may be obtained and can help in identifying inflammatory processes, vascular tumors, and engorged vessels. Calcified lesions are discernible without the addition of contrast.
Magnetic resonance imaging (MRI) excites protons by applying a radio frequency with a strong magnetic field. Hydrogen nuclei emit signal intensities that are assigned specific gray tones to create an anatomical reproduction. Three-dimensional views can be gained directly, in any anatomical plane, offering excellent spatial resolution of orbital masses and soft-tissue enhancement. MRI may provide excellent soft-tissue resolution, but CT scan is superior for gleaning details about orbital bony structures.
Ocular ultrasonography can be used to visualize anterior and middle orbital lesions. Sound waves of 5-15 MHz breech orbital tissues that reflect echogenic energy captured by an oscilloscope. A-scan ultrasonography allows for a 1-dimensional description of echoes, while B-scan ultrasonography provides a 2-dimensional image. C-scan ultrasonography affords coronal views, and D-scan ultrasonography creates 3-dimensional orbital views. With the advent of CT scan, C- and D-scan ultrasonography remains unpopular. Doppler ultrasonography may be used to evaluate orbital vasculature and blood flow.
Contains equivalent of 0.9% NaCl and maintains ocular tonicity. Acts to stabilize and thicken precorneal tear film and prolongs tear film breakup time, which occurs with dry eye states.
Patients should be monitored in intervals tailored to the degree of exophthalmos and complications arising from this ocular malady. Measurement of exophthalmos, visual and color acuities, pupillary function, extraocular motilities, and visual fields should be obtained. In addition, any corneal breakdown sh