Approach Considerations
The recommended approach in the evaluation of potential globe rupture or penetration is to maintain a high index of suspicion for what is often an occult injury. A careful and detailed ocular examination should be followed by appropriate diagnostic studies. Computed tomography of the orbits and adjacent structures is often the diagnostic procedure of choice.
Laboratory Studies
Coagulation studies and complete blood count are appropriate in patients who are likely to have underlying bleeding diatheses.
Otherwise, laboratory studies are indicated as appropriate for coexisting trauma and other active medical problems.
Imaging Studies
Computerized tomography
CT scanning of the eye is the preferred modality for further assessment of occult open globe injuries. [12] CT is the most sensitive readily available imaging study to detect occult rupture, associated optic nerve injury, and small foreign bodies, as well as to visualize the anatomy of the globe and orbit.
Axial and coronal views of the brain and orbits without contrast utilizing 1-2 mm cuts should be obtained.
Some nonmetallic foreign bodies, such as wood, glass, or plastic, may be difficult to visualize acutely on CT.
The sensitivity and specificity of ocular CT in determining occult open globe injury varies. Sensitivities ranging from 56-68% and 70%, and specificities of 70-100% and 98% have been reported in recent studies, [13, 14] illustrating the need for surgical exploration for definitive diagnosis and management.
Radiography
Orbital plain films of the orbits and sinuses are rarely used for diagnosis in orbital trauma.
A 3-view plain film series is most useful in evaluating the bony orbits and the sinuses and in identifying radiopaque foreign bodies.
Waters projection provides the best view of the orbital floor and detects air-fluid levels in the maxillary sinuses.
Caldwell or anteroposterior view visualizes the medial orbital wall, the lateral and superior orbital rims, as well as the ethmoid and frontal sinuses.
The third projection, or lateral view, is most useful in visualizing the orbital roof, maxillary and frontal sinuses, zygoma, and sella turcica.
MRI
MRI is of limited usefulness in the acute stages of ocular trauma and is contraindicated if any concern exists for metallic intraocular foreign body.
MRI is excellent in identifying injuries of the soft tissues of the globe and orbit and can be particularly helpful in localizing an organic foreign body, such as wood, that appears similar to soft tissue or air on CT scan.
Ultrasonography
Ocular ultrasonography by an emergency physician is contraindicated if there is a high suspicion for globe rupture.
Ultrasonography can be used to evaluate noninvasively for lens dislocation, retrobulbar hemorrhage, retinal detachment, and intraocular foreign body. Visualization of periorbital gas may also prompt an ED physician to search for orbital fracture.
Other Tests
Seidel test
The Seidel test is intended to detect the leak of aqueous fluid following globe penetration. It should not be performed if globe rupture or penetration has already been confirmed, as any unnecessary manipulation of the globe is contraindicated. However, the Seidel test may prove useful in the diagnosis of more occult injuries. If an aqueous leak is present, it may be detected on slit-lamp examination following the instillation of fluorescein dye by a clear band in the stain extending downward from the suspected site of injury. The clear band is caused by dilution of the fluorescein by leaking aqueous fluid. If the Seidel test result is positive, any further manipulation of the eye is contraindicated.
Additional diagnostic tests
Further testing is based upon the mechanism of injury and the potential for nonocular injuries.
Life- or limb-threatening injuries should be addressed initially.
Consider injuries to head, spinal cord, and facial bones.
Complete the standard trauma evaluation.
Procedures
Procedures such as repair of eyelid or conjunctival laceration are deferred until globe rupture is ruled out.
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Operating microscope view of a globe rupture secondary to blunt trauma by a fist. Notice the dark arc in the bottom of the photo representing the ciliary body visible through the scleral breach. Subconjunctival hemorrhage of this severity should raise suspicion of occult globe rupture. Photo courtesy of Brian C Mulrooney, MD.
