Investigations
1st investigations to order
CT scan of orbit
Test
Preferred imaging modality for evaluating orbital trauma, including intra-ocular foreign bodies, orbital fractures, and occult open globe injuries.
Perform thin-section axial CT with multiplanar reformation if orbital fracture or foreign body is suspected.[43] Contrast is not usually required.
Sensitive for detecting metallic or glass intra-orbital foreign bodies.[39] However, wood is difficult to detect on CT scan.[40][41][42]
Result
may identify intra-ocular foreign body, orbital-wall fracture, or globe integrity
CT scan of head
Test
Has a complementary role to orbital CT in the setting of concurrent head trauma and suspected intracranial abnormality, calvarial fracture, or orbital roof fracture. Contrast is not usually required.
Result
may identify pathology
MRI scan of head
Test
Use supplementary to CT where greater soft tissue contrast is needed to evaluate orbital trauma and cranial injuries.
Contraindicated if a metallic intra-ocular foreign body is present or suspected, but may be helpful in detecting intra-ocular wooden foreign body.[44]
Result
may identify pathology
Investigations to consider
plain x-ray
Test
Not recommended over CT or MRI.[37]
May be indicated for blunt trauma with suspected orbital-wall fractures and intra-ocular foreign bodies if CT scan is not available.
An intra-ocular foreign body composed of wood is difficult to detect on plain radiograph.[44]
Result
identifies intra-ocular foreign body or orbital-wall fracture
B-scan ultrasonography
Test
Produces a two-dimensional, cross-sectional view of the eye and orbit. Useful for evaluating the globe and its contents. Indicated for evaluation of the posterior pole if the clarity of the ocular media does not permit a dilated fundus examination.
May be useful in the identification and localisation of intra-ocular foreign bodies.
Not recommended if an open globe injury is suspected because tissue extrusion and contamination are a concern. However, it may be useful to detect occult open globe injuries.
Result
identifies intra-ocular foreign body or occult globe rupture
ultrasound biomicroscopy
Test
Uses very high-frequency ultrasound to produce a two-dimensional, cross-sectional view of the eye.
Indicated to evaluate anteriorly located foreign bodies, angle damage (e.g., cyclodialysis cleft), integrity of the lens capsule, and lens position after trauma.
Not recommended if an open globe injury is suspected.
Result
identifies intra-ocular foreign body
optical coherence tomography
Test
Useful for diagnosing macular pathology resulting from trauma such as a macular hole. Ordered by an ophthalmologist or optometrist.
Result
presence of macular holes
fluorescein angiography
Test
Used to identify possible complications after trauma, such as choroidal neovascularisation. Ordered by an ophthalmologist.
Result
areas of choroidal neovascularisation secondary to choroidal ruptures
fundus autofluorescence
Test
A rapid, non-invasive technique that may be useful to predict the function of the retinal pigment epithelium after damage from blunt ocular trauma.
Result
changes in the retinal pigment epithelium secondary to trauma
urine drug screen
Test
Useful if the patient is intoxicated or needs surgery and general anaesthesia.
Result
negative or positive
sickle cell trait screen
Test
Indicated for people of African or Mediterranean ancestry who present with hyphaema. A positive test may influence management and outcome.
Result
negative or positive
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