January 10, 2009

CT Findings of Open-Globe Injuries

Axial CT images of the orbit in a trauma patient show abnormal scleral contour/deformity (red arrow), lens extrusion (yellow arrow) and vitreous hemorrhage (stars). Note extensive preseptal edema/hemorrhage. Normal right globe.

Facts
Difficult clinical exam because of extent of trauma to face, orbit and head.
CT improves ability to assess ocular trauma.

CT Findings of Globe Injuries

  • Scleral deformity -- most common (75% - 95% of cases)
  • Abnormal anterior chamber depth (deep / shallow / flat) -- second most common (48% - 86%)-- an area that needs to be scrutinized on reviewing orbital trauma CT. Highest interobserver variability occurred in the diagnosis of this finding.
  • Abnormal lens (dislocated / absent) -- third most common (65% - 83%)
  • Vitreous hemorrhage
  • Intraocular foreign body / air
How Good Is CT?
Sensitivity 75% (better if exclude isolated corneal injury)
Specificity 93%
False negatives may occur in patients with isolated corneal lacerations
False positives (1% - 5% of cases) may occur in patients with a foreign body that appears to penetrate the eye wall, or with mild scleral deformity.


Reference:
Joseph DP, et al. Computed tomography in the diagnosis and prognosis of open-globe injuries. Ophthalmology 2000;107:1899

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