Metallic foreign body in another patient in right orbit on radiograph (arrow). CT scan axial section of the same patient showing foreign body just posterior to the limbus which is extra occular.
Intraocular foreign bodies (IOFBs) are rather variable in presentation, outcome, and prognosis. With increased awareness and advanced surgical techniques, the outcome and the prognosis for these potentially devastating injuries have substantially improved.
CT scans are the imaging study of choice for IOFB localization. A helical CT scan is the most efficient method to establish a diagnosis. Helical CT scans have a very high identification rate. With conventional CT scans, cuts of 0.5 mm are advised. With the advent of MDCT the role of radiologist has become easier in identification and diagnosis of occular foreign body. Plain x-ray is useful if a metallic IOFB is present and a CT scan is unavailable. MRI is generally not recommended for metallic IOFBs. Ultrasound is a useful tool in localizing IOFBs, and its careful use is possible even if the globe is still open; alternatively, intraoperative use after wound closure can be attempted. The ultrasound biomicroscope may help with IOFBs in the anterior segment.