Plain X-ray and computed tomography of the orbit in cases and suspected cases of intraocular foreign body.

AIM: To evaluate the roles of plain X-ray and computed tomography (CT) orbital imaging in cases and suspected cases of intraocular foreign body (IOFB).

METHODS

Retrospective review of clinical and radiological data relating to 204 consecutive cases and suspected cases of IOFB.SettingRoyal Victoria Eye and Ear Hospital, Dublin, Ireland.

RESULTS

Plain X-rays were performed in the absence of clinically evident ocular penetration in 177 (87%) cases, and no IOFB was demonstrated in any of these radiographs. Twenty-seven (13%) plain X-ray radiographs were obtained in the presence of clinically evident ocular penetration, and an IOFB was clinically visible in 19 (70%) of these cases. CT scans were undertaken in 21 (10%) of the 204 patients. Of these CT images, 9 (43%) and 12 (57%) were undertaken in the absence and presence of clinically evident ocular penetration, respectively. None (0%) and all (100%) of the CT scans obtained in the absence and presence of clinically evident ocular penetration demonstrated an IOFB, respectively.

CONCLUSION

Plain X-ray and CT orbital imaging are non-contributory in the absence of clinically evident ocular penetration. In the presence of clinically evident ocular penetration, and where an IOFB is clinically visible, plain X-ray orbital radiography may have a role in excluding multiple IOFBs. In the presence of clinically evident ocular penetration, but where an IOFB is not clinically visible, CT orbital imaging remains the investigation of choice, and the role of pre-CT plain X-ray orbital radiography, as recommended by the guidelines of the Royal College of Radiologists, merits re-evaluation.