Management and clinical outcomes of intraocular foreign bodies with the aid of orbital computed tomography

Abstract

Background: Computed tomography (CT) is known to be the first-line imaging method for patients with or suspect to have intraocular foreign bodies (IOFBs). The purpose of this study is to evaluate clinical outcomes in the management of IOFBs with the aid of CT.

Methods: Retrospective chart review of patients who received orbital CT prior to the removal of an IOFB between January 2000 and December 2010 was carried out. Patients with an IOFB who did not receive an operation or those without a preoperation CT examination were excluded. Twenty patients with a mean age of 37 years were selected. The duration between injury and surgery ranged from hours to 4 months. Detailed information and ophthalmologic examination results including patient history, visual acuity (VA), slit-lamp examination, fundoscopic examination, operation notes and bacterial culture results were recorded for all patients. The orbital CT images were performed with multidetector CT scanners with a 2-3.75 mm slice thickness.

Results: This study found 18 patients (90%) with only one IOFB on CT image, in which only nine IOFBs were discovered on clinical assessment. The CT image failed to discover the IOFB in two patients who had tiny iron dust fragments located in the cornea stroma or embedded in the lens. Preoperative determination of the IOFB size and location was helpful in the decision-making of the route of extraction. Further, there was a correlation between clinical presentation about vitreous hemorrhage and the development of postoperative retinal detachment (Fisher's exact test, p = 0.029). The presence of positive bacterial cultures was also found to be associated with decreased VA (Fisher's exact test, p = 0.047). The injured eyes were anatomically preserved in all patients. However, two patients had loss of light perception. Eleven patients (55%) had improved VA of more than two lines on Snellen's chart, seven patients worsened, and two patients retained the same initial VA.

Conclusion: Multidetector CT plays an important role in the detection, localization, size measurement, and surgical approach towards the extraction of the IOFB. The presence of vitreous hemorrhage is a predictive factor for postoperative retinal detachment, and positive bacterial cultures result in poorer visual outcomes.

Keywords: intraocular foreign body; orbital computerized tomography; postoperative retinal detachment; vitreous hemorrhage.