Role of Ultrasound Biomicroscopy (UBM) in the Detection and Localisation of Anterior Segment Foreign Bodies

Abstract

Introduction: The aim of this study was to investigate the role of ultrasound biomicroscopy (UBM) in imaging anterior segment foreign bodies and compare it with conventional B-scan ultrasound and computed tomography (CT). Materials and Methods: The charts of 18 eyes with anterior segment foreign bodies were reviewed. The rates of detection of foreign bodies using ultrasound, CT scan and UBM were compared. Results: The foreign body detection rates were 36.5% by ultrasound, 88.9% by CT scan, and 94.4% by UBM. The diagnosis of presence of a foreign body using UBM was made based on high reflective echoes causing shadowing or reverberations. In 7 eyes, UBM detected injury to the zonules, guiding the operative procedure. In the 8 eyes for which all tests were performed, rates of detection of foreign bodies were 25% (2/8) with ultrasound, 87.5% (7/8) with CT, and 100% (8/8) with UBM. Conclusion: UBM is a valuable adjunct for the accurate localisation of small foreign bodies, including cilia. It offers a higher detection rate than that provided by ultrasound and CT scan. Key words: B-scan ultrasonography, Computed tomography, Ocular trauma, Retained foreign bodies