Comparison of ultrasound biomicroscopy and CT in diagnosis of anterior segment intraocular foreign body

Abstract

To report the appearance of anterior segment intraocular foreign body in ultrasound biomicroscopy (UBM) and CT. To investigate the advantage and disadvantage of these two imaging methods and to evaluate the value of combining application of these methods in the diagnosis of anterior segment intraocular foreign body. It was a comparative study. Forty-four cases of suspected anterior segment intraocular foreign body were simultaneously examined by UBM and CT from July 2000 to May 2007, the results were compared with the operation results. In 44 cases examined by CT, foreign bodies in 40 cases showed high density shadows, including iron, copper, stone and other foreign bodies; 2 cases showed slightly high density shadow, which were identified as plastics; in 2 cases, the foreign bodies could not be detected by CT, which were bamboo pick and Chinese chestnut sting. It was difficulty to locate the foreign body exactly and to detect the complications of anterior segment intraocular foreign body by using CT. All 44 cases of anterior segment intraocular foreign body showed strong echo spot with acoustic shadow in the UBM. UBM could provide the exact location of foreign body and could detect all complications. But the examining procedure of UBM was complicated, the examining screen was relatively narrow and the examination was time-consuming. In suspected anterior segment intraocular foreign body, CT examination should be performed first to detect the position and the nature of foreign body, then UBM could be used to obtain the exact position of foreign body and to detect the complications.