[Diagnosis of intraocular foreign body by computed tomography]

To evaluate the computed tomography in diagnosis of foreign bodies in the eye or close to the scleral wall, it was used with routine orbital radiography for comparison. The Simens Somatom DR3 CT Scanner with a 512 x 512 matrix was used in 50 random cases, and 45 cases were confirmed by surgery. The results indicated that the positive rate of CT in detecting intraocular foreign bodies was 98% (49/50), vs 90% (45/50) for radiography. The smallest metallic intraocular foreign body detected by CT was 0.4 x 0.25 mm and a cupric foreign body of 0.2 x 0.1 mm escaped detection. The error rate of CT in detecting single foreign body in the ocular wall was 1/30, while that of radiography was 10/30. Intraocular multiple foreign bodies could be demonstrated by multiple laminae of CT, and non-metallic foreign bodies could also be differentiated.