Clinical Application of X-ray,B-scan,and CT in the Diagnosis of Ocular Foreign Bodies

Purpose:To analyze the sensitivity and specificity of X-ray, B-ultrasound, and CT scan in diagnosing ocular foreign bodies, and to compare the accuracy of these three imaging tools in locating these foreign bodies. Methods:A retrospective review was conducted of radio graphic and clinical eye examination data from 62 patients (66 eyes),suspected of having ocular foreign bodies at time of first presentation to the Zhongshan Ophthalmic Center (Guangzhou, China) between August 2007 and October 2011. The sensitivity and specificity of X-ray, B-ultrasound and CT scan in the diagnosis of ocular foreign bodies were investigated and their accuracy in locating these foreign bodies was compared. Results: A total of 75.8% (n=47) subjects had ocular foreign bodies; 66% of these were metallic. Patients with intraocular, eye wall,and extraocular foreign bodies accounted for 46, 28, and 26% of the total, respectively. The sensitivities of X-ray,CT scan,and B-ultrasound in the diagnosis of ocular foreign bodies were 58.3%, 61.7%, and 75%, the specificityies were 63.3%, 100%, and 87.5%, and the accuracy in locating foreign bodies was 73.4%, 94.7%, and 86.5%, respectively. The properties of foreign bodies affected the diagnosistic accuracy of X-ray,but exerted little impact upon B-ultrasound and CT scan. Conclusion:A fairly high incidence of ocular foreign bodies was noted in patients suspected with ocular foreign bodies at their first presentations.X-ray combined with CT scan or X-ray in combination with B-ultrasound showed a relatively high sensitivity and specificity in diagnosing ocular foreign bodies. CT scan had the highest accuracy in locating ocular foreignbodies.