Diagnostic accuracy of clinical examination, ultrasonography, and computed tomography in detecting and localizing posterior segment intraocular foreign bodies: a surgical correlation study

Background Open globe injuries with retained intraocular foreign bodies (IOFBs) are a major cause of ocular morbidity, particularly among young adults. Management requires a carefully planned sequence of steps, including accurate detection and localization of IOFBs to ensure their safe removal and better prognosis. Purpose To assess the detection sensitivity and localization performance of clinical examination, B-scan ultrasonography, and computed tomography (CT) for posterior segment IOFBs, using intraoperative findings during pars plana vitrectomy as the reference standard. Patients and methods This retrospective study included 60 patients with surgically confirmed posterior segment IOFBs who underwent pars plana vitrectomy. Preoperative data from clinical examinations, ocular ultrasonography, and CT imaging were reviewed and compared with the surgical findings in terms of IOFB detection and localization. A three-point scoring system was used to quantify localization accuracy based on anatomical zone and clock-hour position, and the localization performance was evaluated using three complementary measures: mean localization score, localization accuracy, and sensitivity of localization Results The sensitivity for IOFB detection was 38.3% for clinical examination, 73.3% for ultrasonography, and 95% for CT ( P <0.001). CT also demonstrated the highest localization performance, with 75.4% localization accuracy, a mean localization score of 1.65±0.67, and localization sensitivity of 71.7%. Ultrasonography showed moderate localization accuracy (47.7% localization accuracy, mean localization score of 1.27±0.79, localization sensitivity 35%), while clinical examination had the lowest performance (34.8% localization accuracy, score 1.08±0.79, localization sensitivity 13.3%). The differences between modalities were all statistically significant ( P <0.001). Conclusion CT scan demonstrated superior diagnostic accuracy in both detecting and localizing IOFBs, making it the most reliable preoperative modality. Ocular ultrasonography remains a useful alternative and is superior in detecting associated vitreoretinal complications, while clinical examination alone is insufficient. These findings support the complementary use of imaging modalities in the surgical planning for posterior segment trauma.