Application of ophthalmic magnets in the removal of magnetic intraocular foreign bodies

The aim of this study was to explore a new surgical method for removing magnetic intraocular foreign bodies(IOFB). We systematically reviewed 48 patients (48 affected eyes; 44 males and 4 females; aged 23-74 years, with a mean age of 44.8 ± 12.3 years) with magnetic IOFBs who were admitted to the Department of Ocular Trauma of Hebei Eye Hospital from January 2024 to June 2024. The most common cause of injury was ferrous foreign bodies resulting from working with metallic tools. Thirty-seven of the injuries were sustained in the patient's workplace, and 11 injuries occurred domestically. The patients presented to the clinic 40 min to 60 days after injury. The time from injury to surgery ranged from 1 h to 14 d. In the preoperative examinations and postoperative routine follow-ups, the basic conditions of the patients' eyes were evaluated through visual acuity examination using an international standard chart, slit lamp microscopic examination, anterior and posterior segment examinations with anterior slit lamp lenses, and intraocular pressure measurements. Before surgery, the foreign bodies were properly localized via horizontal and coronal localization CT scans, and type-B ultrasound scans were performed for patients with closed wounds. Ophthalmic magnets were used to remove magnetic IOFBs from 48 cases (48 eyes); in 44 cases, the foreign body was removed successfully during the stage I operation, representing a success rate of 91.7%. Among the included cases, 10 cases of anterior chamber IOFBs and crystalline lens IOFBs were all successfully removed during stage I surgery, for a success rate of 100%; in 38 cases of intravitreal IOFBs, 34 were successfully removed during stage I surgery via pars plana vitrectomy, and 4 cases failed to be removed in stage I surgery and were subsequently removed via stage II vitrectomy, for a stage I surgery success rate of 89.5%. Owing to their strong magnetic force, ophthalmic magnets have been demonstrated to be effective tools for the removal of magnetic IOFBs, enabling simple and time-conserving surgical procedures that are associated with less surgically induced trauma and fewer complications.