Author: Claude (AI), from PubMed abstracts · Reviewed by: Dr Mina Abdelmseih · Reviewed: 2026-11-15 · Review due: 2027-11-15

Educational content only. Not personalised medical advice. Clinical decisions remain the responsibility of the treating clinician.

Intraocular foreign body

An intraocular foreign body (IOFB) is a severe complication of ocular trauma, seen worldwide, that carries significant ocular morbidity [S10]. Most IOFBs are metallic and acquired by hammering, often at work without eye protection [S8] [S9]. A retained IOFB raises the risk of endophthalmitis, and a retained iron IOFB can cause siderosis and late vision loss [S1] [S3] [S7].

Key points - Suspect an IOFB after any hammering injury, even if the eye looks almost normal; 43% of IOFBs in one series were seen only on CT [S8]. - Non-contrast thin-cut CT is the most practical first imaging test [S5] [S11]. A negative CT does not exclude an IOFB [S12]. - MRI is dangerous when a metallic IOFB may be present [S4]. - Intravitreal antibiotics at repair reduced endophthalmitis in eyes with an IOFB in an RCT [S1]. - Same-stage IOFB removal with primary repair within 24 hours is recommended whenever feasible (expert review) [S11].

Evidence last checked: 2026-10-17 (PubMed abstracts).

Red flags

• History of hammering metal, work-related injury or no eye protection [S8] [S9].
• Signs of endophthalmitis: pain, hypopyon, vitritis or retinal periphlebitis [S3].
• Injury in a rural setting, lens disruption or delayed wound closure, which are risk factors for endophthalmitis together with a retained IOFB [S3].
• Vegetable matter or toxic metals, which change surgical approach and timing [S10].
• Planned MRI in a patient with a possible metallic IOFB: a hidden metallic IOFB caused intense ocular pain during MRI despite screening [S4].
• Late signs of a missed iron IOFB: iris heterochromia, a dilated pupil, cataract and pigmentary retinal degeneration [S7].

Recognise it

• Patients are mostly young men: 96.8% male in a Canadian series and 100% in an Irish series [S8] [S9]. In the Irish series the cornea was the route of entry in 70% [S8].
• In the Canadian series 87.5% of IOFBs were metallic, 46.9% were work-related, and traumatic cataract was the most common complication (84.4%) [S9].
• Ocular siderosis may develop from 18 days to years after injury; the most common cause is delayed presentation or a missed IOFB [S7]. ERG b-wave reduction appears before clinical signs [S7].

Confirm it

• Clinical detection is not enough: 52% of IOFBs were clinically detectable and 43% were identifiable only on CT [S8].
• CT: the most practical first step because it detects a wide range of IOFB types at small sizes [S5]. Non-contrast helical CT gives information on size, shape and location [S2]. In a systematic review CT was 69% sensitive for IOFB against intraoperative findings, so a negative CT does not exclude an IOFB [S12]. In a small Canadian series CT detected 100% of IOFBs and B-scan 87.5% [S9].
• Ultrasound: B-scan was 86% sensitive for IOFB compared with CT, but its safety with respect to pressure on an open globe was not studied [S12]. In a meta-analysis, emergency-practitioner point-of-care ultrasound showed high sensitivity and specificity for IOFB, but few studies assessed IOFB and more study is needed [S6].
• MRI and ultrasound are adjuncts, useful for wood, plastic and glass IOFBs [S5]; avoid MRI until a metallic IOFB has been excluded [S4].
• Assess for concomitant life-threatening injuries first [S2].

Manage it

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Tier A (primary care / no specialist)

• Treat any suspected IOFB as an open-globe injury: protect the eye without pressure and arrange immediate transfer to an eye surgeon.
• Do not request MRI [S4].
• Record the mechanism (such as hammering) and the material if known; composition affects surgical planning [S10].

Tier B (general eye clinic)

• Obtain CT where available [S5] [S11].
• Antibiotic prophylaxis. Perioperative systemic and intravitreal antibiotics may reduce endophthalmitis (expert review) [S11]. Perioperative systemic and topical third- or fourth-generation fluoroquinolones may play a role (expert review) [S2]. Doses are not given in these abstracts; follow local formularies.
• Transfer to a vitreoretinal service without delay [S11].

Tier C (specialist centre)

• Timing. Same-stage removal with primary repair within 24 hours is recommended whenever feasible [S11]. Delayed versus immediate removal depends on the patient's medical status, the operating facilities and staff available, and whether endophthalmitis is present [S2]. The advantages and disadvantages of each approach are debated [S10].
• Intraocular antibiotics. In a multicentre RCT, endophthalmitis developed in 7 of 25 control eyes with an IOFB and in none of 27 eyes given intraocular gentamicin 40 µg and clindamycin 45 µg, as reported in [S1]. Intravitreal injection was superior to intracameral [S1]. Intravitreal antibiotics are also considered with a positive Gram stain, suspected endophthalmitis or high-risk settings [S2].
• Established endophthalmitis: intravitreal vancomycin and ceftazidime are routinely used; doses are not given in the abstract [S3].
• Surgery: posterior segment IOFBs are usually removed by pars plana vitrectomy; anterior segment IOFBs may be removed with an intraocular magnet or forceps through a limbal paracentesis [S7] [S10]. Material and size guide the instrument and extraction site [S2].
• Siderosis: remove the IOFB even after siderosis develops, because acuity and clinical signs may improve [S7].
• Follow-up: monitor closely for endophthalmitis, retinal detachment and proliferative vitreoretinopathy [S2]. In one series, 3 of 4 eyes with secondary glaucoma had retained or delayed extractions, so extended follow-up is advised [S9].

Refer when

Pitfalls

• Relying on a normal-looking eye or a negative CT to exclude an IOFB [S8] [S12].
• Sending a patient with a possible metallic IOFB for MRI [S4].
• Delaying repair; delayed wound closure is a risk factor for endophthalmitis [S3].
• Missing siderosis years after an injury that was never investigated [S7].
• Stopping follow-up early in retained or delayed-extraction cases [S9].

Evidence notes

• Apart from one RCT [S1] and two diagnostic syntheses [S6] [S12], the evidence is narrative review and small retrospective series from high-income centres; management recommendations are expert opinion [S2] [S10] [S11].
• Imaging sources conflict: CT detected all IOFBs in one small series [S9] but was 69% sensitive in a systematic review [S12].
• The POCUS meta-analysis had wide confidence intervals for IOFB and excluded children [S6].
• Not covered by these sources: systemic antibiotic choice and doses, tetanus prophylaxis, plain X-ray where CT is unavailable, and outcomes in low-resource settings.

Related articles

• Open-globe injury
• Post-operative endophthalmitis
• Ocular ultrasound and point-of-care ultrasound

References

See the numbered source list below. Each marker [S#] links to its PubMed and DOI record.