Reasoning GP · Algorithm · 1-page summary

Foreign body in the eye

For: anyone with foreign-body sensation, an eye injury, a chemical splash or welding exposure, in hours or OOH. Not for: removing anything beyond irrigation or a moistened cotton bud — needle, burr and slit-lamp work belong to a trained clinician on the local (local) emergency eye pathway.

Reviewed October 2026 · next review April 2027

RCOphth 2024College of OptometristsBSO ocular traumaGreen Book ch 30SPC (emc)

Core rule: the mechanism sets the urgency. High-velocity metal (grinding, drilling, hammering) is an intraocular foreign body until proven otherwise, even with good vision and little pain; a chemical splash is irrigated before anything else.

0Stop — act now — before a full history

Chemical splash (alkali worse than acid) → irrigate now with tap water or 0.9% saline; do not wait for history, acuity or pH. Remove lenses, sweep the fornices, continue until pH is near-neutral → Emergency eye unit / ED same day
High-velocity injury or open-globe signs (wound, peaked or teardrop pupil, hyphaema, reduced vision, positive Seidel, subconjunctival haemorrhage with no posterior border) → stop examining → Emergency eye unit / ED now
Blunt trauma with orbital haematoma, enophthalmos/proptosis, restricted movement or diplopia → Emergency eye unit / ED + CT orbits. Reduced acuity after injury or RAPD → same route.
While waiting: rigid shield, not a pad; no pressure, irrigation (unless chemical), tonometry or removal; no nose-blowing; nil by mouth; analgesia, antiemetic; tetanus. No MRI until a metallic IOFB is excluded. 999 if systemically unstable, major trauma, severe chemical exposure, an eye too painful to open, or no safe transport.

1Triage by mechanism

Mechanism	Means → action
High velocity	Grinding, drilling, hammering metal, explosion → block 0
Low velocity	Dust, grit, insect → blocks 3–5
Organic / soil	Plant, soil: fungal risk → lower referral threshold
Contact lens	Pseudomonas risk → urgent assessment
UV / welding	Bilateral pain hours later → arc eye, not a FB

2Screen — same-day ophthalmology

Worsening pain, redness, discharge or photophobia, infiltrate or ulcer → keratitis → Same-day. Organic injury worsening = suspect fungal.
Rust ring central, deep, extensive, reduced acuity, or you are not trained/equipped → Same-day
Corneal FB central, deep, not fully seen or not removable by cotton bud → Same-day
Contact lens + corneal defect with infiltrate, discharge, photophobia, reduced vision, significant pain, worsening or incomplete examination → Same-day
Abrasion or arc eye not improving within 24–48 h, or arc eye with reduced vision, opacity or severe unilateral features → Same-day
Dendritic staining (herpes simplex) → Same-day; ring lesion in a lens wearer → Emergency

3Assess — in this order; stop if open globe suspected

☐ Acuity each eye (after irrigation starts if chemical) ☐ Pupils, RAPD ☐ Globe position ☐ Cornea, anterior chamber: FB, laceration, hyphaema ☐ Fluorescein + cobalt blue ☐ Seidel, no pressure ☐ Evert upper lid if FB sensation or vertical staining ☐ Fornices if chemical ☐ Tetanus status

Never: needle or burr without slit-lamp training; tetracaine for home; steroid drops without ophthalmology advice.

4Classify — only if blocks 0–2 are negative

Superficial conjunctival or corneal FB — visible, focal staining → block 5.
Subtarsal FB — vertical linear staining → evert the upper lid.
Corneal abrasion — epithelial defect, no FB; usually heals within days.
Arc eye — bilateral, hours after UV; topical anaesthetic for examination only.
Recurrent erosion — pain waking from sleep weeks after an abrasion → ophthalmology or optometry.
Uncertain — FB not fully seen or any doubt → refer.

5Treat today — only these

Remove only if the globe is intact, the FB clearly visible, acuity preserved and you are trained: tetracaine 0.5% 1 drop, then irrigation or a moistened cotton bud; recheck acuity and fluorescein. Not if central, deep, rust ring, reduced acuity or RAPD, uncertain Seidel, infiltrate or hypopyon, or a lens wearer (unless the local service supports it). Child or anxious patient: no forceful manoeuvres.
After removal or abrasion: topical antibiotic per the local eye-injury protocol (chloramphenicol is common) — not for lens wearers (no Pseudomonas cover; fluoroquinolone via local pathway); lubricant; no eye patch. Paracetamol 1 g QDS + ibuprofen 400 mg TDS if no contraindication. Doses: NICE/SPC, BNF, local formulary.
Contact lenses: out now; none until the cornea is healed and the eye symptom-free.

6Refer non-urgently

Within 24–48 h ophthalmology: FB removed but residual staining or symptoms; uncomplicated lens-wearer abrasion per local pathway; any doubt about complete removal.
Work injury: record mechanism and PPE; the employer reports to HSE under RIDDOR; occupational health if recurrent.

7Never reassure by

Good vision or little pain after a high-velocity injury.
A negative Seidel test.
A CT scan alone — it may miss wood and organic material.
No visible FB when the upper lid has not been everted.
"I got it out" while pain or staining persists.
Chloramphenicol given to a contact-lens wearer.

8Safety-net — say it, then document it

Same day “If the pain, redness or light sensitivity gets worse, your vision changes, a discharge starts, or it is not clearly better in 24–48 hours, contact us or eye casualty today.” “Don't rub it while numb; no lenses until fully healed.” Work and driving: no driving until acuity is normal; welders do not weld until ophthalmology clears them if an IOFB has not been excluded.

✓Safe to leave primary care only if — all five, documented

Mechanism recorded; no block 0–2 row applies Acuity each eye and pupils, before and after Fluorescein clear after removal; lid everted if needed Lens use, tetanus and PPE recorded Safety-net and review route given

Summary of the full Reasoning GP foreign body in eye algorithm, which holds the examination technique, equipment, documentation standard and evidence. Sources: RCOphth emergency eye care (2024) and eye casualty guidelines; College of Optometrists corneal abrasion guideline; BSO ocular trauma guidelines; UKHSA Green Book chapter 30; COSHH/PPEWR. Clinical reference — follow the local emergency eye care pathway and check doses: NICE/SPC, BNF.