Makindo Medical Notes

👁️ Introduction

Corneal and conjunctival foreign bodies (FBs) are common ophthalmic presentations, especially in metal workers, DIY enthusiasts, and children. ⚠️ They can cause pain, photophobia, and watering, and if neglected may lead to infection, scarring, and vision loss. Early, careful removal and aftercare are essential.

🛠️ Instruments

• Gloves 🧤, sterile cotton bud, and a 21–25G needle (mainstay).
• Topical anaesthetic (e.g. Amethocaine 1%).
• Slit lamp 🔬 (essential for safe removal).
• Optional: motorised dental burr for metallic FBs (⚠️ never within central 5 mm of cornea).
• ⚙️ Technique: Bend needle tip to 45°; bevel away from eye to reduce trauma.
• Ensure patient’s forehead is firmly against the slit lamp for stability.

📋 Important Notes

• 📉 Visual acuity may initially be reduced — always test with pinhole + topical anaesthetic if discomfort limits accuracy.
• 🌱 Organic FBs (wood, plant matter) → high infection risk.
• 🧲 Metallic FBs → rust rings ⚠️ → scarring if untreated.
• Rust rings in the visual axis must be removed by ophthalmology only.
• Always consider the possibility of an open globe injury — if suspected → shield, nil by mouth, urgent ophthalmology referral.

🔧 Procedure

• 1️⃣ Instil topical anaesthetic (e.g., Amethocaine 1%), repeat every 30s until painless.
• 2️⃣ Seat patient at slit lamp; stabilise head; ask them to fixate on target 🎯.
• 3️⃣ Focus slit lamp beam — use narrow oblique beam at ~45° to assess FB depth.
• 4️⃣ Approach tangentially with cotton bud or bent needle; lift FB away.
• 5️⃣ For superficial metallic FB → gently “flick” with bevel; burr for rust ring (if outside visual axis).

🩺 Post-Procedure Care

• 💊 Topical antibiotic drops (e.g., chloramphenicol qid for 5–7 days).
• 🌙 Cycloplegic drops (e.g., cyclopentolate 1% bd) for pain relief.
• 💊 Oral analgesia (paracetamol, NSAIDs).
• ❌ Avoid eye padding — binocular vision prevents accidents and padding may ↑ infection risk.
• 🚫 No repeat use of anaesthetic drops → toxic to cornea.
• 📆 Follow-up daily with slit lamp until epithelial defect heals (document size + healing progress).

🚩 Red Flags

• ⚠️ Suspected penetrating eye injury (positive Seidel’s test, irregular pupil, iris prolapse).
• FB in central visual axis or deep stromal cornea.
• Persistent rust ring or residual opacity.
• Infective keratitis → pain ↑, photophobia, hypopyon.
• Reduced vision not improving after removal.

👶 Children

• Often difficult to examine; consider sedation or referral if uncooperative.
• Risk of recurrent rubbing and re-injury → protective shield + parental advice.
• Organic FBs (wood, playground material) more common.

🧓 Elderly

• Assess anticoagulation & bleeding risk 💊.
• May present late due to reduced corneal sensation or confusion.
• Healing may be slower; ensure close ophthalmology follow-up.

📌 Teaching Pearls

• Always document visual acuity before and after any intervention.
• Slit lamp exam is gold standard for safe removal.
• Never attempt deep or central FB removal outside specialist care.
• Discharge advice: return immediately if ↑ pain, redness, discharge, or ↓ vision.

🧾 Clinical Case Examples – Foreign Body in the Eye

A 34-year-old construction worker presents with sudden onset pain, watering, and photophobia in the right eye after drilling metal. On exam, visual acuity is intact, and a small metallic speck is seen on the cornea. 👉 Likely diagnosis: Superficial corneal foreign body (metallic). 👉 Management: Topical anaesthetic, fluorescein staining, removal with cotton bud/needle, tetanus check, topical antibiotic drops.

Case 2 – Organic Material 🌾 A 19-year-old farmer reports foreign body sensation and tearing after cutting hay. On slit-lamp exam, a small plant fragment is lodged under the upper eyelid. 👉 Concern: Vegetative matter foreign body (↑ risk fungal keratitis). 👉 Management: Lid eversion and removal, topical antibiotic cover, warn about red flags (increasing pain, vision change), urgent ophthalmology review if keratitis suspected.

Case 3 – Contact Lens Wearer 👁️ A 26-year-old woman wearing contact lenses complains of painful red eye and foreign body sensation after a night out. No visible foreign body but corneal staining with fluorescein shows an epithelial defect. 👉 Likely diagnosis: Contact lens–related corneal abrasion ± retained foreign body. 👉 Management: Urgent removal of lens, ciprofloxacin drops (anti-pseudomonal), ophthalmology referral if worsening.

Case 4 – Penetrating Injury 🚨 A 40-year-old man using a hammer develops sudden severe eye pain and blurred vision. He cannot open his eye. Exam: subconjunctival haemorrhage, peaked pupil, and reduced visual acuity. 👉 Concern: Penetrating globe injury with intraocular foreign body. 👉 Management: Do NOT manipulate. Rigid eye shield, nil by mouth, urgent ophthalmology referral for surgical exploration.

Case 5 – Child with Grit 🧒 A 6-year-old boy is brought by his mother after playing in a sandpit. He is rubbing his left eye, which is red and watering. VA normal for age, small particle found under lower lid. 👉 Likely diagnosis: Superficial eyelid foreign body. 👉 Management: Lid eversion, irrigation with saline, discharge with advice on when to return (worsening pain, blurred vision).