A 34-year-old battery factory worker arrives 20 minutes after concentrated sulphuric acid splashed into his right eye when a container tipped. Co-workers rinsed the eye with tap water at the scene. The eye is intensely painful with profuse tearing and blepharospasm. He wears no eye protection at work. No other injuries.
Examination Findings
Visual acuity: right 6/24, left 6/6. Right eye: lid oedema, conjunctival injection with patchy perilimbal blanching over about three clock hours, cornea hazy with a large epithelial defect staining with fluorescein, anterior chamber quiet. pH paper on the conjunctival sac reads acidic despite field irrigation. No particulate matter seen after lid eversion and fornix sweeping.
Investigations
pH testing of the conjunctival fornices with litmus or pH paper is repeated until neutral — irrigation continues until it stays neutral. Slit-lamp grading records limbal ischaemia (blanched, avascular limbus) and corneal clarity, which together predict prognosis. Fluorescein maps the epithelial defect. Intraocular pressure is checked once the epithelium allows, as chemical injury can raise pressure.
Questions to Think About
- Irrigation had already started at the factory. Why continue it in the department, and what is the endpoint?
- Why does the extent of limbal blanching matter more than the size of the epithelial defect?
- What occupational lesson does this case teach?
Diagnosis
Acid chemical burn (sulphuric acid) with partial limbal ischaemia, right eye.
Reasoning
Reasoning: This is an acid chemical burn. Acids denature surface proteins, forming a coagulum that partly limits deeper penetration — generally a better prognosis than alkali — but concentrated sulphuric acid still threatens the limbal stem cells, and residual acid hides in the fornices, so the pH is still acidic on arrival. The endpoint of irrigation is a neutral pH that stays neutral on retesting. Limbal ischaemia extent predicts healing: a healthy limbus re-epithelialises the cornea; a blanched limbus cannot. Diagnosis: moderate acid chemical burn, right eye. Management: typical management is immediate, copious irrigation (water or saline — never delay irrigation to find a specific fluid), double eversion of lids with fornix sweeping to remove trapped particles, pH checks until neutral, then topical antibiotics, a cycloplegic, preservative-free lubricants, and pressure monitoring per local protocol. He is referred urgently to ophthalmology, and his workplace is counselled on sealed safety goggles and an eyewash station.
Differential Diagnosis
- Alkali burn — the key distinction: alkalis saponify tissue and penetrate deeper with a worse prognosis; acids coagulate surface proteins, which partly limits penetration, but concentrated acids still cause severe injury.
- Thermal burn — ruled out: the agent is chemical, and management overlaps but pH-guided irrigation is specific to chemical injury.
- Corneal abrasion alone — incomplete: the limbal blanching and ongoing acidity mark this as a true chemical burn, not a simple abrasion.
Management
Irrigation is the treatment — litres of fluid until conjunctival pH is neutral and stays neutral. Then topical antibiotics, cycloplegia, and intensive lubrication per local protocol, with urgent ophthalmology referral for grading and follow-up. Steroids, ascorbate, and surgical options are specialist decisions. Prevention: sealed goggles and accessible eyewash at the workstation.
Key Learning Points
- Irrigate first, and keep irrigating until the fornix pH is neutral and stays neutral — never delay irrigation.
- Acids coagulate and penetrate less than alkalis, but concentrated acids still cause severe limbal injury.
- Limbal ischaemia extent, not the epithelial defect size, predicts the outcome.
- Evert both lids and sweep the fornices — trapped particles keep the burn going.
Red Flags
- Extensive limbal blanching or an opaque cornea — severe burn with poor prognosis; urgent specialist care.
- Persistently abnormal pH despite irrigation — retained particulate chemical; re-evert lids and sweep fornices.
- Rising intraocular pressure in the days after injury — secondary glaucoma; monitor and treat per protocol.
Educational content only — not medical advice. Clinical decisions must be made by a qualified professional for the individual patient.
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