Corneal superficial injury
Exam Tips
- In OSCEs, always document visual acuity first in any painful red eye before interventions.
- A contact lens wearer with pain/photophobia is keratitis until proven otherwise: same-day ophthalmology and antipseudomonal strategy.
- Do not discharge with topical anaesthetic drops; this is a common exam safety trap.
- Vertical fluorescein tracks suggest a subtarsal foreign body; evert the upper lid once penetrating injury is excluded.
- If fluorescein appears to stream/dilute from a point leak, suspect globe perforation and refer emergently.
- Photophobia with headache or systemic features should prompt consideration of non-corneal emergencies (e. g, meningitis, acute glaucoma, uveitis).
- Image recognition is high yield: compare linear abrasion, punctate contact-lens staining, and dendritic herpetic pattern (see fluorescein-pattern figure in your ophthalmology revision atlas).
Definition
A corneal superficial injury is a non-penetrating insult to the corneal surface, usually involving the epithelium and causing a corneal abrasion or superficial foreign-body-related defect. It is often very painful despite being anatomically shallow because the cornea is densely supplied by trigeminal sensory fibres, and it typically presents as an acute unilateral red, watery, photophobic eye.
Pathophysiology
Mechanical, chemical, thermal, or ultraviolet injury disrupts the corneal epithelial barrier and tear film, exposing subepithelial nociceptors and triggering intense pain, blepharospasm, and reflex lacrimation. Epithelial loss increases stromal oedema risk and creates a portal for microbial invasion (especially with contact lens wear, where Pseudomonas risk is higher). Healing usually occurs through epithelial cell migration and mitosis over 24-72 hours in small defects, but larger defects, ongoing trauma, basement membrane disorders, or toxic topical exposure can delay re-epithelialization and predispose to recurrent erosion.
Risk Factors
- High-risk occupational/recreational exposure (grinding, cutting, metalwork, sport) without eye protection
- Contact lens wear (overnight wear, poor hygiene, dehydrated lens/eye, difficult removal, poor fit)
- Mechanical trauma (fingernail, tree branch, paper/card edge, make-up applicator, trichiasis)
- Foreign body exposure (dust, glass, metal; ferrous fragments can form rust rings)
- Chemical exposure (acid/alkali liquids, powders, gases)
- Ultraviolet exposure (sunlight reflection, welding arc, tanning beds)
- Previous corneal trauma or anterior basement membrane dystrophy (risk of recurrent erosion)
- Excessive eye rubbing
Clinical Features
Symptoms
- Sudden unilateral eye pain, often worse on blinking
- Foreign-body sensation (gritty/scratching discomfort)
- Epiphora (watering)
- Photophobia
- Blurred or reduced vision
- History of precipitating incident (trauma, foreign body, lens removal, UV or chemical exposure)
Signs
- Conjunctival injection/redness
- Blepharospasm
- Fluorescein-positive epithelial defect (linear/geographic or punctate-coalescent pattern)
- Vertical linear superior corneal staining suggesting subtarsal foreign body
- Visible corneal/conjunctival foreign body or rust ring
- Eyelid oedema/erythema
- Abnormal pupil shape/reactivity, uveal prolapse, hyphema, hypopyon, or positive Seidel pattern as red flags for deeper injury
Investigations
Management
Lifestyle Modifications
- Immediate copious irrigation for any chemical injury (start at scene/triage, continue during transfer)
- Stop contact lens wear until fully healed; discard current lenses/case and restart only after clinical resolution
- Avoid eye rubbing and avoid dusty/dirty environments while cornea is anaesthetised or healing
- Use protective eyewear for future risk activities (workshop, grinding, UV exposure)
- Safety-net urgently for worsening pain, photophobia, reduced vision, purulent discharge, or no improvement within 24-48 hours
Pharmacological Treatment
Oral analgesia
- Paracetamol 1 g orally every 4-6 hours when required (maximum 4 g/day)
- Ibuprofen 400 mg orally three times daily with food if suitable (use lowest effective dose; usual prescription max up to 2.4 g/day in divided doses)
Assess renal/GI/cardiovascular risk and pregnancy status before NSAIDs; avoid NSAIDs in active peptic ulcer disease or significant renal impairment.
Topical antibiotic prophylaxis for uncomplicated non-contact-lens abrasion
- Chloramphenicol 1% eye ointment: apply approximately 1 cm strip 4 times daily for 5 days
- Alternative: Chloramphenicol 0.5% eye drops: 1 drop every 2 hours for 48 hours, then every 4 hours while awake for total 5 days
Avoid chloramphenicol in true hypersensitivity and use caution in pregnancy/breastfeeding per BNF product advice. Contact lens-associated injuries need antipseudomonal cover and same-day specialist assessment.
Topical anaesthetic (diagnostic use only in clinic)
- Proxymetacaine 0.5% eye drops: 1 drop once before examination
- Oxybuprocaine (benoxinate) 0.4% eye drops: 1 drop once before examination
Do not prescribe for home use. Repeated dosing is epitheliotoxic, delays healing, and can mask deterioration.
Contact-lens-related or infected corneal injury (specialist-led)
- Ofloxacin 0.3% eye drops: typically intensive initial dosing then reduced frequency according to specialist protocol
- Ciprofloxacin 0.3% eye drops: specialist protocol for antipseudomonal treatment
Urgent same-day ophthalmology due to risk of infective keratitis/corneal ulcer; avoid topical corticosteroids unless directed by ophthalmology.
Surgical / Interventional
- Removal of superficial corneal or subtarsal foreign body under magnification when safe
- Rust ring removal (often at follow-up by experienced practitioner/ophthalmology)
- Debridement for non-healing epithelial defects or recurrent erosion syndrome
- Emergency ophthalmology procedures for penetrating injury, severe chemical burns, or sight-threatening complications
Complications
- Infective keratitis (bacterial, fungal, herpetic)
- Corneal ulceration
- Iritis/anterior uveitis
- Recurrent corneal erosion syndrome
- Corneal scarring with persistent visual disturbance (uncommon in uncomplicated minor injuries)
Prognosis
Most uncomplicated small abrasions heal within 24-48 hours without lasting visual deficit. Larger epithelial defects may take around 4-5 days, and a minority need debridement if healing is delayed. Chemical injuries are potentially sight-threatening, with outcome strongly dependent on chemical type/concentration, contact duration, and speed/adequacy of irrigation.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Corneal superficial injury[overview]