Corneal Abrasion & Infectious Keratitis
Recognise corneal epithelial injury and infection, especially in contact-lens wearers.
Quick revision ↓ Medical Dictionary
01Corneal symptoms
The densely innervated cornea can produce marked pain, tearing and photophobia when injured. Ask about trauma, lens use, water exposure and previous episodes. Measure vision and inspect for an opacity or foreign body. A small surface defect and a deep infection can both be painful, so the history alone cannot determine severity.
02Fluorescein assessment
Fluorescein helps identify epithelial defects under appropriate illumination when examination is safe. The pattern, size and position matter; a central defect may impair acuity. Vertical scratches can suggest a retained subtarsal foreign body. Suspected penetration changes the examination: avoid pressure and manipulation and arrange emergency specialist assessment rather than completing routine surface tests.
03Microbial keratitis
Pain, reduced vision and a corneal infiltrate or ulcer suggest microbial keratitis. Contact-lens wear, trauma and compromised surface defences increase risk. Arrange urgent same-day ophthalmic review, with treatment and sampling determined by the specialist pathway. Bacterial, fungal and other organisms require different approaches; a generic conjunctivitis prescription may be inadequate for a corneal infection.
04Herpetic and atypical disease
A branching epithelial lesion can suggest herpes simplex keratitis, but diagnosis needs appropriate examination. Steroids without suitable specialist oversight may worsen epithelial infection. Severe pain with contact-lens and water exposure raises additional concerns, including Acanthamoeba. Atypical appearance or poor response should trigger diagnostic reassessment rather than assuming resistant routine conjunctivitis.
05Recovery and prevention
Uncomplicated abrasion care includes appropriate analgesia, infection-risk assessment and follow-up advice. Do not supply unsupervised take-home anaesthetic drops as routine undergraduate practice. Contact-lens wear must stop until safe resumption is advised. Persistent pain, reduced vision or failure to heal needs review; recurrent waking pain may suggest recurrent corneal erosion after previous injury.
High-Yield Revision
- A painful contact-lens red eye needs corneal assessment.
- An infiltrate or ulcer is not simple conjunctivitis.
- Persistent symptoms after an abrasion require review.
Common Pitfalls
- Starting steroid drops before excluding corneal infection.
- Ignoring contact-lens water exposure.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 28 September 2026. Consult current local protocols for prescribing, procedures and escalation.