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Corneal ulcer — red flags and referral priorities

Structured for Australian optometry practice. Source-cited clinical reference; not individually clinician-reviewed.

Quick answer

  • Corneal ulcer suspicion is driven by pain, photophobia, reduced vision, focal epithelial defect, infiltrate, or stromal haze.
  • Contact lens wear, central location, rapid symptom progression, and anterior chamber reaction increase urgency.
  • A corneal ulcer is sight-threatening and must not be observed — treat it as infective until an infective cause has been assessed and considered unlikely.
  • A suspected corneal ulcer raises the same concern as suspected microbial keratitis — the two are one presentation, not two urgencies.

Common causes

  • Microbial keratitis with focal corneal ulceration.
  • Contact lens-related corneal ulcer.
  • Herpetic corneal ulcer or neurotrophic epithelial breakdown.
  • Peripheral ulcerative or inflammatory corneal lesion requiring differentiation.

Red flags (must not miss)

  • Reduced vision or marked photophobia.
  • Central ulcer, dense infiltrate, or stromal haze.
  • Anterior chamber reaction, hypopyon, or rapid progression.
  • Contact lens wear or overnight wear history.
  • Corneal thinning or poor epithelial healing.

Use OptoGuide™ to guide this decision during consult.

What to check

  • Visual acuity and pain severity.
  • Ulcer size, depth, location, and edge characteristics.
  • Fluorescein staining and surrounding infiltrate pattern.
  • Anterior chamber reaction and corneal thinning risk.
  • Contact lens history, trauma, and exposure history.

When to refer

  • Suspected corneal ulcer or microbial keratitis: same-day ophthalmology assessment. Do not observe and do not treat empirically without specialist input.
  • Escalate to emergency assessment if there is hypopyon, corneal thinning, perforation risk, or rapidly worsening pain and vision.
  • A contact lens peripheral ulcer is a different, sterile lesion and is not this pathway — distinguish it before de-escalating.
  • Urgent corneal review for central lesions, vision change, hypopyon, or thinning risk.
  • Do not observe a likely ulcer without specialist input.

Initial management

  • Frame the lesion as corneal ulceration first, then refine the differential.
  • Record acuity, lesion location, stain pattern, and chamber findings clearly.
  • Escalate early when the cornea is threatened or the lesion is not clearly superficial and low risk.

Clinical basis

This guidance reflects standard optometric clinical reasoning based on:

  • Australian optometry clinical practice patterns
  • Australian medicines regulation and PBS prescribing context
  • Common ophthalmology referral standards
  • Evidence-based clinical training and practice
View full clinical basis

Use OptoGuide™ during consult for structured clinical guidance.

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