Corneal Abrasion
A corneal abrasion is a traumatic defect of the corneal epithelium causing severe pain, watering and photophobia; confirm it with fluorescein, exclude a foreign body or open-globe injury, and treat contact-lens-associated abrasions as higher-risk for microbial keratitis.
Definition
A corneal abrasion is a traumatic defect of the corneal epithelium without primary stromal involvement. It causes pain, watering and photophobia and is identified by fluorescein staining; deeper, contaminated, central or infected injuries can scar or threaten vision.
First principles
A small epithelial defect can be intensely painful
The cornea is densely supplied by trigeminal sensory fibres. Removing epithelium exposes the superficial nerve endings and produces pain, foreign-body sensation, reflex tearing, blepharospasm and photophobia that may seem disproportionate to the visible scratch.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.

