Corneal Injuries

The most common types of corneal injuries are:


Corneal abrasions result from scratching, cutting or abrading the protective epithelium of the cornea.

Corneal abrasions mostly are traumatic but can be spontaneous and recurrent.

 Ref: (2018). Recurrent Corneal Erosion: Background, Pathophysiology, Epidemiology. [online] 

After a minor abrasion, healthy cells quickly fill the defect and prevent infection or irregularity in refraction.

Deeper penetration of the cornea results in the healing process taking longer, from 24 to 72 hours [5-6].

Foreign bodies (including rust rings)

Small metallic foreign bodies can come into contact with the eyes, most commonly when someone is drilling or grinding a metal surface [7].

Special attention should be paid to the identification of a corneal rust ring. Iron in its neutral form is relatively insoluble in the corneal layers [8].

However, over time a metallic foreign body’s surface oxidises and diffuses into the stroma. A rust ring is then formed by the combination of oxidised iron and cellular infiltrate at the level of the superficial stroma.

A rust ring can lead to permanent corneal staining, chronic inflammation, corneal vascularisation and necrosis. It therefore should be removed within a few days of it being identified [9-10].

Ultraviolet burns

Ultraviolet keratitis arises from intense or prolonged exposure of the cornea to ultraviolet light, most commonly from welding (arc eye), sunlamps or reflected sunlight from snow (snow-blindness).

The ultraviolet light irritates the corneal epithelium, triggering an inflammatory response with oedema and congestion developing into a superficial keratitis.

Chemical splashes

Chemical injuries represent 7-10% of all eye injuries presenting to the emergency department [11]. Acid and alkaline solutions may cause corneal burns as can aerosol preparations such as ‘pepper’ spray or CS spray (o-chlorobenzylidene malonitrate).

Chemical burns by alkaline solutions have the worst prognosis because they are able to penetrate the tissues quickly, whereas acidic solutions cause more superficial injuries [11]. One should be alert in cases of a painless eye as there may be severe contamination.

In the acute stage, chemical burns induce epithelial defects, corneal oedema, and ischaemic necrosis of the limbus, conjunctiva, iris and ciliary body [12-13].

Airbag deployment can cause chemical burns and eyes to be examined for abrasions in air bag deployments.

Reference:Scarlett, Angela, and Paul Gee. “Corneal Abrasion and Alkali Burn Secondary to Automobile Air Bag Inflation.” Emergency Medicine Journal : EMJ 24.10 (2007): 733–734. PMC. Web. 2 Sept. 2018.