Corneal abrasion is probably the most common eye injury and also one of the most painful. It occurs because of a disruption in the integrity of the corneal epithelium or because the corneal surface is scraped away or denuded as a result of physical external forces. Corneal epithelial abrasions can be small or large.
Corneal abrasions usually heal rapidly, without serious sequelae. Consequently, they are often considered of little consequence. However, deep corneal involvement may result in facet formation in the epithelium or scar formation in the stroma.
Corneal abrasions occur in any situation that causes epithelial compromise. Examples include corneal or epithelial disease (eg, dry eye), superficial corneal injury or ocular injuries (eg, those due to foreign bodies), and contact lens wear. Spontaneous corneal abrasions may be associated with map-dot-fingerprint dystrophy or recurrent corneal erosion syndrome.
A traumatic corneal abrasion is the classic corneal abrasion in which mechanical trauma to the eye results in a defect in the epithelial surface. Common causes of traumatic corneal abrasions include the following:
- Animal paws
- Pieces of paper or cardboard
- Makeup applicators
- Hand tools
- Branches or leaves
Foreign body–related abrasions are defects in the corneal epithelium that are left behind after the removal of or spontaneous dislodgement of a corneal foreign body. Foreign body abrasions are typically caused by pieces of rust, wood, glass, plastic, fiberglass, or vegetable material that have become embedded in the cornea.
Contact lens–related abrasions are defects in the corneal epithelium that are left behind after the removal of an overworn, improperly fitting, or improperly cleaned contact lens. In these cases, the mechanical insult is not from external trauma but rather from a foreign body that is associated with specific pathogens.
Spontaneous defects in the corneal epithelium may occur with no immediate antecedent injury or foreign body. Eyes that have suffered a previous traumatic abrasion or eyes that have an underlying defect in the corneal epithelium are prone to this problem.
The diagnosis of corneal abrasion can be confirmed with slitlamp examination and fluorescein instillation. Prophylactic topical antibiotics are given in patients with abrasions from contact lenses, who are at increased risk for infected corneal ulcers, but many emergency physicians have stopped using these agents for minor injuries. Patching the eye is a traditional measure, but it is not supported by research and should not be performed in patients at high risk of eye infection. Pain relief is important.
Corneal abrasions heal with time. Prophylactic topical antibiotics are given in patients with abrasions from contact lenses. Traditionally, topical antibiotics were used for prophylaxis even in noninfected corneal abrasions not related to contact lenses, but this practice has been called into question.
Patching the eye has been used to help relieve the pain associated with corneal abrasion, but research has not shown benefit from patching. Patching should not be performed in patients at high risk of infection, such as those who wear contact lenses and those with trauma caused by vegetable matter, because of potential incubation of infecting organisms and promoting subsequent infectious keratitis.
Some ophthalmologists advocate the use of a disposable soft contact lens in addition to antibiotic drops. This therapy may be an effective alternative to patching, as it allows the patient to maintain binocular vision during treatment and reduces inflammation. The use of topical NSAIDs for pain control is controversial: while the drugs do reduce ocular pain, they also slow healing of the damaged epithelium. In addition, topical cycloplegics may be required to relieve pain and photophobia in patients with large abrasions until their healing is nearly complete.
Emergent ophthalmologic consultation is warranted for suspected retained intraocular foreign bodies. Urgent consultation is needed for suspected corneal ulcerations (microbial keratitis).