Corneal Abrasion
Disruption of the corneal epithelium is usually associated with immediate pain, foreign-body sensation, tearing, and discomfort with blinking. A slit-lamp examination is essential in determining the presence, extent, and depth of the corneal defect. Fluorescein staining of the cornea is very helpful in diagnosing a foreign body. It is important to distinguish between a corneal abrasion, which generally has sharply defined edges and little to no associated inflammation (when seen acutely), and a corneal ulcer, which is characterized by opacification and an inflammation-mediated breakdown of the stromal matrix and possible thinning. Also, it is important to rule out a foreign body as the cause of the abrasion. Occasionally, a patient may not recall a definite history of trauma but still present with signs and symptoms suggestive of a corneal abrasion. An eye with a corneal abrasion from a fingernail, piece of paper, or tree branch is more likely to develop recurrent erosions, the symptoms of which are the same as those of a corneal abrasion and typically occur upon awakening (see Chapter 4 for a discussion of recurrent corneal erosions). Herpes simplex virus keratitis should also be excluded as a possible diagnosis in such cases.
Pressure patching can relieve pain from an abrasion by immobilizing the upper eyelid to prevent rubbing against the corneal defect, although patching is not necessary for most abrasions and some patients may find patches uncomfortable. Topical antibiotic ointment is suggested in either case. Another alternative is a bandage contact lens, which provides pain relief and facilitates reepithelialization. Antibiotic drops rather than ointment should be used with a bandage lens. Topical antibiotic drops are recommended until the epithelium heals. Cycloplegics can help with the ciliary spasm associated with a corneal abrasion. Topical nonsteroidal anti-inflammatory agents have anesthetic properties and may be used for the first 24–48 hours for pain relief in selected patients; however, these agents should be used with caution, as they can cause local toxicity and delay wound healing. Oral pain management for the first 24–48 hours can be helpful for many patients.
Patients with abrasions caused by organic material require close follow-up to monitor for fungal infection. Abrasions caused by vegetable matter such as a fingernail, paper, leaves, or thorns heal more slowly than abrasions caused by inorganic materials such as steel, glass, or plastic.
Patients with contact lens–associated epithelial defects due to excessive wear or an improper fit should not receive a patch or have a therapeutic contact lens applied because of the risk of promoting or worsening a corneal infection. These patients should be treated with topical antibiotic drops or ointment.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.