A corneal abrasion (scratched cornea or scratched eye) is one of the most common eye injuries. A scratched cornea often causes significant discomfort, eye erythema, and photophobia. Corneal abrasions result from a disruption or loss of cells in the top layer of the cornea, called the corneal epithelium. Corneal abrasions can be classified as traumatic, including foreign body related and contact lens-related, or spontaneous.
Traumatic causes, such as tree branches, makeup brushes, workplace debris, sports equipment all can cause corneal abrasions. Traumatic events do not cause many corneal abrasions. Sand and other small particles can cause a corneal abrasion, especially if you rub your eyes. Damaged contact lenses or prolonged use of contacts lenses may increase your risk of a scratched cornea.
Corneal abrasions are common eye injuries across all age groups. They are particularly common in the workplace, with an annual incidence of 15 per 1000 employees in US autoworkers. In primary care clinics, eye complaints are responsible for 2% of visits.
Difficulty opening the eye, photophobia, foreign body sensation associated with eye pain can be due to a corneal injury. Many times, an eye injury is not reported. It is important to ask if the patient works with wood or metal because small pieces can get caught under the eyelid and cause injury to the cornea. On exam, corneal abrasions can be associated with redness, light sensitivity, excessive lacrimation, decreased visual acuity. Fluorescein staining is the most helpful clinical tool to assess for corneal abrasion. Dye will get caught in the corneal abrasion and fluoresce under cobalt blue light.
Start the eye exam with a penlight. An abnormally shaped pupil could be a sign of globe rupture. Topical anesthetics are helpful to facilitate the examination. Conjunctival injection is typically present. A corneal opacity or infiltrate may occur with corneal ulcers or infection. A hazy cornea is a sign of edema from excessive rubbing. Inspect the anterior chamber for hyphema or hypopyon. The presence of hyphema or hypopyon requires an immediate ophthalmologic referral. Abrasions over the center of the cornea will cause a decrease in visual acuity. Significant decreases in visual acuity require referral to an ophthalmologist. Document extraocular movements.
Fluorescein staining helps identify a corneal epithelial defect. Apply a drop of a topical anesthetic into the eye or on a fluorescein strip and then apply it to the conjunctiva. The fluorescein dye passes over normal cornea tissue but gets stuck in any cornea defects. The dye appears green under cobalt blue light. Traumatic corneal abrasions typically have linear or geographic shapes. If a patient wears contact lenses, the abrasion may have several punctate lesions that coalesce into a round, central defect. Herpes keratitis has dendritic dye uptake and requires immediate treatment. Foreign bodies on the inner eyelid typically cause vertical linear cornea lesions; therefore, everting the eyelids is necessary to assess for foreign bodies.
The administration of topical antibiotics and, for large abrasions, cycloplegics have been the mainstay of therapy, along with daily follow-up until the eye is healed. Patching was previously routine but is no longer recommended for most patients. Tetanus prophylaxis is only necessary for penetrating eye injuries not simple corneal abrasions.
If a corneal foreign body is detected, an attempt can then be made to remove the foreign body with a swab or irrigation under direct visualization. Foreign bodies under the lid should be removed after flipping the lid. If irrigation or a cotton swab fail to remove the foreign body, a metal instrument is needed. Instill topical anesthetic. A 25-gauge needle or an eye spud can be used to remove the object. If the metal instrument fails, then ophthalmology referral within 24 hours is needed for foreign body removal. Initiate topical antibiotics (erythromycin).
There are several antibiotic options. Ointment formulations provide lubrication to the injured eye. Contact lens wearers will need coverage for Pseudomonas with a fluoroquinolone or aminoglycoside. Erythromycin ointment is to be used 4 times daily for 5 days for the non-contact lens wearing patients. Drops are available for sulfacetamide 10%, polymyxin/trimethoprim, ciprofloxacin, or ofloxacin. Aminoglycoside antibiotics should be avoided in non-contact lens wearing patients. Duration of therapy is variable, but a patient can discontinue therapy entirely if the eye is symptom-free for 24 hours. Continued symptoms beyond three days warrant evaluation by an ophthalmologist. Never use topical corticosteroids due to delayed healing and increased risk of infection.
Regarding pain control, small abrasions (less than 4 mm) rarely require analgesia. Mild to moderate pain can typically be controlled with oral nonsteroidal anti-inflammatory drugs (NSAIDs). Ophthalmic topical NSAID solutions provide pain relief.
In the few patients with small abrasions that fail to heal despite these treatments, oral opioid medications may be required. A 1- to 2-day oxycodone prescription should be adequate.
Cycloplegic medications can relieve photophobia. Like the opiate medications, 2 days of cycloplegic drops should be enough to manage the photophobia. There are side effects to cycloplegics, such as difficulty with reading. If a cycloplegic agent is going to be utilized, cyclopentolate is a good choice because of its short duration of action.
Small cornea abrasions usually heal without difficulty. Larger abrasions, visual disturbance, and abrasions caused by a contact lens will require close outpatient monitoring by an ophthalmologist.
Corneal abrasion complications include corneal ulcers, bacterial keratitis, recurrent erosion syndrome, and traumatic iritis.
Use safety glasses when using power tools.
Most corneal abrasions heal regardless of therapy in 1 to 3 days. Vision should return to normal in that time although ointment antibiotic formulations may cause and an iatrogenic decrease in vision.
Contact lens wearers who present with a corneal epithelial defect should be examined with the penlight to look for a corneal infiltrate, which is a white spot or opacity, or an ulcer, representing a surface breakdown, thinning, or necrosis that occurs in an area of infiltration. An ophthalmologist should see any patient with such a finding the same day. An ointment (such as erythromycin ophthalmic ointment) is theoretically better than drops because it functions as a lubricant and may reduce disruption of the remaining and newly generated epithelium. Ointments are preferred to drops in children because they do not sting during application.
Due to the risk of sight-threatening bacterial keratitis, patients with corneal abrasions and history of recent contact lens wear but without a corneal infiltrate receive timely topical antibiotics that are effective against Pseudomonas species (such as the fluoroquinolone class). These patients warrant timely referral to an ophthalmologist or optometrist for daily follow-up care. Patients with uncomplicated, small, traumatic or foreign body corneal abrasions should not undergo patching.
As far as pain control for small corneal abrasions (less than or equal to one-fourth of the corneal surface area, for example, circular abrasion 4 mm in diameter, the use oral analgesias such as ibuprofen or acetaminophen-oxycodone combination medication with or without topical nonsteroidal anti-inflammatory ophthalmic drops (such as ketorolac) is typically sufficient. Large abrasions can require oral opioid analgesia, for example, acetaminophen-oxycodone combination medication, cycloplegic drops, and, in selected patients such as those with abrasions covering greater than 50% corneal surface, eye patching.
Because of the possibility of overuse (greater than 24 hours) and the risk of inappropriate administration to patients with conditions other than simple corneal abrasions, use topical anesthetics or other means of pain control. Most small corneal abrasions heal within 24 to 48 hours. Follow-up may not be necessary for older children, adolescents, and adults as long as symptoms resolve and anticipatory guidance is provided.
After initial treatment, urgent referral to an ophthalmologist is indicated for patients with the following: larger epithelial defects at 24 hours, purulent discharge, or decrease in vision of more than 1 to 2 lines (20/20 to 20/60), corneal abrasions that have not healed after 3 to 4 days, or children who are unwilling to open the affected eye after 24 hours.
Corneal abrasions are a common injury typically seen in urgent care centers and emergency departments. Most of the time, they will heal on their own with the assistance of topical antibiotics to prevent infection. It is important to identify signs of more serious injury that would necessitate urgent ophthalmologic follow-up. The most dangerous injury would be an open globe. It is also important to get follow-up within 24 hours for large abrasion or a decrease in visual acuity. Regions of the country that do not have ophthalmology coverage available to them will need to establish follow-up or have a low threshold for transferring to a tertiary care center. Daily follow-up by an ophthalmic nurse or an ophthalmologist is required for large abrasions, abrasions from the contact lens, abrasions associated with decreased vision, and abrasions in young children The majority of small corneal abrasions heal within a few days and full recovery is the norm. Large corneal lesions may take some time to heal but visual recovery is not always guaranteed. (Level V)