Continuing Education Activity

A corneal abrasion (also called scratched eye or scratched cornea) is an eye injury that causes significant discomfort, photophobia, and erythema. This occurs when there is a disruption of the corneal epithelium caused by contact lens or foreign bodies trauma, or spontaneously. This activity illustrates the evaluation and management of corneal abrasions and explains the role of the interprofessional team in improving care for patients with this condition.

Objectives:

• Describe the etiology of corneal abrasions.
• Identify the use of fluorescein staining in the clinical evaluation of patients with corneal abrasions.
• Summarize the use of topical antibiotics and cycloplegics in the treatment of corneal abrasions.
• Outline the importance of collaboration and communication among the interprofessional team members to provide urgent follow-up and care to improve outcomes for patients affected by corneal abrasions.

Introduction

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.[1]

Etiology

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 contact lenses may increase your risk of a scratched cornea.[1]

Epidemiology

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 and traumatic conditions, and foreign bodies are the reason for 8% of these visits.[2]

History and Physical

Difficulty in 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 corneal abrasion. The dye will get caught in the corneal abrasion and fluoresce under cobalt blue light.

Evaluation

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. The 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 corneal lesions; therefore, everting the eyelids is necessary to assess for foreign bodies.

Treatment / Management

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.[3] Tetanus prophylaxis is only necessary for penetrating eye injuries not simple corneal abrasions.[4]

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 fails 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 an 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.[5] Erythromycin ointment is to be used four times daily for five days for 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.[6][7]

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 two days oxycodone prescription should be adequate.

Cycloplegic medications can relieve photophobia. Like the opiate medications, two 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.[8]

Differential Diagnosis

The differentials of corneal abrasion include but not limited to the following:

• Conjunctivitis
• Dry eye syndrome
• Acute angle-closure glaucoma
• Uveitis
• Infective keratitis (bacterial, fungal, herpetic)
• Corneal ulcer
• Recurrent erosion syndrome

Prognosis

The prognosis is usually excellent if treatment is prompt; however, untreated corneal abrasions can lead to blindness. Small corneal abrasions usually heal without difficulty. Larger abrasions, visual disturbance, and abrasions caused by a contact lens will require close outpatient monitoring by an ophthalmologist. Deep abrasions in the central visual axis heal but leave a scar. In such cases, a permanent loss of visual acuity may result from corneal cloudiness or irregular corneal astigmatism.

Complications

Small corneal abrasions usually heal without difficulty but larger abrasions cause the following complications:

• Corneal ulcers
• Bacterial keratitis
• Recurrent erosion syndrome
• Traumatic iritis

Consultations

In the following cases urgent follow up with an ophthalmologist should be done:

• Open globe injuries require immediate ophthalmology involvement
• Hyphema, hypopyon, a decrease in visual acuity (more than two lines from the good eye on Snellen chart) require urgent ophthalmologic follow-up
• Subacute follow-up with ophthalmology for corneal abrasions not healed after four days

Deterrence and Patient Education

People who work in high-risk occupations, participate in contact sports, and those whose work or recreation increases the risk of corneal abrasion or ultraviolet light exposure should wear protective eyewear. Patients who wear contact lenses should make sure they fit properly and wear them and replace them as instructed. The eye should not be rubbed after a foreign body injury as it may damage the cornea more. For larger corneal abrasions close follow-up with the ophthalmologist should be done.

Pearls and Other Issues

Most corneal abrasions heal regardless of therapy in one to three 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 on the same day. An ointment (such as erythromycin ophthalmic ointment) is theoretically better than drops because it functions as a lubricant and may reduce the 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 a 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), is concerned the use oral analgesias such as ibuprofen or acetaminophen-oxycodone combination 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, 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 one to two lines (20/20 to 20/60), corneal abrasions that have not healed after three to four days, or children who are unwilling to open the affected eye after 24 hours.

Enhancing Healthcare Team Outcomes

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.[9][10]