Corneal Abrasions

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http://www.aapos.org/terms/conditions/39

Definition

A corneal abrasion occurs when there is a defect in the epithelial surface of the cornea, which is caused by some sort of trauma to the eye surface.

1.)   Traumatic Abrasion

2.)   Foreign Body

3.)   Spontaneous Defects

 

Clinical Presentation

Damage to the cornea causes severe pain in the eye due to the fact that the cornea is highly innervated with sensory fibers from the trigeminal nerve.    

- Patients will often present with severe eye pain, with refusal to open
  eye due to sensation of foreign body in the eye

- Patients often complain of photophobia

- Excessive tearing of the eye

 

Diagnosis

The first step would be a complete history. Patients with a history of significant trauma to the eye must have a penetrating eye injury ruled out. A complete history should also yield whether or not there is a possibility of a foreign body in the eye, which depending on the mechanism of how it entered the eye, must also be ruled out for a penetrating eye injury.

1.)   Eye Exam  

The pupil should be examined, and usually undergoes a reactive miosis following a corneal abrasion. Mydriasis or a pupil that is nonreactive should be concerning because it may indicate a penetrating injury to the pupillary sphincter muscle. Furthermore, the patient should be examined for possible hyphema (blood in anterior chamber) and hyophyon (pus in anterior chamber), which necessitates evaluation by ophthalmologist. Other important factors to consider during the eye exam are that there should be injection of the eye, as well as discharge of tears but no other discharge.

2.)   Fluorescein Exam

Fluorescein is a dye that stains basement membranes, which become exposed following an abrasion. Typically, the lids of the eye are opened by the clinician and a drop is applied to the surface of the eye, which then distributes over the eye. The abrasion can easily be seen as yellow by the clinician, especially when using a Woods lamp. It is important to examine the upper eyelid for possible retained foreign bodies once you have established that there is an abrasion.

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a.  It is important to note that a branching pattern with fluorescin
administration indicates an HSV infection and the patient must immediately be referred to an ophthalmologist

 

Treatment:

1.)   If a foreign body is present, it should be removed immediately if this can be accomplished.

2.)   Antibiotic therapy is generally indicated so that infections do not occur as a result of abrasion.

a. Erythromycin is antibiotic of choice. Typically used as an ointment 4 times per day for 3-5 days.

3.)   Pressure Patches are generally not used in children, because they will be pulled off.

4.)   Pain Control

a. Acetaminophen and other NSAIDs can be used to help treat pain, which will usually allow for abrasion to heal.

b. Cycloplegics are used in order to inhibit pupillary constriction that is associated with photophobia in corneal abrasions.

 i.  Typically will use Homatropine 2.5-5% once, allowing its effect to last for a couple of days and improve symptoms in children.

5.)   Typically, a corneal abrasion will heal within a couple of days and does not require extensive treatment.

a. Corneal abrasions that involves serious foreign body damage may require ophthalmology consult

b. Corneal abrasions that do not improve after a couple of days may warrant ophthalmology consult

c. Treatment with antibiotic ointment and analgesics is a mainstay of treatment that usually leads to resolution of symptoms within days.

 

Summary

- While corneal abrasions present with an intense amount of pain and can be concerning to patients and their families, most abrasions will resolve within 24 to 72 hours.

- Treatment of a corneal abrasion depends on the extent of the invasion and the etiology of the irritation (e.g. foreign body).

- Typically, analgesic medication and cycloplegics are used in combination with an antibiotic ointment that reduces the risk of superimposed infection.

- Vision is usually spared and the patient makes a full recovery. More serious abrasions that affect vision or those that do not resolve during the typical time course warrant a visit to ophthalmology.

 

References:

Dargin, J., & Lowenstein, R. (2008). The Painful Eye. Emergency Medicine Clinics of North America26(1), 199-216.

“Corneal Abrasion and Corneal Foreign Bodies,” Deborah Jacobs, MD. UptoDate, 2012

Browner,E. Corneal Abrasions.  Pediatrics in Review June 2012