eMedicine Specialties > Emergency Medicine > Ophthalmology

Corneal Laceration

Author: Andrew A Aronson, MD, Assistant Professor of Emergency Medicine, Drexel University School of Medicine; Consulting Staff, Department of Emergency Medicine, Allegheny General Hospital
Coauthor(s): Nelson M Yang, MD, Staff Physician, Department of Emergency Medicine, Allegheny General Hospital
Contributor Information and Disclosures

Updated: Apr 9, 2008

Introduction

Background

A corneal laceration is a partial- or full-thickness injury to the cornea. A partial-thickness injury does not violate the globe of the eye (abrasion). A full-thickness injury penetrates completely through the cornea, causing a ruptured globe. This topic discusses the full-thickness injury.

History sometimes points to a discrete event after which the patient’s symptoms started; however, this is not always the case. Small foreign bodies, digital trauma, or other more subtle sources of damage may not be quickly recalled by the patient. The physician must be meticulous in examining the cornea and periorbital structures if there is suspicion of a corneal laceration. Typically, patients who present with this type of injury complain of an intensely painful, profusely lacrimating eye. The bulbar conjunctiva will be injected with prominent blood vessels.

The first priority in evaluating a corneal injury is to include or exclude a full-thickness injury and the resulting ruptured globe. A full-thickness injury will allow aqueous humor to escape the anterior chamber, which can result in a flat-appearing cornea, air bubbles under the cornea, or an asymmetric pupil secondary to the iris protruding through the corneal defect.

For more information, see Medscape's Cornea and External Disease Resource Center and Medscape's Ophthalmology Specialty page.

Frequency

United States

The United States Eye Injury Registry (USEIR) is a terrific resource for nationwide eye trauma epidemiology, prevention techniques, and educational resources.

Penetrating eye injury can occur in individuals of any age, but data from USEIR demonstrate that the mean age of the patient with an ocular injury is 29 years (median age, 26 y), with nearly 60% being younger than 30 years.¹

The American Academy of Ophthalmology also has statistics available. These data suggest similar trends to the USEIR data.

The Centers for Disease Control and Prevention/National Institute of Occupational Safety and Health has information pertaining to work-related eye injuries.

International

International epidemiology of penetrating eye injury has similar demographics of who is likely to sustain corneal injury: males, between the ages of 25 and 30 years, associated with alcohol ingestion, injury occurring at home. Be aware of any local activities or traditions that may also predispose the local population to corneal injury.

Mortality/Morbidity

Mortality from corneal lacerations is rare. However, morbidity from corneal lacerations is significant. Corneal lacerations or subsequent secondary infection (endophthalmitis) can result in complete or partial loss of vision, loss of the eye, or systemic infection.

Sex

Males are more likely than females to have penetrating ocular injury.

Age

Although ocular trauma can occur in persons of all ages, most injuries occur in those aged 25-30 years.

Clinical

History

Document information such as the setting of the injury, changes in vision, or sensation of a foreign body on the eye. Even in the absence of foreign body sensation, evaluate whether there is a possibility of a foreign body entering the eye. Eye penetration may go unnoticed by the patient, particularly when small metal fragments break off and penetrate the eye, such as when metal is struck on metal, or when high-speed machinery is the source of the foreign body. Also, be aware that seemingly blunt objects can still cause lacerations if they contact the cornea in the right orientation. In cases like this, the patient may present for care later, after the development of increasing pain, deterioration in vision, or infection.

• Evaluation of visual acuity immediately following the injury is an important examination data point. Test visual acuity in each eye with a Snellen chart, or document the ability of the patient to distinguish number of fingers, movement, or light if the patient cannot read a Snellen chart. This will assist the ophthalmologist in determining what sort of intervention, therapy, and rehabilitation may be required.
• Obtain the patient's preinjury vision assessments as well as any history of previous ocular problems or ocular surgery.
• Document pertinent medical history, current medications, allergies, and tetanus immunization status.
• Determine information regarding the patient's last oral intake if operative intervention is anticipated.

Physical

• Assessment of visual acuity must be performed, taking care not to apply additional pressure to the globe. 
  • If possible, determine visual acuity prior to examination or treatment, and separately test each eye with corrective lenses. Pinhole testing may help differentiate refractive error from uncorrectable vision when spectacles are not available.
  • The objective of the testing is to get a visual reference as soon as possible after the injury. The examiner must be able to report the patient's vision status to the ophthalmologist.
  • Use age-appropriate vision testing devices such as the Snellen distance chart or a hand-held vision card.
  • Ask the patient to identify typed letters, the clock, or objects on the wall if the patient's condition prevents formal (standing upright) testing.
  • If a patient's vision is severely limited, determine whether the patient can count fingers, detect movement, or identify light.
• Slit lamp examination  
  • Examine the cornea using a slit beam to search for anterior chamber penetration. A shallow anterior chamber, irregularly shaped pupil (teardrop shape), hyphema (blood in the anterior chamber), bubbles in the anterior chamber, or a flat cornea can be signs of corneal perforation.
  • Aqueous humor leaking from the anterior chamber can be identified by performing a Seidel test. This test is performed by directly applying fluorescein to the suspected corneal lesion. Visualization of diluted dye under a black light (a positive test) suggests a leak. A negative Seidel test (no dilution of fluorescein) suggests a partial-thickness injury but may be seen in small or spontaneously sealing lesions. One should avoid the temptation to press on the globe to test for a self-sealing injury.
  • Be sure to evaluate for a foreign body in the anterior chamber, especially if the patient’s history suggests that the corneal laceration is from a small, high-speed object (such as from hammering metal).
• Full-thickness corneal lacerations  
  • Ophthalmology consultation is required for all types of corneal perforation.
  • Do not apply pressure to the globe.
  • Immediately place a protective shield (not a patch) over the affected eye.
  • Instruct the patient to avoid ocular movement because extraocular muscle contraction can cause extrusion of intraocular contents.
  • Full-thickness corneal lacerations often result in a loss of aqueous humor producing a shallow or flat anterior chamber.
  • Prolapse or incarceration of the iris may produce a teardrop distortion of the pupil.
  • Hyphema, or blood in the anterior chamber, can be another sign of anterior chamber penetration. Hyphema may also be seen with blunt, nonpenetrating trauma.

Causes

The causes of corneal lacerations are numerous and include but not limited to flying metal fragments, sharp objects, fingernails, air-bag deployment, fireworks, explosions, blunt force trauma, pellets, and BBs.

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