Corneal Laceration Clinical Presentation

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.

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.

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.

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.