A corneal laceration can be 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 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.
United States
The United States Eye Injury Registry (USEIR) is a terrific resource for nationwide eye trauma epidemiology, prevention techniques, and educational resources.
Approximately 2% of all emergency department visits are due to eye injuries.[34]
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 features information pertaining to work-related eye injuries.
More than 90% of eye injuries are preventable with the use of protective eyewear.[34]
International
International epidemiology of penetrating eye injury has similar demographics of who is likely to sustain corneal injury: males, between ages 25 and 30 years, associated with alcohol ingestion, and injury occurring at home. Be aware of any local activities or traditions that may also predispose the local population to corneal injury (eg, fireworks injuries on the Fourth of July in the United States).
Mortality from corneal lacerations is rare, but morbidity can be significant. Corneal lacerations or subsequent secondary infection (endophthalmitis) can result in complete or partial loss of vision, loss of the eye, or systemic infection. Other complications include corneal scarring, cataract formation, and secondary glaucoma.[35]
Males are about 1.7 times more likely than females to have penetrating ocular injury.[34]
Although ocular trauma can occur in persons of all ages, the majority of injuries occur in those aged 25-30 years.
Of patients presenting to the emergency department with eye injury, 45.3% were aged 18-44 years. The highest rate of admission-related eye injuries occurred among persons older than 65 years.
The prognosis after corneal laceration depends on the extent of the injury. Factors to consider include but are not limited to depth and length of laceration, location, and degree of scarring. Extensive corneal scarring may affect vision, requiring corneal transplant in the future. Laceration involving deeper globe structures such as the lens, retina, and uveal tissue may have a guarded prognosis.
Document information such as the setting of the injury, changes in vision, or sensation of a foreign body in the eye.[2] 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 particles are ejected from high-speed machinery. Also, be aware that seemingly blunt objects can still cause lacerations if they contact the cornea in the right orientation. In such cases, the patient may present for care later, after the development of increasing pain, deterioration in vision, or infection.
Obtain the patient's pre-injury 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.
Evaluation of visual acuity immediately following the injury is an important examination data point. Test visual acuity in each eye with a Snellen chart. If the patient cannot read a Snellen chart, document the ability of the patient to distinguish number of fingers, movement, or light. This will assist the ophthalmologist in determining what sort of intervention, therapy, and rehabilitation may be required.
If possible, determine visual acuity prior to examination or treatment, and separately test each eye with corrective lenses. This should be compared to the pre-injury visual acuity. 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.
When examining the orbit, care should be taken to avoid putting pressure on the globe. Instead, the examiner should place fingers on the orbital rim when retracting the eyelids. The bulbar conjunctiva will typically be injected with prominent blood vessels.
Using direct ophthalmoscopy, the lens can be evaluated for dislocation. Ensure that is centered in the pupil.
Examine the cornea carefully, taking care not to apply additional pressure to the globe. Evaluate 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. This requires 10% fluorescein. The patient should be informed not to blink so the examining physician can adequately visualize the tear film without it moving. Visualization of diluted or streaming 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, as it can extrude globe content and lead to a worse outcome.
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).
The most common location for corneal laceration is the inferior aspect of the globe. This is due to Bell phenomenon (also known as palpebral oculogyric reflex), the upward and outward reflex rotation of the globe during blinking as a protective mechanism against the entrance of foreign material.[36]
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.[3, 4, 5, 6]
Corneal lacerations frequently are complicated by corneal or intraocular foreign bodies, infections, traumatic cataracts, and secondary glaucoma.
No laboratory studies are useful for detecting the presence of a corneal laceration.
Radiography, CT, or MRI may be indicated to identify intraocular or intraorbital foreign bodies or associated orbital, cranial, or facial trauma. MRI should generally be avoided if there is suspicion for a metallic foreign body. However, it may be of some use if organic foreign body (eg, wood, plant matter) is suspected.[4] MRI may be difficult to obtain on an emergent basis.
Thin-slice CT scanning is the preferred imaging modality for evaluation of suspected globe rupture. CT scanning can also be used to evaluate for other forms of associated head or facial trauma.
The globe and its contents can be imaged via ultrasonography. When using ultrasonography, plenty of gel should be applied to the eye so that the examining physician can place the probe in the gel but avoid putting pressure on the eye itself. Ultrasonography can be used to evaluate for globe rupture, lens dislocation, foreign body, retrobulbar hemorrhage, and retinal detachment. However, ultrasonography is contraindicated when globe rupture is suspected.[7] A 2002 study showed that ultrasonography has a sensitivity of 100% and specificity of 97.2% in diagnosing orbital pathology such as globe rupture, retrobulbar hemorrhage, retinal detachment, and lens dislocation.[37]
Radiography may be used to evaluate for additional facial fractures. However, many facilities have CT scanning readily available, which is more sensitive for finding such injuries.
Slit lamp biomicroscopy is essential.
Ultrasound biomicroscopy (UBM) may be performed to confirm architecture of the laceration.[8] UBM is a noninvasive diagnostic tool that provides in vivo imaging of the anterior segment in high resolution and with great depth of penetration. It allows visualization of the structures posterior to the iris.[38]
Anterior-segment optical coherence tomography (ASOCT) generates in vivo, high-resolution, cross-sectional imaging and is used to evaluate the structure of the anterior chamber.[39] It can also be used to detect the extent of a laceration and presence of globe rupture. As opposed to UBM, ASOCT cannot visualize structures posterior to the iris such as the ciliary body, zonules, and the peripheral lens.[40]
Cover the patient's eye with an eye shield or polystyrene/paper cup and avoid any pressure to the globe.
Instruct the patient to move the eyes as little as possible.
Administer antiemetic and analgesic medication in order to reduce pressure on the globe.
Perform an examination to ascertain the extent of the corneal, anterior chamber, ocular, and associated injuries (eg, facial, cranial).
Ophthalmologic consultation is indicated to address the practitioner's findings and to decide on the appropriate treatment and timing of ophthalmologic evaluation.
Place a protective eye shield (prefabricated or custom made) on the injured eye. This can be a commercial plastic eye shield or simply a polystyrene/paper cup taped over the eye. Do not use an eye patch.
Administer antiemetics and systemic analgesic medication.
Primary tetanus immunization or booster is indicated.
In consultation with the ophthalmologist, discuss the administration of antibiotics including route (topical or intravenously) and frequency.
In general, topical analgesia and antibiotics should be avoided if a corneal laceration is suspected or confirmed. Use systemic analgesia and antibiotics. Topical anesthetics may be used, if needed, to facilitate visual acuity testing and the slit lamp examination.
Ophthalmologic consultation is necessary. The two practitioners must decide and document when and where the consultation will occur. An ophthalmologist will determine the best form of management for the laceration, whether a medical or surgical approach.
For a small self-sealing corneal laceration, a bandage adhesive soft contact lens may be applied for approximately 3-6 weeks.[41] This will be kept in place in addition to a protective shield until the area heals.
Tissue adhesives have also been used with good success.[41] This should be reserved for select small puncture wounds and lacerations with little to no loss of central tissue. Cyanoacrylate glue can be used to repair small corneal lacerations. Fibrin glue has been found to be a safe and effective alternative to suture in some cases of corneal lacerations.[42]
Surgical management is usually required to repair a corneal laceration, remove foreign bodies, and prevent further damage. The goal is to create a watertight wound, minimize scarring, and restore normal anatomic relationship.
Patients with corneal laceration may develop retinal detachment, infection, secondary glaucoma, phthisis bulbi, and/or vision loss.
Postoperative complications include corneal scarring, pigmentation, cataract formation, and endophthalmitis.[35]
Patients that engage in activities that place their eyes at risk for trauma should be encouraged to wear protective eyewear at all times.
Small full-thickness corneal lacerations require careful outpatient follow-up similar to partial thickness corneal injuries.
Definitive care is determined at the time of the initial ophthalmologic consultation and will take place in the setting of the patient’s overall condition.
A patient who sustains a corneal laceration as part of other trauma may have to be evaluated in the hospital for the other injuries.
Larger full-thickness lacerations require hospitalization, surgical management, and intravenous antibiotics.
Recommendations include a combination of a first-generation cephalosporin (eg, cefazolin) or vancomycin and an aminoglycoside (eg, gentamicin). In addition, add clindamycin if an intraocular foreign body is present or if vegetation has contaminated the wound. The most common organisms identified in posttraumatic endophthalmitis are Staphylococcus epidermidis, bacilli species, streptococci species, and gram-negative species. Fungal endophthalmitis is a relatively rare entity but should be considered in a patient who is recently post-surgical, immunocompromised, unresponsive to antibiotic treatment, or has a history of trauma with vegetable matter. Treatment should be discussed with the ophthalmology consultant if this is suspected.
Clinical Context: First-generation cephalosporin antibiotic for gram-positive bacterial coverage. It is commonly used in combination with an aminoglycoside to achieve broad-spectrum coverage.
Clinical Context: Aminoglycoside that provides coverage for most gram-negative organisms causing endophthalmitis.
Commonly used in combination with both an agent against gram-positive organisms and one that covers anaerobes.
Gentamicin is not the antibiotic of first choice. Consider using this aminoglycoside when penicillins or other less toxic drugs are contraindicated, when bacterial susceptibility tests and clinical judgment indicate its use, and in mixed infections caused by susceptible strains of staphylococci and gram-negative organisms.
Dosing regimens are numerous and are adjusted based on creatinine clearance and changes in the volume of distribution. May be administered IV or IM.
Clinical Context: Lincosamides are useful as a treatment against serious skin and soft tissue infections caused by most staphylococci. They are also effective against aerobic and anaerobic streptococci, except enterococci.
Use in the prophylaxis of endophthalmitis when a foreign body is present or if the injury was soil or farm related to provide an effective agent against bacilli species.
Clinical Context: Potent antibiotic directed against gram-positive organisms and active against enterococci species.
It can be used as an alternative to cefazolin to provide coverage for most gram-positive organisms causing endophthalmitis.
Use in conjunction with gentamicin for prophylaxis in penicillin-allergic patients.
To avoid toxicity, the current recommendation is to assay vancomycin trough levels after the third dose (drawn 0.5 h prior to next dosing). Use creatinine clearance to adjust the dose in patients with renal impairment.
Patient should be given systemic antibiotics and NSAIDs. Also consider steroids and cycloplegics.
The decision to use steroids is at the physician’s discretion and should be made in conjunction with the ophthalmologist. The purpose of using steroids is to decrease inflammation; however, it also increases the risk of infection.
Cycloplegics and NSAIDs help to decrease pain.
These agents are used in prophylaxis of endophthalmitis. Therapy must cover all likely pathogens in the context of the clinical setting.