The cornea is the clear window on the front of the eye that covers the colored iris and black pupil. The two most common types of corneal injuries are abrasions and lacerations. An abrasion is a scraping of the surface of the cornea. A corneal laceration involves a scratch or a puncture through the layers of the cornea. Injury to the cornea can cause
What are the causes and risks of the injury?
The cornea can be damaged by a number of factors, including:
- chemicals that are splashed into the eye
- contact lenses that are left in place too long
- direct trauma from fingernails, tree branches or mascara wands
- foreign bodies that are stuck under an eyelid
- medical conditions that prevent the person from closing his or her eyelids
- sand, sawdust, or other material that is blown into the eye
What can be done to prevent the injury?
It is important to wear contact lenses as instructed. Prompt treatment of eye disorders may prevent some corneal injuries. Safety glasses should be worn in all situations where matter might enter the eye. These include:
- mowing the lawn
- working under a car
- working with sheet metal or wood
How is the injury recognized?
Diagnosis of a corneal injury begins with a medical history and physical exam. Many injuries cannot be seen with the naked eye. A
slit lamp exam uses a microscope and a rectangular light source to examine the cornea. Often, the cornea is stained with a dye called fluorescein.
What are the treatments for the injury?
Treatment of corneal abrasions depends on the nature of the injury. Some steps can be taken immediately, in the place where the injury has occurred. Chemicals or small debris in the eye may be removed by rinsing the eye thoroughly with water.
Some good options for rinsing the eye include:
- a garden hose at a very low flow
- a glass or other container full of water
- a shower
- a sink
- a water fountain
The eyelids must be held apart so that all parts of the eye are washed. This washing must be done within minutes of the injury. The corner of a facial tissue or the tip of a cotton applicator may be used to remove any remaining small debris.
Large foreign bodies or metal objects should be removed by the healthcare professional. The eye may be numbed with a
local anesthetic. A cotton-tipped applicator moistened with saline or salt water may be used to remove the material. If this does not work, the object can be removed, under the microscope, with a small instrument. Once the object has been removed, antibiotic drops or ointments may be prescribed to prevent infection.
A healthcare professional should always examine chemical burns to the eye. Alkali burns can be especially severe and damage the eye in a short period of time. These types of injuries can result in complications, even years after the initial injury. In cases of scratches and chemical burns, the provider will use dilating drops and antibiotics.
The majority of corneal abrasions are from direct trauma. Though very painful, they heal within a few days with topical antibiotics and occasional tight patching. Black "pirate" patches will worsen the condition.
A full thickness corneal laceration where the entire thickness of the corneal is cut is rare but requires immediate medical attention. Repairs are done right away, using
general anesthesia. General anesthesia means the person is put to sleep with medicine, feels no pain, and has no awareness of the procedure. Pain medicines and tetanus booster shots may be ordered by the healthcare professional.
What are the side effects of the treatments?
Drops, ointments, and oral antibiotics may occasionally cause
allergic reactions or irritation. Surgery may be complicated by bleeding, infection, or reactions to the anesthesia.
What happens after treatment for the injury?
Most of the time, treatment is effective and the person has no long-term effects from the injury. Severe injuries, however, may cause permanent
visual impairments. Abrasions caused by organic material such as finger nails, paper and tree branches take longer to heal. The injuries to the cornea are more diffuse and may take up to five to seven days to heal. If healing is delayed, a simple scraping of the roughened healing tissue may be necessary to facilitate healing.
Unfortunately, up to 40% of patients with organic abrasions may have recurrent pain which awakens them from sleep or upon arising. These persons require the attention of on eye care professional. Nightly lubrication with sodium chloride ophthalmic ointment (i.e., Muro 128) will decrease the incidence of these painful recurrences. Daily artificial tears are often used..
Any new or worsening symptoms should be reported to the healthcare professional.