corneal abrasion

Corneal Abrasion 

Definition

A corneal abrasion is a worn or scraped-off area of the outer, clear layer of the eye (cornea).

Description

The cornea is the clear, dome-shaped outer area of the eye. It lies in front of the colored part of the eye (iris) and the black hole in the iris (pupil). The outermost layer of the eyeball consists of the cornea and the white part of the eye (sclera). A corneal abrasion is basically a superficial cut or scrape on the cornea. A corneal abrasion is not as serious as a corneal ulcer, which is generally deeper and more severe than an abrasion.

Causes and symptoms

A corneal abrasion is usually the result of direct injury to the eye, often from a fingernail scratch, makeup brushes, contact lenses, foreign body, or even twigs. Patients often complain of feeling a foreign body in their eye, and they may have pain, sensitivity to light, or tearing.

Diagnosis

Ophthalmologists and optometrists, who treat eye disorders, are well qualified to diagnose corneal abrasions. The doctor will check the patient's vision (visual acuity) in both eyes with an eye chart. A patient history will also be taken, which may help to determine the cause of the abrasion. A slit lamp, which is basically a microscope and light source, will allow the doctor to see the abrasion. Fluorescein, a yellow dye, may be placed into the eye to determine the extent of the abrasion. The fluorescein will temporarily stain the affected area.

Treatment

The cornea has a remarkable ability to heal itself, so treatment is designed to minimize complications. If the abrasion is very small, the doctor might just suggest an eye lubricant and a follow-up visit the next day. A very small abrasion should heal in one to two days; others usually in one week. However, to avoid a possible infection, an antibiotic eye drop may be prescribed. Sometimes additional eye drops may make the eye feel more comfortable. Depending upon the extent of the abrasion, some doctors may patch the affected eye. It is very important to go for the follow-up checkup to make sure an infection does not occur. Use of contact lenses should not be resumed without the doctor's approval.

Prognosis

In typical cases, the prognosis is good. The cornea will heal itself, usually within several days. A very deep abrasion may lead to scarring. If the abrasion does not heal properly, a recurrent corneal erosion (RCE) may result months or even years later. The symptoms are the same as for an abrasion (e.g., tearing, foreign body sensation, and blurred vision), but it will keep occurring. Similar or additional treatment for the RCE may be necessary.

Prevention

Everyone should wear eye protection whenever this is recommended. This should be standard practice when using power tools and playing certain sports. Goggles should even be worn when mowing the lawn, because a twig can be thrown upward toward the face. Contact lens wearers should be careful to follow their doctors' instructions on caring for and wearing their lenses. Ill-fitting or dirty lenses could lead to an abrasion, so patients should go for their prescribed checkups.

Resources

Organizations

American Academy of Family Physicians. 8880 Ward Parkway, Kansas City, MO 64114. (816) 333-9700. http://www.aafp.org.

Key terms

Abrasion — An area of the body whose surface has been worn away by some abnormal process.

Cornea — The transparent structure on the front part of the eye.

Recurrent corneal erosion (RCE) — Repeated erosion of the cornea. May be a result of inadequate healing of a previous abrasion.

Slit lamp — An instrument used to examine the front of the eye.

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corneal abrasion

[kôr′nē·əl]

Etymology: L, corneus, horny, abrasio, scraping

the rubbing off of the outer layers of the cornea.

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corneal abrasion 

An area of the cornea that has been removed by rubbing. The condition ranges from punctate staining with fluorescein to a total removal of the epithelium. Corneal abrasions may result from overwear of contact lenses, foreign bodies, fingernail scratches, etc. There is pain, photophobia, tearing and blepharospasm. The condition usually heals quickly if not severe and if infection has not occurred. Treatment consists of removal of the foreign bodies, if any, usually by irrigation, tight patching of the eye, and antibiotic ointment; if due to contact lenses, discontinue wear until full recovery. Local anaesthetics should not be used in the treatment as they tend to delay the regeneration of the corneal epithelium. See mitosis; overwear syndrome; rose bengal.

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corneal abrasion

Ophthalmology The mechanical scraping of the cornea due to sand, metal dust, hard contact lenses or other foreign bodies