Corneal ulcers and infections

Eye

The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.

Also known as: Bacterial keratitis, Fungal keratitis, Acanthamoeba keratitis or Herpes simplex keratitis

Definition

The cornea is the clear (transparent) tissue at the front of the eye. A corneal ulcer is an erosion or open sore in the outer layer of the cornea. It is often caused by infection.

See also: Corneal injury

Causes, incidence, and risk factors

Corneal ulcers are most commonly caused by an infection with bacteria, viruses, fungi, or a parasite.

  • Acanthamoeba keratitis occurs in contact lens users, especially in people who make their own homemade cleaning solutions.
  • Fungal keratitis can occur after a corneal injury involving plant material, or in people with a suppressed immune system.
  • Herpes simplex keratitis is a serious viral infection. It may cause repeated attacks that are triggered by stress, esposure to sunlight, or any condition that impairs the immune system.

Corneal ulcers or infections may also be caused by:

  • Eyelids that do not close all the way, such as with Bell's palsy
  • Foreign bodies in the eye
  • Scratches (abrasions) on the eye surface
  • Severely dry eyes
  • Severe allergic eye disease
  • Various inflammatory disorders

Contact lens wear, especially soft contact lenses worn overnight, may cause a corneal ulcer.

Symptoms

Symptoms of infection or ulcers of the cornea include:

Signs and tests

Blood tests to check for inflammatory disorders may also be needed.

Treatment

Treatment for corneal ulcers and infections depends on the cause. Treatment should be started as soon as possible to prevent scarring of the cornea.

If the exact cause is not known, patients may start treatment with antibiotic drops that work against many kinds of bacteria.

Once the exact cause is known, drops that treat bacteria, herpes, other viruses, or a fungus are prescribed.

Corticosteroid eye drops may be used to reduce swelling and inflammation in certain conditions.

Your doctor may also recommend that you:

  • Avoid eye makeup
  • Don't wear contact lenses at all, or don't wear them at night
  • Take pain medications
  • Wear an eye patch to keep light out and help with symptoms
  • Wear protective glasses

Severe ulcers may need to be treated with corneal transplantation.

Expectations (prognosis)

Many people recover completely from corneal ulcers or infections, or they have only a minor change in vision.

However, a corneal ulcer or infection can cause long-term damage to the cornea and lead to a noticeable worsening of vision.

Complications

Untreated corneal ulcers and infections may lead to:

  • Loss of the eye (rare)
  • Severe vision loss
  • Scars on the cornea

Calling your health care provider

Call your health care provider if:

  • You have symptoms of corneal ulcers or an infection
  • You have been diagnosed with this condition and your symptoms become worse after treatment

Prevention

Prompt, early attention by an ophthalmologist for an eye infection may prevent ulcers from forming. Wash hands and pay very close attention to cleanliness while handling contact lenses. Avoid wearing contact lenses overnight.

References

Sharma R, Brunette DD. Ophthalmology. In: Mark JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 69.

McLeod SD. Bacterial keratitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 4.12.

McLeod SD. Fungal keratitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 4.13.

Tuli SS. Herpes simplex keratitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 4.15.

Soukiasian S. Peripheral ulcerative keratitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 4.16.

Bouchard CS. Noninfectious keratitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 4.17.

See also:

  • Disease

    Immunodeficiency disorders

    Antibodies

    Immunodeficiency disorders occur when the body’s immune response is reduced or absent. See also:

  • Disease

    Corneal injury

    Cornea

    Corneal injury describes an injury to the cornea. The cornea is the crystal clear (transparent) tissue covering the front of the eye. It works with the lens of the eye to focus images on the retina. See also:

  • Disease

    Allergies

    Allergic reactions

    An allergy is an exaggerated or reaction to substances that are generally not harmful. See also: (eczema) (allergic rhinitis)

  • Symptoms

    Erosion

    Skin layers

    Erosion is a breakdown of the outer layers of the skin, usually because of a cut, scrape, or inflammation. See also:

Review date:
July 28, 2010
Reviewed by:
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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