Formula Medical Group
Apple Valley, CA

James Krider, MD

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Corneal ulcer

What is a corneal ulcer?

A corneal ulcer is an open sore in the cornea, which is the transparent membrane in the center of the eyeball that covers the iris, the colored part of the eye. The ulceration may also extend to the conjunctiva, the layer of tissue that runs along the inside of the eyelid and also covers the eyeball; the aqueous humor, the fluid within the eyeball; and the iris.


  • Severe eye pain.
  • Sensitivity to bright light.
  • Spasms of the eyelids.
  • Blurred vision.
  • Tearing.
  • Redness in the area of the eye that is normally white.

What causes a corneal ulcer?

Most corneal ulcers result from injuries, such as when a foreign object becomes imbedded in the cornea, giving bacteria (usually streptococcal, staphylococcal, or pneumococcal organisms) an opportunity to invade the cornea.

Viruses can also cause corneal ulcers. The most common example involves the herpes simplex virus. Both Type I (the variety that ordinarily produces cold sores or fever blisters) and Type II (genital herpes) viruses can cause corneal ulcers if they invade the eyes. For example, a baby born to a woman with an active genital herpes infection has a high risk of contracting the virus during a vaginal birth, and (in addition to other serious herpes infections) may develop severe conjunctivitis and corneal ulcers.

In recent years, there has been an increase in corneal ulcers among people who wear contact lenses, especially the extended-wear type. Poorly fitted contact lenses can also produce corneal ulcers. Excessive exposure of the eyes to ultraviolet rays, such as might occur in a tanning parlor, is another relatively new cause of corneal ulcers.

In addition to causing severe eye pain and blurred vision, a corneal ulcer makes the eye extremely bloodshot.

In addition to causing severe eye pain and blurred vision, a corneal ulcer makes the eye extremely bloodshot.

Many of the infections that cause corneal ulcers can be passed from one person to another. They may also be spread from one part of the body to another - for example, by touching a cold sore on the mouth and then rubbing the eye.

How is a corneal ulcer diagnosed and treated?

Diagnosis is based on an examination of the affected eye, followed by laboratory studies to identify the bacterium, virus, or fungus that is responsible for the infection and ulcer.

After the infecting agent is identified, the most effective medication can be prescribed. If bacteria are responsible, treatment usually consists of antibiotic eye drops or ointments and oral antibiotics. Different medications are used to treat viral and fungal infections. Non­prescription painkillers such as acetaminophen help relieve discomfort.

If scars from previous corneal ulcers result in a serious loss of vision or blindness, a corneal transplant may be needed to restore vision. This involves removing the damaged cornea and replacing it with a healthy one from a donor.

What can I do myself?
Self-treatment of a corneal ulcer is not effective. If you wear contact lenses and suspect an ulcer has developed, remove your lenses and contact your

ophthalmologist as soon as possible. When you see your eye specialist, ask about applying cool-water compresses to your eye or about wearing an eye patch.

When should I see my doctor?
Eye pain and reddening warrant prompt medical attention, preferably from an ophthalmologist (an eye specialist).

What will the doctor do?
The doctor inspects the infected eye with a slit-lamp microscope. This instrument has a strong light beam that is directed into the eye. The doctor looks through a magnifying device to view the outer layers of the eye, paying particular attention to the location and depth of the ulcer. Vision tests may also be done to assess the degree of eye damage.

The course of a corneal ulcer

Corneal ulcers can usually be cured in 1 to 3 weeks if treated promptly. If left untreated, however, they may penetrate the cornea and allow the infection to enter the eyeball, causing permanent vision loss.

Is a corneal ulcer dangerous?
Yes. Without prompt treatment, it can damage sight.

What can I do to avoid a corneal ulcer?

  • Wash your hands frequently, particularly before inserting or removing contact lenses, and avoid touching your eyes. Never use saliva to moisten your contact lenses, since the mouth normally harbors many different bacteria.
  • Do not touch your eyes if you have a cold sore or fever blister.
  • Prevent eye injuries by wearing approved safety goggles when you are exposed to flying wood shavings, splinters, bits of metal, or stones. Goggles should also be worn when mowing the lawn.
  • Protect your eyes from ultraviolet rays by wearing sunglasses and avoiding tanning parlors.

In addition to causing severe eye pain and blurred vision, a corneal ulcer makes the eye extremely bloodshot.

Eye drops containing a fluorescent dye are used to determine the depth of a corneal ulcer.
This article was last reviewed November 22, 2005 by Dr. James Krider.
Reproduced in part with permission of Home Health Handbook.
Contact use
Eye trauma with infect
Herpes type 1
Herpes type 2

Ultraviolet light

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