What is a corneal ulcer?

A corneal ulcer is an open sore on your cornea. It's often caused by an eye infection. It may also be caused by other eye disorders.

The cornea is the clear layer that covers the front of the eye. It helps protect the rest of the eye from germs and debris. It also plays an important role in focusing your vision. Infections or injury to your cornea can cause an ulcer to form. A corneal ulcer is a medical emergency that needs treatment right away.

Corneal ulcers are common and may occur in people of any age. Corneal ulcers may differ in severity based on their cause. In the U.S., contact lens use often plays a role. Vitamin A deficiency is a factor in many developing countries. Corneal infections and corneal ulcers are a leading cause of vision impairment and blindness in these countries. In the U.S., such problems are much less common.

What causes a corneal ulcer?

Many health conditions can cause a corneal ulcer. These include:

• Bacterial infections (such as Staphylococcus)

• Viral infections (such as herpes)

• Fungal infections

• Parasitic infections

• Scrapes (abrasions) or burns to the cornea

• Conditions that dry out the cornea, such as dry eye syndrome or Bell palsy

• Autoimmune disease, such as rheumatoid arthritis

• Injury to the cornea

• Reduced blood flow (for example, from diabetes)

• Allergies causing allergic keratoconjunctivitis

• Vitamin A deficiency (rare in the U.S.) 

Using contact lenses increases your chance of an infection of your cornea. This can lead to a corneal ulcer.

Who is at risk for a corneal ulcer?

If you use contact lenses, some things put you more at risk:

• Wearing soft contact lenses

• Wearing extended-wear contact lenses

• Wearing your lenses longer than advised

• Not cleaning your lenses and lens case as your eye care provider advises

• Exposing your contact lenses to water

• Sleeping in contact lenses that are not meant for overnight wear

Having a weak immune system due to another health condition may also raise your risk of getting a corneal ulcer.

What are the symptoms of a corneal ulcer?

If you have a corneal ulcer, you may have one or more of these symptoms:

• Severe eye pain

• The feeling that something is in your eye

• Tearing

• Eye discharge

• Sensitivity to light

• Blurred vision

• Eye redness

• Swollen eyelids

• A white spot on your cornea

It’s important to seek treatment right away if you have any of these symptoms. Most of them should go away once you have the corneal ulcer treated and it has healed. If untreated, a corneal ulcer can lead to vision loss and even blindness.

How is a corneal ulcer diagnosed?

Your eye care provider will start with a health history and a full eye exam. This will include checking your vision in both eyes. Your provider will likely place a dye on your eye. This lets your provider more closely check your cornea. Your provider will likely need to use a device called an ophthalmoscope. This uses a light to look into the back of your eye. You also might need to look into a large microscope called a slit lamp. This lets your provider see your eye in more detail.

Often your eye care provider will scrape your cornea and send it for culture to find out if there is an infection. If you wear contact lenses, your provider may also send your contacts for culture. In some cases, your provider might also want to take blood tests to help find the cause of your corneal ulcer. Finding the cause of the ulcer is important because certain causes have different treatments.

How is a corneal ulcer treated?

Treatment will vary depending on the cause. Possible treatments include:

• Antibiotics to treat a bacterial infection of the cornea

• Antiviral medicines to treat a viral infection

• Antifungal medicines to treat a fungal infection

• Pain medicine

• In some cases, steroids

You may need to take some of these medicines in the form of eye drops. Your eye care provider may also give you specific instructions about protecting your eye as it heals. For example, you may need special eye drops or a special contact lens while your eye heals. (Don't wear your normal contacts unless your provider says it's OK.)

Your eye care provider may also want to treat any other hidden diseases that could be causing your ulcer. This can help prevent new ulcers from developing. Examples of other conditions that might need treatment include dry eye, vitamin deficiency, and autoimmune disease.

Complications from a corneal ulcer might need more treatment.

What are possible complications of corneal ulcer?

If your cornea has lasting (permanent) scarring and damage, your vision can be impaired in the long term. If not treated right away, corneal ulcers can lead to permanent scarring. If your complications are serious, you may need more treatment. Possible treatments include:

• A special type of contact lens

• Eye surgery with a laser (phototherapeutic keratectomy)

• Transplant of a new cornea

Treating the corneal ulcer right away reduces the chances that you will need these sorts of treatments.

What can I do to prevent a corneal ulcer?

Not all types of corneal ulcer can be prevented. Wear protective eyewear when doing any activity that might lead to eye injury. If you use contacts, be sure they fit well and that you care for them correctly. If you have problems with your eyes, get medical care as soon as possible. Treating your other health conditions quickly may also help prevent ulcers. Contacting your eye care provider at the first sign of infection may also help.

If you wear contact lenses, caring for them correctly can help reduce your chances of corneal infection and corneal ulcer:

• Don't wear your contacts longer than recommended.

• Clean your contact lenses exactly as your eye care provider advises.

• Never re-use lens solution or use homemade lens solution.

• Clean, rinse, and air-dry your lens case every time you remove your lenses.

• Don't expose your contact lenses to any water.

When should I call my healthcare provider?

Contact your eye care provider right away if you have any symptoms of a corneal ulcer. These include severe eye pain, blurred vision, or eye discharge. A corneal ulcer is a medical emergency that will need treatment by an eye care provider as soon as possible.

Key points about corneal ulcer

• A corneal ulcer is an open sore on your cornea. This is the outermost layer of the eye.

• Infection, injury, and other health conditions can lead to corneal ulcers.

• You might need antibiotics, antiviral medicine, or other treatments.

• To help prevent corneal ulcers, follow your eye care provider’s instructions about contact lens care and wear.

• Get medical attention right away if you have severe eye pain or other symptoms.

• If you have serious damage to your cornea, you may need follow-up treatments such as a corneal transplant.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.