What is a corneal ulcer?

A corneal ulcer is an open sore on your cornea. Usually, but not always, it’s caused by an infection.

The cornea is your eye’s outermost layer. It is a clear layer that caps the front of the eye. It helps protect the rest of the eye from germs and debris. It also helps focus light into the eye. Infections or injury to your cornea can cause an ulcer to form. A corneal ulcer is a medical emergency that needs immediate treatment.

Corneal ulcers are not rare. They can happen in people of any age. Corneal ulcers may differ in severity based on their cause. In the United States, contact lens use often plays a role. Vitamin A deficiency is a factor in many developing countries, where corneal infections and corneal ulcers are a leading cause of vision impairment and blindness. In the United States, such complications are much less common.

What causes a corneal ulcer?

Multiple medical conditions can cause a corneal ulcer. These include:

  • Bacterial infections (like Staphylococcus)
  • Viral infections (like herpes)
  • Fungal infections
  • Parasitic infections
  • Abrasions or burns to the cornea
  • Conditions that dry out the cornea, like dry eye syndrome or Bell palsy
  • Autoimmune disease like rheumatoid arthritis
  • Injury to your cornea
  • Ulcers from reduced blood flow (for example, from diabetes)
  • Allergies causing allergic keratoconjunctivitis
  • Vitamin A deficiency (rare in the United States) 

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

What are the risks for a corneal ulcer?

If you use contact lenses, certain factors put you more at risk:

  • Wearing soft contact lenses
  • Wearing extended-wear contact lenses
  • Wearing your lenses longer than recommended
  • Not cleaning your lenses and lens case as your eye care professional recommends
  • Exposing your contact lenses to water

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

What are the symptoms of a corneal ulcer?

If you have a corneal ulcer, you might have one or more of the following symptoms:

  • Severe eye pain
  • The sensation that something is in your eye
  • Tearing
  • Discharge from your eye
  • Sensitivity to light
  • Blurred vision
  • Eye redness
  • Swelling of your eyelids
  • A white spot on your cornea

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

How is a corneal ulcer diagnosed?

Your healthcare provider will begin with a medical history and physical exam. Your provider will do a thorough eye exam. He or she will check your vision in both eyes. Your provider will probably place a dye into your eye that allows for closer examination of your cornea. Your provider will probably need to use an ophthalmoscope. This uses a light to look into the back of your eye. You also might need to look into a large instrument called a slit-lamp, so your provider can see your eye in more detail.

Often, your healthcare provider will scrape your cornea and send it for culture. If you wear contact lenses, your provider may also send your contact lenses 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. You may need to see an ophthalmologist, a healthcare provider who specializes in eye conditions, to have your condition diagnosed and treated.

How is a corneal ulcer treated?

Treatment for corneal ulcers varies according to the cause of the corneal ulcer. Possible treatments include:

  • Antibiotics, to treat a bacterial infection of the cornea
  • Antiviral medicines to treat viral infection
  • Antifungal medicines to treat fungal infection
  • Pain medicine
  • In some cases, steroids

You may need to take some of these medicines in the form of eye drops. Your healthcare provider may also give you specific instructions about protecting your eye as it heals. For example, you may need special eye drops or contact lenses while your eye heals. (Do not wear your normal contact lenses unless your provider says it is OK.)

Your healthcare provider may also want to treat underlying causes of your ulcer to help prevent new ulcers from coming back. Examples of underlying conditions that might need treatment include dry eye, vitamin deficiency, and autoimmune disease.

Complications from a corneal ulcer might need further treatment.

What are the complications of corneal ulcer?

If your cornea has permanent scarring and damage, your vision can be impaired in the long term. If not treated promptly, corneal ulcers can lead to permanent scarring. If your complications are significant, you may need further 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 promptly 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 are preventable. Make sure you wear protective eyewear when doing any activity that might lead to eye injury. If you use contact lenses, be sure that they fit well and that you care for them appropriately. If you have problems with your eyes, get medical attention as soon as possible. Treating your other medical conditions promptly may also help prevent ulcers. Contacting your eye care professional at the first sign of infection may also help.

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

  • Do not wear your contacts longer than recommended.
  • Clean your contact lenses exactly as your eye care professional recommends.
  • Never reuse lens solution or use homemade lens solution.
  • Clean, rinse, and air-dry your lens case every time you remove your lenses.
  • Do not expose your contact lenses to any water.

When should I call my healthcare provider?

Call 911 if you have any symptoms of a corneal ulcer, like severe eye pain, blurred vision, or discharge from your eye. You may need to see an ophthalmologist that same day.

Key points about corneal ulceer

A corneal ulcer is an open sore on your cornea, the eye’s outermost layer. It’s usually, but not always, caused by an infection. If not treated quickly, it can lead to serious complications, including severe vision impairment:

  • Infection, injury, and other medical conditions can lead to corneal ulcers.
  • You might need antibiotics, antiviral medicine, or other treatments for your corneal ulcer.
  • To help prevent corneal ulcers, carefully follow your eye care professional’s instructions about contact lens care and wear.
  • Seek treatment immediately if you have severe eye pain or other symptoms of a corneal ulcer.
  • If you have serious damage to your cornea, you might need follow-up treatments to protect your eye from further damage. Follow-up treatments may include eye surgery, such as 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.