Corneal ulcer

What is a corneal ulcer?

A corneal ulcer is a wound on the surface and deeper layers of the cornea (the clear, dome-shaped area at the front of the eye). Your cornea protects your eyes, but an ulcer damages it and leaves it vulnerable to serious complications. A corneal ulcer can cause permanent eye damage and possibly even blindness. It needs immediate treatment. 

Keeping the cornea intact is important for healthy vision. A corneal ulcer damages your cornea and causes it to lose some of its tissue. It may also cause scarring. 

There are several causes of a corneal ulcer, including infections, inflammation or eye injuries. Contact lens wear can increase your risk of infection, especially if the lenses are misused. If an ulcer develops in your eye, immediate treatment will be important to potentially prevent permanent damage. 

What are the symptoms of a corneal ulcer?

Your eye may be red or irritated, and at first, it might look like you have pink eye (conjunctivitis). You may be able to see a white spot on your eye. 

Other symptoms can include: 

• Eye pain or sensitivity to light
• Teary eyes
• Blurry or hazy vision
• Mucus coming from the affected eye
• Swollen eyelids 
• Feeling like something is stuck in your eye (foreign body sensation) 

A corneal ulcer is a medical emergency. Leaving it untreated can damage your vision and may even cause blindness. See your eye care provider immediately if you have any symptoms, but especially if: 

• You are experiencing sudden vision changes (like blurry vision). 
• Your eye pain is severe or getting worse over time. 
• Your symptoms get worse after treatment. 
• The skin around your eyes is red and swollen.
• There is discharge from your eyes.
• You wear contact lenses and experience any of these symptoms.

What can cause a corneal ulcer?

A corneal ulcer is often the result of an infection, but there may be other causes. These can range from an eye injury to inflammatory diseases and disorders such as severe dry eye or allergic conjunctivitis. 

Eye infections

An eye infection is a common cause of a corneal ulcer. Corneal infections can be caused by four types of organisms and can be transmitted in the following ways:

• Bacteria – Bacteria don’t normally pose a risk to the eye, but they can get inside the cornea if there’s been recent injury or other damage. Contact lens wearers are typically at a higher risk of bacterial infection.
• Viruses – One type of viral infection may eventually lead to a corneal ulcer. The most common cause is infection with the herpes simplex virus (HSV), which also causes herpes and cold sores. 
• Fungi – A fungal corneal ulcer is more common in warm, humid locations. These infections usually happen when soil or plants contact the eye following an eye injury (for instance, it might happen when gardening). 
• Parasites – The most common cause of a parasitic corneal ulcer is Acanthamoeba. This parasite primarily comes from water, so the risk is higher for people who swim or shower with their contacts in. 

SEE RELATED: Fungal eye infections and contact lenses

Eye injuries and exposure

Eye injuries could lead to a corneal ulcer if they don’t heal properly. They also make it easier for your eyes to get infected. 

Your cornea protects your eye from the outside environment, but too much exposure can lead to damage. Your eyelids and the tear film (layers of tears that lubricate the eye when you blink) help protect the cornea and keep it moisturized. 

Certain conditions that make it hard to close your eyes all the way, like facial paralysis, can leave the cornea exposed for too long. This incomplete closure of the eyelids is known as lagophthalmos. This can lead to the cornea drying out too much, which may cause a corneal ulcer to develop. 

Diseases that affect the cornea

A disease or condition of the cornea, like dry eye disease, may lead to a corneal ulcer. The tear film keeps the cornea lubricated and helps protect it from infection. If the tear film is dysfunctional, like in dry eye, the cornea is more vulnerable to damage.

Other corneal diseases that could lead to an ulcer include: 

• Keratitis – Keratitis describes inflammation of the cornea. Sometimes the terms keratitis and corneal ulcer are used interchangeably, especially for infectious keratitis. However, keratitis may exist without the open wound and loss of tissue that describes a corneal ulcer specifically.
• Corneal abrasion – A corneal abrasion is a scratch on the cornea. These injuries can heal by themselves but may sometimes progress to a corneal ulcer. 

Systemic diseases (ones that affect the whole body) may also affect the cornea. For example, a condition that affects your immune system can lead to inflammation in the eye. This inflammation can prompt the formation of a corneal ulcer. Additionally, damage to the nerves that provide sensation to the cornea may also result in an ulcer known as a neurotrophic ulcer. 

Who is most at risk for corneal ulcers?

Bacterial infections are the most common cause of corneal ulcers. People who wear contacts are especially at risk. This is because bacteria can grow on contaminated contact lenses, then get trapped between the lens and your eye. If there’s been a recent injury (which may also be caused by contact lenses), the bacteria can get inside and cause an infection.

Wearing contacts overnight or while swimming increases your risk. If you wear reusable contact lenses, it is important to routinely replace your storage case and to discard the lenses as instructed. It’s important to maintain your contacts and contact lens solution properly to lower your risk of infection. You should never “top off” existing solution, and should always replace your solution completely in addition to thoroughly rubbing and rinsing your lenses with solution (never water) as directed.

Other risk factors for corneal ulcers include: 

• Infection with the herpes simplex virus (which causes herpes and cold sores) or the varicella zoster virus (which causes chickenpox and shingles) 
• A recent eye injury
• A history of eye diseases (especially relating to the cornea)
• A disease that affects the immune system or causes inflammation 
• Damage to the corneal nerves
• Conditions that make it difficult to close your eyes
• Dry eyes
• Taking eye drops that contain steroids

SEE RELATED: Types of contact lenses: What to know before you choose

How is a corneal ulcer diagnosed?

Your eye doctor will examine your cornea using a slit lamp exam and a special dye called fluorescein that helps them see if there is damage to the cornea. In some cases, your doctor may decide to take a sample of the cornea to help them determine the cause of an ulcer.

How are corneal ulcers treated?

Treatment for a corneal ulcer will depend on what causes it. If you wear contact lenses, your doctor will instruct you to stop wearing them until any infection is gone or until they tell you it is safe to start using them again, along with potentially prescribing an eye drop. 

Medications

If a corneal ulcer is from an infection, a targeted medication will be prescribed, like an antibacterial, antiviral or antifungal. Some more general medications may also be prescribed to help with symptoms. Over-the-counter medications can also help for comfort. 

Medicated eye drops

Targeted medication for an infection may take the form of medicated eye drops, like antibiotic eye drops. Topical steroid eye drops may be used after the infection is under control to keep the cornea from scarring and help with swelling. It is important to only use steroid drops as your doctor instructs, as they can potentially make infections worse if used incorrectly.

Scleral or bandage contact lenses

Special contact lenses can help your eyes heal. These are known as bandage lenses. They help with pain and protect the surface of the eye. It is important to note that bandage lenses are usually only used for ulcers that are not infectious. Contact lenses should never be worn when an active infection is present unless instructed otherwise by your doctor.

Scleral lenses may also be used. Most contact lenses sit directly on the cornea, but scleral lenses vault over the cornea and sit on the sclera, or the white of your eye. Because they cover more of the eye, avoid touching the cornea and are filled with saline, they can offer better protection. 

READ MORE: Bandage contact lenses

Surgery

If a corneal ulcer is severe or cannot be treated using medications, surgery may be needed. A corneal transplant (keratoplasty) replaces a damaged cornea with a healthy donor cornea. This surgery may also be needed if there was central corneal scarring following healing that significantly impacts vision. 

Tarsorrhaphy

Tarsorrhaphy may be recommended to help the cornea heal. A tarsorrhaphy keeps the eye closed for a period of time by temporarily closing a portion of the eyelids. This gives the cornea a “shielded” environment for healing purposes. The eyelids can be sutured so they stay closed, or a medication can be given that weakens the muscle that holds the eye open so the lid closes and covers the cornea.

Amniotic membrane

Amniotic membrane, a layer of the placenta, is sometimes used as a graft and healing material for the eye. It can be applied to a corneal ulcer to rebuild any tissue loss. In some cases, this may prevent the need for a corneal transplantation. In other cases, it may help stabilize the corneal ulcer until a transplant can be done. 

How long does a corneal ulcer take to heal?

How long a corneal ulcer takes to heal will depend on the size of the ulcer. It also depends on where it was located on the cornea, what caused it and how well it responded to treatment. Healing is a complex process with several stages. 

It is possible to recover from a corneal ulcer with little to no lasting effects, but a corneal ulcer can cause permanent damage if it’s not treated. It’s important to seek treatment as soon as possible.  

Can corneal ulcers be prevented?

There are several ways to lower your risk of getting a corneal ulcer. 

If you wear contacts, practice good contact lens hygiene. Don’t wear them past their lifespan, and it is generally not recommended to sleep in them unless there is an overnight indication. In general, wash your hands, and avoid sharing anything that touches your eyes (like makeup or washcloths). It’s ideal to avoid contact with water, such as swimming or showering while wearing contacts. Additionally, contacts should only be rinsed with solution, never water.

Protective eyewear can stop your eyes from getting injured during outdoor activities or playing sports. This lowers the risk of developing an ulcer, as corneal injuries increase the risk of getting an infection. 

SEE RELATED: Caring for your soft contact lenses

When should you see an eye doctor?

Corneal ulcers can cause permanent damage to your vision or even blindness. They are a medical emergency and should be treated as soon as possible.  

You should see an eye doctor immediately for any symptoms of a corneal ulcer, especially if those symptoms include:  

• Severe pain in your eye
• Eye discharge
• Changes in vision
• Sensitivity to light
• A white spot on the cornea
• Contact lens use with any of these symptoms