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What Is a Corneal Ulcer?

What Is a Corneal Ulcer?
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Published on May 6, 2025
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A corneal ulcer is an open sore or wound on the cornea — the transparent, dome-shaped surface that covers the front of the eye and focuses light into it. Often beginning as keratitis (inflammation of the cornea) from an eye infection, injury, or other cause, corneal ulcers are considered a medical emergency that can lead to vision loss if left untreated.

In the United States, there are an estimated 30,000 to 75,000 yearly cases of corneal ulcers. Each year, keratitis, the precursor to corneal ulcers, accounts for about one million clinic and emergency department visits.

Types of Corneal Ulcers

There are two broad categories of corneal ulcers: infectious and noninfectious.

Infectious corneal ulcers can be further divided by their specific cause:

  • Bacteria
  • Viruses
  • Fungi
  • Parasites

Noninfectious corneal ulcers include those caused by:

  • Autoimmune disorders and inflammatory diseases

  • Very dry eyes
  • Corneal injury
  • Eyelid disorders
  • Allergies
  • Toxins
  • Degenerative eye disease

  • Nutritional deficiencies

Signs and Symptoms of Corneal Ulcers

Common signs and symptoms of corneal ulcers include:

  • Significant eye pain
  • Eye redness
  • Foreign body sensations (as if something is in the eye)
  • Excessive tearing
  • Photophobia (light sensitivity)
  • Blurred or decreased vision
  • White or grayish spot on the cornea
  • Pus or discharge from the eye

  • Eyelid swelling
  • Itchy eyes

Causes and Risk Factors of Corneal Ulcers

Contact lens use is the biggest risk factor for corneal ulcers, especially the infectious types.

Your risk increases if you:

  • Wear contacts to bed
  • Wear soft contacts that have expired
  • Wear disposable contacts longer than recommended
  • Don’t properly clean and store contacts, particularly if you use tap water to clean them instead of contact lens solution
  • Use contaminated lenses (by not washing your hands before putting them in, for example) or lens solutions

Various other conditions can also increase your risk of corneal ulcers, including:

  • Malnourishment
  • Diabetes
  • Alcohol or drug addiction
  • Cancer
  • AIDS
  • Weakened or suppressed immune system
  • Previous eye or eyelid surgery
  • Irregular or prolonged use of corticosteroids
  • Work in agriculture

Infectious Corneal Ulcer Causes

Bacteria Many species of bacteria can cause corneal ulcers, sometimes called bacterial keratitis. The most common of these are:

  • Staphylococcus aureus
  • Coagulase-negative staphylococcus
  • Pseudomonas aeruginosa
  • Staphylococcus epidermidis and Staphylococcus fusarium (dual infection)

  • Staphylococcus pyogenes
  • Staphylococcus pneumoniae
Viruses Herpes simplex virus, which causes cold sores, is the most common cause of viral corneal ulcers, or viral keratitis. After initially infecting a person, the virus will live in a dormant state until triggered by external factors like stress, sunlight, and immune suppression.

Herpes zoster, the virus behind chicken pox and shingles, can also cause corneal ulcers.

Fungi The fungi that most commonly cause fungal corneal ulcers include:

  • Aspergillus
  • Fusarium
  • Scedosporium apiospermum
  • Candida albicans and other candida species
Fungal keratitis is more common in warmer, humid parts of the United States and world, and it usually develops after eye trauma or getting plant material in your eye (people who work in agriculture or landscaping have an increased risk). Fusarium keratitis is usually associated with contact lens use.

Parasites The amoeba Acanthamoeba can cause parasitic corneal ulcers, primarily in people who use contact lenses. They’re most commonly found in freshwater habitats and soil, but you can also be exposed to them through tap water, swimming pools, and hot tubs.

The parasitic, fungus-like organism Pythium insidiosum can cause severe corneal ulcers that closely resemble fungal keratitis. It’s usually found in aquatic habitats in tropical, subtropical, and temperate regions and most often affects males, especially those who work in fields.

Noninfectious Corneal Ulcer Causes

There are numerous causes of noninfectious corneal ulcers, including:

  • Dry eye disease
  • Eyelid conditions like chronic blepharitis (eyelid inflammation), ectropion (eyelid inversion), trichiasis (eyelash misalignment), and Bell’s palsy (nerve problem that can prevent the eyelid from closing completely)

  • Autoimmune or inflammatory diseases like rheumatoid arthritis and Sjögren’s syndrome

  • Vitamin A deficiency
  • Protein deficiency
  • Corneal injury from abrasions (scratches, scrapes, and cuts) and burns from corrosive chemicals
  • Neurotrophic keratitis, or keratopathy, a degenerative disease of the cornea

  • Severe allergic eye disease

How Are Corneal Ulcers Diagnosed?

Diagnosis of corneal ulcers begins with your ophthalmologist (eye specialist) asking you about your:

  • History and severity of symptoms
  • Contact lens use
  • Prior eye surgery or trauma
  • Lifestyle and occupation to determine your exposure to microorganisms and chemicals

  • Use of immunosuppressant medications
  • History of systemic diseases like diabetes and rheumatoid arthritis

Your provider will then conduct a thorough examination of your eyelids and eyes, looking for issues like eyelid inversion, inflammation (indicative of uncontrolled autoimmune disease), and corneal injury.

Specific tests include:

  • Visual acuity tests

  • Fluorescein dye stain and slit lamp examination, which uses a special dye and microscope to reveal any abrasions, debris, or ulcers on your cornea

  • Microbial cultures of corneal scrapings

  • Confocal microscopy, an imaging technique that can reveal organisms like fungi and Acanthamoeba in different layers the cornea

Treatment and Medication Options for Corneal Ulcers

The specific treatment for a corneal ulcer depends on its underlying cause.

Bacterial corneal ulcers are treated with frequent doses of one or more broad-spectrum antibiotic eye drops called fluoroquinolones. Because most corneal ulcers are bacterial, corneal ulcer treatment usually begins with these antibiotics even if the exact cause is unknown:

  • Moxifloxacin
  • Gatifloxacin

  • Besifloxacin

  • Vancomycin
  • Tobramycin
  • Cefazolin
  • Ceftazidime
  • Gentamicin

Viral corneal ulcers are treated with antiviral medications such as trifluridine drops, ganciclovir gel, and oral valacyclovir or acyclovir, while fungal corneal ulcers are treated with antifungal medications such as natamycin, amphotericin B, and voriconazole.

Acanthamoeba keratitis is treated with antiamoebic drops including:

  • Propamidine
  • Neomycin
  • Polyhexamethylene biguanide
  • Chlorhexidine
Pythium keratitis is mainly treated with various antibacterial medications, the most common of which are linezolid and azithromycin.

For noninfectious corneal ulcers, treatment focuses on correcting the underlying cause — such as using immunosuppressant drugs for autoimmune diseases — and managing the ulcer with supportive antibiotics or lubricating ointments.

If your ulcer is sterile (there’s no infection present), your provider may also prescribe you steroid eye drops to help with:

  • Wound healing
  • Scar prevention
  • Pain
  • Light sensitivity
But steroids are generally only recommended if you need to return to normal functioning quickly, such as if you need to get back to work or drive.

Other options that can help your wound heal include specialty contact lenses like scleral lenses and bandage contact lenses, and tarsorrhaphy, a procedure that temporarily sutures your eye closed.

If you don’t respond to any of these treatments or the ulcer has left a perforation (hole) in your cornea, you may need a corneal transplant.

Prevention of Corneal Ulcers

Some habits that can prevent corneal ulcers include:

  • Good contact lens hygiene: Use lenses as recommended (clean them with lens solution, never sleep with them in, replace them as necessary).
  • Wash your hands before touching your contact lenses or eyes.
  • Use protective eyewear during high-risk activities.
  • Treat dry eye and eyelid disorders promptly.
  • Manage autoimmune and other chronic diseases.

Lifestyle Changes for Corneal Ulcers

If you’re recovering from a corneal ulcer, make sure to wear an eye shield or protective lenses to prevent accidental trauma, and take pain medications, as recommended.

Also avoid:

  • Eye makeup
  • Contact lenses
  • Touching or rubbing your eyes
  • Swimming
  • Strenuous activities that may injure your eyes or expose them to dirt, dust, or other irritants

Seek immediate care if you experience worsening symptoms, such as increased eye pain and redness, sensitivity to light, and decreased vision.

Corneal Ulcer Prognosis

How quickly and how well your corneal ulcer heals varies widely depending on:

  • The cause, size, severity, and location of the ulcer
  • How well you respond to the treatment
  • Your overall eye health, immune status, and socioeconomic status
  • Complications

But most people recover successfully with treatment with only a minor change in vision.

Complications of Corneal Ulcers

Left untreated, corneal ulcers can lead to:

  • Permanent corneal scarring
  • Corneal perforation
  • Vision loss or blindness
  • Glaucoma
  • Cataracts
  • Irregular astigmatism
  • Serious eye inflammation

Research and Statistics: Who Gets Corneal Ulcers?

Corneal ulcers are most common in people who wear contact lenses, especially extended-wear lenses. They are much more common in developed regions like the United States and Europe, because these places have higher rates of contact lens use.

One study in California found that nearly 8 in 100,000 people were diagnosed with corneal ulcers in emergency departments each year. They were more common in people who were:

  • Male
  • Black
  • Primarily English speaking
  • Age 20 to 60 years

Related Conditions of Corneal Ulcers

Many conditions can cause red, painful eyes similar to corneal ulcers, including:

The Takeaway

  • Corneal ulcers can develop quickly and lead to serious, lasting consequences, including vision loss.
  • They’re also highly treatable with medications when caught early.
  • To prevent corneal ulcers, protect your eyes, practice good contact lens hygiene, and promptly treat or manage any chronic conditions you may have.

Common Questions & Answers

Are corneal ulcers serious?
Yes, without prompt treatment, corneal ulcers can cause permanent damage to your eyes and vision.
Contact lens use is the biggest risk factor for corneal ulcers, especially if you don’t practice good lens hygiene.
Corneal ulcers are treated with antimicrobial eyedrops, which differ depending on the cause of the ulcer. 

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
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Edmund Tsui, MD

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Edmund Tsui, MD, is an assistant professor of ophthalmology at the Jules Stein Eye Institute in the David Geffen School of Medicine at UCLA.

He earned his medical degree from Dartmouth. He completed an ophthalmology residency at the NYU Grossman School of Medicine, where he was chief resident, followed by a fellowship in uveitis and ocular inflammatory disease at the Francis I. Proctor Foundation for Research in Ophthalmology at the University of California in San Francisco.

Dr. Tsui is committed to advancing the field of ophthalmology. His research focuses on utilizing state-of-the-art ophthalmic imaging technology to improve the diagnosis and monitoring of uveitis. He is a co-investigator in several multicenter clinical trials investigating therapeutics for uveitis. He is the author of over 80 peer-reviewed publications and has given talks at national and international conferences.

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