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.
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
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
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:
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:
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)
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
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
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.
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.
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.
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.
Left untreated, corneal ulcers can lead to:
Permanent corneal scarring
Corneal perforation
Vision loss or blindness
Glaucoma
Cataracts
Irregular astigmatism
Serious eye inflammation
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
Many conditions can cause red, painful eyes similar to corneal ulcers, including:
