If one of your eyes is red and painful, you may have an eye infection or trauma. A corneal ulcer is an abrasive lesion on the eye's surface caused by irritation, bacteria or fungus. Many cases of red eyes are benign, but you shouldn't take a corneal ulcer lightly. It's considered a medical emergency because it can cause vision loss or blindness. Find out what are the causes, symptoms and treatments of corneal ulcers.

What's a corneal ulcer?

A corneal ulcer is an eye infection accompanied by a lesion or ulceration of the cornea. The cornea is the thin, transparent membrane that protects the eye's iris and pupil.

A corneal ulcer also causes severe inflammation. This eye infection is a medical emergency that must be remedied immediately to prevent the infection from progressing, as well as to prevent further complications such as:

  • The infection spreading deeper
  • Perforation of the cornea
  • Destruction of eye tissue
  • Reduced visual acuity
  • Blindness, in the worst-case scenario.

Has your eye been red and painful for 48 hours without the symptoms improving? Make an appointment for an examination quickly to obtain an accurate diagnosis.

What causes a corneal ulcer?

An infection, bacteria, fungi or parasites can cause corneal ulceration.

A bacterial infection often occurs due to an eye injury or trauma. The opening created in the cornea exposes the eye to bacterial penetration.

A fungal infection is often associated with keratitis, an eye infection that sometimes results in a corneal ulcer. People who wear contact lenses are more likely to get this infection when they keep their lenses on while swimming.

Corneal ulcers can also be caused by parasites such as amoebas and acanthamoeba or be caused by the herpes virus.

Underlying health conditions are also likely to cause a corneal ulcer. This is the case, for example, of psoriasis and multiple sclerosis or immune system disorders.

What are the symptoms of a corneal ulcer?

Symptoms of an eye ulcer differ from person to person and according to the severity of the infection. These may include:

  • Pain in the eye
  • Redness in the eye
  • Tearing
  • Sensitivity to light (photophobia)
  • The sensation of a foreign body in the affected eye
  • A white or grayish spot on the cornea
  • The presence of pus behind the cornea (hypopyon)
  • The presence of blood in the conjunctiva
  • Impaired visual acuity

As the ulcer grows, the symptoms worsen accordingly.

What is the treatment for a corneal ulcer?

The treatment for a corneal ulcer depends on the origin of the ulceration. Most of the time:

  • Topical antibiotics are prescribed to treat a bacterial corneal ulcer
  • Antifungals are used to treat a corneal ulcer of parasitic or fungal origin
  • Antiviral eye drops are prescribed to treat an ulcer caused by the herpes virus
  • Certain eye drops, such as atropine and scopolamine, can also be prescribed to relieve pain

At the beginning of the treatment, it must sometimes be administered hourly for several days and nights.
How long does it take a corneal ulcer to heal?
A corneal ulcer's healing time depends on the infection's severity. Treatments can last for several weeks. Sometimes, a corneal transplant is necessary, especially when it has been perforated.