Definition of Corneal ulcers and infections:

The cornea is the transparent area at the front of the eyeball. A corneal ulcer is an erosion or open sore in the outer layer of the cornea. It is associated with infection.

See also: Corneal injury

Causes, incidence, and risk factors:

Corneal ulcers are most commonly caused by an infection with bacteria, viruses, fungi or parasite. Other causes include:

• Abrasions (scratches)
• Foreign bodies in the eye
• Inadequate eyelid closure
• Severely dry eyes
• Svere allergic eye disease
• Various inflammatory disorders

Contact lens wear, especially soft contact lenses worn overnight, may cause a corneal ulcer. Herpes simplex keratitis is a serious viral infection. It may cause repeated attacks that are triggered by stress, exposure to sunlight, or any condition that impairs the immune system.

Fungal keratitis can occur after a corneal injury involving plant material, or in immunosuppressed people. Acanthamoeba keratitis occurs in contact lens users, especially those who attempt to make their own homemade cleaning solutions.

Risk factors are dry eyes, severe allergies, history of inflammatory disorders, contact lens wear, immunosuppression, trauma, and generalized infection.