Alternate Names : Bacterial keratitis, Fungal keratitis, Acanthamoeba keratitis, Herpes simplex keratitis
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
Overview, Causes, & 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.
Pictures & Images
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
Review Date : 12/12/2008
Reviewed By : A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Paul B. Griggs, MD, Department of Ophthalmology, Virginia Mason Medical Center, Seattle, WA. Review provided by VeriMed Healthcare Network (8/22/2008).