An eye, or corneal, ulcer is an area of infection or inflammation in the cornea. These can be caused by bacteria, viruses, parasitic organisms, fungi or the organism Acanthamoeba. Eye ulcers present with pain, eye redness and decreased vision. If not treated appropriately and immediately, eye ulcers can lead to permanent scarring and vision loss in the eye. In order for a corneal ulcer to form, there has to be an injury or insult to the corneal epithelium in order to allow the infecting organism access to the underlying tissues in the cornea.
Corneal Injuries
A corneal abrasion or other corneal trauma that causes a break in the epithelial layer can lead to the development of a corneal ulcer. Because contact lens wear can cause problems with the epithelium, especially in extended-wear lens patients, people who wear contact lenses are at risk for developing an eye ulcer. Corneal burns caused by either chemicals or heat can lead to eye ulcers as well.
Corneal Abnormalities
Some diseases of the cornea can change the corneal epithelium and make it easier for infecting organisms to enter and cause infection. Herpes simplex infection of the cornea is one such disease. Because of the breakdown of the epithelium of the cornea, dry eye syndrome can also lead to eye ulcers. Bullous keratopathy is another condition that affects the cornea and can cause an eye ulcer. This disease is a breakdown of the epithelial layer, which is caused by the failure of the endothelial layer.
Eyelid Problems
When the eyelids do not function properly, or close correctly, the cornea is subject to exposure, which can lead to epithelial breakdown. Anatomical problems with the eyelids, such as ectropion, whereby the eyelid edge does not rest against the eyeball, or trauma to the eyelid, can lead to eye ulcers after prolonged exposure. If the cornea comes in contact with eyelashes repeatedly, as occurs in entropion or trichiasis, the epithelium is likely to be affected and can lead to infection.
Nutritional Problems
Nutritional problems can cause corneal epithelial dysfunction. Vitamin A deficiency can lead to drying of the cornea, and other nutritional problems can lead to corneal disease. Dry eyes can also be worsened by nutritional deficiencies, which can lead to corneal problems and possible infection.
