Definition The cornea is the clear window on the front of the eye that covers the coloured iris and pupil. There are different types of corneal ulcers. The ulcers may be cause by bacteria, a virus or fungus. The corneal tissue breaks down starting at the surface. Poor healing can cause an ulcer to form.
What is going on in the body? Bacteria infects and ulcerates the cornea after the eye is injured, a foreign body lodges in the eye, or the eye is irritated by a contact lens. When the eyelids don't close properly, corneal ulcers may develop from dryness and irritation.
What are the signs and symptoms of the infection? Symptoms of a corneal ulcer include:
clouding of the cornea
redness of the eye
sensitivity to light
weeping with a possible discharge from the eye
swelling of the eyelids.
What are the causes and risks of the infection? Ulcers that are not infected can be caused by conjunctivitis, an inflammation often seen as a red or pink eye. Ulcers can also be due to an allergy or unknown causes. Ulcers may be found in contact lens wearers when a breakdown and clouding of corneal tissue occurs. When an ulcer is infected, it can be bacterial, viral or fungal in nature. Most of these infections occur after an injury to the surface of the cornea. An unusual type of infection occurs in people who wear soft contact lens and do not clean their contacts adequately or who wear them for extended periods of time. Viral infections and ulcerations of the cornea, particularly blisters from the Herpes simplex virus, usually can be easily identified with a microscope.
What can be done to prevent the infection? A person should keep his or her eyes clean to prevent all infections of the cornea. People who wear contacts should clean them as directed and remove them when sleeping. Individuals should wear safety glasses to prevent injury and contamination of the eyes in high-risk situations.
How is the infection diagnosed? Corneal ulcer is diagnosed when there is:
clouding of a portion of the cornea
decrease in vision
Scrapings from the cornea should be sent for a laboratory test or culture to determine if a bacteria or fungus is present. If the infection is bacterial, cultures will usually grow in a few days. Fungus infections may not grow for several weeks.
What are the long-term effects of the infection? If corneal ulcers are not treated, it can lead to corneal scarring, permanent loss of vision or even a hole in cornea.
What are the risks to others? An infection in the eye can spread to another person if proper cleanliness is not carried out. A person with an eye infection should wash their hands frequently.
What are the treatments for the infection? The cause of the ulcer needs to be determined. Antibiotic therapy may be used. If the ulcer is serious, hospitalisation and intravenous (IV) antibiotics may be necessary. Antifungal drops or oral pills, such as fluconazole or terbinafine, can be used for fungal infections. Herpes is the most common viral infection of the cornea. It produces a branching ulceration of the cornea. Antiviral drops, such as acyclovir, or pills, such as acyclovir or famciclovir, should be started immediately. Herpes can cause recurrent infections of the cornea.
What are the side effects of the treatments? Side effects are specific to the medication used.
What happens after treatment for the infection? If treatment was started within hours of symptoms, visual impairment can be prevented.
How is the infection monitored? The infection is monitored by the patient's symptoms and by their doctor.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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