CORNEAL ULCER

The cornea is a clear dome-shaped structure that covers the iris and pupil. It is the window through which we see the world. A corneal ulcer is a very serious infection, which may result in damage to this normally clear surface of the eye. The surface of the cornea, just as the rest of the body, is protected by a cell layer called the epithelium. A corneal ulcer is a break or defect in the corneal epithelium with damage to the underlying tissue (stroma). The damage is most often due to microorganisms, which gain access to the corneal stroma through a break in the epithelium.

Most healthy people do not develop corneal ulcers without a predisposing condition. Conditions which may lead to corneal ulcers are a corneal abrasion (scratch of the corneal skin) and soft contact lens wear. Overnight wear of contact lenses is particularly dangerous for two reasons. First, sleeping in contact lenses seriously deprives the cornea of oxygen. This makes the cornea less resistant to infection. Second, microbes tend to adhere to soft contact lenses. If the contact lens is left in overnight, it gives the microbe more time to invade the cornea and set up an infection. Fortunately, not all contact lens wearers will develop corneal ulcers. A recent study estimated the annual incidence of corneal ulcers related to contact lens use is 0.04% with daily wear lenses, and 0.21% with extended wear lenses.

Corneal ulcers are usually painful, and patients may feel like there is something in the eye. They are most often associated with a red eye, light sensitivity, and tearing. An area of corneal whitening may be visible if the ulcer is large.

Prompt examination by an eye doctor is required to diagnose and treat a corneal ulcer. Treatment most commonly consists of topical antibiotic drops taken as frequently as every hour.

While there is no absolute guaranteed way to prevent infection when there is injury to the corneal epithelium, there are ways to dramatically reduce the risk of developing a corneal ulcer. First if you sustain an injury to the eye, even as minor as getting a particle of debris blown into your eye by the wind, you should see your optometrist. Even minor injury may result in corneal abrasion and your optometrist can prescribe an antibiotic to help prevent this break in the corneal epithelium from getting infected.

If you are a contact lens wearer, meticulous lens care, and avoiding excessive contact lens wearing time are the keys to lower the risk of infection. You should always wash your hands before handling your lenses. Contacts should be removed from the eye every evening and disinfected. If you are not using disposable lenses you should enzymatically treat them weekly to remove debris. Regular cleaning of the contact lens case is also very important, as many microbes take refuge in dirty contact lens cases. When storing lenses overnight it is critical that they are stored in a disinfecting solution (NOT saline solution). Finally NEVER sleep in your contact lenses. People who sleep in contact lenses increases your are 5 to 10 times more likely to develop a corneal ulcer than someone who removes their lenses nightly.

Corneal ulcers generally heal well if treated early and aggressively. However, if neglected, corneal clouding and even perforation (hole in the cornea) may develop, resulting in serious loss of vision and possibly loss of the eye. Corneal ulcers are a very serious, potentially vision-threatening eye condition. If you suspect a corneal ulcer, particularly if you have had a corneal abrasion which has not healed within a couple days, or if you are a contact lens wearer, you should see your eye doctor immediately.