The Importance of Proper Contact Lens
Care and Maintenance

In a recent study almost one in 13 contact lens wearers had abrasions on the cornea severe enough to lead to infections or other problems. Mild abrasions happens to just about all people, whether they wear contacts or not. But the chances are increased for contact lens wearers if they don't clean and replace their lenses on a regular basis.

Like our skin, the surface of the cornea regenerates new cells. Old cells are slough away in order to make room for new cells. But often too many cells are shed leaving a gateway for bacteria, viruses, and other microorganisms.

Notes Kelly Nichols, a study coauthor and a clinical assistant professor of optometry at Ohio State University, Columbus. "We were looking for extreme cases where the subject had a lot of staining." Corneal staining gets its name from the orange-yellow fluorescein dye used to "stain" the surface of the cornea temporarily. After staining the eyes, an optometrist looks at each eye under a special light that causes the dye to fluoresce. The abrasions show up as bright spots on an otherwise smooth, dull surface.

In a study Nichols pointed out that 56% of the patients had mild staining, and 8% had moderate to severe staining in at least one eye. The severity was directly related to how often the patient replaced their lenses with a new pair, if they wore conventional rather then disposable lenses, and how meticulous they were in caring for their lens.

An interesting note, of the nine subjects that used disposable lenses only one had evidence of staining, and that was mild. Nearly 2/3 of the patients who use conventional lenses (those that are replaced once a year) had evidence of mild staining and 14% had signs of moderate to severe staining.

Those that used less rigorous cleaning methods were obviously more prone to staining. They were three times more likely to have moderate to severe staining. Nichols cautions. "If staining progresses, the underlying layers of the cornea may be affected. Like a cut that doesn't heal properly, the eye could eventually scar. But that's rare--the disease has to be pretty advanced. It's nothing you'd see from the normal wearing of contact lenses." In most instances, the stains heal on their own. People with moderate to severe staining may simply have to stop wearing lenses for a while or replace their old lenses and adopt better cleaning habits.