"This lack of oxygen leaves the eye vulnerable to infection. Under the pressure of a rigid contact lens during sleep, the flow of tears and oxygen to the cornea is further reduced. But during sleep, the eye produces fewer tears, causing the cornea to swell. Saviola, who is chief of the vitreoretinal and extraocular devices branch at the FDA's Center for Devices and Radiological Health, explains that when the eyes are open, tears carry adequate oxygen to the cornea to keep it healthy. The risk of corneal ulcers for people who keep extended-wear lenses in overnight is 10 to 15 times greater than for those who use daily-wear lenses only while awake. Saviola says using rigid or soft extended-wear (overnight) contact lenses increases the risk of corneal ulcers. James Saviola, OD, tells WebMD that overnight use poses the most serious safety concern with any contact lens. "Still, studies show only about 25 to 33% of contact lens wearers follow all the directions recommended by the doctor and the lens manufacturer," he says. in Atlanta, says with a corneal ulcer, the cornea becomes infected as microorganisms eat away at tissue, and that can mean a loss of vision. ![]() Weisbarth, executive director at CIBA Vision Corp. Symptoms of corneal ulcers include vision changes, eye redness, eye discomfort or pain, and excessive tearing. Rick Weisbarth, OD, says dirty lenses as well as contaminated storage cases can cause problems such as corneal ulcers. Since contact lenses come in direct contact with the eye, whatever is on the lens - dust, pollen, bacteria, and chemicals - also reaches the eye's surface. So, before a contact lenses wearer switches to one of these systems, they should first discuss it with their eye care professional, because the fact is, contact lenses require more daily, and delicate, care than eyeglasses. To date, though, no independent studies have been performed on the devices comparing them to traditional cleaning by hand. "Anything that helps them clean their lenses and prevent problems is a help." Wai, an OD in New York City, says his patients who have tried one of the systems say they have seen an improvement over cleaning their lenses the traditional way. The lens case shields the lenses from the UV light. Germicidal light then kills the microorganisms. Waves of solution in the device create a whirlpool effect to remove debris from the lens surface. Prices range from about $30 for the Clensatron system to $90 for Lens Comfort, which comes with a three-month supply of multipurpose cleaning solution.Ī different type of system called PuriLens combines subsonic cleaning and UV-C light. Products go by the names Clensatron, LenSoClean, Lens Comfort, Lens Medic, and Quick Care. The process - known as cavitation - causes oils, dirt, and deeply bound protein to fall off the lens. Here's how they work: When high frequency ultrasonic waves pass through the cleaning solution, microscopic bubbles form, expand, then collapse within the liquid. They can be used with all types of contact lenses: hard, soft, gas permeable, and disposable. The new devices - approved in 1999 by the FDA - use either ultrasonic or subsonic waves to clean protein buildup, oils, pollen, and dust from lenses, eliminating the need for handling by the wearer. However, the American Optometric Association suspects a good portion of users don't clean them properly and may develop serious eye diseases as a result, such as corneal ulcers. ![]() With some 32 million Americans wearing contact lenses for vision correction today, they're often viewed as a commodity, not a medical device. And that's important, because unclean contacts carry high risks. ![]() There are new devices on the market - using ultrasonic waves - that claim to do a better job than many contact lens wearers can do by hand. Even with the all-in-one cleaners that are popular today, some people feel that cleaning lenses is still a difficult task and may not keep an eye on how well they do it.īut don't fret, there may be good news. 8, 2000 - If you have been wearing contact lenses for a while, you probably remember the cumbersome task that cleaning the lenses used to be with the heat disinfection units and the multiple cleaning solutions.
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