The government Friday approved the sale of a new soft contact lens considered safe enough for people to wear for a month without removal.
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October 15, 2001
By Robert H. Shmerling, M.D.
Harvard Medical School
How does this article relate to me?
The development of a safe, extended-wear contact lens will be of particular interest to you if you are among the millions of people already wearing contact lenses or considering it. The impact of improving vision with glasses or contact lenses is difficult to underestimate — for many, the improvement in vision provides an enormous improvement in quality of life and ability to function. A more recent advance includes laser surgery or LASIK that can eliminate the need for glasses or contact lenses.
For those choosing contact lenses, keeping the eye healthy and comfortable can be a challenge, a nuisance, and a big expense. The extended-wear lenses described in this news item were worn by study participants day and night for a month and then discarded. A new lens was used each month for a year. At the end of one year, their eyes were compared to those of people who changed their lenses weekly, looking for evidence of corneal damage (ulcer) or infection.
Corneal damage is important to avoid because the cornea, the clear, protective surface over the front of our eyes, allows light to enter the eye; a damaged cornea may not heal well, reducing or eliminating vision. Wearing contact lenses day and night can lead to damage, inflammation and an increased risk of infection unless the cornea is able to get enough oxygen.
The 30-day lenses in the study reportedly increased the oxygen available to the cornea. Even so, researchers found an increased rate of corneal infection, though it was not considered significant.
Keep in mind that a larger study would be needed to detect an increased rate of corneal damage from the 1 in 500 occurrence observed among users of currently available one-week extended wear lenses.
What changes do I need to make?
If you are interested in wearing lenses continuously for one month (rather than taking them out each night for cleaning, or discarding them each week) and are willing to pay the estimated $30 per month, you may want to purchase these lenses when they are available. However, there are important cautions to note:
- The safety of these 30-day extended-wear lenses is not entirely clear.
- Only one-third of people in the study could tolerate the lenses for a full 30 days.
- Regular monitoring with your eye doctor will be important if you use these new lenses.
If you wear any type of contact lens, other changes may be in order, depending on how you wear them:
- Give your eyes some "time off" — when it's time to change your extended-wear lenses, you should spend at least one night without wearing them.
- Do not sleep in your contact lenses if they are not designed for extended-wear. Be sure to follow your eye doctor's specific advice about how to care for your lenses and how long to wear them.
- Avoid wearing your lenses longer than the recommended period before discarding them; many people using lenses designed for one-week use wear them longer.
- Don't smoke. Besides the other health problems associated with smoking, a higher incidence of cornea problems has been found among contact lens wearers who smoke.
What can I expect in the future?
You should look for the results of additional research that assesses the risks of wearing extended-wear contact lenses continuously for a month at a time. The U.S. Food and Drug Administration has required the makers of these 30-day lenses to conduct a larger study to better define the small risks that could be associated with longer use. In the meantime, you can expect continued advances in the safety and convenience of contact lenses and possibly a reduction in the price of lenses as more companies make them.
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