Carol Melzer, 30, of La Grange, Ill., was visiting friends in France when the trouble began. "My eye started bothering me on Sunday night," she recalls. "By Tuesday morning I was in the American Hospital of Paris." Her problem: a severe infection apparently caused by her use of extended-wear contact lenses. Though doctors managed to control the infection, Melzer's cornea was so badly scarred that she was virtually blind in her right eye.
Melzer is one of several million Americans who have purchased extended-wear contact lenses, which were introduced six years ago. Like the others, she was attracted by the convenience of the devices; they are more comfortable than hard lenses, easier to care for than traditional soft lenses and have Food and Drug Administration approval for a maximum of 30 days of continuous use before being removed for cleaning. But along with the soaring sales has come an alarming increase in complications, complaints and lawsuits against lens manufacturers and retailers. Lens-related infections like Melzer's have become so commonplace, says Dr. Kenneth Kenyon of Massachusetts Eye and Ear Infirmary in Boston, "it's rare that we don't have a patient in the hospital with one on any given day." In a small number of cases, the wearers develop severe ulcers and scarring of the cornea, the transparent layer of cells stretching over the pupil and the iris, or colored part of the eye. Last year Dr. Donald Doughman of the University of Minnesota treated six patients for serious infections. Some of them may require corneal transplants to restore their vision, he says. "We just feel lucky that no one lost an eye."
Ophthalmologists offer several possible explanations for the extended-wear problems. The lenses can be worn for weeks because they contain many more tiny pores than traditional soft lenses, allowing an increased supply of oxygen and water to reach and nourish the cornea. But the myriad pores encourage the buildup of deposits on the lenses, creating a perfect breeding ground for bacteria. The resulting infection spreads to the cornea and can cause partial or complete blindness in just 24 hours. Even if the problem is caught and treated early, Kenyon says, a scar often remains, interfering with vision.
Trouble may also occur because the lenses are worn at night. With eyes shut and lenses in place, says Doughman, the oxygen supply to the cornea may be reduced enough so that, in some cases, the corneal cells are damaged, thus making the eye vulnerable to attack by bacteria.
Users are often at fault. Some wear the lenses longer than their doctors recommend or fail to clean them properly when they are removed, allowing the buildup of deposits and proliferation of bacteria. Others ignore early signs of trouble. "Continuing to wear these lenses after the eyes have become red or uncomfortable is like driving 80 m.p.h. in a 55-m.p.h. zone," warns Dr. James Aquavella of the University of Rochester. "When in doubt, take them out."