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Time Proves Long-Wear Lenses Can Imperil Eyes

July 29, 1986|NANCY CHURNIN DEMAC

SAN DIEGO — England had them. Canada had them. America was determined to have them and, in 1981, they arrived: extended-wear contact lenses. The best thing for eyes since Helen of Troy. They were safe, comfortable, easy. You could insert and forget them for up to a month. Hardly anyone, in all the studies conducted by the Food and Drug Administration, reported any problems.

But now, doctors nationwide are reporting problems.

The most serious threat, corneal ulcers--literally holes in the eye--can result in permanent vision impairment and, if untreated, loss of the eyeball.

Estimates on the number affected varies with the information source, ranging from .1% to 6% of the roughly 4.5 million Americans wearing the lenses. Citing the higher figure, the Wisconsin Optometry Board of Examiners recently passed an emergency rule requiring optometrists in their state to have patients sign an informed consent warning of potential hazards.

The FDA quotes the lower percentage but, according to an official memo, "The agency is worried not so much by the absolute numbers of problems reported, as by what appears to be a sharp jump in the rate of problems reported."

Not coincidentally, Wisconsin is also the scene of what may be the first contact lens lawsuit in this country. The parents of a 15-year-old in Wisconsin are suing Ipco Corp. and Bausch & Lomb for $5.3 million. They claim a Sterling Optical chain store, owned by Ipco, sold him Bausch & Lomb lenses with inadequate construction. After three weeks of wear, he developed a corneal ulcer that has required corneal transplants which may or may not save the sight of his right eye.

Other serious, but less urgent, concerns are conjunctivitis, a red irritated eye caused by an excessive number of bacteria on the eye, and corneal vascularity, a condition where an oxygen deprived cornea sends hungry blood vessels scavenging into the eye. This process takes months but, unchecked, it, too, can lead to loss of vision.

Seventeen companies produce the 37 different kinds of extended-wear lenses on the market today. According to industry sources, extended-wear have been outselling all other types of lenses for the past two years.

Increasing numbers of independent research institutes, in addition to the FDA, are investigating whether the fault lies with the lenses themselves, with eye doctors who do not examine patients properly, or with patients who do not take care of their lenses.

One thing on which most experts agree is that not everyone who wants to wear extended-wear should get them.

Bad candidates include people with weakened immune systems, recurrent eye infections, diabetes, arthritis and dry eyes. In addition, people with allergies or hay fever who are forgetful or unhygienic, and women who carelessly apply eye makeup or who take oral contraceptives, may be bad risks, experts say.

Even a patient's profession can make a difference. Sanford Feldman, a San Diego ophthalmologist who has seen some ulcerous eyes removed, says he would hesitate to prescribe lenses for a short order cook who is exposed to smoke and heat all day.

Dr. Robert S. Rosen, an Escondido ophthalmologist who has had referrals of 25 cases of ulcerous eyes in six months, adds children under 21 to that list. "We don't know the long-term effects," he says. "I turn down half the people who ask me for them. I don't want hassles."

The bottom line, when it comes to lenses, is oxygen transmission.

So far, only soft lenses have been approved for extended wear, although there are now on the market some rigid gas-permeable daily lenses which may be approved for extended-wear use by the end of the year.

Soft lenses are 1 1/2 times the size of hard lenses. Like Saran Wrap, soft lenses are thin and clear. Unlike smooth hard lenses, they are constructed of highly porous hydrogelpolymers that soak up tears laden with oxygen so the cornea can "breathe."

If the lens fits too tightly or if the pores clog up with dust or debris, the eye may be deprived of oxygen, leading to a condition called hypoxia.

Hypoxia makes the eye vulnerable to cuts. Because the lens works almost like a bandage, masking the feeling of pain, the wearer with an abrasion may think he merely has a speck of dirt under his eyelid. During sleep, the closed eye gets even less oxygen and the condition worsens. The combination of the cut and the low-oxygen environment provides fertile ground for bacterial, fungal and viral infections which can enter the eye from a number of sources including contaminated cleaning solutions or an unwashed hand inserting the lens.

If the infective agent is pseudomonas, a fungus found in ordinary tap water, the organism might eat its way into the crack, causing permanent sight impairment in a matter of hours.

Jerome Leiblein, chairman of the contact lens section of the American Optometric Assn., suggests that another reason the lenses aren't for everybody is that there is no extended-wear lens at present that meets everyone's oxygen needs.

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