Q. I saw a program on TV that described a type of eye surgery to correct being nearsighted.

Does this operation work? Is it safe?

What are my chances of not having to wear glasses or contacts if I have this procedure?

A. You're probably referring to an operation called radial keratotomy (RK).

This procedure is supposed to correct your vision by the use of small cuts on the surface of the eye. Radial refers to the spoke-like series of cuts, and keratotomy means cutting of the cornea, the clear surface in front of your eye.

This operation works by flattening your cornea, which changes the refraction or way light is focused inside your eye. Although performed in the United States for more than a decade, RK remains a controversial procedure. Perhaps the biggest question it faces is: Is seeing well without glasses worth the risk and uncertainty of this operation?

When a group of 35 eye specialists were asked about this procedure two years ago, only half felt it was safe enough for people with small degrees of nearsightedness. Similarly, only half felt the operation was effective.

Recently, doctors reported the results of a four-year study of 435 people who had RK done in one eye. On the positive side, they found that about two out of three people were able to give up their glasses or contacts.

On the negative side, some people's vision continued to change over time, including some whose vision was "over-corrected."

In all, about one in four people had fluctuations in their vision, including 11 (3 percent) whose vision worsened so much that it couldn't be returned to its pre-operation state even with glasses.

Serious complications were rare. Two people had a bacterial eye infection that was treated without further problem.

One of the major drawbacks of RK is its unpredictability. Doctors can't say how good your vision will be after the operation or whether it will remain stable.

Another potential problem is that RK can create a glare in the vision of some people.

Another shortcoming is that RK works best in people with small degrees of nearsightedness. It seems clear that this operation is not meant for everyone.

On the horizon is a form of keratotomy performed with a laser, called photo-refractive keratotomy. Fewer than 100 people in the United States have had this procedure, so I think it's too early to tell how this will compare with RK.

Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician.

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