THE EYES HAVE IT
Doctor's tool refines radial keratatomy
By JOAN WHITLOW
Star Ledger Medical Editor

   Eye surgeon John Kung of Perth Amboy holds a tool that looks like it might be a kitchen gadget. It is actually the doctor's refinement for what is becoming one of the most frequently performed cosmetic surgeries-radial keratatomy (RK) to correct nearsighted vision.

   He uses the tool to hold his patient's eye still as he makes a series of micro-thin cuts into the cornea, using the guides on the device to make the cuts straight and sure.

   His patient is one of some 250,000 Americans annually who opt for RK.

   The surgery flattens the cornea, changing the way the eyes focus light so vision improves and there is no longer a need for glasses or contact lenses.

   Lasers are being tested for vision correction. The laser beam does the job by shaving a few cell layers from the cornea. But, except for some experimental studies, the surgical knife provides vision correction in this country.

   A report last year said some RK patients may eventually need glasses again, not for the nearsightedness that radial keratatomy is to eliminate, but for farsightedness. The study found that the operation causes a continuing shift in vision over time.

   Also, it may take more than one surgery to accomplish the vision correction desired. And, as with any surgery, there is a mall percentage of patients who will have serious complications.

   But the number of people seeking the procedure continues unabated.

   One of my patients is a corrections officer. He is ecstatic now that he doesn't have to wear glasses. He feels more confident. He always worried what would happen if someone knocked his glasses off. He would be powerless." Kung said.

Above and below, Dr. John Kung, an ophthalmologist,
demonstrates the use of his invention,
the Kung Guide, at his office.

   Another patient has a neurological problem that makes his hands shake too much for him to insert contact lenses, and the man hates glasses, said Kung.

   He has performed RK on delivery service workers who say they need to see without worrying that rain, sleet or snow on their glasses will obscure vision.

   There are other patients in professions where good vision is important. But in most cases, the RK patients are people who simply want to do away with glasses and contact lenses and are not squeamish about paying $2,500 or more to have their eyes cut.

   Kung said that while RK is "safe, good surgery" he is increasingly concerned about making the cuts freehand. "Just think about it. You have this diamond blade in your hand and you're about to operate, and the patient turns his eye... you could go right through the pupil," he said.

   Patients receive drops to anesthetize the eye, but typically there is nothing to keep the eye from moving during the procedure.

   Kung's device fits over the eye to hold it in place, and provides triangle-shaped guides to help position the cuts symmetrically and make them straight.

   "It adds another level of precision," he said.

   The amount of pressure he exerts when he pushes down on the device also affects the depth of the cuts.

   It is the depth, length and number of cuts that affects the amount of correction.

   One of the controversies about RK is the percentage of patients who in fact regain normal vision. In most states 20/40 vision is required to drive, and some physicians claim that 90 percent to 95 percent of RK patients are achieving that level.

   But many surgeons, including Kung, said patients should be told up front that vision correction may take more than one operation.

   "The reoperation rate can go as low as 10 percent to as high as one-third to one-half," said Kung. Most physicians do not charge for the additional surgeries.

   Staging is the term for a doctor making a few cuts, waiting to see how the vision is after the eye heals and then operating again to enhance the correction.

   In reoperations, the surgeon will make additional cuts, or go over the old ones to make them longer or deeper.

   Kung believes that staging makes the operation safer. Trying to correct too much in "one shot" can create problems, including over-correction which can cause farsightedness.

   Kung said he advocates "aiming for a little less" on the first procedure. "You can always add a cut. You can never take one away," he noted.

   Dr. Cary Silverman, a Parsippany eye surgeon, said, "You try to under-correct a little bit. What I'm finding is that when someone is a little bit under-corrected ... they have good distant and close vision," Silverman said.

   "I don't tell anybody they are not going to wear glasses ever again," he stressed.

   Silverman said he does not see the need for guides to position the cuts, and believes that making the cuts perfectly straight or symmetrical is not an issue. "You want to get it as close as possible, but it really is not going to make any difference," he added "There is room for error."

   The Prospective Evaluation of Radial keratatomy (PERK) study is an ongoing look at more than 400 RK patients and how their eyes fare over time.

   Last year, PERK results showed that after 10 years, half the RK patients had perfect vision, but many of the others needed corrective lenses for reading or distance, or both.

   Some ophthalmologists took issue with the report, charging it was based on surgeries 10 years ago when there was a lot more variation in quality and before doctors began to stage or under-correct to allow for the natural drift toward farsightedness.

   The most common complication of the surgery is a glare during the day or a starburst effect at night.

   The problem is generally said to affect 1 percent of RK patients, and can be corrected by applying an anti-glare coating on their glasses or contact lens - which means patients will have to sometimes wear the vision aids they were trying to get rid of.

   Most reports state that while loss of vision, or even an eye, has occurred from surgical complications or infection, those problems are considered rare.

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