Post-operative problems with night vision, including glare and halos, may be less likely with a newer, more precise Lasik procedure recently approved by the U.S. Food and Drug Administration (FDA).

Last May, the FDA approved the CustomVue system by VISX Inc. after a study found that 94 percent of patients had 20/20 vision after six months and 98 percent had 20/20 vision after a year. David Hardten, M.D., an ophthalmologist with Minnesota Eye Consultants in Minneapolis and advisor to the Sight & Hearing Association, was one of the principal investigators for the VISX procedure and is training doctors to use it. The FDA approved another system, CustomCornea by Alcon Inc., in October.

"This is really a refinement of Lasik - or an incremental improvement in the way Lasik is done," explained Hardten. "We have done now about 200 procedures."

Unlike conventional Lasik, where the patientıs eyeglass prescription tells the doctor how the cornea needs to be reshaped to correct nearsightedness, farsightedness or astigmatism, this procedure uses "wavefront" technology. Beams of light aimed at 200 spots on the eye bounce off the retina, taking detailed measurements as the light leaves the eye. Slight distortions on the cornea, which canıt be detected in a standard vision test, are then mapped on a computer. The map is used to customize the patientıs surgery, allowing the surgeon with a laser to make subtle changes to the cornea.

According to Margie Schmidt, communications director for Minneapolis-based Phillips Eye Institute, wavefront is 25 times more precise than traditional Lasik.

"It actually captures a fingerprint of the eye," she explained, "tailoring a unique correction for each individual."

This newer technology is similar to traditional Lasik in terms of length of time for surgery - taking 10 to 15 minutes - and minimal to no pain. It differs in cost, ranging $1,700 to $2,400 per eye - at least $600 more than conventional Lasik.

Potential candidates are those who are nearsighted or have astigmatism, says Hardten. Wavefront technology is not available for people with farsightedness, but conventional Lasik is. You are also not a candidate if you changed your prescription for contact lenses or glasses in the past year.

So, do people like Rouse, who have already had Lasik, need to have this procedure done? No, says Dr. Hardten. "Most who have already had Lasik would not need this, as they are doing well the way they are. There have been maybe 5-10 percent of patients that had Lasik once who may need an enhancement, and this may be a good way to do that. Up to three percent of patients will need enhancements with wavefront Lasik also."

In the Minneapolis/St. Paul metro area, there are several groups using the technology, including Minnesota Eye Consultants, Phillips Eye Institute and the Edina Laser Center.

According to Hardten, this new technology overcomes the downside to traditional Lasik: the idea that no two people who have their vision corrected with glasses see at the same level.

"We have, over the past few years, tried to identify those patients with irregularities and have told them to wait for this technology," he said. "I think youıll see most of refractive surgery done this way in about three years."