Study Reports More Precise Way to Remove
THURSDAY, Nov. 18 (HealthDay News) -- Cataract surgery, already
an extremely safe and successful procedure, can be made more
precise by combining a laser and three-dimensional imaging, a new
Researchers found that a femtosecond laser, used for many years
in LASIK surgery, can cut into delicate eye tissue more cleanly and
accurately than manual cataract surgery, which is performed more
than 1.5 million times each year in the United States.
In the current procedure, which has a 98 percent success rate,
surgeons use a micro-blade to cut a circle around the cornea before
extracting the cataract with an ultrasound machine. The laser
procedure uses optical coherence technology to customize each
patient's eye measurements before slicing through the lens capsule
and cataract, though ultrasound is still used to remove the
"It takes some skill and energy to break the lens with the ultrasound," explained lead researcher Daniel Palanker, an associate professor of ophthalmology at Stanford University. "The laser helps to speed this up and make it safer."
After practicing the laser procedure on pig eyes and donated
human eyes, Palanker and his colleagues did further experiments to
confirm that the high-powered, rapid-pulse laser would not cause
Actual surgeries later performed on 50 patients between the ages
of 55 and 80 showed that the laser cut circles in lens capsules 12
times more precise than those achieved by the traditional method.
No adverse effects were reported.
The study, reported in the Nov. 17 issue of
Science Translational Medicine, was funded by OpticaMedica Corp. of Santa Clara, Calif., in which Palanker has an equity stake. The results are being reviewed by the U.S. Food and Drug Administration, while the laser technology, which is being developed by several private companies, is expected to be released worldwide in 2011.
Dr. Scott Greenstein, a comprehensive ophthalmology and
cataracts expert at Massachusetts Eye and Ear Infirmary, said he
was uneasy that the research was funded by a company with a stake
in the outcome. But he added that the data was encouraging.
"I personally am excited by it," said Greenstein, who teaches ophthalmology at Harvard Medical School. "It's an enhancement of something we're already doing that's quite successful."
"We need a number of centers studying this with more patients," he added. "It would be useful to see if there is a significant statistical difference in the outcomes."
Both Greenstein and Dr. Richard Bensinger, a Seattle
ophthalmologist and spokesman for the American Academy of
Ophthalmology, expressed concern that the laser-guided cataract
surgery would be much more expensive than manual surgery and were
skeptical that health insurance companies would be willing to pick
up the tab.
"It's a fairly expensive way to do something we do right now with a $120 instrument that makes the opening," Bensinger said. "It's beneficial to the extent that it can avoid a tear [in the cornea] . . . but the downside is you need a very expensive machine to do it. It's at best a little refinement that adds a little precision."
Although the femtosecond laser technique is unquestionably more
precise, Palanker's claim that it results in a better fit for the
artificial lens replacing the clouded one is dubious, Bensinger and
Greenstein said. Experienced surgeons performing manual cataract
surgery rarely have trouble aligning the new lens with the pupil
and keeping it in place, they noted.
"Over the thousands of cases I've done, I'm really not aware personally of this being a problem," Greenstein said. "If you have a less precise, experienced surgeon then this would be a benefit for the patient. It makes reproducible, perfect incisions every time."
Palanker said further research will focus on whether
laser-guided cataract surgery results in better postoperative
vision than traditional surgery. Among the small group of study
participants, he said, there was no significant difference in
outcomes between the two.
Find out more about cataracts at the
U.S. National Eye Institute.
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