Laser system shows promise for cataract surgery

Thursday, November 18, 2010

WASHINGTON - A team of US scientists believe laser treatment could make eye operations more safer and precise for hundreds of thousands who have cataract surgery each year.

The new technique, developed at Stanford University, uses femtosecond lasers that would make the process up to 12 times more precise than those achieved by the traditional method.

Researchers said 50 patients undergoing the laser treatment showed no adverse effects and their vision improved more than from traditional surgery, though not enough to be statistically significant.

“The results were much better in a number of ways - increasing safety, improving precision and reproducibility, and standardizing the procedure,” said ophthalmologist Daniel Palanker, who led the study.

“This new approach could make this procedure less dependent on surgical skill and allow for greater consistency,” he added.

His team used a laser made by ophthalmic device company OptiMedica Corp., based in Santa Clara, California, who funded the study.

With the new system, a laser can pass through the outer tissue - without the eye being opened - to cut the hole in the capsule and to slice up the cataract and lens, all of which occurs just before the patient enters the operating suite.

It also creates a multi-planar incision through the cornea that stops just below the outermost surface, which means that the surgeon needs to cut less once the operation begins, as well as decreasing the risk of infection.

Because of the laser work, once the operation is under way, the removal of the cut section of the capsule and the sliced-up lens can be done relatively easily, with much less need for the ultrasound energy.

Femtosecond lasers, which deliver pulses of energy per quadrillionths of a second, are already being widely and successfully used to reshape the cornea of the eye to correct nearsightedness, farsightedness and astigmatisms.

Palanker and his team found the proper balance through a series of experiments on enucleated porcine and human eyes. They then did further experiments to confirm that a laser at those settings would not cause retinal damage.

The laser is guided by optical coherence tomography - a noncontact, noninvasive in vivo imaging technique - to get a three-dimensional map of the eye.

Using that image, he and his colleagues developed software that pinpoints the ideal pattern for the laser to follow. It is then superimposed on a three-dimensional picture of the patient’s eye, so that the surgeon can confirm it’s on track before starting the procedure, in addition to monitoring it as the cutting proceeds.

“This will undoubtedly affect millions of people, as cataracts are so common,” said Palanker, though he expects that it will take time for the new procedure to be adopted.

It will take some time before insurers will cover the procedure, he said, and it will cost more than conventional cataract surgery at first.

“But there will be people who elect to have it done the new way if they can afford it. There are competitors coming out with related systems. This is what’s exciting. This technology is going to be picked up in the clinic,” Palanker added.

The study is published in the journal Science Translational Medicine. (ANI)

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