Stanford starts doing laser cataract surgery
July 31--For many, cataract surgery is a fact of aging the same as gray hair or wrinkles. As the eye ages, often its usually clear lens grows cloudy.
By age 80, more than half of Americans either have a cataract or have had surgery to remove one, according to the National Eye Institute.
Mary Savoie, 79, was one such average American. On April 4, she underwent standard surgery at Stanford's Byers Eye Institute to remove a cataract from her left eye. Two weeks later doctors removed the cataract from her right eye, this time using a different procedure.
Savoie became Stanford's first patient to undergo femtosecond laser cataract surgery, a relatively new technique that some doctors say represents a potential paradigm shift in the field.
"The healing in the right eye was so much faster," said Savoie, a Palo Alto resident. "It was unbelievable."
Femtosecond lasers, so-called because they deliver ultrafast pulses of light per quadrillionths of a second (a femtosecond), have long been used in optic surgeries to correct conditions such as nearsightedness, farsightedness and astigmatism. The near-infrared pulse of the laser essentially vaporizes targeted tissues, allowing for precise "cuts."
The lasers, though, were only approved for cataract surgery by the Food and Drug Administration in 2010.
"I think that everyone was surprised it took so long for this to be invented," said Dr. Artis Montague, a director of cataract surgery services at Stanford. "It's the best thing to come along in a long time. I would say there hasn't been a substantial innovation in cataract surgery since phacoemulsification was invented."
Phacoemulsification is the standard modern cataract surgery technique.
Introduced in 1967, it uses ultrasonic frequency to emulsify the eye's internal lens, after a surgeon first makes a small incision in the cornea and then tears a circular opening in the eye's lens capsule by hand. That lens then is removed by suction and replaced with an intraocular lens implant. A far less common method in developed countries is extracapsular surgery, in which the lens is removed in one piece.
Cataract surgery is generally considered to be safe and effective, but it does require a surgeon to make extremely precise cuts inside of someone's eye. A slip of the hand could mean blindness. Lasers, so the thinking went, might be more accurate and precise, as well as less invasive, than even the best surgeon's dextrous hands.
There were a few hurdles. In procedures to correct issues such as nearsightedness, a laser is used to reshape the cornea. Cataract surgery would require a laser to cut tissues past the cornea, deep inside the eye. Doing so would require precise guidance to ensure the laser didn't accidentally cut into surrounding tissues. There would also have to be better control over the intensity of the laser.
One of a handful
The Catalys laser system, developed by OptiMedica of Santa Cruz, is one of a handful of femtosecond laser systems for cataract surgery that have been introduced in recent years.
"Basically what it does is allow a noninvasive laser to do several of the most demanding steps of cataract surgery that I would typically do by hand before," said Montague, who has now performed about 25 surgeries using the Catalys.
The Catalys system uses a laser to make the corneal incision and to cut a circular opening in the lens capsule. It also creates a detailed, three-dimensional map of the eye to help the laser stay on track.
"I've done thousands of these surgeries, so my circles are pretty good, but the laser gets it perfect every time," Montague said.
She said the laser allows the procedure to be much more precise, resulting in a perfectly centered lens implant and better vision acuity.
The laser is also used to break up the cataract into tiny pieces, which then requires less ultrasound energy to emulsify and remove. Montague said this allows patients like Savoie to heal much faster. The initial cut and breaking up of the lens are done before the patient is even moved to an operating room.
Other femtosecond lasers developed for cataract surgery, such as LensAR and LenSx, vary in exact methodology but also use the lasers in combination with precise mapping.
A successful option
Scientists have explored the use of various types of lasers in cataract surgery since the 1970s, but systems using femtosecond lasers are seemingly the first to gain significant traction. Even so, the procedures are controversial.
Critics say that the surgeries aren't worth the increased cost, since the current procedures are largely safe and successful already. The Catalys cost Stanford about $500,000, said Montague, compared with about $80,000 for a new phacoemulsification system.
There are about 60 Catalys systems in use around the world, said Mark Forchette, OptiMedica's president and CEO. About half are in the U.S. Three are in California, including the one at Stanford.
Savoie, the Stanford patient, first developed cataracts in her 50s. They grew progressively worse. Eventually she just couldn't see well, with or without glasses. She stopped driving at night or taking long road trips. Reading became more difficult.
After the surgery, she said, she only requires glasses when reading.
Both surgeries were a success, but the right eye seemed to heal before the left, even though surgery on the right eye took place two weeks after the left.
In the right eye she experienced none of the swelling or grainy feeling she felt after the first surgery. Her vision is also better in the right eye, though it's difficult to tell whether that has anything to do with the surgery.
"After the surgery, one of the greatest things was to see how blue the sky was. I didn't even know it was that way, I hadn't seen it in so many years," Savoie said. "The downside was I didn't know I had so many wrinkles."
Kristen V. Brown is a San Francisco Chronicle staff writer. firstname.lastname@example.org @kristenvbrown
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