Catching a Glimpse of New Vision Advances
Patients now have more choices for a 20/20 view of the world.
By Richard Trubo
Reviewed By Brunilda Nazario
Just when you've finally made up your mind to join more than 1 million other Americans who undergo laser eye surgery each year, you may suddenly find yourself staring face-to-face with another big choice to make.
A growing number of ophthalmologists are now offering a significant new advance in LASIK (or Laser in Situ Keratomileusis) -- an enhanced (and somewhat more expensive) version of the traditional laser surgeries.
LASIK is a type of refractive surgery in which the cornea of the eye is reshaped to change its optical power -- correcting vision.
This new improvement in LASIK is called "wavefront" or "custom LASIK." It is a highly sophisticated approach with impressive results thus far. It's also catching the eye of many consumers in the highly competitive LASIK marketplace.
With the new technique, Wavefront is a new way of mapping the refraction of the eye by bouncing light into the eye and catching it as it comes out. It provides a fingerprint pattern of the eye that allows the surgeon to reshape the cornea in a very precise manner.
As a result, eye doctors can detect even the smallest corneal imperfections or abnormalities that would have been missed in the past, literally bringing the world into focus for those more accustomed to squinting their way through life.
"This is clearly a superior technology," says H. Dwight Cavanagh, MD, PhD, professor of ophthalmology at the University of Texas Southwestern Medical Center at Dallas. "We have a higher percentage of patients reaching 20/20, and they're also happier with their night vision."
Coming Into Focus
According to the American Academy of Ophthalmology, early studies comparing wavefront with conventional LASIK found that 90% to 94% of patients undergoing wavefront treatment could see 20/20 or better after the procedure, compared with up to 80% among those undergoing traditional LASIK. In particular, wavefront LASIK has provided a quantum leap for people seeking correction of so-called "higher-order aberrations," which are visual imperfections that cause problems such as glare, halos, shadows, and decreased night vision.
"With conventional LASIK, we had some people who would undergo the procedure and could read the 20/20 line on the chart, but would complain of difficulties with their night vision," says Cavanagh. "The new wavefront technology appears to produce better night vision (or 'contrast sensitivity') after their surgery, particularly in patients who have had a significant amount of higher-order aberrations going into the procedure."
Neil Martin, MD, a LASIK and cataract specialist in Chevy Chase, Md., and a spokesperson for the American Academy of Ophthalmology (AAO), concurs that night vision difficulties are significantly reduced with the new technique. "There are fewer complaints of glare and halos," says Martin. "At the same time, keep in mind that conventional LASIK remains a very good procedure, and most of the results with it are just fine."
When choosing a LASIK eye surgeon, search for one who is certified in the use of the new technology and who has a good reputation in the community, says Martin. Although costs can vary considerably, wavefront LASIK averages about $500 more per eye than conventional LASIK techniques.
Nonsurgical Vision Improvement
If the thought of using a laser to shave tissue from your cornea is a little more than you can bear, new developments in contact lenses may be worth a look. Despite the popularity of LASIK, about 30 million Americans still wear contacts, and have more to choose from as new contact-lens materials are creating buzz within the industry, including the recent emergence of continuous-wear, around-the-clock lenses.
New 30-day soft lenses, called Focus Night & Day, manufactured by CIBA Visioncan correct nearsightedness or farsightedness and can be worn for an extended period of time. Compared with conventional lens materials, they are considered to have "hyper-oxygen transmissibility," which means that greater amounts of oxygen reach the eyes, and fewer bacteria bind to the corneal cells where they can cause infections.
"The high-oxygen lenses are far better products than the conventional ones they're now replacing," says Cavanagh.
Because the extended-wear lenses can be left in the eye for up to a month, there is a lower likelihood of problems created by the repeated handling of the lenses, says Peter Kastl, MD, professor of ophthalmology and biochemistry at Tulane University in New Orleans, and an AAO spokesperson. "There is much less chance of tearing or ripping them," he adds.
Robert L. Davis, OD, an optometrist in Oak Lawn, Ill., says, "People wearing these lenses find them more comfortable than in the past, with much less burning, stinging, and 'red eye.' This is probably because the lens material is a little gentler on the ocular tissue, and its ability to allow more oxygen to flow through the lenses to the eye. They provide five to six times more oxygen than the extended-wear lenses of the past."
Reshaping the Eye
There's another new type of contact lens -- used in a technique called corneal refractive therapy (CRT) or accelerated orthokeratology -- that works on a different principle: It seems capable of improving your vision while you sleep, and is capturing the interest of a growing number of nearsighted people. With this approach, you would wear specially designed, contacts that actually reshape the cornea while you're catching your eight hours of shut-eye during the night. Upon awakening in the morning, you'd remove the contact lenses, and should notice improvements in your vision during the day.
Orthokeratology (or "ortho-k") isn't a new idea, but the latest lens designs -- and their recent FDA approval for overnight wear -- have produced better results than earlier generations of the technique. Instead of changing the shape of the cornea in a slow, progressive manner, the new approach produces these changes rapidly (hence the name "accelerated" ortho-K), with improvements noted in just days or even hours, rather than many weeks as in the past.
"Changes in the design of the lens are producing higher success rates," says Davis, former chair of the contact lens and cornea section of the American Optometric Association. He describes patients with modest amounts of nearsightedness who he has fitted with the CRT lenses; after wearing them during just a single night of sleep, they've come into the office the next day with 20/20 vision.
However, those kinds of almost instant improvements don't happen for everyone. "It's very patient-specific," says Davis. "But generally the positive effect takes days as opposed to months."
Kastl points out that CRT's "ocular retainer lenses" have to be worn regularly during sleep. "Once your eyes are 'trained,' you can wear them every second or third night," he says. But, he explains, if you leave the lenses unused in their case for days or weeks at a time, you'll go back to your old level of visual acuity.
CRT is not appropriate for everyone, including individuals with high degrees of astigmatism. "But for those who have considered LASIK, and perhaps can't afford it or are a little frightened of the surgery, this is the perfect procedure," says Kastl.
As with most new technologies, consumers should find an eye doctor who is experienced with CRT. "There is an expertise in fitting these lenses, and when doctors who don't have the proper training fit them, the patient's risk of adverse eye reactions increases," says Davis.
Published Feb. 9, 2004.
SOURCES: H. Dwight Cavanagh, MD, professor, ophthalmology, University of Texas Southwestern Medical Center, Dallas. Robert L. Davis, OD, optometrist in private practice, Oak Lawn, Ill. Peter Kastl, MD, professor, ophthalmology and biochemistry, Tulane University, New Orleans. Neil Martin, MD, ophthalmologist in private practice, Chevy Chase, Md.
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