Published April 28, 2008
| Associated Press
Frightened by headlines about Lasik side effects? Lasik gets all the advertising, but there are half a dozen alternate eye surgeries — from a simpler laser approach to implantable lenses — that might solve your squint.
They all have their own risks. A key is finding a surgeon who doesn't have a favorite but is qualified to evaluate patients for all of the options, to find the best fit.
Topping the list is a pre-Lasik laser that's making a comeback thanks to precision-improving computer software. It goes by two names: Surface ablation, or wavefront-guided PRK, which stands for photorefractive keratectomy. What's most important is that it doesn't require cutting a flap into the cornea, the eye's clear covering, like Lasik does, a cut widely considered that procedure's riskiest step.
"There's a lot of us that are doing more and more surface ablation and much less Lasik," says cornea specialist Dr. Craig Fowler of the University of North Carolina.
PRK accounts for about 15 percent of the roughly 700,000 laser vision correction surgeries performed each year, up from 5 percent during Lasik's peak in popularity earlier this decade, says David Harmon of Market Scope, which tracks the industry.
Other Lasik alternatives have virtually no advertising and attract far fewer patients.
Tragic testimony before the Food and Drug Administration last week reinforced warnings that Lasik does come with risks: lost vision, painful dry eye, glare and other night-vision problems. Serious complications appear rare, affecting 1 percent or fewer cases, and the FDA estimates 5 percent of patients aren't satisfied with the outcome.
But aggressive marketing makes patients falsely believe clear sight is guaranteed, complained Dr. Jayne Weiss of Detroit's Kresge Eye Institute, who chaired the FDA advisory panel.
"Lasik is not a commodity. It's a surgical procedure, but it is being sold as a commodity," she told the meeting.
Here's the real rub: One in four patients who seeks Lasik and undergoes a battery of pre-surgery testing is deemed a poor candidate. Maybe the cornea is too thin, or the pupils too large, or nearsightedness too severe, or their expectations unrealistic. But it's not clear just how many patients get screened appropriately, and some forge ahead anyway.
"Some patients are just not a cornea laser eye surgery patient," stresses Dr. Kerry Solomon of the Medical University of South Carolina, a spokesman for the American Society for Cataract and Refractive Surgery. "There are still other options for them. ... And some are, quite frankly, better suited to staying with their glasses and contacts."
With Lasik, doctors peel back a flap in the cornea's surface and zap the underlying layer to reshape the cornea and ease either nearsightedness or farsightedness. The newest version, considered safer, makes ultra-thin flaps using a second laser instead of the original disposable blade.
—With PRK, a laser reshapes the cornea's surface, no flap-cutting needed — important because making a flap cuts nerve receptors that critics say never fully return to normal, thus increasing the risk of painful dry eye. The trade-off: Patients occasionally suffered haze as their corneas healed, not a Lasik risk.
The updated version is wavefront-guided PRK, using computer software actually developed to improve Lasik. It lets surgeons map subtle irregularities in the cornea before zapping, providing a three-dimensional map that customizes treatment, minimizing but not eliminating side effects in both Lasik and PRK.
The Navy compared wavefront-guided PRK to wavefront-guided Lasik, and 12 months after surgery, "the results of both procedures were almost identical," says Dr. Steven Schallhorn, a San Diego ophthalmologist who oversaw the Navy's refractive surgery program until last year.
Still, he says people with thin corneas or corneal irregularities can be better PRK candidates, and UNC's Fowler contends it can provide better night vision. But, it takes a few weeks of healing, with eye drops for the discomfort, before sharper vision emerges.
—CK, or conductive keratoplasty, corrects farsightedness or astigmatism by beaming radiofrequency waves around the cornea's edge.
—Lasers aside, a hard plastic lens can be implanted through a small incision in the eye, in front of the natural lens. These "phakic intraocular lenses" are for severe nearsightedness, too bad for Lasik and PRK. They refocus light entering the eye for improved distance vision. Because the natural lens stays in place, patients seem to retain close-up vision, too.
But they've been on the market only a few years, so long-term effects aren't yet known. Warnings of rare problems include retinal detachment, infections, or an increased risk of cataracts.
—Refractive lens exchange goes the next step and replaces the patient's own lens with an artificial one. It's essentially cataract surgery offered to some cataract-free people who wanted Lasik but are bad candidates, perhaps because of extreme near- or farsightedness. Lens options include a multifocal type that can allow for both distance and reading vision. Again, retinal detachment is a risk.
—Finally, corneal rings are transparent crescents about the thickness of a contact lens implanted to form a ring around the cornea's edge. Called Intacs, their slight weight flattens the cornea without permanently destroying tissue. While they're only for mild nearsightedness, they can be removed if patients suffer side effects such as glare.