I Can See Clearly Now the Cataracts Are Gone
May 26, 2000 -- If you think that lasers are used to remove cataracts, you're a tad ahead of your time. Contrary to what many people believe, lasers are normally used in cataract surgery only after surgery, and then only if patients have clouding of the tissues that surround the new artificial lens or growth of abnormal tissues that stick to the lens and threaten to harm vision.
But if laser makers have their way, laser-assisted cataract removal could be coming soon to an eye surgery center near you. Two companies are awaiting approval for laser cataract removal systems, and one other company has just started U.S. clinical trials, required by the FDA prior to approval.
Cataracts, which are a clouding and hardening of the natural lens within the eye usually associated with aging, are normally removed either through surgical extraction -- a method that is becoming increasingly rare -- or through a technique called phacoemulsification, or "phaco" for short. Phaco uses ultrasonic vibration to liquefy the lens, which is then removed with a suction tube. A new, artificial lens (called an intraocular lens, or IOL) is put in its place. The phaco technique is the most common type of cataract surgery today.
Because phaco uses a needle that vibrates rapidly, it generates a good deal of heat that could potentially burn the cornea, which is the clear, central-outer portion of the eye, or the sclera, which is the white part. But laser cataract removal "is a cold procedure, incapable of producing this complication," cataract surgeon Jack M. Dodick, MD, tells WebMD.
If approved as expected, laser-assisted cataract extraction technology will allow surgeons to remove softer and less dense cataracts with a greater margin of safety than with phaco, proponents say.
"[Laser systems] can safely and effectively remove about 75% of cataracts that are removed in the United States. The other 25% are just too hard," says Dodick, chairman of ophthalmology at Manhattan Eye, Ear, and Throat Hospital in New York City. Dodick invented, and has a proprietary interest in, a laser-based cataract removal system.
Some eye surgeons who have tried lasers for cataract removal in clinical trials say the technique may also give some patients better, more stable vision after surgery than phaco because it requires only a very small surgical incision. This is therefore less likely to distort the cornea, which can result in an astigmatism that can affect the quality of vision.
But what really has laser makers salivating is the prospect that lasers could one day be used to correct vision in people who do not have cataracts. The technique would differ from current vision correction methods that require cutting into the cornea with blades or blasting away at it with lasers to change its shape and thus bring light coming into the eye into better focus.