Posted: Sep 27, 2011 2:03 PM
For most people, breaking, losing, or misplacing their glasses is an annoying inconvenience. But for Christiaan Rollich, who was severely nearsighted, not wearing glasses or contacts meant not seeing at all.
"My vision was so bad the army wouldn't accept me," says Rollich, who grew up in the Netherlands and moved to the U.S. 15 years ago. "If I took out my contacts, I wouldn't be able identify anybody in the room, no matter how close they were."
Fortunately for Rollich, implanted contact lenses can now help people who have moderate to severe nearsightedness, or myopia. Called phakic intraocular lenses (IOL), these lenses are surgically implanted in the eye in front of the natural lens. They work by bending light rays onto the retina to form a clear image. Studies have found that IOL surgery is as safe as LASIK, which cuts the cornea to change its focusing power.
"It's the best money I ever spent," says Rollich. "Now I have pilot vision -- 20/15. I can do anything I want now. I surf, I do Thai boxing. It's really amazing."
There are two types of phakic implantable lenses available in the U.S. Studies show that both types are safe and work equally well to correct vision, but they do have different risks.
Note: Vision error is measured in diopters. The greater the number, the more correction needed.
A myopia correction from -3 diopters to -16 diopters.
A myopia reduction from -16 diopters to -20 diopters.
Neither lens treats astigmatism, an eye problem that often accompanies nearsightedness. So you must have astigmatism of 2.5 diopters or less to be a candidate for these two lenses.
There are other phakic implantable lenses used in Europe that can treat both myopia and astigmatism, but they have not yet been approved by the FDA for use in the U.S.
"The Verisyse lens is not foldable, so it has to go in through a large incision. And that's a negative," says D. Rex Hamilton, MD, FACS, director of the UCLA Laser Refractive Center. "It also clips on the iris, and sits in front of the iris, so it's closer to the inner surface of the cornea." This means that there is a slightly higher risk of damage to the cornea, which can lead to the need for a corneal transplant.
The Visian lens is foldable, so it can be inserted through a smaller incision that usually requires no sutures. But because it sits close to the natural lens of the eye, it can cause cataracts in a small percentage of people, says James J. Salz, MD, clinical professor of Ophthalmology at the University of Southern California. "And we don't know how many patients will get a cataract if they've had that lens in their eye for over 10 years." The Visian lens has been modified recently to decrease the risk of cataracts.
Also, as with any surgery, both implantable lenses pose a small risk of infection, which in rare cases could cause blindness.
In clinical trials, both brands corrected vision well. With the Visian lens, 95% of patients had 20/40 or better vision, the level needed to obtain a driver's license, and 59% had 20/20 or better after three years. With the Verisyse lens, 92% had 20/40 or better vision, and 44% had 20/20 or better after three years.
Phakic surgery is an elective procedure, so it's not covered by insurance. It costs $3,500 to $5,500 per eye. Surgeons operate on just one eye at a time, so you need to have it twice to correct vision in both eyes.
"The lens is expensive and the procedure is more involved and intensive than LASIK," says Hamilton.
The surgery itself takes about 10 to 15 minutes, he says. "We use topical numbing drops and IV sedation, and you can see out of the eye immediately. There's no need to patch the eye shut."
"The recovery time is essentially overnight," Hamilton tells WebMD. "The next day a patient's vision is excellent." In comparison, it can take up to six months for vision to stabilize after LASIK surgery.
"A big question is: who are the candidates for these lenses?" says Salz. "Because you're putting the lens inside the eye, it's a different set of risks than LASIK surgery, which is done on the cornea outside the eye."
Implantable lenses are a good choice for people who are extremely nearsighted, says Salz. "Patients who are above -10 diopters or -11 diopters often can't get enough correction with a LASIK procedure."
"These patients...have to wear contact lenses every waking hour because they can't see otherwise, or they have to wear super-thick glasses, which most people find unacceptable," Hamilton says. With implantable lenses, "you really change their lives."
For people who have nearsightedness of -8 diopters to -11 diopters, Salz says the choice isn't so clear. Some surgeons prefer to use phakic lenses, while others prefer LASIK, he says. If you fall into that group, it's important to ask your ophthalmologist to explain the benefits and risks of each surgery. You might also consider getting a second opinion.
Take your time and find a surgeon who has a lot of experience doing phakic IOL surgery. Be sure to find out what the fee covers. If you need additional procedures to correct astigmatism, for example, it may cost more. Here are some good questions to ask:
Hamilton foresees phakic surgery someday being used to treat other complex vision problems such as keratoconus, an irregular-shaped cornea. "These patients tend to have irregular astigmatism that's not corrected by glasses, and contact lenses don't fit well," says Hamilton. They are not a candidate for LASIK or other similar procedures because they have a weaker cornea, he says. "There is the potential for customizing the optics of these phakic lenses to compensate."