Sep 14 2004
The Food and Drug Administration
(FDA) has approved a plastic lens that is permanently implanted into the eye
to correct moderate to severe nearsightedness.
The lens, called an intraocular lens (IOL), is similar to the type of lens
implanted in the eye to restore vision following cataract surgery.
Manufactured by Ophtec USA
Inc., of Boca Raton, Fla., the new lens is intended to reduce or eliminate
nearsightedness in adults, and will offer people another alternative to glasses,
contact lenses and laser surgery such as LASIK.
The new IOL, called the Artisan, is intended for use in healthy eyes, in
people with stable vision. It should not be used in people who have more than
minor (2.5 diopters) astigmatism (distorted vision caused by an uneven curvature
of the cornea).
Unlike the IOL implanted during cataract surgery that replaces the eye's
natural lens, the new IOL for nearsightedness does not replace the natural lens
but is implanted in front of it.
FDA approved the new lens based on a review of clinical studies of safety and
effectiveness conducted by the manufacturer and on the recommendation of the
Ophthalmic Devices Panel of FDA's Medical Devices Advisory Committee.
Ophtec studied use of the IOL in 662 patients with moderate to severe
nearsightedness at 22 medical centers in the U.S. After three years, 92 percent
had 20/40 or better vision (considered standard vision necessary to obtain a
driver's license), and 44 percent had 20/20 or better.
One potential concern raised by the study was the loss of endothelial cells
in the corneas of patients who received the implants. The endothelium is a layer
of cells that line the undersurface of the cornea and are essential to keeping
the cornea clear. The three-year data showed a continual steady loss of
endothelial cells of 1.8 percent a year. At this point, it is not known whether
this loss will continue at the same rate, or what the long-term effect of this
device on the cornea's health might be. To minimize any potential long-term
effects of the device on the corneal endothelium, FDA is requiring the labeling
for the new lens to specify that it should be used only on patients whose
corneal endothelial cells are dense enough to withstand some loss over time.
Other adverse events reported in the study included retinal detachment
(0.6%), cataract development (0.6%), and corneal swelling (0.4%).
FDA is requiring Ophtec to conduct a five-year post- marketing study to
better assess the rate of cataract development, retinal detachment and other eye
problems.
The Artisan lens is intended to be a permanent implant. Although it can be
removed surgically, vision may not return to what it was before receiving the
lens.
The lens may not eliminate the need for glasses because the Artisan lens does
not correct astigmatism. Glasses may need to be worn for night driving or other
activities performed in low light. They may also be needed for reading.