SAN FRANCISCO, March 16 /PRNewswire/ -- Crystalens, the first and only U.S. Food and Drug Administration-approved accommodating intraocular lens (IOL), today underscored its command of the premium lens channel with data to be presented at the American Society of Cataract and Refractive Surgery annual meeting in San Francisco. Recent clinical data from accommodative arching studies show that the crystalens closely mimics the innate focusing action of the natural crystalline lens -- something no other IOL can claim. This action explains why the majority of crystalens patients are able to achieve a continuous range of vision -- near, distance and intermediate.
"The performance of the crystalens defines the premium lens channel. No lens technology comes closer to mirroring the eye's natural lens than the crystalens, making it one of the few implantable devices available that is delivering the medicine of tomorrow ... today," said J. Andy Corley, chief executive officer of eyeonics, the manufacturer of crystalens. "The objective scientific evidence of accommodative arching further supports our product's performance in this category."
Approved by the FDA in November 2003 and already implanted in more than 40,000 eyes worldwide, crystalens replicates the action of the original crystalline lens it replaces by using the eye's natural muscles to move both back and forth and change its curvature -- just like the natural crystalline lens. This unique natural focusing dynamic delivers 100 percent of available light rays at all distances and makes crystalens the only available IOL to provide a continuous range of vision -- near, far and everything in between.
"After wearing readers for so long, you forget how nice it is to have clear, continuous vision without reaching for a pair glasses," said Pat Summerall a renowned NFL sports broadcaster. "After the crystalens surgery, my vision kept improving. Now, 10 months later, I have terrific vision no matter what the distance."
Accommodative Arching Theory Brings Human Vision Into Focus
For centuries, medical scientists have been fascinated by the eye's ability to rapidly change focus between distances. Some of history's most famous philosophers and scientists, including Keple and Descartes, have added to our understanding of the how the eye achieves focus -- or, accommodates. By the 1800s, evidence was uncovered that showed conclusively that the lens of the eye changes shape, increasing its curvature and, therefore, its focusing power, to bring vision into focus through the range of distances. In the early 1900s, physicians postulated that the tension of ciliary muscles pressed the crystalline lens against the vitreous body -- forcing the lens to flex and increase its curvature. This dynamic, in combination with the back and forth motion of the lens in the eye, today is understood to be the eye's natural method of focus.
Recent work in this area has led Kevin L. Waltz, OD, MD to understand how closely the only FDA-approved accommodating IOL -- the crystalens -- mimics the natural focusing mechanisms leading to his theory of accommodative arching. Until now, the crystalens' capacity to move back and forth was generally believed to be the primary action of its focusing ability. However, accommodative arching describes newly discovered changes in the radial curvature of the crystalens brought about by fluctuations of force in the ciliary body which increases the focusing power of the lens.
The clinical data presented at ASCRS involves multiple studies and focuses primarily on crystalens' mechanism of accommodation. Specific objective and subjective measures were designed to distinguish the true accommodative changes provided by crystalens from the pseudo-accommodative effects offered by multifocal IOLs, contact lenses, corneal refractive procedures and other approaches. Among the key findings:
Anterior/posterior lens movement: The primary mechanism of
accommodation, resulted, as intended
in the crystalens' design, from
contraction of the eye's natural
ciliary muscle to which the crystalens
Accommodative arching: The flexing of the lens that results
in refractive power changes and
provided a secondary, additive effect
to the crystalens' natural focusing
ability -- the first time scientific
data have confirmed this hypothesis;
Sustained accommodative effect: No significant differences in near and
distance visual acuities were reported
between one- and three-year intervals
among subjects in the clinical trial
that led to FDA approval of the
"By virtue of its incorporation into the ciliary musculature and the precision of its manufacturing process to produce a remarkably thin lens, the crystalens is able to replicate all of the known focusing mechanisms of the natural lens," said Dr. Waltz. "Consequently, the accommodating IOL is able to deliver premium vision through the entire continuum of distances."
Crystalens Delivers on the Promise of Futuristic Vision
Many Baby Boomers assumed that, by the time they turned 60, they would benefit from futuristic medical technologies -- including medical implants that are just as good, if not better, than their biological counterparts. The good news for the 90 million American adults over the age of 45 that face a future of diminished vision due to presbyopia and cataracts, crystalens' accommodating technology performs just like the natural lens in the eye and provides a clear, continuous range of vision.
This full range of clear vision -- especially the intermediate or "lifestyle" vision, where reading a newspaper, seeing facial expressions and other daily tasks occur -- distinguishes crystalens from other, older IOL technologies. Multifocal IOLs, for example, are "fixed" in the eye, resulting in "stepped" or "zoned" vision, and often require patients to wear glasses or contacts to make up for the gaps. Multifocal IOLs also have higher incidences of vision problems, including complaints of glare and halos, resulting in FDA warning on their labeling.
The crystalens is the result of more than 14 years of research and development by J. Stuart Cumming, M.D., F.A.C.S., and was approved by the FDA in November 2003. More than 40,000 lenses have been implanted worldwide to date. During clinical trials, all of the patients who received the crystalens greatly reduced their need for corrective lenses or eyeglasses. The patented crystalens technology is designed to allow the lens to move in the eye in a manner similar to the natural lens. By using the eye's muscle to move the lens back and forwards naturally, patients can focus through a continuous range of vision including near, far and everywhere in between. All other intraocular lenses are designed to remain fixed in the eye. For more information about the crystalens go to www.crystalens.com
About eyeonics Inc.
eyeonics is a privately held medical device company headquartered in Aliso Viejo, Calif., founded in 1998. eyeonics is committed to developing a new class of visual enhancement systems that will enable patients to see up close, far away and all distances in between. For more information about eyeonics, inc., go to www.eyeonics.com.
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