Approved and investigational accommodation IOLs
Article Tags: IOLs
As we know, some people above 40 can not see clearly at multiple distances, which is caused by the lens’ natural aging and becoming too rigid to move smoothly. Toady, eye doctors can take use of artificial intraocular lenses to replace or treat their patients’ aging or damaged eye lenses. Among all of the IOL products, accommodation ones such as the Crystalens have a special design that they can correct presbyopia described above. An accommodation IOL provides sharp vision by shifting its position with the action of eye muscle movement, rather than by simply replacing the natural lens. Accommodation IOLs belong to presbyopia-correcting IOLs, so that patients can get clear vision at multiple distances.
The only FDA-approved accommodation intraocular lens
First approved in 2003, the Crystalens is the only approved product of IOL that takes use of the accommodation technology. It is still the only FDA-approved presbyopia correcting IOL for cataract patients. Moreover, Crystalens IOL uses the natural focusing ability of the eye. Bausch & Lomb now is marketing several versions of Crystalens. The newest version claims that it has better near vision and lower incidence of causing side effects. Patients using Crystalens IOLs seldom experience visual problems like glare, halos and poor night vision.
The upside of Crystalens IOL
Among the four types of presbyopia-correcting IOLs, Crystalens IOL differs from the other three types, which are called multifocal IOLs. Multifocal IOLs perform just like multifocal lenses that the patient should look through an appropriate zone to get vision aid at a certain distance. However, IOLs are much smaller than contact lenses, so that these divided zones on IOL are too small to provide clear single vision. Using accommodation, Crystalens can always maintain one focus zone for any distance vision. In other words, this product only focuses one image to the back of the eye. A disadvantage of Crystalens IOL is that it provides a narrowed range of focus.
The downside of Crystalens IOL
Patients should be aware that neither monovision IOLs nor presbyopia-correcting IOLs can provide perfect vision correction. Even standard monofocal IOLs may bring night glare and halos. This situation is also true for Crystalens IOLs, which suit people with both presbyopia and cataract. In addition to common complications, Crystalens is reported to bring potential astigmatism and posterior capsule clouding.
Accommodation IOLs under trials
Besides Crystalens, there are several types of accommodation IOLs that are still under clinical tests. Approved in Europe, the Synchrony IOL is undergoing clinical trials in U.S. Synchrony has been proved to bring fewer visual distortion and better intermediate distance vision than ReSTOR. Another product is Tetraflex, which has a square-edged, acrylic optic.