Made of a photosensitive silicone material, this threepiece lens is implanted in the standard fashion.One to 2 weeks postoperatively, the surgeon measures the patient’s refractive error.The dual-optic design yields a power that is equivalent to that of a standard IOL.While the ciliary body is relaxed, the two optics are relatively close together for distance vision.
This accommodating IOL has four broad haptics that fill the capsular bag, which may allow better coupling of the movements of the ciliary body and zonule with the IOL.
The mechanism of accommodation is similar to that of the Crystalens, which moves anteriorly when the zonule relaxes with accommodative effort and thus increases its effective power and reduces myopia (Figure 3).
Also, the eye tends to be myopic after the lens’ implantation and to have a variable drift toward emmetropia as the capsular bag heals.
Another accommodating IOL in the FDA approval pipeline is the Tetraflex (Lenstec, Inc., St. Like the Crystalens (Bausch & Lomb, Rochester, NY), the Tetraflex has two haptics, but it is anteriorly vaulted, unlike standard PCIOLs (Figure 2).
All patients in the FDA phase 3 study have completed 1 year of follow-up, and the company plans for an FDA premarket approval submission this fall (Jim Simms, oral communication, August 2009).
The 1CU lens (Human Optics AG, Erlangen, Germany) is available in Europe but not the United States.
As the ciliary body contracts and the zonule relaxes, the optics move apart, thus increasing the power of the lens and resulting in near acuity.
Theoretically, 1.5 mm of separation should result in about 3.50 D of accommodation.
The approval of toric multifocal lenses, such as the Acri.
Lisa (Carl Zeiss Meditec AG, Jena, Germany),2 should not be far off, and these IOLs more accurately correct preoperative astigmatism than limbal relaxing incisions.