Contact Lens Design & Materials
Three New Multifocal Lens Options
BY RONALD K. WATANABE, OD, FAAO
As stated in Dr. Neil Pence’s December 2013 Contact Lens Design and Materials column, manufacturers are constantly improving their products. As a result, we have seen better products emerge each year, including options for ever-challenging presbyopes. Following are three to check out.
Astera Multifocal Toric
The Astera Multifocal Toric (Alden Optical) lens is a center-near aspheric soft multifocal that incorporates C2 multifocal optics developed by Precilens.
It features a central near zone surrounded by a progressive intermediate zone and a stabilized distance zone. The stabilized near and distance zones provide relatively large spherical areas for distance and near viewing, improving vision for many wearers.
The lens is available in three add profiles to fit early, moderate, and advanced presbyopes. Dual Elliptical Stabilization is designed to provide rotational stability with reduced overall lens thickness. It is available in a range of base curves and diameters as well as in a non-toric version. Consider it for patients who have 0.75D or more of refractive cylinder and are unable to attain acceptable vision with disposable multifocals.
Art Optical designed its mPower! lens for patients who have high near vision demands that were not being met by their previous aspheric GP multifocal lenses. The front surface has four power zones, each of which can be varied in power, diameter, and eccentricity.
The central zone is spherical and set for distance vision. Its standard diameter is 1.5mm, but can be made larger or smaller depending on patient pupil size. The remaining three zones are adjusted to enhance and fine-tune intermediate and near vision. Art Optical’s fitting consultants incorporate practitioner observations of patients’ visual performance to determine the appropriate change in these zones. The back surface has a low-eccentricity curve that is intended to fit with alignment and minimize corneal distortion.
Though Art Optical still recommends its other designs, such as Renovation, for the majority of presbyopic patients, those who are not attaining acceptable near acuity can be refitted into this new design.
The Duette Progressive (SynergEyes) shares the same material combination as the Duette HD, Duette Multifocal, and Ultra-Health designs. The GP center has a Dk of 130 at a diameter of 8.5mm, and the soft silicone hydrogel skirt has a Dk of 84 at a diameter of 14.5mm. The back surface design is the same as its Duette predecessors, so it should be easy to fit for those who are already familiar with these lenses.
The 7.0mm optic zone has a central aspheric near zone that seamlessly transitions into an aspheric distance zone. The new lens is available in three add powers, +1.00D, +1.75D, and +2.50D, so the near power can be tailored to meet patients’ needs. This is different from the original Duette Multifocal, which has one add profile that is made to fit all patients regardless of their near vision needs.
As a result, the new design can provide better distance vision for those who have lower add power needs and better near vision for more advanced presbyopes.
These new soft, GP, and hybrid multifocal options are just a few of the new and improved tools available to help us give our contact lens-wearing presbyopes better visual performance. CLS
Dr. Watanabe is an associate professor of optometry at the New England College of Optometry. He is a Diplomate in the American Academy of Optometry’s Section on Cornea and Contact Lenses and Refractive Technologies, and is in private practice in Andover, Mass. You can reach him at email@example.com.