Contact Lens Design & Materials
Contact Lens Design & Materials
The Newest Generation of Hybrid Contact Lenses
BY NEIL PENCE, OD, FAAO
“Hybrid contact lens” is a term used to describe designs that employ a GP material centrally with a soft lens material peripheral skirt. The first hybrid lens received FDA approval in 1984. Since then, improvements in manufacturing technology, materials, and lens design have led to a number of improved versions of hybrid lenses. Today, you can get hybrid contact lenses from SynergEyes. First FDA approved in 2005, its first generations of lenses included the SynergEyes A, KC, and Multifocal lenses, followed by the ClearKone design.
The Latest Generation
Its newer hybrid lenses fall into two categories: Duette lenses targeted for various vision correction needs, and UltraHealth lenses designed for irregular corneas.
Both lenses represent significant advancements from earlier products, and they also employ fairly different fitting approaches. The GP portion of these lenses is produced in a 130-Dk material, while the soft skirt is now an 84-Dk silicone hydrogel material. The increased oxygen provided by these new materials is a significant advancement for both challenged corneas as well as for normal ones.
Corneal health is further enhanced by lens design changes that have resulted in a less steep fitting relationship compared to earlier lenses. Duette and UltraHealth lenses now utilize two landing zones. The addition of the intermediate, as well as a peripheral, landing zone results in a better alignment-type fitting relationship. This allows better tear exchange, while also distributing the weight of the lens landing more evenly on the eye. The result of all of these changes is a healthier, more comfortable lens fit.
Duette Lenses in SynergEyes’ Duette arm are meant to be fit empirically, with no fitting set necessary. The Duette HD employs an aspheric central GP portion. The newly introduced Duette Progressive is a center-near design, with both the near and distance power portions of the GP being aspheric. The Progressive lens benefits from the generally excellent centration of hybrid lenses. It is available in three add powers. Revised warranty and exchange policies support the ability to empirically fit Duette lenses, as do fitting information and videos on the company’s website and consultation availability.
UltraHealth To determine the best fit for UltraHealth lenses, use diagnostic lens sets. The UltraHealth series adds a reverse geometry curve to allow the lens to vault irregular corneas without having to be fit as steeply as previous hybrid designs.
SynergEyes has several fitting set options for UltraHealth. Fitters experienced with previous products need to recognize that the fitting approach is very different for this lens series. To ensure success, it is important to follow the fitting guide.
Final Thoughts on Hybrid Contact Lenses
With higher oxygen transmission, better tear exchange, and closer to alignment fits, SynergEyes’ newest offerings are recommended for all new hybrid fits.
What about patients already in existing hybrid lenses? While it is tempting and certainly easier to allow patients currently wearing older-version SynergEyes lenses to simply reorder at their yearly exam (and these lenses do remain available), this may not be the best practice. The newer options are certainly healthier and are often more comfortable, and the long-term interests of all patients are probably best served by offering them the improvements found in the newest generation of hybrid contact lenses. CLS
Contact Lens Spectrum, Volume: 29 , Issue: June 2014, page(s): 19