Contact Lens Design & Materials
New Lens Technology Targets Improved Vision and Comfort
BY DAVID L. KADING, OD, FAAO
Once again a novel innovation has come from one of the major contact lens manufacturers: Bausch + Lomb (B+L) has launched its Ultra contact lenses with MoistureSeal technology throughout the United States. This is a major development for the company, which has been enhancing its monthly sphere, toric, and multifocal designs in the PureVision silicone hydrogel material (balafilcon A) since 1999. Additionally, this is the first spherical, non-daily disposable, silicone hydrogel contact lens advancement in the industry to be released in some time.
The company’s aim with the Ultra lens is to target the trifecta of contact lens success: improved health, comfort, and vision.
MoistureSeal Technology
The lens’ MoistureSeal technology is created through a curing chamber that uses radiant energy to polymerize the lens material in two distinct phases, which is a process unique to the technology. The first phase creates a matrix that has a combination of long- and short-chain silicone molecules. The longer chains are responsible for the lower modulus, while the short chains increase the Dk/t.
The second phase of the polymerization process grows polyvinylpyrrolidone (PVP, a water-loving polymer) around the meshwork of long- and short-chain silicone molecules. PVP is a common wetting agent that is used in contact lenses and eye drops to increase wettability and moisture retention. This process of growing the PVP around the chains is unique; other processes wrap silicone around fully formed PVP. As a result, MoistureSeal technology reportedly has four times more PVP compared to other silicone hydrogels. B+L believes that this process of growing PVP will help to keep moisture on the surface of the lens and away from the hydrophobic silicone, which, as we all know, is the major challenge for all silicone hydrogel lenses. B+L reports that the Ultra lens achieves a high level of both overall and end-of-day comfort while exhibiting a very low level of deposition at the end of the monthly wearing cycle.
Material | Samfilcon A |
Technology | MoistureSeal |
Water Content | 46% |
Dk/t | 163 |
Optics | Aspheric |
Base Curve | 8.5mm |
Diameter | 14.2mm |
Modality | Monthly: daily wear indication |
Vision Performance
In addition to the MoistureSeal technology, B+L has incorporated aspheric optics into the Ultra lens. The company feels that these two features together provide patients with a superior visual performance due to the combination of reduced spherical aberration and a moist surface.
Promising Technology
I haven’t had the opportunity to try the Ultra lens in my practice, but I am very much looking forward to prescribing it for my patients. I believe that this is a breakthrough in polymerization. And, I am anxious to see how the lens’ aspheric optics and surface-rich PVP will impact patients’ end-of-day vision for driving and while they are using their electronic devices. CLS
Dr. Kading owns the Specialty Dry Eye and Contact Lens Center in Seattle. He is the co-owner of Optometric Insights with Dr. Mile Brujic. He has received honoraria for consulting, performing research, speaking and/or writing from: Alcon Laboratories, Allergan, Bausch + Lomb, Biotissue, Contamac, Essilor, Nicox, Oculus, RPS Detectors, TearScience, Valley Contax, and ZeaVision. Follow him on Twitter @davekading.