Nov 13 2009
Data presented at American Academy of Optometry meeting
Bausch & Lomb today announced that the company's Lo-Torque lens design demonstrates significantly better rotational recovery, which can lead to more consistent vision, compared with Acuvue's accelerated stabilization design. These findings from two clinical studies were presented at Academy 2009, the American Academy of Optometry annual meeting in Orlando, Fla.
Rotational recovery is defined by how quickly a contact lens returns to the desired orientation following a disruption such as eye rubbing. Exceptional rotational recovery is fundamental to providing stable vision for toric lens wearers, and can be an important factor in lens wearer satisfaction. According to a recent survey, more than 80 percent of soft toric contact lens wearers in the U.S. have experienced a rotational recovery issue such as blurred or fluctuating vision.
"Toric lenses for patients with astigmatism must maintain consistent orientation to provide stable, clear vision," said Gerard Cairns, Ph.D., MCOptom, lead clinical investigator and manager of global medical affairs at Bausch & Lomb. "People with astigmatism face unique vision challenges, and lens stability is key to successful lens wear in these patients."
Both studies compared the fitting and orientation characteristics of Bausch & Lomb PureVision for Astigmatism lenses with an Acuvue lens for astigmatism in 32 subjects. One study used Acuvue Advance for Astigmatism, while the other used Acuvue Oasys for Astigmatism. A broad range of sphere powers and cylinders was used to optimize the design of both studies.
Rotational recovery was determined by allowing the lens to settle for three minutes after insertion, then manually rotating the lens 45 degrees, waiting one minute, and re-measuring the orientation. PureVision for Astigmatism demonstrated statistically significantly better rotational recovery than Acuvue Advance for Astigmatism, with means of 6 degrees and 11 degrees, respectively. In addition, PureVision for Astigmatism demonstrated statistically significantly better rotational recovery compared with Acuvue Oasys for Astigmatism, with means of 4 degrees and 8 degrees, respectively.
"When prescribing lenses for their patients with astigmatism, eye care professionals should consider how well the lens returns to its primary orientation when the lens unexpectedly rotates out of position," Dr. Cairns indicated.