Allegretto wavefront-guided system on the horizon

April 18 - Washington, DC - Preliminary results from the ongoing FDA clinical trials of the Allegretto Wave wavefront-guided excimer laser (WaveLight Laser Technologie AG) demonstrate the safety and efficacy of this new platform, when compared with the approved wavefront-optimized platform, reported Steven Brint, MD, medical monitor for the FDA study, during a Sunday evening presentation at the American Society of Cataract and Refractive Surgery annual meeting.

In a prospective, randomized study, which started in September 2004, patients were randomly assigned to treatment for myopia up to -7 D and astigmatism up to -3 D and were treated with either the wavefront-guided excimer laser or the wavefront-optimized system. The IntraLase femtosecond laser (IntraLase Corp.) was employed to create the flap.

So far, 240 eyes have been followed for 3 months with 122 undergoing wavefront-guided correction and 118 being treated with the wavefront-optimized approach.

Uncorrected visual acuity (UCVA) of 20/20 or better was achieved in 92% of the wavefront-optimized group and 95% of the wavefront-guided group. UCVA of 20/16 or better was seen in 68% of the wavefront-optimized group and 65% in the wavefront-guided group.

The postoperative UCVA compared with the preoperative best-corrected visual acuity (BCVA) was the same or better in 80% in the wavefront-optimized group and 84% in the wavefront-guided group.

Both platforms are extremely safe, with no eyes losing 2 lines of BCVA. In fact, 54% in the wavefront-optimized group and 56% in the wavefront-guided group gained 1 or more lines of BCVA, Dr. Brint noted.

In terms of induced spherical aberration, both platforms showed no difference as there was no induced spherical aberration, he said.

As far as total higher-order aberrations, the wavefront-guided system started out with slightly more higher-order aberrations, not including spherical aberration.

"It was not quite as high as seen in the wavefront-optimized system," Dr. Brint noted.

"Both groups did extremely well. They met the protocol targets for safety and effectiveness. We assumed they would do well and they did," Dr. Brint said, "We assumed that the eyes that had higher preoperative higher-order aberrations would be able to be treated and corrected with the WaveLight system and that was true. It seems to perform as well or better than the other (wavefront-optimized) system."

When the final testing is complete, it is hoped that this correlates to better visual acuity and contrast sensitivity in this patient group with higher-order aberrations.

"We don't have the data yet to comment on this," he said.

The enrollment in the study is almost complete and FDA approval for the wavefront-guided platform should be forthcoming, Dr. Brint said.