With the FDA approval of WaveLight AG's wavefront-guided LASIK treatment using the Allegro Analyzer for wavefront analysis in conjunction with the company's 200-Hz Allegretto Wave excimer laser, U.S. refractive surgeons now have another choice for their patients. The indication is for the reduction or elimination of up to –7 D of spherical equivalent myopia or myopia with astigmatism, with up to –7 D of spherical component and up to 3 D of astigmatic component at the spectacle plane.
The Aug. 28 approval from the FDA was based on a review of 6-month data from a pivotal trial in which 374 eyes were randomly selected at five U.S. centers to undergo wavefront-optimized treatment to treat spherocylinder errors or wavefront-guided LASIK based on aberrometry measurements with the Allegro Analyzer. All eyes in the study had flap creation performed with the femtosecond laser (IntraLase). The ablation was performed with a 6.5-mm optical zone. Accountability at 6 months exceeded 92% in both groups, and there were five re-treatments, all in the wavefront-guided group.
The 6-month data showed that in both treatment arms, about 93% of patients achieved 20/20 or better uncorrected visual acuity (UCVA), and all could see 20/40 or better. Low contrast acuity was preserved or improved overall, and there were no symptomatic increases in aberrations.
In the wavefront analyses for eyes with between 0.3 and 0.4 μm RMSh, there was generally better improvement in higher-order aberrations with the wavefront-guided treatment, especially in eyes with lower amounts of spherocylinder error. Among eyes with 0.4 μm or higher RMSh (~7% of the study population), the wavefront-guided treatment resulted in a significant reduction in higher-order aberrations.
Karl G. Stonecipher, MD, a private practitioner in Greensboro, NC, was one of the investigators in the FDA clinical trial. He noted the results are important for both reinforcing the outstanding performance of the wavefront-optimized procedure and demonstrating the safety, efficacy, and predictability of the wavefront-guided treatment.
"This parallel comparison study showed that wavefront-guided treatment was a benefit in a subset of the population with higher levels of higher-order aberrations, which would represent about 15% to 20% of the LASIK candidates I see in my practice," Dr. Stonecipher said. "However, the flip side is that because the wavefront-optimized treatment is a purely refractive treatment and does not induce new aberrations, eyes with low levels of higher-order aberrations preoperatively do very well with that procedure. Therefore, 80% to 85% of patients can achieve excellent outcomes with a wavefront-optimized treatment, and that translates into an important practice efficiency advantage in terms of faster throughput on the day of surgery."