Medical Device Daily Associate

Though LASIK procedures have been one of the fastest technologies to reach maturity, refinements and advancements in the technology keep coming.

WaveLight (Sterling, Virginia) yesterday reported that the FDA has approved its wavefront-guided procedure, a LASIK treatment approach that combines the Allegro Analyzer with the 200-hertz Allegretto Wave excimer laser. WaveLight said it now offers U.S. physicians the choice of Wavefront Optimized and wavefront-guided LASIK treatment options, both of which demonstrate similar outcomes in clinical studies, according to the company.

The company says that the primary difference between WaveLight's standard WaveFront Optimized systems and its Wavefront-guided LASIK system is that Wavefront-guided technology can help those patients that have spherical aberrations, which are associated with glare and halo effects and nighttime driving problems, a side effect of LASIK procedure ranging from occasional to frequent.

The Allegretto Wave wavefront-guided LASIK procedure was approved by the agency for the reduction or elimination of up to -7.00 D of spherical equivalent myopia or myopia with astigmatism, with up to -7.00 D of spherical component and up to 3.00 D of astigmatic component at the spectacle plane.

The procedure may be performed on patients who are 18 years of age or older and on patients with documentation of a stable manifest refraction, defined as less than or equal to 0.50 D of preoperative spherical equivalent shift over one year prior to surgery. The refractive surgeon will also have the ability to adjust the spherical correction performed by +/- 3.00 D.

The wavefront measuring system is different from conventional laser surgery in that high- and low-order aberrations, or curvatures, of the cornea unique to each patient, are measured by the LadarWave aberrometer. This information is then transferred to the excimer laser where it goes through electronic registration and computer matching to create a precise ablation, with the intent to give the patient a customized laser surgery.

Wavefront Optimized LASIK is designed to treat spherocylinder errors without affecting higher order aberrations, especially spherical aberration. Wavefront-guided LASIK is based on what the company calls “aberrometry measurements” and is designed to treat both spherocylinder and higher order aberrations.

“We are pleased that in addition to receiving mixed astigmatism approval last May, the Allegretto Wave has been granted yet another important FDA approval,” said Max Reindl, CEO of parent company WaveLight AG (Erlangen, Germany). “WaveLight's philosophy is to provide physicians with the technology to achieve superior outcomes, whether they choose to perform Wavefront Optimized or wavefront-guided treatments. Because we are confident that both options will provide excellent outcomes, WaveLight will not increase the procedure fee for wavefront-guided treatments with the 200 Hz Allegretto Wave.”

A company spokesperson noted that several other companies, including Alcon (Hunenberg, Switzerland), Bausch & Lomb (Rochester, New York) and Visx (Santa Clara, California), have developed wavefront-guided systems, since the company's Allegretto system came to market much later than many of its competitors (Medical Device Daily, Oct. 24, 2003).

However, she said that WaveLight's standard wavefront platform “is many generations advanced” over that of its competitors, additionally noting that the company's basic platform technology already includes most of the advanced wavefront algorithms that have been added to competitors' systems.

A randomized clinical study of 374 eyes treated at five U.S. centers validated that patients enrolled in either the wavefront-guided treatment group as well as the Wavefront Optimized group achieved similar visual results for uncorrected visual acuity (UCVA), manifest refractive spheroequivalent (MRSE) and postoperative UCVA vs. preoperative best spectacle visual acuity (BSCVA). Myopic patients (up to +7D with up to +3D of astigmatism) were eligible to participate in the study.

The company said that at six months, 93% of patients in both study groups achieved 100% vision or better. Additionally, 85% of eyes in the Wavefront Optimized cohort and 87% of eyes in the wavefront-guided cohort achieved postoperative UCVA as good as or better than their preoperative BSCVA. At three months, all patients in both study groups were able to drive without glasses after treatment.

Results demonstrated similar wavefront outcomes in both groups in eyes with less than 0.3 microns of pre-operative higher-order aberrations (HOAs), accounting for 83% of eyes. Eyes with 0.3 to 0.4 microns of pre-operative HOAs demonstrated slightly more improvement with wavefront-guided treatments than with Wavefront Optimized treatments. In cases with more than 0.4 microns of HOA, it was discovered that post-operative HOAs were reduced significantly in the wavefront-guided cohort.

No symptomatic increases in aberrations were observed in either cohort. Also, the Allegretto Wave is the only standard LASIK platform that has demonstrated the ability to preserve and improve low-contrast acuity, the company said.