About Allegretto WaveLight Excimer Laser System

The Allegretto Wave excimer laser system, designed by WaveLight Laser Technologies AG (Erlangen, Germany) and distributed by Lumenis, Inc. (Santa Clara, CA) was specifically designed to perform wavefront-optimized ablation profiles. With a repetition rate of 200 pulses per second, WaveLight's laser is the fastest on the US market today. It operates three to four times as fast as the ALCON Autonomous 4000 flying spot laser, which has a similar spot size (0.95-mm) and can treat one diopter of prescription every 4 seconds. This rapid treatment speed translates into less dehydration of the corneal bed and improved refractive predictability due to fewer hydration changes. The laser is very reliable, extremely quick, highly accurate, and has a fast-responding infrared eye tracker.

The Allegretto laser system was granted final FDA approval in October 2003. It was the first US system to receive concurrent approval for a broad range of nearsightedness and farsightedness, with and without astigmatism. The FDA data that was submitted demonstrated that "visual outcomes were better than data we have seen in the past from competitor's lasers," said Tom Liolios, Senior Director of Ophthalmic Marketing at Lumenis. "The Allegretto's new larger treatment zone of eight mm is also appealing." Moreover, "the scanning algorithm does not consume as much tissue as older lasers, so one can perform surgery on higher myopes and hyperopes," he explained. "The big fear with most excimer lasers is that if you try to treat too high of a prescription, you end up with instability. This does not seem to be the case with the Allegretto."

Allegretto WaveLight technology also features a unique approach to corneal sculpting. The normal curvature of a healthy cornea is prolate or higher in the center. Most laser systems flatten centrally to create an oblate cornea. This oblate shape causes spherical aberration, which degrades the quality of vision, especially at night, and often produces glare or halos.

The Allegretto laser not only treats the cornea centrally, but also peripherally. The laser uses proprietary nomograms to adjust the asphericity of the cornea to perform a prolate ablation based on the anterior curvature readings. This prolate curvature, in part, accounts for the excellent quality of vision during the day and night.

Our eyes are constantly making small, rapid jumps called saccadic eye movements. These movements are beyond your control and may affect the result of your surgery. This advanced laser uses high speed, precise infrared active eye tracking with a response time of less than 8 milliseconds to neutralize these movements and assure a quality treatment.

A small diameter laser beam, also known as spot size, is very important for both accuracy and smoothness. The ideal beam size is 1 millimeter or less. While beam size is critical, so is the type of laser beam that is being used. A gaussian beam allows for the smoothest corneal surface as compared to non-gaussian beams. The result is that with a small beam less than 1 millimeter with a gaussian profile allows for the proper and accurate treatment of the smallest curvatures of the cornea and also allowing for a smooth corneal surface.

This laser can effectively treat people with larger pupils. The expanded optical zones allow for larger treatment zones, up to 8mm, which can minimize glare, haloes, and potential night vision problems. Many patients with high prescriptions who previously were not candidates because of unacceptable risks of visual side effects are now candidates with the advent of this new laser technology.