Allegretto

ALLEGRETTO WAVE by WaveLight

PerfectPulse Technology™ represents a new approach to laser vision correction – it accounts for speed, precision, and safety in the ALLEGRETTO WAVE laser and offers improvements that are revolutionary in the field. Smart Energy Control measures and adjusts energy levels in the laser pulse from creation to delivery. High Speed Eye Tracking charts the eye’s movement 200 times per second. As a result, every laser pulse is completely controlled and accurate, achieving the most accurate level of correction possible.


You can have peace of mind that the amount of energy in the laser has been calibrated to exactly the right level. After the beam has been created, it passes through three checkpoints on its way to your eye. At each of these points, the energy level is checked and adjusted if necessary, ensuring that the beam is perfectly attuned at its destination.

ALLEGRETTO WAVE’s laser is essentially a precise, controlled beam of energy. The laser employs a proprietary overlapping method to ensure accurate laser placement, and is one of the ways that ALLEGRETTO WAVE achieves a rounder, more natural corneal surface than many other lasers used for vision correction.


Due to the remarkable speed of both the eye and the ALLEGRETTO WAVE procedure, the laser beam needs to be constantly and minutely adjusted to the position of the eye at any given time. Every 4-6 milliseconds, the eye’s location is measured and the internal mirrors of the ALLEGRETTO WAVE are automatically aligned. Right before the pulse is released, a second check is made to confirm that the eye has not moved. This happens 200 times every second, once for every laser pulse. If, at any time, the eye moves too quickly to be measured or moves out of range, the laser will stop and wait for the eye to move back into position.


Currently, the ALLEGRETTO WAVE is the fastest vision correction laser for LASIK available in the United States. At 200 laser bursts per second, it only takes about four seconds of treatment to correct one diopter. Of course, spending less time under the laser means less stress and discomfort for the patient.

WAVEFRONT OPTIMIZED

One of the most innovative features of the ALLEGRETTO WAVE is the way it uses wavefront-optimized technology to automatically compensate for the curvature of the cornea. In earlier laser correction systems, the optical zone, or area of correction, was centered on the front of the cornea; the result was a flattened circular area that ended with an abrupt edge, causing unwanted side effects like poor night vision,glare, and halos.

ALLEGRETTO WAVE changes all that. The ALLEGRETTO WAVE sends extra pulses to the peripheral cornea area in order to compensate for the angle of the laser beam. In this manner, the aspherical shape of the cornea is preserved to a degree that older lasers simply could not achieve. This compensation, combined with the incredibly small, 1mm size of the laser, produces a smooth, effective optical zone that results in what can only be described as high performance vision.

Imagine a glass ball. If you took a flashlight and aimed it directly at the top of the ball, the light would form a circular shape on the surface of the ball. If you now aimed the flashlight towards the side of the ball, the light would form an elliptical shape and not seem as bright anymore. This is because the same amount of light is suddenly distributed over a larger area and some of the light is reflected away due to the angled surface of the glass ball.

The illustration below demonstrates the need for additional pulses to the corneal periphery, in order to compensate for the energy lost through reflection. Therefore the natural cornea shape of each patient can be maintained.

HIGH PERFORMANCE VISION


ALLEGRETTO WAVE is capable of producing some of the largest available optical zones. The optical zone refers to the portion of the cornea that has been corrected by the laser. A larger optical zone is especially important for night vision, and for patients with very large pupils. If a patient’s pupil is larger than the optical zone, they may experience poor peripheral vision, poor night vision, and a higher than normal incidence of halos and glare. In the past, this has been one of the biggest drawbacks to conventional laser correction surgery. Wavefront-optimized technology built into ALLEGRETTO WAVE addresses this limitation.


At night and in dark conditions, the pupil becomes larger to permit the maximum amount of light to enter the eye. Laser eye correction needs to take this fact into account. If the optical zone is smaller than the size of the pupil at its largest, there is a good chance that the patient will experience poor night vision or problems with glare and halos around bright objects such as oncoming headlights. ALLEGRETTO WAVE is able to produce a larger optical zone, virtually eliminating glare and night vision problems associated with older generation lasers