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This is the name of the cool beam 193 nanometer excimer laser that was designed by Autonomous Technology Corporation, a division of Alcon. This laser was approved by the FDA for laser vision correction in 1998 and is the only small spot scanning, closed loop tracking excimer laser. The technology behind the laser was first developed by NASA for docking two spacecraft moving thousands of miles an hour and for the Space Defense Initiative (Star Wars) in order to track enemy satellites in the sky and shoot them down with a laser
In October 2002, Alcon received the first and only FDA approval for CustomCornea laser treatments using the LADARVision 4000 excimer laser programed with an advanced custom algorythm developed from the wavefront aberration information measured by LADARWave.
The laser features a number of innovations that are not available in the other excimer lasers previously approved such as:
Small spot scanning:
One of the problems of earlier technology broad beam lasers was the importance of a homogeneous beam profile. The excimer laser beam is inherently irregular (Gaussian) in its beam distribution, and much of the size of earlier technology lasers was allocated to optically smoothing the beam. Just as the laser ablates the surface of the cornea to reshape it, the optics of the laser slowly degrade as it is used, and require replacement at regular intervals. Broad beam lasers would magnify any inconsistency by placing the inconsistency in the same spot over and over again. With a small spot that scans over the eye, the original Gaussian distribution is able to be used to precisely reshape the eye. The laser does not require a cabinet to handle the optics of refining the beam, so there are fewer optics to degrade. This also allows the laser to be smaller and less claustrophobic to the patient.
Smoother and gentler to the eye:
The smaller spot is also gentler to the eye. With broad beam lasers, optical irregularities in the cornea called "central islands" were problematic. These were areas in the central portion of the optical zone that did not get treated adequately. There are a number of theories of central island formation. They range from the laser plume from the prior pulse of the laser blocking the central portion of the next pulse, to the buildup of fluid in the central portion due to the shock wave of the large pulse. Broad beam laser manufacturers have handled this problem by adding additional pulses to the center of the correction into their correction algorithm. Small spot scanning lasers do not place the spot near a prior pulse, avoiding the shadow of the plume, and the nature of the smaller spot does not allow fluid buildup centrally. There have been no reports of central island formation with the Autonomous LADARVision excimer laser.
Tracking of the patient's eye:
This technology was developed as a way of tracking satellites during the Reagan administration's space defense initiative. The active tracker of the laser will track the eye with laser radar 4000 times per second, and the scanning mirrors will adjust in order to place the laser beam in the correct position, even when the eye moves. No other FDA approved laser offers tracking capability. Most newer lasers that are undergoing the approval process are using some sort of tracker, however they usually use video image stabilization, passive trackers that track too slowly to accurately follow the eye, and can be turned off by the surgeon. The LADARTracker on the Autonomous LADARVision excimer laser is an active tracker that cannot be turned off, and will not allow treatment if it cannot track the eye. The LADARTracker is also the only "Closed loop" tracker in use for eye surgery. Because it is closed loop it has the lowest latency to get the lser in position after every eye movement. Closed loop tracking also allows a continuously tracked and captured image of the eye to appear frozen on the computer screen allowing the surgeon to register or exactly position the treatment on the surface of the cornea.
Expandable optical zone size:
Small or eccentrically placed optical zones relative to the patient's pupil size are the major cause of long term glare in dim light after laser vision correction surgery. Tracking accurately places the optical zone centrally, and the ability of the surgeon to enlarge the optical zone size when appropriate allow for better coverage of the cornea to minimize the potential for post operative glare.
In order to be able to use this laser, the patient's prescription must be in the approved range, and the pupil size must be large enough for the laser to track their eye. The future of this technology platform promises the ability to treat patients with irregularly shaped eyes, by using wavefront technology for improved corrections. This is the same technology that was used to design the lens that was used to correct the aberrations of the Hubbell space telescope.
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