In order for the Lasik process to be automated, it is necessary to gather information about the patient’s visual system. This is necessary so that the laser is able to make the appropriate cuts on the cornea so that the procedure is customized to the patient’s requirements. Wavefront technology is currently the best method for obtaining this information.
Wavefront technology has bee available for quite some time, but it has only recently been used to assist in the Lasik eye surgery procedure. Wavefront has been used for several years by astronomers to adjust the optics in their telescopes. When the reflecting mirror inside the telescope becomes deformed, astronomers have used Wavefront to adjust the mirrors. The data would be used to remove aberrations.
Wavefront technology is a system that is able to provide a measurement of the refraction at multiple points on the eye as light is reflected upon it. This creates a unique “map” of sorts, which is like a fingerprint of the patient’s eye because it is unique to the individual. Certain conditions within the cornea affect the refraction of light on the eye. Some of these are considered higher-order aberrations. These aberrations are usually associated with irregular astigmatism. The ability to correct the aberrations can result in a better result after Lasik surgery has been performed. The possibility of achieving 20/20 vision, or better is increased with the use of Wavefront technology.
Wavefront technology has also been able to reduce the likelihood of losing the best-corrected vision as well as visual quality and having difficulty with night vision. Clinical trials have shown that almost 80% of Lasik eye surgery patients undergoing custom surgery achieved 20/20 vision. There is a higher number of people who are reporting higher quality vision after having Lasik and Wavefront rather than traditional Lasik surgery. Wavefront is also used to help determine whether patients are ideal candidates for Lasik. In some conditions, Lasik can actually make visual problems worse. Wavefront can help prevent this from occurring.
Traditional eye exams can detect two corneal abnormalities, including cylindrical and spherical. A cylindrical abnormality is usually the cause of astigmatism. A spherical abnormality results in myopia and hyperopia, or near sightedness and farsightedness.
Wavefront technology can also detect an infinite number of the abnormalities. It does this by using a fixation target along with an input laser beam. The laser beam then generates a light source, which is a Wavefront sensor that is used to measure the slope of the Wavefront. The software then determines the characteristics of the eye.
The fixation target is used to help the patient maintain the proper view while the software measures the eye. As the patient fixates on the target, the laser beam is shined into the eye. The light is reflected off of the retina and back through the pupil. The Wavefront of the light leaves the pupil and is then relayed into the Wavefront sensor. The refractive properties of the human eye distort the Wavefront. The laser beam that enters the eye is flat. In theory, this Wavefront of a perfect eye would remain flat and then reflect back. In actuality, the beam of light travels through a crystalline lens that is imperfect. The light then travels through the irregular cornea of the eye and various other parts of the eye. The combination of the light and laser causes the Wavefront to be irregular, which then results in data that helps to determine the shape of the cornea. This information is then evaluated and the aberrations of the eye are diagnosed. The information is then used as a prescription for reshaping the cornea.
There are three Wavefront manufacturers in the United States. These go by the names:
• CustomVue (Visx 4S Laser)
• CustomCornea (Alcon LADARVision Laser)
• Zyoptix (Bausch & Lomb Technolas 217z Laser)
Each laser has the ability to create a map of the cornea and a customized prescription.
This technology is an advanced method of creating precise prescriptions for Lasik eye surgery patients.