The latest major advance in the LASIK procedure came with the introduction of wavefront technology to the field of refractive surgery. Studies indicate that wavefront-guided LASIK produces visual outcomes superior to conventional LASIK. To understand how wavefront technology works, we first need to know that there are actually two categories of visual irregularities: lower-order aberrations and higher-order aberrations. The differences are easiest to understand if we think of lower-order as being responsible for how much we see, while higher-order determines how well we see. Traditional LASIK is limited to correcting lower-order irregularities, commonly called refractive errors. These include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism, and account for over 80% of optical errors.
Custom LASIK: Wavefront Technology:
Higher-order aberrations are irregularities other than refractive errors which can cause problems such as glare, halos, and shadows. For example, while two different people may be able to read the same 20/20 line on the eye chart, one may see the letters more distinctly, with better contrast and clarity, due to fewer higher-order aberrations. Wavefront technology works by accounting for these higher order abberations. Because the laser treatment patterns are more refined than those used in traditional LASIK, there is a greater chance for achieving 20/20 vision or better. Wavefront LASIK also may limit the chances of reduced contrast sensitivity and night vision problems, including glare and halos.
The Arizona Eye Laser Center now offers the Alcon WaveLight Allegretto® Wave Eye-Q laser, the most advanced excimer laser available in the United States today. Only two practices in Tucson use this technology, which combines the best refractive outcomes with the shortest treatment times. The WaveLight Allegretto laser can perform a number of different types of wavefront-optimized corrections, with the specific program chosen based on the needs of each individual patient. The laser is capable of treating the greatest range of refractive error of any laser approved for use in the U.S. by the FDA, from -12 diopters to +6 dipoters of sphere (nearsightedness or farsightedness), and up to 6 diopters of cylinder (astigmatism). Laser pulses can be delivered up to 200 times per second, leading to treatment times of 5 to 15 seconds for most patients.