Laser vision correction (LVC) is the most revolutionary, rapidly changing area in ophthalmology. First approved for clinical use in 2002, wavefront technology involves measuring the optical imperfections of the eye and then guiding the excimer laser to correct them. Used for many years to measure the quality of optical lenses in astronomy, wavefront technology is now available for use in LVC.
All human eyes suffer from optical aberrations or distortions. Low order aberrations are the familiar sphere and cylinder of myopia, hyperopia, and astigmatism, measured through refraction and denoted by diopters on your prescription. Higher-order aberrations such as trefoil, coma, and other similarly unfamiliar terms cannot be measured with a standard refraction. Instead, they are measured with a complex, computerized instrument called an aberrometer. The aberrometer measures the total amount of aberrations in the eye, including the familiar refraction, and transforms this complex data into a wavefront map. To generate a wavefront map (called a WaveScan by AMO, the laser model I use), the aberrometer sends an infrared wave of light into the eye and analyzes the wave of light that is reflected. The more aberrations in the eye, usually in the cornea and lens, the more irregular the reflected wave of light will be. In a wavefront-guided LVC, aberrometer findings (the WaveScan), are transferred to a hard drive, and then loaded into the excimer laser. The laser ablation pattern to improve your vision is derived from the total set of aberrations in the WaveScan, including the refraction used in standard laser vision correction.
To better understand wavefront technology, picture the surface of a pond, smooth and flat, undisturbed by the wind. This is analogous to the ideal optical system, without any aberrations. If wind blows across the surface of the pond, or if a pebble is tossed into the water, the surface of the pond is disrupted by ripples. These surface ripples are aberrations. In general terms, the flatter and smoother your wavefront, the better your vision will be. Although no one has a perfectly flat wavefront or a perfect optical system without aberration, most people have mainly second-order aberrations (myopia, hyperopia, and astigmatism), easily correctable by glasses or contact lenses. A wavefront guided ablation that can correct the remaining third-order and higher aberration promises unsurpassed vision.
As of this writing, four excimer laser systems have been approved by the Food and Drug Administration (FDA) for wavefront-guided laser treatments. Alcon Pharmaceutical’s LADAR Wave Customized Ablation System received approval in October 2002, the AMO CustomVue System in May 2003, Bausch & Lomb’s Zyoptix System in October 2003, and Allegretto’s wavefront-guided WaveLight in August 2006. Results have been excellent, most patients have achieved 20/20 or better vision. Customized treatments are now approved for almost all levels of refractive errors, but as more studies are completed and more data becomes available, the range of approved treatments will be expanded.
Your Surgeon’s experience combined with the latest advances in laser vision technology are the two most important elements that determine how you will see after laser vision correction. At Eastside Eye Associates, we invest heavily in training and in leading-edge technology. Our commitment to you is that we will not take shortcuts to save you a few dollars.
State-of-the-art diagnostic equipment is important because it’s used to determine whether you are a candidate for laser vision correction, and if so, which procedure is most appropriate for you. It’s also used to calculate the customized settings for the laser for your particular treatment.
We use the Visx S4 laser and WaveScan, the most widely used laser in the country. Custom treatments with the AMO laser are possible with almost any prescription, giving unsurpassed results in vision and clarity.