LVC is the most revolutionary, rapidly changing area in ophthalmology. Refractive surgeons worldwide have vowed to reach the goal of super vision-“20/10 by 2010,” and it may well become a reality in the near future. It is driven by innovations in LVC that will change the future of vision correction forever. One such innovation-wavefront technology-holds the most promise for “20/10 by 2010.” 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. Loworder 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 VISX, 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 aber rations 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 LVC.

To better understand wavefront technology, picture the surface of a pond, smooth and flat, undisturbed by 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 wavefrontguided 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 VISX 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 having 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.

Surgeon 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 training and in leading edge technology. Our commitment to you is that we will not take short cuts to save you a few dollars.

Diagnostic Technology:

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.

Lasers:

We use the Visx S4 laser and WaveScan, the most widely used laser in the country. Custom treatments with the VISX laser are possible with almost any prescription, giving unsurpassed results in vision and clarity

Intralase Blade-Free LASIK

Although the complication rate for LASIK is low, 1% or less, most complications are flap-related rather than laser-related. Flaps that are too thin, irregular, incomplete, contain a “button hole,” or contain a large area of loose or abraded epithelium may give suboptimal results or may cause the surgeon to abort the laser step completely. The precision of a flap created by a laser, rather than a microkeratome with a steel blade, may greatly reduce or even eliminate serious flap problems. The IntraLase Corporation of Irvine California received FDA approval for its femtosecond laser about three years ago, and is now the preferred method in our practice for making the flap in LASIK. The laser pulses, each lasting one quadrillionth of a second (femtosecond), are programmed to pass harmlessly through the surface of the cornea and create a flap of predetermined thickness. As with the standard mechanized microkeratome, a small hinge of tissue remains uncut, forming an area where the flap can be folded out of the way so that the excimer laser can reshape the cornea.

The entire IntraLase flap procedure takes less than thirty seconds, and with the use of standard anesthetic drops, is painless. There are several advantages to the IntraLase system. Flap thickness is generally more precise and predictable than with a microkeratome, where flap thickness can vary by 20ì to 30ì or more. Some patients with borderline cornea thickness may become eligible for IntraLase LASIK rather than PRK because the femtosecond laser can be programmed to make a thinner flap, leaving behind more residual corneal tissue.

With IntraLase, the likelihood of epithelial abrasion and incomplete flaps is greatly reduced, though not totally eliminated, because there is less friction on the cornea with IntraLase than with a microkeratome blade. Patients with surface cornea problems, such as basement membrane dystrophy, might become eligible for LASIK if the flap is made with a laser rather than a blade.

Another advantage of the IntraLase procedure is a more uniform flap thickness that may better fit into the cornea following laser ablation like a manhole cover into the street. IntraLase does not eliminate other flap problems, such as stria and folds.

There are several potential disadvantages of using the Femtasecond laser to create the LASIK flap. These include slightly more inflammation after surgery (readily treated with eye drops) and slightly more difficulty lifting the flap months or years later for an enhancement. Lifting an Intralase flap for an enhancement is also somewhat more difficult than lifting a flap made with a standard microkeratome. These disadvantages are minor compared to the potential increased safety of using a laser rather than a blade to make the flap.

Although there are advantages to the IntraLase, the long-term safety record of a standard micokeratome and its continued success for millions of patiets may justify its use by LASIK surgeons.