Lasik is an elective surgical procedure designed to eliminate the need for glasses and contact lenses. In order to accomplish that goal, Lasik surgery involves two basic steps:
- Creating a very thin flap on the cornea surface
- Reshaping the cornea according to the patient’s refractive error
Over the past 25 years, significant improvements have been made in the surgical method and technology involved in Lasik surgery. The most advanced Lasik technique is the Wavefront Guided Bladeless Lasik technique used at Will Vision, used by both the US military warfighter program and NASA for astronauts visiting the International Space Station.
Creating a Lasik Flap
The human cornea is approximately the thickness of a credit card, so creating a flap that is thinner than a human hair on its surface requires precision surgical techniques. This process can be performed using the modern bladeless Lasik technique that employs a sophisticated femtosecond laser or the older microkeratome, a surgical device equipped with an oscillating metal blade that operates much like a power planer.
The two most advanced femtosecond lasers used today for bladeless Lasik are the iFS Advanced Femtosecond laser from Johnson and Johnson® and the VisuMax system from Carl Zeiss®. Both technologies utilize an infrared laser and complex software to create a corneal flap at a pre-programmed depth and position on the patient’s cornea. As a low-pressure soft suction ring holds the eye in proper position, the laser cleaves the corneal tissue at the predetermined depth using a process known as photodisruption that forms bubbles of water and carbon dioxide. These bubbles connect to create a smooth surface that will become the interface between the flap and the corneal bed. The laser energy neither alters corneal curvature nor affects the prescription and there is no significant damage or change to the surrounding tissue.
The pinpoint accuracy of the extremely small laser spot size and low laser energy used provides a very smooth surface. The iFS laser moves in a raster (back and forth) pattern starting at the hinge and then continuing back and forth across the cornea while the VisuMax moves in a circular pattern from the outside in. Finally, the laser cuts the edge of the flap, leaving the hinge area untouched. The whole process takes approximately 15 seconds per eye.
There are many, many advantages that bladeless Lasik has over the microkeratome. Specifically, with bladeless Lasik there is little to no possibility of causing a corneal abrasion, a thin flap, thick flap, a partial flap, an incorrect flap diameter or a buttonhole flap. No one has ever gone blind or needed a corneal transplant with a femtosecond laser Bladeless Lasik system. Furthermore, because the flap thickness is uniform from center to edge (like a manhole cover), there is less chance of flap slippage or wrinkling if accidentally rubbed or bumped during healing after surgery. Also, because the corneal flap can be programmed to be very large, very thin as well as have an oval shape, bladeless Lasik is ideal for far-sightedness, high amounts of nearsightedness, large pupils, moderate to high astigmatism and small corneal diameters where producing a large enough flap for treatment far into the periphery is critical. In addition, bladeless Lasik has the ability to create the thinnest flap possible to help maintain optimal corneal thickness when treating higher prescriptions or thinner corneas.
Bladeless Lasik has propelled Lasik eye surgery to a whole new level of safety and precision for our patients. As a result, at Will Vision and Laser Centers we are committed to using only bladeless Lasik for all of our patients.
In contrast, some Lasik centers continue to offer the older microkeratome or steel blade technique for performing Lasik surgery – often offered at a steep discount for marketing purposes (ie. :Lasik starting at $399) intended to bait consumers into calling them about their cheap Lasik. It is well documented that most of the risks and complications from Lasik arise from using a microkeratome in the creation of the flap.
Advantages of the iFS Advanced Femtosecond laser over the microkeratome:
- More accurate and more predictable visual results
- Significantly less “dry eye”
- Flap thickness and diameter is programmed on the computer and is very predictable
- Flap thickness can only vary 3-4 microns compared to 30-40 microns with the microkeratome
- Flap thickness is consistent across the flap diameter
- Flap diameter is very predictable
- Able to create very thin flaps that maintain superior structural integrity of the eye
- Thin flaps are particularly beneficial for patients with:
- Thin corneas preoperatively
- High degrees of correction
- Large pupil dilation at night
- Safer with fewer complications
- No significant epithelial injury or damage
- No free flaps
- No partial flaps
- No thin or thick flaps
- No buttonhole flaps
- No perforation of the eye
- Serious vision threatening complications not seen
- More comfortable for patients
- Low vacuum more comfortable
- No sound during procedure – less “surprise” effect
Correcting the Vision
Just as a high end camera requires a near perfect lens system for clear photos, clear vision is highly dependent upon the precise shape of the corneal surface. The leading edge technology enhancing our ability to perform that reshaping process more accurately than ever is called Custom Wavefront guided Lasik.
You’re familiar with the high quality of TV images obtainable using High Definition technology compared to standard TV systems. The program content is the same but the image clarity is worlds apart. That’s the type of difference that we can observe with Wavefront guidance compared to conventional Lasik surgery.
In the past, the laser was only capable of creating shapes on the cornea that were symmetrical, like farsightedness, nearsightedness, and astigmatism. These are the aberrations that are typically corrected by wearing glasses. However, once you factor out these simple optical distortions, there remain additional complex shapes in the optical system that keep your eyes from seeing perfectly. These complexities are called higher order aberrations and include such things as: coma, trefoil, tetrafoil, and spherical aberration to name just a few. These higher order aberrations, if not corrected during your Lasik procedure, can still leave you with imperfect optics and occasionally glare or halo side effects.
These higher order aberrations are completely unique to your eyes and can now be precisely measured using a wavefront measuring device that creates an optical “fingerprint” of your visual system. The newest wavefront analyzer known as the iDesign available at Will Vision and Laser Centers is considered to be nearly 50 times more accurate than measuring your vision with lenses, as has been the standard in the past.
Most importantly, this wavefront data can be sent to the excimer laser to create an extremely complex and accurate wavefront-guided treatment, effectively correcting ALL of the aberrations that are present in your visual system. This high-resolution, 3-D, custom wavefront treatment allows us to provide you with your optimal best personal vision that often exceeds that of glasses, contacts, and older Lasik surgery. Wavefront guidance also provides a higher quality of vision, consistently superior night vision, and measurably reduces the chance for needing a laser enhancement compared to older conventional non-Wavefront guided treatments. By analogy, it is like comparing high definition TV to standard TV – Wavefront guidance delivers superior clarity and superior quality.
There are other methods available for reshaping the cornea. These include wavefront optimized, topography guided and traditional spherocylindrical lens based treatment algorithms. Unfortunately, none of these methods provide the quality of vision delivered by wavefront guided excimer treatments.
Why would any patient knowingly choose to have a non-Wavefront guided treatment when Wavefront is scientifically proven to be superior? Or, why would a surgeon even offer a procedure that they know is inferior, less precise and has more side effects? Those are questions you just might just want to ask other laser centers when you are weighing their medical ethics and professionalism.
At Will Vision, by using the combination of advanced Bladeless Lasik technology and wavefront guided customization with the iDesign wavefront aberrometer, we only offer the best, safest, and most accurate leading edge technology for your optimal visual outcome. Customized Wavefront guided Bladeless Lasik — Better Technology, Better Results, Better Vision.