Clearing Up Confusion in LASIK and Wavefront Terminology
Especially with Wavefront and related terminology, be careful about marketing terms, slogans, and marketing hype!
There is now a bewildering array of vision correction terminology in the public arena. Sadly, much of it is intentionally designed to confuse the consumer. This includes terms like CustomVue, WavePrint, WaveScan, Custom Treatment, and All-Laser LASIK (to name a few). All of these terms are marketing terms, trade names or slogans rather than simply descriptive terms. These terms were invented by the marketing departments of certain laser companies to promote their products, and they are regurgitated by certain surgeons and other personnel at various laser centers that use these machines.
The proliferation of bad terminology and intentionally deceptive marketing has created a large amount of dis-information and mis-information, confusing to any potential consumer of vision correction care. I will endeavor here to define terms, debunk myths, and help clafiry meaning. On this page I will differentiate between optical and descriptive terms by displaying them in Violet bold font, and by comparison will display trade names, slogans, product names and marketing terms in orange bold font.
A bit of history may be helpful here. The first vision-correcting lasers were designed in the mid 1980s, initially by Taunton Technologies which became Visx. The Visx laser was designed initially as (and still is) a broad-beam laser. Initial Visx lasers were manufactured without pupil trackers and were capable only of a very crude, simple optical corrections. In aggregate, these are referred to as conventional Visx treatments. These produced adequate correction for small pupils and daylight viewing, but created glare, halo and imperfect optics in large pupil cases and night vision viewing for a significant proportion of patients.
One of the problems with early lasers was the lack of pupil tracking. Lasers could not guarantee that the corrections they were designing would be accurately and optimally targeted to the tissue needing treatment. The first laser to introduce a good pupil tracking system was the Autonomous Technologies LADARVision laser. The term LADAR was a contraction of the description "Laser Radar." The LADARVision 4000 laser became relatively popular in the US market in the late 90's; this company was acquired by Alcon Laboratories in about 2001. Many other modern lasers now incorporate pupil tracking as an essential component of their design, including Visx, Wavelight, Bausch & Lomb/Technolas, Schwind and Meditec. One notable exception is Nidek; their EC-5000 laser (popular among deep-discount centers in the US) does not incorporate pupil tracking.
During the '80s and 90s, aerospace and defense contractors were building spy satellites and other very high-resolution imaging instruments (deep space telescopes, etc.). The science of aberrometry (measuring tiny optical imperfections called aberrations) was brought to bear in these imaging systems with great success, in order to eliminate blur, glare, flare, and ghosting; thereby increasing image clarity. In about the late 90's it was appreciated that attention to aberrometry would be important in human optics, and the correction thereof by lasers. Because the term 'aberrometry' was relatively intimidating to people outside the field of optical engineering, the more consumer-friendly term wavefront measurement became popular. The terms aberrometry and wavefront measurement are now used interchangeably but the precise distinction is that aberrometer instruments measure the wavefront properties of an optical system (either a telescope lens or the human visual system, for instance).
By the late 90s, Visx had grown to become the market leader globally and in the US. Rather than re-engineering a new laser from the ground up, a decision was made to institute a series of patches or post-fixes in the (already FDA-approved) existing laser platform. One after-market fix was to add a pupil tracker to the Visx laser. This used infra-red tracking technology and was not as fast, or accurate, as the LADARVision laser pupil tracker. Another post-fix was to introduce Variable Spot Scanning ("VSS") to ostensibly facilitate more delicate, more refined laser sculpting of target tissue. Each of these "upgrades" were brought to market and sold to user surgeons at steeply inflated prices, with big marketing campaigns.
Both Visx and LADARVision recognized that aberrometry-guided treatment might have benefit, and each separately developed their own proprietary wavefront measuring devices called aberrometers (or "wavefront sensors"). The LADAR instrument was trademarked and nicknamed the LADARWave. Visx created the marketing term WaveScan to describe it's aberrometer instrument and the term WavePrint to describe the individual wavefront measurements, respectively. Bausch & Lomb developed the term Zyoptix to describe their aberrometer system.
Importantly, there are no common standards that allow comparison of different aberrometer instruments one to another. This is a significant shortfall in my opinion, for which both professionals and manufacturers are to blame. There is no national testing laboratory (in any country, not just the U.S.) that can perform impartial, careful, accurate and unbiased engineering analysis of aberrometers or even vision correction lasers, for that matter. This keeps both surgeons and the public relatively in the dark about comparative benefits, advantages, etc. of one system over another.
Another company named Wavelight entered the US market in about 2003. This was a German company and in the opinion of many it designed a more advanced laser marketed in the US as the Wavelight Allegretto. This laser was designed as a small-spot laser with a Gaussian beam profile and an excellent pupil tracker. The Allegretto laser treats at a very rapid pulse rate of 200 per second; a slightly later version called the Eye-Q laser treats at a pulse rate of 400 per second. Wavelight has introduced its own marketing terms into the public arena including Perfect Pulse Techonlogy (which describes the accurate registration of laser pulses one to another.
Wavelight also introduced the concept of Wavefront-Optimized treatment, which means asphericity-neutral treatment. Asphericity (also known as spherical aberration) is one of the major forms of higher order aberration measured by aberrometers. Other lasers (Visx, LADAR, etc.) are not capable of rendering asphericity-neutral (wavefront-optimmized) treatment, so to achieve similar results they must recommend Custom or wavefront-guided treatments on their platforms. You may read more about Wavelight Allegretto Technology by linking to that section on our site.
Another arena where marketing terminology has run amok is in the arena of flap-making lasers. IntraLase was the first company to introduce a femtosecond laser capable of creating a LASIK flap. IntraLase built market share through very clever and sometimes guerilla marketing tactics, creating and then exploiting fear of mechanical blades. Surgeons using IntraLase technology introduced phrrases such as We use the laser, not the razor, All-Laser LASIK, and blade-free LASIK into their markets. Use of femtosecond laser technology adds significantly to per-procedure cost the way fees are structured and passed along in this industry; typically adding about $375 per eye in hard cost to the surgeon. This is passed through directly to the patient. I have had an opportunity to use the IntraLase laser in my practice and have found that it adds significantly to cost but does not add even marginally to accuracy or safety of outcomes. Therefore I do not push it or maintain that it is in any way desirable, recommended or necessary when counseling my patients.
This hodge-podge of technospeak and marketing terminology creates tremendous confusion for the prospective consumer, and even for many laser vision correction surgeons. It is difficult, if not impossible, for the intelligent consumer to ascertain "which is better" from all the multiplicity of claims, marketing phrases, suggestive language and appealing graphics employed by manufacturers and surgeons alike. That's marketing for you. I encourage you to do your best due diligence, become informed, ask good questions, and approach the process of selecting a vision correction specialist the same way you would approach any substantial major purchase. You know how to recognize sales speech when it comes from a used car salesman; try not to get swayed by similar forms of "persuasion speech" (as good as it sounds!) when it comes from someone wanting to sell you on their particular brand, and their technology complement, of laser treatment.