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Wavefront Laser Eye Surgery: Personalized Laser Surgery

One of the recent breakthrough in laser refractive surgery technology is the development of wavefront laser eye surgery. 

It is a technology that enables surgeons to provide laser eye surgery customized to your unique vision correction requirements. 

What is Wavefront Technology?

Did you know that wavefront technology has its roots in astronomy? 

It was developed in the 1900s by an astrophysicist, Johannes Hartmann. It was a method to measure irregular light refraction of mirror and lenses.

Dr. Roland Shack and Dr. Ben Platt then further applied the wavefront theory to create the an optical instrument called Hartmann-Shack sensor in the 1970s.  

Many notable wavefront researchers like Dr, Josef Bille, Dr. Liang Junzhong and Dr. David Williams then refined the technology to apply it in ophthalmology.

Major manufacturers like VISX, Alcon and Bausch & Lomb saw the business opportunities (KA-CHING!) provided by the technology and began designing wavefront analyzers to be incorporated in their laser systems to be used for vision correction. 

In 2002, the LADARVISION 4000 EXCIMER LASER SYSTEM by Alcon Laboratory became the first wavefront-guided custom LASIK application approved by the FDA. 

Since then, 11 more wavefront-guided systems for LASIK applications have been approved by the FDA (as of Jan 2017).

As you will notice, the FDA approvals for wavefront seems to be applied only for applications in LASIK. 

However, surgeons have also made use of the wavefront technology to customize other laser refractive surgery procedures like PRK and LASEK. 

If you are curious, you can access this FDA link to read on the market approval for all the lasers approved for PRK and other refractive surgery.

Interestingly, all these lasers were approved before 2002. 

In the US, lasers for LASIK applications are considered as Class III medical devices, which meant that to gain FDA approval, manufacturers of the device must provide sufficient evidence to assure that the devices are safe and effective for their intended uses. 

Technically, the technology behind wavefront guided laser is the same. There are surgeons that offer wavefront guided PRK. It’s your call whether or not to go ahead. 

Curious to know if wavefront guided lasers for PRK application exist, I wrote to FDA and got a reply from them days later. 

And this was what they said in their reply,

“I apologize for the delay in getting a response to you.  I needed to speak to my colleagues and learned that currently no lasers are approved in the U.S. market for wavefront-guided PRK.”

So now you know, the wavelength guided PRK procedures in the US are not FDA approved. 

What is Wavefront Laser Eye Surgery?

Wavefront laser eye surgery is the application of the wavefront technique in laser eye surgery to customize treatment needs.

Wavefront technology in laser eye surgery is basically used to create a 3-D map of the aberrations on the eye. 

The word aberration refers to irregularity/abnormality. We have vision issues due to the aberrations of our eyes.

To understand how wavefront technology works, imagine light waves being projected into the eye. 

And because what goes in must come out, the light waves that went in are bounced back from the retina through the pupil. 

This pattern of bouncing light waves is then mapped to create a wavefront map. 

A perfect wavefront map would be completely flat. Which is technically impossible, by the way.

Just so you know, everyone’s wavefront map is unique, just like thumbprints. 

This unique information from the wavefront map is then keyed into the computer system that controls the excimer laser which is used in laser eye surgery. 

This enables the surgeon to perform laser eye surgery that is customized to your unique vision needs. Based on that information, he can have a better grasp on where and how much tissue to remove.

Wavefront LASIK vs Wavefront PRK

Wavefront LASIK

Wavefront PRK

So now that we know what wavefront is, you may be wondering, “Mmm.. wavefront LASIK or wavefront PRK?”

Let’s look at some of the clinical data thus far.

A review paper done in 2011 to compare the effectiveness of wavefront LASIK and PRK concluded that wavefront LASIK outperformed PRK in myopia correction one month postop, but no significant differences were detected between the two procedures by the third month.

This meant that with time, the outcomes of both wavefront LASIK and PRK are not much different from each other. 

This was supported by another paper that looked at one year postoperative outcomes of both wavefront LASIK and wavefront PRK, indicating no significant difference either.

Hence, it may be safe to assume that even if you are not a candidate for wavefront LASIK, wavefront PRK should also produce equally favorable outcomes in successful procedures.

Typical Costs of Wavefront Laser Eye Surgery

In general worldwide, if you want to customize your laser eye surgery with wavefront technology, it will cost at least a few hundred dollars more. 

For example, in the UK, the average cost of standard LASIK per eye is about £1500, whereas Wavefront LASIK can cost about £1900 per eye.

It can certainly cost more, depending on a variety of factors, such as surgeon’s skill/reputation, as well as location of centre. You may like to read here for more information on average costs of laser eye surgery.

Advantages of Wavefront Laser Eye Surgery

One important technical term you will need to know, which is what gives wavefront system the advantage is “aberration”.

According to UCLA Stein Eye Institute, there are two category of aberrations of the eye - lower order aberrations (LOAs) and higher order aberrations (HOAs).

The degree of your visual acuity (both quality and quantity) is dependent on your LOAs and HOAs. Which in layman terms, means LOAs and HOAs affects how well and how far you can see clearly.

LOAs include the degree of refractive errors (near or farsightednessastigmatism) present in the eye.

These are irregularities of the eye that can be corrected with eye wear instruments like glasses or contact lenses.

Correcting Both LOA and HOA

 Standard LASIK can only measure and correct for LOAs. 

On the other hand, HOAs are irregularities of the eyes that CANNOT be corrected with eye wear instruments. One such HOA that is of notable importance, and present in many people, is spherical aberration. 

Spherical aberration is linked with poor night vision (e.g. Halos, shadows, night glare, etc.) and poor contrast sensitivity (difficult to distinguish shades of darker color).

Within wavefront technology for laser eye surgery, there are two types of treatment - Wavefront guided (WFG) and Wavefront optimized (WFO).

WFG have been found to be effective in treating spherical aberrations. The difference between WFG and WFO is that WFO takes a step further by minimizing the amount of corneal tissue removed, while treating for spherical aberrations.

In general, the beauty of wavefront technology lies in that it can address not only your LOAs, it can also correct for your HOAs. 

This may mean that the risks of developing post LASIK complications like poor night vision and poor contrast sensitivity can be reduced.

Furthermore, because wavefront technology allows surgeons an opportunity to measure HOAs, this also meant that vision issues previously undetected by conventional laser eye surgery procedures can now be treated.

This means that your vision quality may improve as compared to preoperative standards, and you may have increased potential in achieving 20/20 vision or better. 

Higher Satisfaction And Lower Retreatment Rate

A 2016 research paper evaluating the effectiveness of Wavefront guided LASIK for myopia correction and patient satisfaction rates found the technology to be effective and predictable for myopia correction with high patient satisfaction rates.

Another paper that compared effectiveness of wavefront guided laser eye surgeries and conventional laser eye surgeries found the former to produce the best postoperative outcomes. 

In addition, as compared to conventional LASIK, the need for enhancement postoperatively are lesser in wavefront guided LASIK. 

According to Steinert and colleagues (2013), the retreatment rate for conventional laser ranged from 5.5% to 36% (depending on a myriad of reasons) while they reported another study that found that retreatment rate using wavefront optimized LASIK and PRK treatments were only 6.3%. 

It means that if you choose wavefront instead of conventional LASIK, your probability of having to return for enhancements is lesser, saving you from much agony, time and money.

That being said, wavefront laser eye surgery IS a surgical procedure and does carry risks.

Do discuss with your surgeon about the potential risks and complications and get an accurate evaluation for your suitability.

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