What are the pros and cons of the different lasers used to perform bladeless LASIK?
I've seen the following machines and technology for bladeless LASIK offered in Singapore: Intralase iFS 5th generation, Ziemer Femto LDV Z6 Excimer laser, Wavelight Ex500 excimer laser, Schwind Amaris 750s. It can be confusing as many of these are often advertised as the newest/latest technology, with a better safety profile, better results, more precision, faster etc. What are the advantages and disadvantages of the different technology used to perform bladeless LASIK? Can technology affect the outcome of bladeless LASIK? I am deciding which to go with.
Thanks for the question. This is indeed a common question, and one that I anticipated patients would be wondering as well when I perused the different websites offering Lasik.
The multiple machines you have mentioned previously perform one of 2 functions, namely:
a. Flap creation - this is the first step in femto-laser assisted LASIK.
This is performed by 1. Intralase iFS 5th generation, and 2. Ziemer Femto LDV Z6 Excimer laser,
b. Once the flap is created, the flap is lifted off the cornea-stromal bed, where the stromal ablation (or power-correction) is performed with an excimer laser. This is the second step in femto-laser assisted LASIK.
This is performed by 1. Wavelight Ex500 excimer laser, and 2. Schwind Amaris 750s.
These machines are all the current generation laser machines that offer fast, comfortable and accurate surgical outcomes with minimal side-effects (common to all Lasik procedures).
Suffice to say that if your surgeon is using any of these machines, then the differences in outcomes between machines is negligible and not statistically significant. In my practice, I have the privilege of using all of the above machines.
There are some minor anecdotal differences between the manner of performing the surgery including how the eye is stabilised for the procedure, and minor differences in patient visual experience on day 1.
However the overall visual outcome by 1 week, and certainly the long-term visual outcome and success of the procedure is almost identical.
I would say that if your choice of surgeon is using any of the above machines, then you don't have to worry about the technical aspects of your surgery.
You should however concentrate on choosing a surgeon that you are comfortable with, and you trust to help you perform your surgery, who you feel is able to help you identify and manage complications at an early stage.
Most importantly your surgeon should help you identify the correct procedure for yourself, as femto-assisted laser surgery is one of only several options available for spectacle-independent vision (the other include Epilasik, Smile / ReLEX and an implantable collamer lens).
Best of luck in your journey!
I agree with many of the points Dr Chan has mentioned.
Very simply, the doctor is more important than the machine in many ways. A good, experienced doctor will automatically use a good machine, and also be good at all the other non machine aspects of the procedure such as planning the treatment, the manual parts of the surgery as well as taking care of potential complications. It's also important that the doctor knows all the ins and outs of the machine (which ever he or she uses) so that he/she can troubleshoot any problems quickly as they arise, and make the most of the particular machine's capabilities.
Having said all that, there are differences between machines.
However, the biggest differences are between generations of machines, rather than within generations of machines. If you are into photography you could draw an analogy where there are more differences between a Nikon D4 and D5 than between say the D5 and a Canon 1Dx Mk II.
And I would consider all the machines you have mentioned to be of the same, current generation. Yes, each has their strengths and weaknesses, but in the right hands, the visual outcome for a particular patient is likely to be very similar regardless of the machine used.
Personally, I am most familiar with the iFS and the Schwind Amaris 750s, so perhaps I will just say a few things about these machines.
The iFS is a femtosecond laser (like the Ziemer) and is used to create LASIK flaps. Its strengths are flaps that are relatively easy to lift, and that tend to be larger rather than smaller. Owing to relatively stronger suction pressures, it is less likely that the dreaded 'suction loss' occurs, which may necessitate repeating the flap creation or converting to a surface ablation procedure. The iFS allows real time monitoring of flap creation, so that the procedure can be stopped at any time a problem is noticed. On the other hand, the strong suction pressures make it somewhat more likely that some patients may get 'subconjuntival haemorrhages' or little red spots on the eye after the procedure.
The Schwind Amaris' strengths are fast speed, topography or wavefront guided capabilities, as well as both static and dynamic cyclotorsion control. The latter allows more accurate astigmatic and wavefront corrections, and is a capability I particularly value.
As you can see, it all gets rather technical and complicated. It is likely that many people will still be rather confused with all the facts laid out in an answer here.
At the end of the day, find a doctor that you trust and that you are comfortable with. The doctor should be able to offer you a range of different surgical options, like LASIK vs epiLASIK/PRK vs ICL surgery, so that he/she can offer you something that suits you best. You can check what machines he or she uses, but I think as long as it is a current generation machine (like the ones you mentioned above), don't get too caught up in the marketing spiels.
As technology becomes more advanced, unfortunately it also means that machines can become outdated.
While fundamentally the surgeon plays the most important role in deciding which treatment option works best for the eye and the patient, scientifically speaking, the machine does make a difference.
Case in point: a research paper I co-authored years ago, based on very careful studies on real life patients in Singapore published in 2012 in a peer-reviewed scientific journal:
The study found that the Wavelight is better in predictability.
There are numerous other similar studies comparing other different LASIK lasers and the results that are published in respectable journals are usually referred to by doctors in the know.
Unfortunately it can get real confusing for the lay person with so many different lasers around.
In fact, the few laser names you quoted are in two groups: the first two are the femtolasers to create the LASIK flaps, and the last two are the excimer lasers to sculpt and change the focusing power of the cornea, all of which I am quite privileged to be familiar with and have used before.
There certainly are some subtle differences between them.
I would suggest if you find it interesting, take your time finding out more about the different lasers, and consulting a trusted, knowledgeable surgeon who may be able to explain more about his or her choice of recommended lasers versus others. After all, LASIK is an elective surgery, and as a patient, you do have a right to know.
Cheerio and all the best!
I am glad you have taken a keen interest on some of the various makes and models of lasers that are in use in LASIK practices today. To be sure, each laser platform does have its individual strengths and weaknesses. Different surgeons will favour different equipment much like how different musicians would have a preference for a specific make and type of musical instrument.
Suffice to say, the differences are quite technical. Any attempt to differentiate all of them would require a detailed article to fully explain. So rather than cause more confusion, I would instead encourage you to find the right surgeon rather than the machine. As with all things, it’s the operator not the machine that makes the most difference.
Find a well-qualified surgeon whom you trust, who has a great track record and who does not just sell you the idea that one treatment is better than all else. Rather, find a surgeon who would customise the treatment option to your eyes. Just as there is no such thing as a “best” treatment, there is no such thing as a "best" machine either.
I wish you every success in your journey towards spectacles independence.
Dr David Chan
Senior Consultant Eye Surgeon