I had this interesting question recently from Kevin:

Hi Doctor, Would you please advise if “zlasik” is still better and newer technology compared to “ilasik with iFS Advanced Femtosecond Laser”?  Thanks

Hi Kevin, I prefer the Ziemer system (Z-LASIK). We have the brand new Ziemer LDV Crystal Line system, currently the only one in the UK, and it is a remarkable flap creation tool. It has a 33 times faster repetition rate than the latest iFS 150KHz model, with energy per pulse far lower, tighter energy focus and the shortest suction-on time. We can do both eyes safely and very accurately in around 6 minutes.

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Here are the answers to one of today’s questions:

From Ian, who said:

A fantastic site, very informative.  A quick (but naive) question.  I am very excited about the prospect of having intra Lasik to correct a minus 5 prescription.  However, I have read some scare stories on US web sites which suggest that it is possible that the cornea can be irreparably damaged during the flap creation process.  How often have you seen this happen?

Thanks Ian. Correcting a -5.00D prescription is quite routine and should give you no problems. You mentioned IntraLASIK, which is a brand name when the Intralase femtosecond laser is used to create a Lasik flap. I don’t know whether you refer to femtosecond Lasik in general or you are looking at the Intralase machine for treatment. Manufacturers AMO now refer to iLasik rather than IntraLASIK. Other version are Z-LASIK when the Ziemer femtosecond laser is used, and Visumax and Femtec systems from other companies.

The femtosecond lasers have replaced the blade-cut keratome Lasik procedures in many clinics. One of the reasons to do this is to eliminate the possibility of a seriously damaged flap from a keratome, which I have seen happen (although it’s occurrence is rare). I have never seen this occur with a femtosecond laser and it is not possible to ‘mangle’ a flap with these technologies, so added safety.

For LASIK laser eye surgery safety, there are 3 things you must look for when you plan to go ahead. This LASIK safety trio means a more accurate result and the safest procedure we know of today:

1. Choose a blade-free all laser LASIK technique – using the latest femtosecond lasers means no blade is used in the surgery. Check with any clinic you talk to that they can offer blade-free LASIK – if they can’t then they are out of date and should be avoided.
2. Wavefront-based LASIK is a must today, so make sure you go for that option. For example, at FOCUS Laser Vision we only do wavefront treatments so that is taken care of. At other centres such as Optical Express, do not choose their non-wavefront option.
3. Get the safety and reassurance of NHS consultant corneal specialist surgeons to do your treatment – the three laser eye chains do not offer this for the great majority of their treatments. Premier centres like Moorfields Eye Hospital, Centre for Sight and FOCUS Laser Vision do.

WHENEVER a patient undergoes any type of surgical treatment there is a possibility for a complication. The main questions are: are these complications serious and could affect the final outcome – or minor and short lived and which do not affect the ultimate vision? Also, what are the chances of a complication occurring that would require adjustment or follow-up correction?

LASIK surgery is no different from any other operation, despite how it may be pitched by some clinics, in that it IS a surgical correction and should be approached as such. However, and fortunately, most complications are in fact minor and easily resolved.

Technology

LASIK risk continues to drop as doctors and engineers perfect the equipment used in the treatment. Advances in technology have made a big part of the difference here so make sure you are getting that latest equipment and not an older fashioned approach.

The risks drop as doctors continue to screen for the right candidates to have the procedure, and screen out those with any chance to have a problem. Research also shows that with the right pre-testing and surgical handling, the risk of complications in LASIK surgery is less than 1% and most of these are minor problems which will be fully corrected afterwards without undue ongoing problems.

The most common risk with LASIK surgery is a complication with the flap, created by the surgeon in the first part of the procedure.

In the original LASIK procedure, the flap is cut by a surgical blade device known as a microkeratome. The blade cut is, however, less precise than those from newer femtosecond lasers.

Blade Free LASIK

LASIK risk is reduced by the newer “bladeless” dual laser technique.

In bladeless (blade free) LASIK surgery, the risk of complications is lower because the blade or microkeratome is no longer used. It is replaced by special type of infra-red laser that greatly reduces human or machine error.

The original laser to make a LASIK flap came from the USA, manufactured by Intralase. You may see this surgery called IntraLASIK or iLASIK.

The newer machine is from Switzerland and produced by the Ziemer Group of companies. There appear to be some advantages of the tighter focus of the Swiss laser. This procedure may be called Z-LASIK.

Summary

When assessing these LASIK risks it is recommended that when you are considering surgery that you ask your doctor what technology the clinic has and whether or not a blade free dual laser approach will be used.

OK. lots of new laser eye surgery names appearing, so let’s confirm what they mean!

Z-LASIK: means blade free LASIK using the new Swiss Ziemer laser to make a corneal flap, rather than a traditional blade.

iLASIK: means blade free LASIK but using the American Intralase laser to make a corneal flap.

So, simple so far. Z for Ziemer’s laser and i for Intralase’s laser. Both of these devices allow elimination of a blade to make a physical cut in the cornea. Instead they use millions of precise laser pulses to create a very accurate flap, removing the potential risks associated with a metal-blade mechanical system.

Click here to watch an FDA animation of mechanical blade LASIK (N.B. Caution: watching this will put you off ever having bladed LASIK in the future! You will definitely want to opt for all laser LASIK after this!)

So what’s the difference between Ziemer and Intralase lasers?

The Ziemer laser is a new system, with potential advances upon the older American Intralase laser flap maker. Ziemer’s lasers, called the LDV, appears to eliminate occasional complications found with iLASIK. Some iLASIK patients (around 7%) get a marked discomfort and aversion to light for several days after laser vision correction, know as “transient light sensitivity”.

This side effect is not seen with Z-LASIK, possibly because of a much more tightly focused laser energy pulse and greatly reduced energy per pulse, compared to Intralase’s looser focus and wider dispersion of energy through the cornea.

Studies are ongoing to compare the two systems in greater detail.

Background on the LASIK procedure:

Creating the corneal flap is the first stage in a LASIK procedure. Treatment to correct your eyesight is actually done on the corneal tissue that’s below the surface and access to it is done by making a surface flap and folding it back (quite painlessly!).

This flap creation is critical for a successful result of your LASIK surgery – it needs to be of exactly the right thickness and in exactly the right place. When the surgery is completed, it’s easily folded back into position and acts as a delicate bandage over the treated eye. It heals up by itself.

The microkeratome devices used in traditional LASIK surgery are hand-held tools with a steel blade that oscillates, moving back and forth at very high speeds. When used expertly it makes a good flap but the thickness can vary more than laser flaps and they can be more irregular, tending to be thinner in the centre.

LASIK complications are quite rare. Fact. But when they do happen, they often arise from a poorly created corneal flap. Use of new femtosecond lasers (Ziemer or Intralase) greatly reduces the likelihood of any such complications.

I get asked about the so-called ‘femtosecond‘ lasers now being used in LASIK laser eye surgery, and what these devices do. OK, here are the answers.

First of all, LASIK eye surgery is a laser procedure with two parts. First we have to make a thin flap from the top part of the cornea, basically a thin hinged layer we can temporarily fold to the side (painlessly!).

Next we use an ‘excimer‘ laser to reshape the exposed cornea to correct the vision focusing problem. The laser will polish away certain areas, depending on your prescription, to bring back clear vision.

The flap is put back in place and heals over very quickly. The eye feels gritty or scratchy for about 3-4 hours only. OK, so far so good.

For the first stage, making a flap, we have used a mechanical device called a keratome (or microkeratome). Keratomes have been around for 50 years and use a blade to make a controlled cut. This stage is where significant complications can occur, so we have been looking for a way to make this corneal flap but without the need for a blade.

Along come femtosecond lasers.

The eye lasers use ultra-short infra-red low energy pulses to create microscopic bubbles at a precise depth below the surface of the cornea. If you do this millions of times, you can create a super precise separation as a sheet, and hence a near-perfect corneal flap, which you can now fold to the side ready for vision correction with a second laser.

The femtosecond laser means we no longer run risks from using a blade to cut a flap. This means safer LASIK eye surgery.

You can watch a video of femtosecond laser eye surgery here.

More on femtosecond lasers coming soon.

Definition for femtosecond:

(This definition follows U.S. usage in which a billion is a thousand million and a trillion is a 1 followed by 12 zeros.)

A femtosecond is one millionth of a nanosecond or 10^-15 of a second and is a measurement sometimes used in laser technology. So that’s one billionth of a millionth of a second! As a comparison, one femtosecond to a second is like one second to 32 million years.

For comparison, a millisecond (ms or msec) is one thousandth of a second and is commonly used in measuring the time to read to or write from a CD-ROM player.

A microsecond (µs) is one millionth (10^-6) of a second.

A nanosecond (ns or nsec) is one billionth (10^-9) of a second and is a common measurement of read or write access time to random access memory. A picosecond is one trillionth (10^-12) of a second, or one millionth of a microsecond. An attosecond is one quintillionth (10^-18) of a second and is a term used in photon research.

[tags] LASIK, femtosecond, laser eye surgery, safety, risks, compications [/tags]

 We have been using the Ziemer LDV for 3 weeks now with great results. Vision results and flap creation have been excellent and without any complications.

For eyes with pre-existing corneal scars there has always been a question mark over the ability of femtosecond lasers to create LASIK flaps as the scar tissue may prevent the laser from passing through the tissue. Intralase users report that they found an inability perform LASIK to treat eyes that have pre-existing moderate to dense corneal scars.

Unlike the Intralase (American made femtosecond eye laser), the Swiss-made LDV will pass through even fairly dense corneal scars without a problem. So far the LDV has created excellent flaps in these cases. I will keep you updated on our progress.

[tags] laser eye surgery, complications, femtosecond, flap, Intralase, LASIK, risks, safety, Z-LASIK, Ziemer [/tags]

The Daily Mail featured a half page article this week on the new Z LASIK surgery procedure that took place at FOCUS Laser Vision (www.focusclinics.com) on January 18th. Jenny Hope from the Mail wrote a great piece covering the new technology and the impact for Bella Roberts, the first UK patient to get rid of her glasses through Z LASIK surgery.

You can read the full article on LASIK eye surgery on the Daily Mail website

Z LASIK uses a brand new technology to create a corneal flap in the first part of the LASIK laser eye surgery procedure. The new system from Swiss company Ziemer uses a different principle to create much lower energy pulses at 20 times the speed of older technology lasers from Intralase in the US, commonly used in other UK clinics.

[tags] LASIK, London, laser eye surgery, Technology, femtosecond, new [/tags]

OK, it’s here at FOCUS Laser Vision in London. The video of our breakthrough next generation Z-LASIK laser eye surgery procedure! I can tell you the results have been amazing. Twelve treatments on our first day, and everyone can see better than 20/20, 60% of them seeing an incredible 20/12! (that’s two lines smaller than 20/20 on the vision test chart, clarity usually seen by teenagers, and approaching the finest limit of human vision) And that’s just 24 hours after treatment. Wow.

Enough talking, it’s time to watch the video. just keep rolling after the procedure to hear Bella talking the following morning about her ‘miracle’! As a surgeon, this is the best bit of the job.

Z LASIK at FOCUS in London starts from £595 per eye for short sight – FOCUS want to make this treatment affordable for everyone. You can reach the clinic on 0845 5000 500.

[flashvideo filename=http://www.youtube.com/watch?v=A61T5mFG730 /]

You can hear Bella Roberts talking with me just 24 hours after her breakthrough Z-LASIK laser eye treatment. You can read more about Z-LASIK in my previous posts, and compare to Bella talking about her LASIK just before having the surgery!

Why have Z-LASIK all-laser eye treatment? Why have FOCUS Laser Vision spent more than £300,000 on this next generation laser technology, when a mechanical bladed microkeratome is only(!) £30,000? The answer. Safety, accuracy and vision results.

Femtosecond lasers have been shown to be more accurate, safer and give better vision results for LASIK laser eye surgery. Many UK clinics have installed the Intralase femtosecond laser as up until now it has been the only game in town. That will change now the Ziemer LDV has arrived. So watch this space!

Z-LASIK laser eye treatment at FOCUS Laser Vision in London starts at £595 per eye.

[tags] femtosecond, Z-LASIK, Ziemer, FOCUS Laser Vision, Intralase, LASEK, laser eye surgery, LASIK, long sight, longsight, PRK, short sight, shortsight, surgeon, technology [/tags]

Z-LASIK laser eye treatment has arrived in London. The first procedure happened at FOCUS Laser Vision on Thursday January 17th 2008. Yours truly was the surgeon behind the wheel. I did 12 Z-LASIK treatments and by the next day every patient could see better than 20/20! It’s a pretty amazing technology.Bella Roberts was the first patient to see the difference (pun fully intended!). Bella is 33 and a mother of three. She was quite badly short sighted and has used glasses for most of her life. She had been pretty nervous about laser eye surgery, whether PRK or LASIK, but was convinced by the new Swiss technology and put herself forward as the first ever patient to get Z-LASIK in the UK.You can see Bella talking about her vision and how she feels, just 20 minutes before she gets the op!Z-LASIK uses a new laser to create the flap in the first part of the LASIK procedure, instead of a blade as in traditional LASIK. Getting rid of the blade eliminates many of the main risks from LASIK, when formerly the flap was cut with a fine blade.Treatments start from £595 per eye for all-laser blade free Z-LASIK.

[tags] femtosecond, Ziemer, Intralase, astigmatism, LASEK, laser eye surgery, LASIK, long sight, PRK, short sight [/tags]