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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Gill asked this question about laser eye surgery for varifocal and reading glasses:

Dear Mr Allamby, I was told last year by my optician I would benefit from varifocal lenses, which I hate. My prescription was:
R: Plano (zero) /-2.75 x 180
L: Plano (zero) /-1.25 x 175
Near Add: +1.50D
I am 51 years old. I had a consultation for corrective surgery and told I only need right eye done. Is this correct and how much would this be likely to cost at Focus? Thank you, (brilliant and most helpful blog by the way)
Gill

Hi Gill, You have myopic (short-sighted) astigmatism, with mild astigmatism in the left eye and a moderately higher amount in the right. Additionally, at age 51 you also have presbyopia, which is an age related loss of near vision (itself a form of long-sight). So you have three eye conditions together – myopia, astigmatism and presbyopia, which all need correcting (!) if you want to be pretty independent of glasses. However, correction is certainly possible.

I specialise in correcting these kind of prescriptions, over the last 7-8 years, and have done thousands of cases. I would need to assess which is the dominant eye and correct that eye fully. However, contrary to what the other clinic said, leaving astigmatism in the eye which is to read rarely is successful. So with your prescription I almost always treat both eyes. Of course, everything depends on what we find at the consultation, but this will give you a strong idea of what you likely need.

I charge just under £4,000 for both eyes for wavefront Ziemer Z-LASIK. If you want me personally to do your initial consultation rather than one of my team, add £200. The blended vision presbyopia treatments will be increasing soon, likely to £4,400 for both eyes.

Hope that helps explain somewhat Gill. If you post on the comments below, your reply will also come to me.

I was recently asked by Kaz to explain the Z-LASIK procedure in more detail. Watch this video and in a second post I will run through why I consider Z-LASIK combined with the WaveLight excimer laser to be the ultimate in LASIK laser eye surgery.

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.

Let’s look at the second of Carlo’s questions on laser eye surgery:

My name is Carlo and I have recently discovered this great blog. I would like to ask a couple of questions regarding eye surgery:
Question: Is it true that the LASIK procedure has not been approved for air-force pilots and astronauts in the US but PRK and LASEK has?

No, this is not true.

LASIK was approved for use on consumers a decade ago and reportedly more than 11 million LASIK procedures have been performed in the US. This means LASIK laser eye surgery is the most-common American elective surgical procedure.

NASA has approved LASIK for use on pilots, mission and payload specialists who face extreme and often physically demanding conditions in space. The all-laser LASIK technologies, using a blade free femtosecond laser approach, have also been cleared for U.S. military personnel, including most recently Air Force pilots.

“NASA’s approval is further evidence that today’s LASIK exceeds all established standards of safety and effectiveness,” said Steven Schallhorn, M.D., retired captain of the U.S. Navy.

Though LASIK has been around for a long time, concerns about the harsh environment in aviation prevented its use. To date, aero-medical professionals have been cautious of employing the procedure on military pilots who often encounter environmental extremes such as high altitude, dry air, wind exposure and “G” forces. In space, other conditions further add even higher levels of concern due to the very high level of precision needed during flight and space walks.

Defense Department’s research into laser vision correction included the following results:

# In a study of different methods to create the LASIK flap, 370 naval personnel underwent bilateral (both eyes) wavefront-guided LASIK with either the femtosecond laser (blade free) or microkeratome blade. One week after surgery more than 76 percent of femtosecond laser patients achieved an uncorrected visual acuity of at least 20/16 (better than 20/20) compared to only 58 percent of microkeratome patients

# In an evaluation of 785 pilots, 89% of Navy aviators evaluated their ability to land on an aircraft carrier as moderately to significantly better after laser eye surgery. None said it was worse after treatment

# A separate study determined that over 90 percent of marksmen had improvement in marksmanship skills after laser eye surgery; an impressive finding given the visual precision of marksmen

LASIK, particularly blade free femtosecond LASIK, appears to have established itself as a very effective and reliable procedure. The move from blade to laser blade free has allowed another significant improvement in results (now targeting better than 20/20 as a standard of care) according to the above research findings.

Advanced Medical Optics Inc. in Santa Ana, announced on Wednesday that the Food and Drug Administration (FDA) has approved a new laser for use in laser eye correction. The iFS femtosecond laser is set to be at the centre of AMO’s iLasik products for laser vision surgery. The laser has an increased speed of 150kHz, up from the existing 60kHz.

However, competitor Ziemer from Switzerland recently launched its own femtosecond laser offering more than 1000kHz speed, integral to its Z-LASIK offering. Click here for a discussion blog post comparing iLASIK and Z-LASIK.

AMO has pushed into laser vision correction, including its $800 million buy of Irvine, California-based IntraLase Corporation last year. The iFS laser uses technology from IntraLase. The femtosecond laser is used to create a corneal flap which is the first step in laser vision surgery. Advanced Medical’s lasers have been gaining market share over traditional metal blades. The laser is due to be shipped to U.S. laser eye surgeons in the third quarter, according to Advanced Medical Optics.

Tags: Z-LASIK, iLASIK, AMO, FDA, femtosecond, eye, laser, surgery

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.

Since we introduced the Z-LASIK blade free LASIK laser eye surgery procedure into the UK in January 2008, more than 90% of our patients have opted to go dual laser (no blade) for their vision correction.

The LASIK procedure has two parts – the first is the preparation of a thin flap followed by the second stage of vision correction itself. Traditionally, a bladed device has been used to cut this flap and gave some people pause about going ahead with the surgery.

Laser blade free flap makers were introduced in 2002 by the Intralase Corporation in the US. A next generation system was released in 2007 by Swiss ZIemer Group.

The added level of safety offered by eliminating the need for a physical blade cut has proved to be very popular for patients at FOCUS Laser Vision, with 9 out of every 10 people choosing to have Z-LASIK (blade free Ziemer technology). The additional cost of Z-LASIK leaves 1 in 10 people going with the traditional blade version, M-LASIK.

The high cost of femtosecond lasers means somewhat higher LASIK prices, usually around £300 per eye higher than bladed LASIK. The reason is that the blade systems cost around £30,000 per machine compared to £200-250,000 for a femtosecond laser.

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]

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]

The UK’s first Ziemer LDV [tag]femtosecond[/tag] laser has just arrived in the country and the first procedure will be carried out pretty soon. So watch this blog space!

If you are not familiar, femtosecond lasers are used for performing the first stage of [tag]LASIK[/tag] [tag]laser eye surgery[/tag]. (LASIK simply comes in two parts – first create a thin top layer of the cornea which can be folded to the side and secondly applying the treating laser to reshape the cornea to get rid of the need for glasses. See this weeks posting on LASIK Video – the Basics).

Traditionally, and still in many clinics, this has been done with a mechanical blade device called a ‘microkeratome’. Micro because, well, the blade is pretty small, about a centimetre or so across. ‘Kera’ means the cornea and ‘tome’ refers to cutting. These devices have been around for decades. The blade oscillates to and fro at very high speeds to make a precision cut. Modern microkeratomes are very reliable but can still occasionally cause problems and tend to cut deeper and with significantly less accuracy than the new femtosecond flap makers. So many clinics have invested in the new technology – it means safer and more accurate LASIK.

So when you read about All-Laser LASIK, Blade Free LASIK or IntraLASIK, they are talking about using these new lasers (called femtosecond lasers) to create the flap in the first part of the LASIK procedure. The Ziemer LDV femtosecond laser is a next generation machine that looks to outperform all current femto lasers (there are 3 models around) because it works in a different way. Much more on this coming soon!

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