Category Archives: In the News

LASIK vs LASIK vs LASIK

By Dr Rick Wolfe

LASIK was a breakthrough in laser eye surgery.  It was first performed by Dr Pallikaris in Crete in 1989.  I performed the first LASIK procedures in Melbourne in 1996.

It was an absolute game changer for laser eye surgeons from only having one option to offer our patients: ALSA (also known as PRK).    LASIK allowed us to offer another type of laser eye surgery and it provided patients with a much faster recovery.  That is not to say the modern version of ASLA is not a good procedure in some elected cases.  LASIK, however, if the patient is suitable, is far more convenient for the patient.

LASIK always involves the creation of a corneal flap.  This flap creation was first invented by Dr Barraquer in Colombia in 1962.  It was the combination of the flap and the excimer laser (used in ASLA) that made all the difference.

There are different types of LASIK available in Melbourne currently and we’ve received feedback from many patients that the various meanings and marketing tactics circulating in our industry about LASIK are difficult to decode.  There are claims of “Lasik without a flap”, “Flapless Lasik”, “No-Cut Lasik” being used. Let me be clear: there are no such medical procedures!  These terms refer to surface treatments (and using just one laser) such as ASLA (PRK) – not LASIK.  LASIK necessarily has a flap by definition and always involves the use of two lasers.

The word “LASIK”, always referred to in correct medical terms in capitals, stands for Laser In Situ Keratomileusis.  LASIK treats short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism, eliminating the need for glasses or contact lenses.  LASIK is the most commonly performed laser eye surgery procedure available today, with over 50 million cases performed worldwide.  The convenience of LASIK is the reason for its popularity.  LASIK provides a fast recovery, allowing patients to return to normal activities more quickly.

LASIK always involves the use of two lasers.  The first laser creates the corneal flap and the second laser (Excimer Laser) re-shapes the cornea and corrects vision.   LASIK can be divided into different types in two ways:

1st Laser: Bladeless vs Manual with a Blade

Bladeless

The most popular method to create the corneal flap performed today is blade-less – this is performed using a femtosecond laser (also known as Femto LASIK).

Manual with a blade

Another method, which is rarely used today, is the older method, where the flap is created using an ultra-sharp oscillating blade (also known as Microkeratome or Keratome LASIK).  At VISTAeyes, we do not perform Keratome LASIK, as this is an outdated method.

2nd Laser: Customised LASIK vs Non-Customised LASIK

It’s important to distinguish between the different types of LASIK (and indeed ALSA), by the pattern of treatment performed with the excimer laser: the laser that reshapes the cornea and corrects vision. The treatments can either be customised or non-customised.

Customisation refers not only to the various prescriptions different people have,  but rather a process by which corneal irregularities are dealt with. There irregularities are referred to as aberrations. Addressing aberrations is aimed at improving the quality of vision and preventing reduction in quality of vision, in addition to getting the prescription right.

Some clinics incorrectly refer to customised or personalised LASIK treatment based only on the prescription data collected.  This is not customised treatment, this is the Standard or Traditional LASIK, which does not address aberrations. Other clinics simply change the cornea just by what is in the patients’ glasses. This is not enough anymore.  VISTAeyes is the only clinic in Melbourne to offer Customised LASIK.

Diagram 1. LASIK explained – the different types of LASIK   

Types of Customised LASIK

Topography-Guided LASIK

This is customisation taken to the next level.  It is a personalised vision correction treatment, which uses a computerised device called a corneal topographer to measure a patient’s individual cornea, examining specific corneal irregularities (called aberrations) and calculating how to best improve their vision (in excess of simply correcting what is in the patients’ glasses).  It would appear to have better results in providing lower aberrations, accurate outcomes and improved quality of vision.  This procedure, sometimes called Contoura, is the main LASIK mode we use at VISTAeyes.  We have pioneered the procedure and I have presented on it several times in Australia and overseas.  Admittedly, it is more complex and costly for surgeons to perform topography-guided LASIK than the non-customised LASIK, but we believe the benefits, to those patients who are suitable, are worth it.

Wavefront-Guided LASIK (WFG)

We have been performing WFG for nearly 20 years now. It involves the use of a costly piece of equipment called an aberrometer. It not only accurately measures the prescription but also the aberrations. The complex treatment required is transferred to the excimer laser.

Custom Q LASIK

This is another type of customisation we use at our clinic. It especially targets one sort of aberration, known as spherical aberration.

 

Types of Non-Customised or Standard/Traditional LASIK

Wavefront-Optimised LASIK (WFO).

This is the non-customised form of LASIK.  It makes no attempt to address aberrations. As a result, they are usually increased. A recent study of WFO LASIK with the Schwind laser1 revealed an increase of 100% in aberrations. This can’t help the final quality of vision.  Most other clinics only offer the Non-Customised or Standard / Traditional LASIK because it is less time consuming and cheaper to administer than Customised LASIK.

There is another laser eye procedure called SMILE laser eye surgery.  We do not perform SMILE at VISTAeyes, as it cannot be customised, probably because precision is not adequate and certainly not as precise as an excimer laser used in LASIK.  SMILE is over a decade old and there have been little or no technological advances.

Diagram 2. LASIK Advances over Time

Taking into account all the laser eye technology available today, Custom LASIK shows the most promise as the way forward for achieving the best quality of vision.   It is by far the most advanced procedure available today including WFO LASIK, SMILE or “LASIK without a flap”.

For more information about Custom LASIK (Topography-Guided LASIK) read here:

What is Custom LASIK?

 

 

Exceeding Expectations in Refractive Surgery: CSO MS-39 AS-OCT – writes Dr Rick Wolfe

In a recent article titled “Exceeding Expectations in Refractive Surgery: CSO MS-39 AS-OCT”, published in the mivision journal, Dr Rick Wolfe writes about his clinical experience with this new technology at VISTAeyes Laser Eye Clinic.

Dr Wolfe adds: “In laser eye surgery we look at maps of the cornea for various reasons. The main one is to check the cornea is healthy. This new device (MS-39) uses different technology to give us so much more useful information than we’ve ever had before.

As well as being a very sensitive screening tool for dry eye, it employs artificial intelligence to warn us to avoid surgery on weaker corneas, which we might not have otherwise detected. Its unique ability to measure the epithelium or superficial skin of the cornea also provides us with safety information not obtainable with other standard devices.

The MS-39 allows us to approach all cases with increased confidence that we have not missed any underlying disease.”

Read article online: www.mivision.com.au/exceeding-expectations-in-refractive-surgery

DR RICK WOLFE, “EXCEEDING EXPECTATIONS IN REFRACTIVE SURGERY: CSO MS-39 AS-OCT”, MIVISION, ISSUE 157, P82-83, JUNE 2020

SMILE Laser Eye Surgery – What Does The Scientific Evidence Say?

Nearly a decade ago, we had to decide if we would make the investment in SMILE technology. We decided against it and I am pleased that we did. So much of the promise of SMILE has not eventuated.

After 10 years SMILE has been slow to grow in popularity. The technology has had no major upgrade.  The initial promise that SMILE would provide better visual outcomes, have shorter recovery time and be less invasive to the corneal integrity did not eventuate.

But what does the scientific evidence say?

One hears a lot of claims about vision correction procedures such as LASIK, SMILE and ASLA (or PRK) and it can be very confusing, even for eye surgeons.  There is a lot in the peer-reviewed literature and one can cherry-pick articles to conclude anything.

It is important, though, to look for high quality studies, examples of which are randomised studies. These are the gold standard in medical research.  Other powerful studies are meta analyses, which seek to evaluate all quality publications to come up with a conclusion.  In this article, I refer to these types of studies.

Does SMILE provide better visual outcomes?

A most important study1 randomly treated a group of patients with each patient having SMILE performed on one eye and topography-guided LASIK on the other eye.  The study clearly showed the LASIK eyes had better vision than the SMILE eyes in every visual parameter tested.

Another very recent  study was performed by Dr Ron Kruger, a pioneer in laser eye surgery, to test assertions by SMILE surgeons that SMILE had as good outcomes as LASIK. It took into account 120 publications2.  The study showed that visual outcomes for patients undergoing SMILE are worse than of those undergoing LASIK.”

Several problems with SMILE are possible explanations. Firstly, today’s topography guided LASIK takes a complex picture of the eye’s individual optics and seeks to improve what are called aberrations, in addition to how far out of focus the eye is.  SMILE (like the original LASIK of 20 years ago) is unable to address aberrations.

Secondly, there is no way for the surgeon, other than by eye, to center the SMILE procedure on the pupil of the patient or to rotationally orient the procedure for astigmatism control.  By comparison, the LASIK procedure is centered and put in the correct rotational position by computer registration of preoperative and intraoperative images. This precise registration is less haphazard.

After laser eye surgery, the reason why post-operative vision might be less than perfect is some residual astigmatism.  Residual astigmatism is not common in topography guided LASIK3, but is more of a problem for SMILE.  A review article (an article looking at multiple studies) of SMILE astigmatism outcomes4-9 concluded that SMILE astigmatism outcomes were “less favourable” than LASIK.

Thirdly, the current SMILE laser would seem not to have the axial accuracy for customization like the laser in LASIK does. Future SMILE models working at shorter wavelengths might well be able to get better results with smoother, more accurate lenticules. We await this sort of technology.

In fact, current SMILE technology was the subject of an opening address at a major conference in China recently10. Prof Theo Seiler, one of the pioneers and great minds in laser surgery, said of lenticule extraction (the “LE” in SMILE): “Lenticule extraction is the future of refractive surgery… just not with the current technology’. He alluded to newer technologies that could make a lenticule that was “not so rough”.

Does SMILE have shorter recovery time?

Sometimes SMILE might have rapid recovery like LASIK, but many patients take longer to achieve optimum results. This is a significant limitation. Some years ago a Melbourne clinic acquired a SMILE laser only to return it, citing slow recoveries as one of the problems.

Is SMILE less invasive?

The promise that SMILE would be less invasive to the strength of the cornea and prevent the rare but serious complication known as ectasia was shattered by several reports around 2015 of this potentially devastating complication11-16 of laser surgery.

At VISTAeyes we offer a wide range of vision correction procedures, including the latest customised and topography-guided LASIK.  I proudly stand by our ongoing investment in LASIK technologies and welcome the opportunity to discuss this with anyone interested in learning more about the advantages and disadvantages of the different laser eye procedures.

 

Learn more about LASIK here.

For more information on SMILE laser eye surgery read these related articles:

Laser eye surgery: to SMILE or not to SMILE? Top 10 things you need to know about SMILE.

SMILE laser eye surgery – No big grin

 

References:

  1. Kanellopoulos AJ Topography-Guided LASIK Versus Small Incision Lenticule Extraction (SMILE) for Myopia and Myopic Astigmatism: A Randomized, Prospective, Contralateral Eye Study J Refract Surg. 2017;33(5):306-312
  2. Kruger RR Evaluation of Small-Incision Lenticule Extraction and LASIK Efficacy: A Comprehensive Literature Review Analysis Presentation: American Society of Cataract and Refractive Surgery. May 4 2019 San Diego CA USA
  3. Own data
  4. Alio de Barro J, Vargas V, Al Shymali O, Alio J Small incision lenticule extraction (SMILE) in the correction of myopic astigmatism: outcomes and limitations – an update Eye and Vision (2017) 4:26
  5. Pedersen IB, Ivarsen A, Hjortdal J. Changes in Astigmatism, Densitometry, and Aberrations After SMILE for Low to High Myopic Astigmatism: A 12- Month Prospective Study. J Refract Surg. 2017;33:11–7.
  6. Chan TC, Ng AL, Cheng GP, Wang Z, Ye C, Woo VC, et al. Vector analysis of astigmatic correction after small-incision lenticule extraction and femtosecond-assisted LASIK for low to moderate myopic astigmatism. Br J Ophthalmol. 2016;100:553–9.
  7. Zhang J, Wang Y, Chen X. Comparison of Moderate- to High-Astigmatism Corrections Using WaveFront-Guided Laser In Situ Keratomileusis and Small- Incision Lenticule Extraction. Cornea. 2016;35:523–30.
  8. Ganesh S, Brar S, Pawar A. Results of Intraoperative Manual Cyclotorsion Compensation for Myopic Astigmatism in Patients Undergoing Small Incision Lenticule Extraction (SMILE). J Refract Surg. 2017;33:506–12.
  9. Qian Y, Huang J, Zhou X, Wang Y. Comparison of femtosecond laser small- incision lenticule extraction and laser-assisted subepithelial keratectomy
  10. Seiler T Opening Address International Refractive Surgery Symposium 26 May 2018 Shanghai China
  11. Sachdev G, Sachdev MS, Sachdev R, Gupta H. Unilateral corneal ectasia following small-incision lenticule extraction. J Cataract Refract Surg. 2015;41:2014-2018.
  12. Mastropasqua L. Bilateral ectasia after femtosecond laser-assist- ed small-incision lenticule extraction. J Cataract Refract Surg. 2015;41:1338-1339.
  13. Wang Y, Cui C, Li Z, et al. Corneal ectasia 6.5 months after small-incision lenticule extraction. J Cataract Refract Surg. 2015;41:1100-1106.
  14. El-Naggar MT. Bilateral ectasia after femtosecond laser-assisted small-incision lenticule extraction. J Cataract Refract Surg. 2015;41:884-888.
  15. Mattila JS, Holopainen JM. Bilateral ectasia after femtosecond laser-assisted small incision lenticule extraction (SMILE). J R fract Surg. 2016;32:497-500.
  16. Randleman B Editorial: Ectasia After Corneal Refractive Surgery: Nothing to SMILE About J Refract Surg. 2016;32

 

Dr Rick Wolfe presents on “Vision: Quantity and Quality”

This week, Dr Rick Wolfe presented at an Optometry Educational Evening titled “Vision: Quantity and Quality”.

Dr Wolfe explained that in cataract and refractive surgery the emphasis is now focussed more on the ‘quality’ of vision: better BCVA, lower higher-order aberrations and fewer photic phenomena – but not all laser treatments are created equal.  Dr Wolfe discussed the latest developments in topography-guided laser ablations and IOL technologies.

Thank you to all our guest optometrists for participating in this evening of interactive learning and discussion.

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Peninsula Eye Centre hosts “Clinical Update 2019”

On 30th July, the Peninsula Eye Centre hosted an educational evening titled “Clinical Update 2019” to local optometrists.  The CPD accredited event included presentations from ophthalmologists Dr Rick Wolfe, Dr Zelda Pick and Dr Elvis Ojaimi.

Presentations and discussions included:

Dr Rick Wolfe: Corneal Imaging – technology, interpretation and therapeutic applications

Dr Zelda Pick: Oculoplastic Cases – eyelid tumours and pathology

Dr Elvis Ojaimi: AMD – OCT and 2RT

Thank you to all our guest optometrists for participating in this evening of interactive learning and discussion.