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Innovations in Refractive IOL & Laser Technology 5 September 2010
Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
Contents
Advances in Refractive IOLs and Laser Technology Improve Outcomes and Safety
2
Theo Seiler MD, PhD
Global Cataract and Presbyopia Market Huge and Growing Fast
3
Thomas Kohnen MD, PhD, FEBO
AcrySof® IQ Toric IOL adds Asphericity to Astigmatism Correction Improving Vision
4
Francesco Carones MD
AcrySof® IQ ReSTOR® Multifocal Toric IOL: The New Frontier of Cataract/Refractive Technology
5
Thomas Kohnen MD, PhD, FEBO
My Personal Experience with the AcrySof® IQ ReSTOR® Multifocal Toric IOL
6
Francesco Carones MD
Speed and Precision Part 1: The WaveLight® EX500 Excimer Laser
8
Arthur Cummings MB ChB MMed(Ophth) FCS(SA) FRCSEd
Speed and Precision Part 2: The WaveLight® FS200 Femtosecond Laser
10
A John Kanellopoulos MD
Speed and Precision Part 3: Outcomes and Outlook for the WaveLight® Refractive Suite
12
Matthias Maus MD
1
Innovations in Refractive IOL & Laser Technology 5 September 2010
Advances in Refractive IOLs and Laser Technology Improve Outcomes and Safety Theo Seiler
T
hanks to 25 years of continuous technical innovation in both intraocular lens and laser vision correction technology, the fields of cataract and refractive surgery are truly merging, says Theo Seiler MD, PhD, Institute for Refractive and Ophthalmic Surgery and professor at the University of Zurich, Switzerland. Ophthalmic surgeons now have a range of lenticular and ablative options to treat cataracts, presbyopia and corneal astigmatism that can be combined and tailored to individual patient needs. The results are ever-improving visual outcomes, higher patient and surgeon satisfaction, and greater safety, he says. “Today we are a big family which consists of cataract and refractive surgeons, and we are mutually learning from each other and mutually benefiting from each other. It is just part of living together in the cataract and refractive world,” Professor Seiler adds. Advances in multifocal, aspheric and toric IOLs have made cataract surgery a truly refractive procedure, with most surgeons now incorporating one or more of these technologies into their daily routine. In particular the Alcon AcrySof® IQ ReSTOR® Multifocal Toric IOL, which received the CE mark this year, makes it possible to treat cataract and presbyopia, and minimize residual astigmatism in patients with up to 2.32 D of corneal cylinder in a single surgical procedure. With the proven rotational stability of the AcrySof® IQ Toric IOL, this lens potentially can reduce astigmatism and improve visual outcomes for the majority of cataract patients without the need for less-predictable limbal relaxing incisions or a separate laser touch-up. For cataract patients with astigmatism beyond the range treatable with toric lenses alone, a combined multifocal procedure with a planned laser enhancement can improve outcomes. Since the advent of femtosecond laser technology, Professor Seiler has routinely cut a flap before implanting a multifocal lens, then lifting the flap a month later to correct residual astigmatism. “There is still a niche for this approach,” he says. On the purely refractive side, advances in both lenses and lasers also have expanded the range of patients who can safely be treated, Professor Seiler notes. The WaveLight® EX500 Excimer Laser’s advanced ablative profiles can
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WaveLight® FS200 Femtosecond Laser
treat up to -14.0 D sphere and -6.0 D cylinder, at speeds of up to 1.4 seconds per dioptre. Combined with precise lamellar flaps cut with the new WaveLight® FS200 Femtosecond Laser, the WaveLight® Refractive Suite in my practice produces visual outcomes as good as, or better than, any existing LASIK system. Complementing the treatment of myopia, the AcrySof® CACHETTM angle-supported phakic lens has been shown to be a safe refractive alternative through clinical trials. “I had given up on anterior chamber lenses 10 years ago, but in the last year I went back and I now implant the CACHET IOL,” Professor Seiler says. Reliable phakic lenses combined with the precision of the WaveLight® EX500 Excimer and FS200 Femtosecond lasers also make it possible to safely treat patients with thin corneas not suitable for LASIK. “We can do a surface ablation or sub-Bowman’s keratomileusis to get rid of corneal irregularities,” Professor Seiler says. The greater speed and flexibility possible with the WaveLight® FS200 Femtosecond laser also
improves corneal procedures, Professor Seiler says. “It helps for DSAEK and it is wonderful to have a machine to make a top hat keratoplasty upside down that needs just eight sutures. It cuts the surgery time down from 45 minutes to 30 minutes. It is a very useful tool for the cornea.” Femtosecond cataract applications are next, Professor Seiler notes. “People are talking about doing capsulorhexis, and maybe replacing phaco by damaging the nucleus that takes so much time to remove.” Most importantly, these lens and laser innovations enable surgeons to do the best for patients in terms of better visual outcomes and quality of vision, while reducing the risk of complications, Professor Seiler says. “We can offer a much safer procedure for our patients and for ourselves. And we can all sleep better after it all.” Theo Seiler MD, PhD info@iroc.ch
Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
Global Cataract and Presbyopia Market Huge and Growing Fast Multifocal, aspheric and toric IOLs are popular; multifocal aspheric toric is next step
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y 2020, there will be about one billion people in the world over age 60, or about 230 million more people than there are today, according to United Nations population estimates. Of those, clinical studies suggest that 40 percent over age 70 and 65 percent over age 75 are likely to have cataracts(1), says Professor Dr. Thomas Kohnen MD, PhD, FEBO of Goethe University, Frankfurt, Germany. “There is an increase of cataracts worldwide coming in the near future.” Most of those cataractous eyes also have astigmatism, Professor Kohnen adds. In a 2009 study of 4,540 eyes, 87 percent had some degree of astigmatism before cataract surgery, with 64 percent between 0.2 and 1.25 D cylinder, and 22 percent at 1.5 D or more(2). “We also know that five or six percent have higher than 2 D of astigmatism,” Professor Kohnen notes. Presbyopia is even more widespread and often undertreated. The number of patients with presbyopia worldwide is projected to rise to 1.4 billion by 2020 and 1.8 billion by 2050. That’s up from about 1.0 billion in 2005, of whom about half had no spectacles or inadequate spectacles, and 40 percent were prevented from performing near tasks(3), Professor Kohnen adds.
Combining cataract and refractive treatments These population statistics add up to a huge unmet need for treatment solutions that combine cataract, astigmatism and presbyopia correction, Professor Kohnen says. “At the moment cataract procedures are trending toward refractive/cataract technology. There is a need, I think, for surgeons to expand their refractive offerings to meet the growing patient demand.” This shift toward combined cataract/refractive technology is reflected in the rapid growth of the global market for advanced technology IOLs, which Professor Kohnen says includes multifocal and toric lenses. In 2009, global unit volume of advanced technology lenses reached about 700,000 and is expected to top one million by 2011, according to the ophthalmic industry research firm Market Scope LLC, St Louis, US. Market Scope projects global volume to exceed two million by 2015.
Thomas Kohnen
As of 2009, the Alcon AcrySof® Toric IOL was far and away the most preferred in both Europe and the US, Professor Kohnen notes. According to the annual surveys conducted by David Leaming MD, 73 percent of ESCRS members and 98 percent of ASCRS members preferred the AcrySof® Toric over its toric rivals (4). “This is due to the FDA situation in the US. In Europe we have other options, but the vast majority of toric lenses are the AcrySof®,” Professor Kohnen says. The aspheric AcrySof® IQ Toric IOL, which received the CE mark this year, is gaining popularity due to its reduced higher order aberrations, which potentially increase contrast sensitivity. Similarly, ALCON® IQ ReSTOR® multifocal lenses enjoy an overwhelming lead in both markets, with 54 percent of ESCRS and 58 percent of ASCRS members naming the ReSTOR® IOL as their preferred lens for presbyopia correction, according to the 2009 Leaming surveys. “Today the AcrySof® Toric and IQ ReSTOR® aspheric +3.0 D multifocal are the leading cataract/refractive technologies,” Professor Kohnen notes. So what is the new frontier? “The multifocal toric lens, of course,” Professor Kohnen says. The AcrySof® IQ ReSTOR® Multifocal Toric combines multifocality, asphericity and toricity to provide a single-surgery solution for cataract, presbyopia and astigmatism, addressing a burgeoning worldwide need and increased patient demand. (1) Acosta R, Hoffmeister L, Román R, Comas M, Castilla M, Castells X. Systematic review of population-based studies of the prevalence of cataracts. Arch Soc Esp Oftalmol. 2006 Sep;81(9):509-16. (2) Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, González-Méijome JM, Cerviño A. Prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg. 2009 Jan;35(1):70-5 (3) Holden BA, Fricke TR, Ho SM, Wong R, Schlenther G, Cronjé S, Burnett A, Papas E, Naidoo KS, Frick KD. Global vision impairment due to uncorrected presbyopia. Arch Ophthalmol. 2008 Dec;126(12):1731-9. (4) Leaming D. 2009 ESCRS survey, 2009 ASCRS survey. 2010 www.analeyz.com. Thomas Kohnen MD, PhD, FEBO Kohnen@em.uni-frankfurt.de
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Innovations in Refractive IOL & Laser Technology 5 September 2010
AcrySof® IQ Toric IOL: The Best Solution for Treating Astigmatism at the Time of Cataract Surgery Offsetting corneal spherical aberration increases spectacle independence and low-light vision
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mong the new cataract/refractive technologies available in Europe is the AcrySof® IQ Toric IOL. The lens adds an aspheric profile similar to that which has improved quality of vision on other AcrySof® IQ monofocal and ReSTOR® Multifocal lenses to ® the AcrySof Toric IOL, which has proven its long-term stability in correcting astigmatism in thousands of patients since its launch in 2006. “This lens takes the trusted AcrySof® Toric platform for precise astigmatism correction and adds the enhanced image quality of an aspheric lens,” says Francesco Carones MD, cofounder and medical director, Carones Eye Center, Milan, Italy. “The benefit of the AcrySof® IQ Toric IOL is that it combines the advantages of toricity and asphericity to treat both cataract and astigmatism at the time of surgery.” The AcrySof® IQ Toric IOL is currently available in cylinder powers ranging from 1.50 D to 6.0 D at the IOL plane. At the corneal plane, this translates into a correction range from 0.75 D to 4.00+ D, Dr. Carones notes. “This range includes more than 95 percent of eyes with astigmatism of more than 0.75 D.”(See figure below)
Reduced residual astigmatism The AcrySof® IQ Toric IOL has proven highly effective in reducing residual refractive cylinder compared with standard monofocal spherical lenses, Dr. Carones notes. In Alcon trials comparing more than 200 toric lens implants with more than 200 controls, 87 percent of the toric lens group had less than 1.0 D residual astigmatism and 63 percent less than 0.5 D. Among controls, only half achieved less than 1.0 D and less than 20 percent less than 0.5 D. Similarly, 94 percent of the toric group achieved 20/40 or better uncorrected distance vision compared with 76 percent of controls(1).
Francesco Carones
In these tests, 60 percent of toric eyes achieved distance spectacle independence compared with 38 percent for controls. The result is improved quality of life and patient satisfaction. “Obviously having patients closer to plano not only in sphere but also astigmatism results in a higher percentage of patients being spectacle-independent for distance vision,” Dr. Carones says. Dr. Carones finds the rotational stability of the one-piece AcrySof® IQ Toric IOL platform one of its most attractive features. Six months after implantation, rotation averaged less than 4.0 degrees, with 81 percent less than 5.0 degrees off the intended axis and 97 percent less than 10 degrees off. Maintaining the orientation of the lens axis is essential to maintaining the cylinder correction, and the AcrySof® single-piece IOL design has been shown to be more rotationally stable than some plate or multi-piece lenses.
Reduced spherical aberrations Asphericity further improves quality of vision with the AcrySof® IQ Toric IOL, Dr. Carones points out. With a spherical lens, rays from the margin are over-refracted, coming to focus in front of rays passing through the lens paraxially. This leads to blurring on the retina and measureable loss of contrast sensitivity. The aspheric lens is designed to correct this problem. Its negative spherical aberration aligns light rays to compensate for the positive spherical aberration of the cornea. “With the aspheric lens it is possible to focus all the rays together and enhance quality of vision for the patient, particularly at night time,” Dr. Carones says. Compared with 73 patients implanted with spherical lenses, 73 patients implanted with aspheric AcrySof® IQ IOLs showed less than 0.3 microns spherical aberration and less than 0.75 microns total higher order aberration compared with 0.6 microns spherical and more than 1.1 microns total for spherical lenses at 90 and 120 days after the second eye implant. Contrast sensitivity at six cycles per degree under mesopic conditions was also significantly in the aspheric group both with and without glare. “Correcting some, but not all, spherical aberration results in vision similar to a young, natural crystalline lens. The average spherical aberration in the human eye is 0.28 microns for populations with normal vision. With the AcrySof® IQ it is possible to correct 0.2 microns, leaving a residual 0.08 microns as a final outcome,” Dr. Carones says. The result is better visual outcomes for patients, Dr. Carones adds. “The AcrySof® IQ Toric IOL offers cataract surgery patients with astigmatism reduction in residual refractive cylinder, improved uncorrected distance visual acuity and increased spectacle independence. The aspheric design provides improved functional vision in challenging, low-visibility environments. This allows patients to more quickly detect and identify objects and allows for greater reaction time, which may increase patient safety, for instance in night driving.” (1) Based on unilateral clinical study results with AcrySof® (Models SA60T3, SA60T4, SA60T5). See package insert. Compared with AcrySof® Single-Piece IOL (SA60AT).
Francesco Carones MD fcarones@carones.com
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Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
AcrySof® IQ ReSTOR® Multifocal Toric IOL: The New Frontier of Cataract/Refractive Technology Combining proven multifocal, toric platforms treats presbyopia and astigmatism in one procedure
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ith cataract, corneal astigmatism, corneal spherical aberrations and presbyopia typically presenting together, the ideal solution would be a single procedure that addresses them all, says Professor Dr. Thomas Kohnen MD, PhD, of Goethe University, Frankfurt, Germany. For many patients, the AcrySof® IQ ReSTOR® Toric IOL provides this solution. Essentially the new lens combines a posterior toric lens surface identical with the AcrySof® Toric IOLs with an anterior aspheric multifocal lens surface identical with the AcrySof® IQ ReSTOR® +3.0 IOL. Because the AcrySof® IQ ReSTOR® Toric IOL builds on proven ALCON® AcrySof® platforms, it is relatively easy for surgeons to incorporate it into their armamentaria. “The design is well-known to all of us,” Professor Kohnen says. The lens’ nine apodized diffractive steps for +3.0 add power and balanced light management while its negative 0.1 micron spherical aberration corrects for the positive spherical aberration of the typical older cornea. “It has nine diffractive apodized steps like the current +3 add compared with 12 for the previous +4.” At the same time, the toric posterior surface, on which the axis is marked as with existing AcrySof® Toric IOL models, allows the lens to correct pre-existing corneal astigmatism.
Full range of vision at all pupil sizes The +3.0 apodized diffractive design delivers several advantages over refractive and earlier diffractive designs, Professor Kohnen says. Because it is diffractive, the lens projects near and distance images at all pupil sizes, unlike refractive lenses which switch from one power to the other as the pupil dilates. Near vision is retained under mesopic conditions and for tasks such as night driving. However, while the amount of light directed to near vision remains nearly constant from a 3mm to 6mm pupil size, the proportion of light energy directed to distance vision increases with pupil size, improving distance vision in mesopic conditions and reducing glare and haloes. This is accomplished by precisely varying the height of the nine steps within the lens’ 3.6mm apodised region from 1.3 microns to 0.2 microns, which progressively shifts the energy transfer to distance and more of the lens is uncovered, Professor Kohnen explains. The width between the steps controls the add power, Professor Kohnen notes. The +3.0 demonstrates two focal peaks at distance and
Thomas Kohnen
31 percent and 21 percent for the non-toric multifocal lens(3). The defocus curve for the IQ ReSTOR® Multifocal Toric IOL is also very similar to the IQ ReSTOR® +3.0, with distinct peaks above 20/20 at distance and near 20/20 between 40cm and 50cm, with a low of about 20/30 at intermediate range. The IQ ReSTOR® Toric IOL is currently available in T2 to T5 models, with cylinder power measured at the IOL plane ranging from 1.00 to 3.00, Professor Kohnen notes. This translates into slightly less cylinder power at the corneal plane, resulting in a recommended corneal astigmatism correction range from 0.50 D to 2.32 D. This range covers about three-quarters of cataract patients with significant pre-existing astigmatism.
Online calculator simplifies lens selection
AcrySof® IQ ReSTOR® Toric IOL
at about 40cm, compared with 33cm for the +4.0 (1). However, the lower add and fewer steps have improved the lens’ intermediate range performance, leading to improved visual performance overall. Indeed, six months post-op, 78 percent of 138 patients implanted with the AcrySof® IQ ReSTOR® +3.0 IOL never needed glasses, while 20 percent used them sometimes and only two percent always. Overall patient satisfaction without glasses jumped from 0.5 on a scale of 4.0 to 3.25 after implantation. Similarly, self-reported vision quality without glasses rose from 4.2 on a scale of 10.0 to 8.5 six months after implanting the AcrySof® IQ ReSTOR® +3.0 IOL, according to a 2009 multicentre study by Stephen Lane MD and colleagues. That study also found patient trouble with glare down from 2.8 on a scale for 4.0 to 1.0 after surgery, and problems with haloes down from 4.8 on a scale of 7.0 to 2.8. The findings were all statistically significant at p<0.0001(2). Optical tests of the AcrySof® IQ ReSTOR® Multifocal Toric IOL indicate that its performance will be just as good. In modulation transfer function tests of the IQ ReSTOR® Multifocal Toric IOL compared with the IQ ReSTOR® +3.0 D IOL non-toric model, mean distance MTF values at 3mm and 5mm apertures were 34 percent and 25 percent for the toric, very similar to the
To select the proper lens and orientation, Alcon provides an online calculator similar to those available for its monofocal toric and multifocal lenses. Entering flat and steep K values and their axes along with cylinder power, a value for surgically induced astigmatism and incision location generates an output summary that includes an appropriate IOL model number, the spherical equivalent lens power, optimal axis location for the IOL, and anticipated residual astigmatism. “It is all done in a single calculation,” Professor Kohnen notes. “The AcrySof® IQ ReSTOR® Toric IOL has been designed to deliver true performance at all distances for patients with astigmatism. It allows a single surgical procedure for presbyopia correction and corneal astigmatism management. We don’t have to add other technologies such as limbal relaxing incisions or laser corrections for these patients in the future,” Professor Kohnen says. (1) AcrySof® IQ ReSTOR® IOL clinical data on file (models SN6AD1 and SN6AD3). Fort Worth, TX: Alcon Laboratories, Inc. (2) Lane S, Javitt J, Nethery D, Waycaster C. Improvements in patient-reported outcomes and visual acuity after bilateral implantation of AcrySof® IQ ReSTOR® +3.0 intraocular lenses: a multicentre clinical trial. Accepted for publication in JCRS 5/20/2010. Exact Publication date TBD. (3) Schwiegerling J. Image Quality Analysis for an Aspheric Toric Apodized Diffractive Intraocular Lens Using Modulation Transfer Function Testing. Invest Ophthalmol Vis Sci, 2010, 50, E-Abstract # 5727.
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Innovations in Refractive IOL & Laser Technology 5 September 2010
My Personal Experience with the AcrySof® IQ ReSTOR® Multifocal Toric IOL First bilateral implant leads to spectacle independence for an active 49-year-old professional
Francesco Carones
Corneal topography showed regular corneal astigmatism in a classic bow-tie. Using the online calculator, Dr. Carones determined the lens power and axis, as well as a target residual astigmatism of about 0.3 D at 90 degrees. The calculator also provides a printable graphic showing the correct orientation of the lens. “It is very helpful to bring into the operating theatre for memorising the correct location of the axis in terms of rotation,” Dr. Carones says. As he does with a monofocal toric lens, Dr. Carones marked the patient’s horizontal axis at the slit lamp before surgery. He uses a gauge in surgery to orient the axis relative to the horizontal axis rather than marking the axis itself.
Standard surgical technique
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oward the end of June 2010, Francesco Carones MD, cofounder and medical director, Carones Eye Center, Milan, Italy, implanted the first AcrySof® IQ ReSTOR® Toric IOLs in a patient. The results exceeded both the patient’s and his expectations. The patient was a 49-year-old female architect and interior designer with a very active lifestyle. “She plays tennis, does night driving and obviously has a significant amount of work to be done. This patient was pretty challenging, as most of multifocal patients are because they are very demanding,” Dr. Carones says. The patient’s left eye had a grade 2 cataract with induced myopia of -4.0 D with -1.0 D cylinder at 175 degrees, leaving her with 20/32 best corrected vision. “Basically it was a subcapsular cataract due to abuse of corticosteroids as a nasal spray,” Dr. Carones says. In her right eye, vision was -1.0 D with -1.25 D cylinder corrected to 20/20, but the patient complained of vision problems, especially in night driving. “This is why the patient decided and I decided to go through with surgery for both eyes,” Dr. Carones says.
Having implanted thousands of one-piece monofocal, multifocal and toric AcrySof® IOLs over the years, inserting the lens in the injector and delivering it into the eye was routine. “The IOL goes very easily through 2.0mm incision. It is pretty much the same as the ReSTOR® or the Toric, so in terms of the surgery there was really nothing new,” Dr. Carones says. As he does with the non-multifocal AcrySof® Toric IOL, Dr. Carones had a second instrument inserted before injecting the lens so he could immediately align it roughly with the desired axis with protective viscoelastic still in place. Then he removed the viscoelastic from the anterior chamber and from behind the lens so that it settles into position. “If you are accurate in grossly aligning the lens, you can easily finely adjust it,” he says. In this case, he was able to position the lens precisely on axis using an irrigating cannula, as he often does.
“What I really like about this IOL is the possibility that a single surgical procedure can correct presbyopia as well as preexisting astigmatism and gives patients full spectacle independence” Near-plano outcome The outcome was excellent from the start with the patient able to read a newspaper while still on the operating table. Within a week she was back at work, able to read text, her phone, and her computer. She was able to play tennis and drive at night, and reported no drop off in intermediate vision as might be expected given the lens’ defocus curve, Dr. Carones says. “We were accurate in terms of biometry, so the patient ended up very close to plano,” Dr. Carones says. Her right eye ended up -0.25 D sphere with -0.37 D cylinder at 90 degrees, and the left at +0.13 D sphere with -0.31 D astigmatism at 95 degrees – almost precisely the target outcome generated by the online calculator. Uncorrected visual acuity measures 20/15 in each eye and binocularly.
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Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
“The patient is extremely pleased. She feels she made the right choice in terms of spectacle independence,” Dr. Carones says. “What I really like about this IOL is the possibility that a single surgical procedure can correct presbyopia as well as preexisting astigmatism and gives patients full spectacle independence,” Dr. Carones adds. “As far as I can comment on very early results, the patient feedback is extremely pleasing. The AcrySof® IQ ReSTOR® Multifocal Toric, which is designed to deliver true performance at all distances, really gave me that result. I really believe that combined with the femtosecond laser, all of us will greatly reduce residual astigmatism and reduce the need for additional surgical procedures like LRI or laser fine tuning.”
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Innovations in Refractive IOL & Laser Technology 5 September 2010
Speed and Precision Part 1: The WaveLight® EX500 Excimer Laser As part of the WaveLight® Refractive Suite, innovations are designed to improve safety, outcomes and patient flow
Arthur Cummings
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hen it comes to refractive surgery, speed counts. And the WaveLight® Refractive Suite is the world’s fastest laser refractive platform, says Arthur Cummings MB ChB MMed(Ophth) FCS(SA) FRCSEd, of Wellington Eye Clinic, Dublin, Ireland. Not only does the suite include the new WaveLight® EX500 Excimer Laser and WaveLight® FS200 Femtosecond Laser, which, at 500 Hz and 200 kHz, offer the fastest treatment times in their respective classes, it also links the two lasers via the WaveNetTM network, allowing them to share data with each other as well as WaveLight® diagnostic devices and medical records. This saves time reentering data and improves safety by avoiding transcription errors. The two lasers also are linked mechanically by a single bed that swivels between them at an angle of 30 or 45 degrees. This swivel set-up reduces the system’s footprint while increasing patient comfort and decreasing throughput time. It also has changed the way Dr. Cummings operates. “The swivel bed is key to the way the procedure runs. It is very smooth, very controlled. In fact it is so good, I thought I would do flap-flap, LASIKLASIK, but I don’t. I do flap-LASIK, flap-LASIK, and it is a smooth, controlled procedure,” Dr. Cummings says. There’s no time wasted waiting for bubbles to dissipate under the flap or moving the patient from table to table. The speed of the WaveLight® EX500 Excimer Laser is especially helpful, Dr. Cummings adds. “It’s very fast. At a 6mm optical zone it is doing a dioptre in approximately 1.4 seconds. Sometimes speed is dismissed, but speed is very important to good quality vision. Speed and precision go hand in hand.” A fast ablation helps minimise the effects of dehydration, which can change the ablation rate – and refractive profile – as the stroma dries out after the flap is lifted, or cause flap shrinkage, which can lead to healing difficulties, Dr. Cummings explains. A quick ablation time also cuts down on patient fatigue and the risk of ablation errors due to the patient losing fixation. “It’s very handy having speed like that.”
Precision and safety But speed requires control, which the WaveLight® EX500 Excimer Laser delivers, Dr. Cummings notes. “One of the issues you can have with a laser this quick is thermal effects. This is avoided by the way the profile is designed. No spots overlap until five have passed so you don’t get a thermal effect.” The laser also compensates for energy loss due to spots obliquely at the periphery of the ablation zone, preserving the integrity of the intended ablation profile. At 1050 Hz and a latency time of two milliseconds, the WaveLight® EX500 Excimer Laser also has one of the fastest eye trackers on the market – with an advanced ability to track and compensate for eye movements, Dr. Cummings says. In addition to tracking vertical and horizontal eye movements, the system compensates for the shift in corneal location away from the pupil centre that occurs when the eyes roll and dynamically tracks the pupil from 1.5mm to 8.0mm and corrects for centroid shift, keeping spots on target regardless of pupil size. It supports both line-of-sight and corneal vertex centration. The system also compensates for cyclotorsion, though with the NeuroTrack feature carried over from previous WaveLight® models that limit cyclotorsion this is seldom a problem, Dr. Cummings adds. “It is a wonderful eye tracker that doesn’t have much to do.” If the eye moves outside a predetermined zone, the ablation automatically stops. This is an important safety feature.
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WaveLight® EX500 Excimer Laser
Another safety feature is automatic non-contact pachymetry. This enables the surgeon to monitor corneal thickness before, during and after ablation. One can measure flap thickness without touching the cornea.
Surgeon-friendly design Information on the procedure, including the patient’s name, refraction and progress appear on a heads-up display integrated into the WaveLight® EX500 Excimer Laser’s high-quality microscope. “You can see what you are doing at all times right in the optic of the microscope,” Dr. Cummings notes. The system also includes a fibre optic slit projector with an LED light source for examining the eye during the procedure. “This is very valuable. We don’t often take patients back into the theatre to remove debris under the flap,” Dr. Cummings says. Other features that make the system easier for surgeons to work with include an increased working distance from the laser head to the eye of 25cm, and high resolution video, he adds. The WaveLight® EX500 Excimer Laser is also engineered for reduced maintenance and improved energy output consistency, which contribute to more-consistent results, Dr. Cummings points out. The internal laser beam path is completely nitrogen-flushed, and is checked at three points from generator to laser head for maximum beam control and safety. “What’s new is there isn’t a cylinder to provide nitrogen, but an onboard nitrogen generator. We expect this will produce a longer laser head life.”
“It’s got advanced ergonomic design and the network makes it more of a pleasure to use for the patient, the staff and the doctor”
Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
The computer-integrated network, WaveNetTM, also makes life easier – and saves money, Dr. Cummings says. “One thing I’m excited about, and my staff are even more excited about, is you now have the potential to enter data once, date of birth, name, address, and everything all devices becomes populated. Whether it lands first on your EMR or a device, it populates throughout the entire network.” This feature is also clinically useful, Dr. Cummings says. Data from diagnostic devices are automatically fed to the EX500, where an ablation profile is calculated. This information is fed to the WaveLight® FS200 Femtosecond laser, where it can be superimposed on the cornea to adjust the flap profile to fit the ablation.
WaveLight® Refractive Suite
Advanced ablation capabilities All of the capabilities of previous WaveLight® excimer lasers are carried over, Dr. Cummings points out. The system maintains a very wide range of treatment parameters, from -14.0 D myopia to +6.0 hyperopia, and up to 6.0 D cylinder. In addition to the Wavefront Optimized® treatment that is suitable for perhaps 90 percent of patients, the EX500 also accommodates Wavefront-Guided procedures based on the Tscherning principles, Topography-Guided by either Scheimpflug or Placido disk imaging, Custom-QTM to adjust corneal asphericity, and PTK (photo-therapeutic keratectomy). “There are also some very interesting profiles in the pipeline that have been proven on the machine,” Dr. Cummings says. “All the existing applications are carried over plus more. It is a very fast machine with a very fast eye tracker. It’s got advanced ergonomic design and the network makes it more of a pleasure to use for the patient, the staff and the doctor,” Dr. Cummings concludes.
WaveLight® EX500 Excimer Laser
Arthur Cummings MB ChB MMed(Ophth) FCS(SA) FRCSEd abc@wellingtoneyeclinic.com
WaveLight® EX500 Excimer Laser
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Innovations in Refractive IOL & Laser Technology 5 September 2010
Speed and Precision Part 2: The WaveLight® FS200 Femtosecond Laser Six-second flaps, 12mm applanation zone, automated vacuum and shutoff are just the start
John Kanellopoulos
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John Kanellopoulos MD, director, Laser Vision Institute (www. laservision.gr), Athens, Greece, and clinical professor of ophthalmology at NYU Medical School, New York, US, has two femtosecond lasers in his clinic – an older 60 Hz model and the new 200 Hz WaveLight® FS200 Femtosecond Laser. He likes to show a side-by-side video, in which the FS200 flap is finished at about six seconds, while the 60Hz laser labours on at 30 seconds. “I am done with patient A, but with Patient B I can hear my heartbeat pulsing and I am praying that the patient doesn’t move,” Professor Kanellopoulos says. “This is the anxiety time for the patient, but for the surgeon as well. Speed is of the essence.” Combining speed with customised capabilities, the WaveLight® FS200 Femtosecond Laser delivers, Professor Kanellopoulos adds. “I have been doing femtoLASIK for four years now and what I find exciting is the very short suction-on to suction-off time. You can potentially do six-second flaps and this is astonishing speed.” Having earned its CE mark, the FS200 is now available in Europe, and is an integral part of the WaveLight® Refractive Suite.
Predictable flap depth The FS200’s speed is clinically useful because it decreases the risk that a flap will be uneven or detach due to patient movement, Professor Kanellopoulos says. “In my patient population the most difficult part of femtosecond LASIK is the femto part. It is the most pressure, it is the most uncomfortable and the patients usually can’t see, so reducing that anxiety time increases comfort and increases patient compliance.” A speedy flap cut potentially also improves safety by reducing the time of increased intraocular pressure due to suction on the cornea, Professor Kanellopoulos adds. The FS200 laser’s innovative automated suction system also reduces peak intraocular pressure and suction duration. Unlike most suction rings, the FS200 vacuum is applied and controlled by the device rather than through a separate manual system. If the system loses suction during the procedure, the laser stops automatically. “It does not rely on the surgeon stepping off the laser pedal and possibly amputating the flap. This is a great safety feature,” Professor Kanellopoulos says. In addition, pressure within the eye remains low until the applanation cone on the laser docks with the fixation ring, flattening the cornea, Professor Kanellopoulos adds. The suction ring and applanation head are also shaped to minimise patient discomfort. Both suction ring and applanation cone are disposable. “Everything that comes in contact with the patient gets thrown away.” To aid in precise positioning of the applanation cone, the FS200 laser head can be manipulated in three axes using a joystick. The device is also shaped to accommodate deep-set eyes. “You see some of those in my practice,” Professor Kanellopoulos says.
Flexible size and position
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At close to 12mm diameter, the applanation region created by the FS200 laser is exceptionally large. It will also cut a consistent depth flap no matter where it is located in the applanation zone. “It is a refractive surgeon’s dream come true as this gives you a lot of flexibility with flap positioning and allows you to make larger flaps,” Professor Kanellopoulos says. Because the FS200 laser can share data with the WaveLight® EX500 excimer through the WaveNetTM interface, it is also possible to superimpose the planned ablation zone onto the cornea to position the flap. The surgeon may then adjust the size, shape, depth, position and hinge location after the applanation cone is attached. “How is that as
a planning tool for the perfect laser flap for your procedure?” Professor Kanellopoulos asks. The WaveLight® proprietary Beam Control Check system further contributes to flap consistency. The applanation cones come precalibrated from the factory, but the Beam Control Check compensates for other factors, including the temperature of the laser and the thickness of the glass within the cone, as well as patient variables such as displacement in the z-axis. Any misalignment of the applanation glass on the cornea also will be detected, all of which helps avoid variations in flap thickness and reducing the standard deviation of flap thickness to less than six microns* (reference data on file). “This is a remarkable innovation,” Professor Kanellopoulos says. Entering diagnostic and patient ID information automatically through the WaveNetTM software also enhances safety by reducing transcription errors, saves money and staff time, Professor Kanellopoulos says. “This is always my big anxiety; doing the wrong numbers because there has been a mistake in transcription.”
Speed, safety, healing The WaveLight® FS200 Femtosecond Laser incorporates features that help further speed the procedure and ensure safety. The LASIK flap cut starts with creation of a tunnel in the cornea designed to allow bubbles and water to escape during the lamellar laser cut. The system combines a small focus with low pulse energy and a unique cutting pattern for accurate flap creation. Histologic examination suggests that the precision achieved by the FS200 laser promotes better outcomes, Professor Kanellopoulos notes. “The very sharp cutting edge gives you the highest quality flap. The smooth stromal bed gives good quality of vision afterward. These are very easy to lift flaps, with a minimised opaque bubble layer,” Professor Kannelopoulos notes. Two healing lines are visible on a well-formed femto flap; an external line from the healing of the epithelium, and a second inner line, Professor Kanellopoulos says. “We do not see the inner line with a mechanical microkeratome. This is where the side cut meets the lamellar cut, and this ensures better attachment of the flap and thus better safety.” The speed, safety features and energy distribution of the FS200 laser help ensure flaps precise enough to consistently deliver these advantages.
Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
“The very sharp cutting edge gives you the highest quality flap. The smooth stromal bed gives good quality of vision afterward. These are very easy to lift flaps, with a minimised opaque bubble layer”
The WaveLight® FS200 Femtosecond Laser also supports treatment options including sub-Bowman’s keratomileusis, intracorneal rings, and lamellar, perforating and penetrating keratoplasty. “If you are a cataract surgeon who is not doing laser surgery you may want to pay attention to femtosecond laser technology. From what we are seeing it is knocking on the door of cataract surgery as well,” Professor Kanellopoulos says. Indeed, the microscope on the FS200 laser is good enough to perform cataract surgery, he adds. “Most of my dreams for femtosecond laser surgery are embodied in this device,” Professor Kanellopoulos concludes. “I am sure you will be impressed with it as well.” A John Kanellopoulos MD ajkmd@mac.com
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Innovations in Refractive IOL & Laser Technology 5 September 2010
Speed and Precision Part 3: Outcomes and Outlook for the WaveLight® Refractive Suite Matthias Maus
Consistent lamellar flaps, 7 D eye tracking, high-speed data yield outstanding refractive results
WaveLight® Refractive Suite
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s a long-time WaveLight® laser user, Matthias Maus MD, of Sehkraft, Cologne, Germany, was keen to get his hands on the FS200, the firm’s first femtosecond laser. It didn’t disappoint. But neither did the EX500 Excimer Laser or the WaveNetTM software also included in the WaveLight® Refractive Suite. Together they have produced results as good as or better than any system he’s used – while improving the efficiency and safety of his practice. Above all, the WaveLight® Refractive Suite has proven remarkably consistent, Dr. Maus says. “The ability to reliably create predictable flaps is of major importance to the procedure planning process and to outcomes,” Dr. Maus says. In his series of 363 consecutive LASIK cases aiming for 120 micron flaps, they achieved a mean thickness of 122 microns. “More important, all the flaps were between 110 and 131 microns,” Dr. Maus says. This consistency gives him the confidence to go thinner with the FS200 Femtosecond laser, he says. “The standard deviation of 5.6 microns speaks for itself.” In his first ISO flaps, mean flap diameter was even better – perfect, in fact, with a standard deviation of 0mm for flaps of 8.5, 9.0, 9.5 and 10.0mm. “If you aim for nine, you get nine. If you aim for 10, you get 10. We skipped measuring after the first 150 flaps,” he says. OCT imaging one day after surgery also showed even lamellar cuts from edge to edge, Dr. Maus adds. “They are planar from one end to the other. This means they apply less biomechanical stress to the periphery,” which enhances adhesion and reduces risk of dislocation. Flap thickness was consistent regardless of where they were cut or how their hinges were
oriented within the applanation zone, Dr. Maus notes. “When you move the flap around nothing is cut off and the quality does not go down. If you move to the outer edge, lifting the flap there is as easy as in the centre. This is very important.”
Excellent visual outcomes As a user of the WaveLight® 500 Hz ConcertoTM excimer laser, Dr. Maus wasn’t quite as excited to see the EX500 laser. “‘OK, so it’s another 500 Hz laser in my office, so let’s get it,’ I thought.” But the combination of the improved eye tracker and the networking of the EX500 with the FS200 into the integrated WaveLight® Refractive Suite have made a difference, he says. “Visual acuity and quality of vision are key factors defining excellent outcomes and patient as well as surgeon satisfaction,” Dr. Maus notes. “With my EX500 excimer the visual results were as good as or slightly better than with the ConcertoTM.” At three months, 95 percent of my patients achieved uncorrected vision of 1.0 or better and 100 percent 0.8 or better, he says. “This was really no surprise.” Dr. Maus is particularly impressed with the EX500 laser’s 1050 Hz eye tracking system, which is twice the ConcertoTM laser’s repetition rate, and responds to eye movements in just two milliseconds, he says. “From taking the picture to delivering the shot is three or four times as fast as before, so really the patient’s eye has no chance to escape you,” he says. The multidimensional compensation algorithm built into the EX500 laser’s eye tracker also keeps it on target, Dr. Maus says. Conventional eye trackers are 2-D, centering on the pupil and moving the laser in x and y axes. But the cornea
does not move in two dimensions, it rolls. To keep track of this forward and sideways motion, the EX500 excimer projects a moiré pattern onto the cornea and measures the distance between points. This enables it to adjust the aim of each shot to keep the ablation profile centred around the intended axis even as the angle and number of shots to sculpt the profile change. A fifth dimension is cyclotorsion. Iris landmarks from pictures from the WaveLight® TopolyzerTM VARIOTM taken at wide and narrow pupil sizes are programmed into the EX500 system’s eye tracker to help it compensate when the landmarks shift. By projecting how the landmarks will move as a result of iris contraction as opposed to actual rotation of the eye helps the system distinguish and compensate for true cyclotorsion while ignoring pseudo-cyclotorsion that may result from iris movement. Initially, cyclotorsion compensation will be static, but a dynamic system is scheduled for release early next year. A sixth dimension is movement in the z axis. “When you have an anxious patient who is really pulling his head away from whatever it is he thinks is hitting his eye you can easily have movement in the z axis,” Dr. Maus says. The eye tracker also compensates for pupil centroid shift, which can be a half millimetre or more along the horizontal and vertical axes from mesopic to scotopic conditions. “When the pupil gets smaller the centre may shift and you may displace the treatment on the cornea, inducing unwanted astigmatism.”
Data for quality improvement The WaveNetTM system also increases practice safety and efficiency, protects valuable patient data, and facilitates quality improvement, Dr. Maus says. “You enter the data once and it is sent all around the network. You can sit at your desk and plan a treatment, and you can have the central server store and replicate all your data.” The WaveNetTM system comes with a standardised interface for electronic medical record software. It can also automatically export data to nomogram development and quality management software, and to EUREQUO or other Internetbased data transfer systems. This makes it easy to meet outcomes and process monitoring standards required for ISO and other quality management programmes, and to collect outcomes data for process improvement, Dr. Maus says. “The WaveLight® Refractive Suite is a big step toward safety and security,” Dr. Maus says. Matthias Maus MD maus@sehkraft.de
Innovations in Refractive IOL & Laser Technology XXVIII Congress of the ESCRS, Paris, France
Supported by an unrestricted educational grant from
MCA10544JS