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Bye, bye, microkeratome? 2010 will be the year of the femtosecond laser, many ophthalmic surgeons predict. First, the femtosecond laser has come of age thanks to studies that show safety, predictability, and reproducibility with its use during refractive surgery.
“Femtosecond LASIK creates a better flap,” said Capt. (Ret.) Steven C. Schallhorn, M.D., San Diego, and medical director, Optical Express, London. “Patient outcomes and safety are improved.” Dr. Schallhorn has been involved with two independent studies that show how the femtosecond laser is efficient, effective, and has a low complication rate. One study published last year in the Journal of Refractive Surgery found that a larger percentage of eyes in which the femto laser was used achieved a post-op uncorrected visual acuity of 20/20 or even 20/16 up to three months after surgery compared with mechanical microkeratome use.
“When I talk to patients about the laser, I talk about reproducibility and greater safety—there’s less chance of irregular cuts or complications. Buttonholes, free caps, and partial flaps are almost eliminated with the femtosecond laser,” said Ronald R. Krueger, M.D., professor of ophthalmology, Cleveland Clinic, and medical director, refractive surgery, Cole Eye Institute, Cleveland.
“Another advantage with the femto laser is if you go part of the way and lose suction, you can stop, reapply suction, and start over,” Dr. Krueger said, adding that surgeons do not have that same luxury with the mechanical microkeratome.
“If I have 20 cases scheduled at the start of the day, I have confidence that I won’t have difficult complications with the femtosecond laser. I never had that comfort with the microkeratome,” said Steven E. Wilson, M.D., professor of ophthalmology and director, corneal research, Cole Eye Institute. “Even though complications were not that common with the microkeratome, when they did occur, they could be very severe.”
Safety and efficacy are no doubt the primary reasons that the femto laser has gained steam, but Daniel S. Durrie, M.D., clinical professor of ophthalmology, University of Kansas, Overland Park, Kan., believes that laser technology reaching the 10-year mark makes a difference as well.
“There’s something magical about 10 years in ophthalmology,” he said. Often, technology has to remain in the field for about this length of time to prove itself before a larger mass of surgeons will use it more often or exclusively, he said.

The numbers behind laser use

Although these surgeons’ enthusiasm for the femtosecond laser in refractive surgery is obvious, statistics show that 62.2% of refractive procedures (including surface ablation) performed in the third quarter of 2009 in the U.S. were done with the femtosecond laser, according to MarketScope, St. Louis. This statistic focuses on the actual number of procedures done and not the number of practices that own a femtosecond laser.
The interest in lasers is also obvious in the growing number of manufacturers who are now making femto lasers. Originally, IntraLase (Abbott Medical Optics, AMO, Santa Ana, Calif.) was the major player. Now, WaveLight (Alcon, Fort Worth, Texas), Ziemer (Port, Switzerland), and Technolas (St. Louis), among others, are manufacturing these lasers. “They wouldn’t invest in the market if there was not a demand,” Dr. Durrie said. Several other potential manufacturers also are purportedly entering the market soon, Dr. Schallhorn said.

The cost factor

The biggest downside to the femtosecond laser may be its cost compared with mechanical microkeratomes, many surgeons said. In fact, were it not for the cost issue, many more surgeons would likely already be using the laser now during refractive surgery, they said.
[Additionally, from a global perspective, microkeratomes are still used more often than the laser in refractive surgery. “Individual practices have to do a cost analysis,” Dr. Schallhorn said. In some markets, there are surgeons who perform LASIK with the femtosecond laser at a very cheap price and ones who perform it more expensively, yet both still survive, Dr. Krueger said.]
That all said, the economy has not made a complete recovery yet, and the laser’s steep price means it should not be an impulse purchase. “Few practices, even those with their toes back in the water promotionally, are seeing much of a first-quarter case-volume resurgence,” said John B. Pinto, president, J. Pinto and Associates, San Diego. “As a result, capital spending in the least-affected refractive surgery practices remains a tender subject.”
[“Initially we offered patients the option of femtosecond or the microkeratome. Almost none chose the microkeratome, so we dropped that after awhile,” Dr. Wilson said. “Surveys find the patients are less concerned about cost because it’s a one-time surgery. It’s doctors who say it’s expensive,” Dr. Durrie said.]

Exploring the laser’s potential

Because the femto laser is a relatively new and evolving technology, manufacturers and physicians are still exploring its potential. For example, its role in lowering dry eye after refractive surgery is one area under study. Dr. Wilson was co-investigator in a study published in the October 2009 Journal of Cataract & Refractive Surgery that found in the first 6 months after LASIK, there was far less dry eye—what investigators referred to in the study as LASIK-induced neurotrophic epitheliopathy—with the femto laser compared with mechanical microkeratome use.
Dry eye incidence did not change dramatically with thin or thick flaps created by the microkeratome, he said. Lowering dry eye after surgery can translate into fewer patients with fluctuating vision, fewer patients using Restasis (cyclosporine ophthalmic emulsion, Allergan, Irvine, Calif.), and, ultimately, fewer unhappy patients, he said.
Dr. Durrie would like to see the laser’s same-day visual recovery improved. “We have excellent one-day vision, but if you look at one hour after surgery, it’s not very good. There’s edema, vision is a little fuzzy, and 60%–70% of patients measure 20/40.” Although Dr. Durrie said he and other surgeons know that vision will improve rapidly by the next day, he considers the patient’s perspective. “When do friends call [and ask about the results]? Right after surgery,” he said.
Dr. Durrie would like to see femto LASIK become something like a dentist appointment, where patients can drive themselves to surgery and go back to work that same day. This will enable them to report better vision immediately and avoid depending on friends or family to assist them before and after the appointment.
The move to use femto lasers in other aspects of eye surgery also intrigues many surgeons. Recent promising reports of femtosecond laser use during cataract surgery to make the capsulorhexis and soften the nucleus, as well as with corneal transplants, keratoconus, and even presbyopia inside the lens all merit further study, surgeons said.

Editors’ note: Dr. Schallhorn has financial interests with Abbott Medical Optics (Santa Ana, Calif.). Dr. Durrie has financial interests with AMO and Alcon (Fort Worth, Texas). Drs. Kruger and Wilson and Mr. Pinto have no financial interests related to their comments.

EyeWorld Magazine

by Vanessa Caceres EyeWorld Contributing Editor

While up to this point the book on surgical correction of presbyopia has not exactly been a page-turner—with monovision essentially serving as the only widespread option—exciting new possibilities are now beginning to emerge. From presbyLASIK to corneal inlays and more, new surgical options are now filling the once-blank pages here.
All this may be just in time to catch the wave of highly motivated Baby Boomers who are eagerly awaiting a surgical option, according to Michael Gordon, M.D., San Diego. “This was the same population that was so anxious to be out of their glasses and to have LASIK. I think it’s the same mentality,” he said. “I think that they don’t want to be encumbered with glasses and contact lenses.”
Indexing presbyLASIK options
For some time practitioners have been striving to put the excimer laser to work in correcting presbyopia, with what has been loosely dubbed presbyLASIK. W. Bruce Jackson, M.D., director general, University of Ottawa Eye Institute, Ottawa, chronicles three varied approaches here. “In the beginning the concept was using an off-center treatment whereby you had distance right through the center and a little below that you had near, almost like a multifocal effect,” he said. “That’s not being used very widely now.”
In another off-label approach, termed central presbyLASIK, the center of the cornea is used for near vision. “For hyperopes this central presbyLASIK has worked very well,” Dr. Jackson said. “It means that you’re adding a little bit of central steepening to the central 3 or 3.5 mm.” This approach was popularized by Luis Ruiz, M.D.
In a third approach, the periphery of the eye is used for near vision. “The center of the cornea is used for distance, so patients still have good distance vision but some spherical aberration is induced in the mid-periphery and that gives them the reading,” Dr. Jackson said. He thinks that this third approach may be easiest to do off label. “What surgeons will do is over-correct the myopes and make them hyperopic and then treat them with the hyperopic treatment and bring them back,” he said. “By doing that they create that negative spherical aberration in the mid-periphery.”
Dr. Jackson began using the presbyLASIK approach in the VISX (Abbott Medical Optics, Santa Ana, Calif.) trial back in 2001. “We treated patients with the central presby and the peripheral,” he said. His work with presbyLASIK was stalled by Food and Drug Administration (FDA) wrangling. However, he found that the approach held promise. “Binocularly our target was 20/25 and J3 with 28 subjects; all of them got 20/25 J3 and 88% got to 20/25 J1,” he said. “When it was done according to the plan it really worked well.”
Recently, presbyLASIK began making new inroads in the United States. Dr. Gordon helped to bring the approach pioneered by Roberto Pinelli, M.D., to the country. He describes the approach this way. “The technique that we use basically creates a prolate cornea and induces negative spherical aberration and gives an increased depth-of-field,” Dr. Gordon said. He stresses that it’s really not a “multifocality.”
“Even the term progressive multifocal LASIK is a misnomer,” he said. “You’re really reducing the blur circle that falls on the retina and that allows you the depth-of-focus.”
Dr. Gordon has found the approach to be applicable for those in the –5 D to +3 D spectacle range. So far he terms his results as excellent. “We’ve found that 97% of our patients are actually 20/25 or better and somewhere around 95% are J3 or better,” he said. The enhancement rate, however, is slightly increased. “Our [traditional LASIK] enhancement rate with our WaveLight Allegretto (Alcon, Fort Worth, Texas) depending upon the prescription is somewhere between 1 and 2%,” Dr. Gordon said. “With this it’s about 8%.”
To help keep enhancement rates low Dr. Gordon recommends putting a framework for routine handling of procedures in place. “One of the problems in doing this surgery is that you’re doing a myopic and hyperopic correction on the same eye on each eye of the same individual,” he said. “There is a time delay in rearming the laser, which I think adds to the enhancement rate.” However, he finds that by doing things in a routine way practitioners can potentially minimize the lag time here.
While the technique should work with any laser, Dr. Gordon urges practitioners to perform this with an excimer that offers some leeway in selecting optical zones. “You have to be able to change the optical zones,” he said. “I think we certainly have more flexibility in picking optical zone sizes in the U.S. with the WaveLight Allegretto compared with the VISX, which we also have but we don’t use for this treatment.”
Roy S. Rubinfeld, M.D., Chevy Chase, Md., and clinical professor of ophthalmology, Georgetown University, learned of the presbyLASIK approach from Dr. Gordon. Initially Dr. Rubinfeld was very skeptical. “I was on a treadmill adjacent to Mickey Gordon and we were talking about what’s new and he said, ‘Well, I’m doing presbyLASIK,” Dr. Rubinfeld said. “I said, ‘Mickey, that doesn’t work. The last five approaches to that haven’t done anything good,’ and he said, ‘No, it does.’”
In the course of the discussion Dr. Gordon mentioned that he had performed the procedure on his wife and also on his office manager. “I saw [the office manager] later that day and she was reading J1 and seeing 20/20 or 25,” Dr. Rubinfeld said. “I looked at Mickey and said, ‘Really?’ and he said, ‘No, this time, really.’”
Dr. Rubinfeld has found that his patients are generally likewise very happy with the approach. “Patients are generally delirious,” Dr. Rubinfeld said. “I have a 70-year-old man who read J1 plus and who is 20/20 at distance.” He stresses that it is negative asphericity, not an “add” that is at work here. “I’ve done a lot of patients who are eye doctors, particularly optometrists, and they often say to me that it’s not an add sort of issue,” Dr. Rubinfeld said. “They say that everything is in focus as opposed to [there being] zones.”
The majority of Dr. Rubinfeld’s patients have done well with the approach. “Most can read J2 or J1,” he said. “Some can even read J1 plus.” However, he stresses the results are not usually attained overnight. “I tell them that this is the slow LASIK procedure. This is not the same as the one your 22-year-old friend had and could then read the next day, saw 20/20, and could drive at night,” Dr. Rubinfeld said. “This is the six-month process LASIK; you’re really not going to know what you’ve got for about six months.”
One trick he uses to determine if someone is a good candidate for the presbyLASIK procedure is to push the plus power and then demonstrate for the patient what his or her vision might be like. “Let’s say someone is really a –4.5 D, I’ll put up a –4 [lens] and say, ‘How is that?’” Dr. Rubinfeld said. “If the patient says, ‘Good Lord, that’s awful, I can’t stand it,’ I won’t do presbyLASIK, but if the patient says, ‘It’s OK, but it’s not as good,’ I will do presbyLASIK.” This, he finds, helps to weed out those who are more visually sensitive to small refractive errors.
Complications with the procedure have been low. However, one key issue that Dr. Rubinfeld finds that many presbyLASIK patients contend with is dryness. “I often have patients on hot compresses and fish oil prior to the procedure to make their ocular surface pristine,” he said. “I’m also very quick to use plugs and oral doxycycline and maybe some short-term topical steroids.” He finds that following the procedure, even when patients don’t look dry, they in fact are. “I have had several patients who at first were doing great and then two weeks later their reading really disappeared,” he said. “I called Mickey and I said, ‘What’s going on?’ and he said, ‘They’re dry.’ I said, ‘I’m a cornea specialist, Mickey, and they’re not dry,’ and he said, ‘They’re dry, Roy.’” After plugging the patients as per Dr. Gordon’s advice, Dr. Rubinfeld found that these patients ultimately got great results.
Stephen G. Slade, M.D., Houston, has likewise tried this presbyLASIK approach. “We use the presbyLASIK approach that was similar to what many people have done,” he said. “It’s basically doing a hyperopic and a myopic ablation with the attempt to increase the asphericity of the cornea and lengthen the depth of focus.” As a rule he finds that patients do well with this but he stresses that it’s not for everyone. “The results were generally good, but not everyone is going to see 20/20 and J1, so I think it’s a bit of a compromise,” he said.

Other options on the jacket

Dr. Slade also has an eye on other presbyopic options under investigation, including use of the femtosecond laser for presbyopic correction and use of various corneal inlays.
With the femtosecond laser, investigators are working with the IntraCor (Technolas Perfect Vision, Munich, Germany) to painlessly improve near vision. Dr. Slade has closely followed the procedure, which uses the femtosecond laser to make five or six little rings around the center of the cornea. “It actually sort of resets the cornea to make the central part a little bit steeper,” Dr. Slade said. “That has a lot of supporters simply because it is so non-invasive.” While this procedure has not yet been done in the United States it has received CE Mark approval in Europe.
Dr. Jackson is also excited about the possibilities with the femtosecond IntraCor procedure. “If you can do a 15-second procedure that’s painless and provides people with no change in distance vision but good near vision, that’s pretty space age,” he said. “It basically puts a vertical relaxing type of incision in the central cornea.” With the procedure, approximately five rings are used. “Really what that does is allow the intraocular pressure in the eye to move the central cornea a little bit more forward and give a slightly myopic effect.” Dr. Jackson sees this as akin to what is being done with presbyLASIK. “That’s the same thing that we are accomplishing with the presbyLASIK with the central near where we were creating a little bit more hyper-prolate central area,” he said. “We’re just doing it by relaxing the central cornea as opposed to having a flap and taking away tissue.” One benefit of using the femtosecond laser here is it is painless. “It doesn’t go through the surface epithelium so it’s a painless procedure,” Dr. Jackson said.
Dr. Slade agrees that the non-invasiveness of this technique is very appealing. “I like how with the femtosecond laser IntraCor procedure there are absolutely no cuts that go through the cornea,” he said. “It’s all done intrastromally so you don’t even have to put the patient on antibiotics.”
Also attractive to many is the idea of creating a flap and putting in a corneal inlay. These work in one of three ways, according to Dr. Jackson. “Either you’re changing the curvature, you’re changing the power, or you’re creating a pinhole but changing the optics,” Dr. Jackson said.
Dr. Slade is also intrigued by the corneal inlays. He is currently in the FDA clinical trial for keratophakia involving the ReVision optics inlay (Lake Forest, Calif.). “We’ve just done the first set of patients with that and we’re very impressed,” he said. “We have just a few weeks of experience but when I look at the experience of surgeons who have been doing it longer outside of the United States, it looks pretty good.”
Overall, Dr. Slade sees all of these current innovations as dovetailing nicely with the emerging needs of Baby Boomers. “I think that it’s a huge field because it’s exactly what we need,” he said. “Presbyopes are the largest part of our practice—for Baby Boomers this is the biggest problems that they have and we can’t address it.” However, with surgical options such as these in the offing Dr. Slade hopes that it will serve to keep patients in the fold for life. “It’s a bridge procedure in that we can take care of patients in their 20s and 30s with LASIK and then we can take care of patients in their 60s or over with cataract surgery, but there’s really nothing that we can do for the middle people,” he said. “They tend to leave our practice, and it would be nice to be able to keep those patients in the practice.”

Editors’ note: Dr. Gordon has financial interests with Alcon (Fort Worth, Texas) and Presbia (Los Angeles). Dr. Jackson has financial interests with Abbott Medical Optics (Santa Ana, Calif.) and Allergan (Irvine, Calif.). Dr. Rubinfeld has no financial interests related to his comments. Dr. Slade has financial interests with Technolas (Munich, Germany).

EyeWorld Magazine by Maxine Lipner Senior EyeWorld Contributing Editor

At Millennium Laser Eye Centers, we have invested in the best technology for our patients. We utilize the IntraLase for flap creation to reduce complications and preserve more tissue then the microkeratome. See article below for more comparisons.

Surgeons cite various reasons for preferring mechanical keratome over laser systems in flap creation, including specific eye characteristics, patient comfort, cost, and laser shortcomings.
Although the use of femtosecond laser systems for flap creation has increased in recent years, many surgeons continue to rely on mechanical microkeratomes. The higher cost of laser systems is often sighted as the primary reason for continued mechanical keratome use, but some surgeons note other reasons to opt for the manual blades even when the laser is available.
A large and growing number of surgeons have reported switching to femtosecond laser systems to create flaps for a variety of procedures. However, many surgeons continue to rely on mechanical microkeratomes, including a newer generation of models that have shown increased precision and reliability.
A 2008 survey of ASCRS members found 33% used the IntraLase femtosecond system (Abbott Medical Optics, Santa Ana, Calif.), while 66% said they continued to primarily rely on mechanical microkeratomes. However, a slim majority—52%—of polled members of the International Society of Refractive Surgery (ISRS) reported in a 2009 survey that they now rely on one of two femtosecond devices listed by pollsters. Forty-eight percent named 1 of 9 mechanical microkeratomes as their primary instrument in refractive surgery.
Many surgeons who continue to rely on mechanical microkeratomes often cite the high cost of femtosecond devices as a major reason but other clinical reasons may add to the use.
[However, he switched to the IntraLase for most LASIK procedures on the basis of other research that found “improved uniformity of the flap, better predictability of flap thickness, and increased safety of the procedure.” “Also, flap creation by the femtosecond laser is more predictable and reliable than traditional microkeratomes,” Dr. Pallikaris noted.]
Conversely, Dr. Pallikaris moved in recent years to mechanical epikeratomes for PRK procedures for low myopia when the use of mitomycin C is not required. He concluded that either the later generation mechanical microkeratomes or femtosecond lasers can provide high-quality corneal flaps. A “surgeon’s experience is the most important factor for the predictability of the results,” Dr. Pallikaris said.

Newer blades, better results

Improvements in surgical outcomes with more recently introduced mechanical microkeratomes have been noted in several studies, including some that found comparable surgical results when compared to femtosecond systems.
Dr. Peters has found improved standard deviation rates with modern mechanical microkeratomes, such as the XP or the Carriazo-Pendular microkeratome (Schwind eye-tech-solutions, Kleinostheim, Germany). Although he relies on a femtosecond system in all cases where corneal thickness is a concern, Dr. Peters is comfortable using one of the newer mechanical microkeratomes on normal corneas.
Several surgeons report that they will switch from femtosecond systems to mechanical microkeratomes if the higher cost is a concern for patients. In such cases, Richard L. Lindstrom, M.D., Adjunct Professor Emeritus, department of ophthalmology, University of Minnesota, Minneapolis, and founder, Minnesota Eye Consultants, Minneapolis, uses the Hansatome (Bausch & Lomb), which was the most commonly utilized microkeratome as recently as 2004, according to the ISRS survey.
When cost is not a major issue for patients, however, Dr. Lindstrom relies on the IntraLase system to provide “better day one vision, a lower complication rate, a more reproducible planar flap, and a lower enhancement rate” than mechanical microkeratomes.
Stephen S. Khachikian, M.D., Rapid City, S.D., similarly relies on a femtosecond system for most procedures, unless the patient has significant scarring. “The only problem is if there is significant scarring, but even then it is worth trying the laser because I have been surprised at the scars that the laser can reasonably penetrate,” Dr. Khachikian said. However, he uses either the One Use or the LSK Evolution System (Moria) for Descemet’s stripping endothelial keratoplasty.

Editors’ note: Dr. Lindstrom has financial interests with Abbott Medical Optics (Santa Ana, Calif.), Alcon (Fort Worth, Texas), and Bausch & Lomb (Rochester, N.Y.), among other companies. Drs. Peters, Norden, Pallikaris, and Khachikian did not indicate any financial interests related to this article.

EyeWorld Magazine by Rich Daly EyeWorld Contributing Editor