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Up Front | Apr 2008

The Future of Presby-LASIK and the Multifocal Cornea

Presby-LASIK is one option for treating presbyopia, a panel of experts says. A large number of baby boomers may be appropriate candidates.

Pinelli: Do you think that a multifocal cornea is a viable option for presbyopia correction?

Tamayo: Performing presbyopic LASIK (presby-LASIK) to produce a multifocal cornea is an attractive option to correct presbyopia plus any refractive defect—for instance, to correct presbyopia and myopia at the same time. For patients who can see at near without their glasses when they are myopic, this gives them the option to not wear glasses for near vision after surgery.

Avalos: Yes, presby-LASIK has advantages over other surgeries to correct presbyopia. Presby-LASIK is an excellent option for patients with this age-related defect. Patients with a large range of refractive conditions can be treated with this technique, including those with emmetropia, hyperopia, low myopia, and low astigmatism.

Alió: A multifocal cornea is an attractive alternative to currently available multifocal and accommodating IOLs. Presby-LASIK is a promising technique, and the development of better multifocal and accommodating IOLs is also encouraging.

Gordon: In the future, we will have many ways to correct presbyopia, and a multifocal cornea will be one. We will have to determine what characteristics and baseline factors will predict which procedure will yield the best results for any given individual. It may be, for instance, that a young, very active individual in his early- to mid-40s is an ideal candidate for this procedure. Or maybe it will be better for a young person who is not so active. The indications for different surgical choices must be sorted out. But yes, it is one viable option for presbyopia correction.

Pinelli: In my opinion, presbyopic LASIK is a good option for the correction of presbyopia. We have 9 years experience in this field, and we are obtaining prolate corneas, a particular curve created by specific algorithms. The method we use to achieve the prolate cornea is called presbyopic multifocal LASIK (PML; See page 30 for more information). If we consider that the normal cornea is a prolate ellipsoid, we use PML to reshape the cornea to give the patient the ability to see both far and near through a particular curve, which is specifically not multifocal but aspheric.

Can everyone describe their experience with presby-LASIK?

Avalos: I began doing presby-LASIK treatments in 1998, and my experience to date includes approximately 900 treated eyes (450 patients). In general terms, 90% of these patients are totally satisfied with their optical results.

Alió: We have been using presby-LASIK for approximately 8 years, first with the Technovision platform (Technovision, Inc., Munich, Germany) and later with our own method called PresbyMax, which is now available with the Esiris laser (Schwind eye-tech-solutions, Kleinostheim, Germany).

We have analyzed our results with PresbyMax software in patients with accommodative loss of up to 2.00 D, and it works well, as long as you select patients properly. We pay careful attention to adequate pupil size. In my opinion we will be able to achieve good results in patients with larger presbyopic correction as long as they have adequate pupils. Presby-LASIK provided good vision for both distance and near in most patients bilaterally: 20/20 or better for distance and J3 or better for near. We achieve excellent outcomes, and patients are happy.

Tamayo: We treated the first patient with myopia and presbyopia at our clinic in June 2000. Since then, we have developed several software updates, and now we are using the fourth version of the software with the Visx laser (Advanced Medical Optics, Inc., Santa Ana, California). We have treated approximately 800 patients in Colombia and approximately 60 in Canada in an independent study supported by Advanced Medical Optics, Inc.

Gordon: Most of us in the United States do not have any direct experience with new software developed specifically for presby-LASIK, but we do have experience with the procedure in other ways. Early in our experience with LASIK, many of us observed the following phenomenon: If we had overcorrected a myopic patient, meaning that he was now hyperopic, and we went back and did a hyperopic correction over the myopic correction, the patient had a disparate improvement in reading vision compared with distance vision for a given refraction. In other words, we had a plano 50-year-old who could read without correction. The reason was that we had done presby-LASIK without knowing we were doing it. We gave the patient a multifocal cornea. So, we know it works in principle.

I think it will be a good option for presbyopic correction. The studies that have been done outside the United States, where this is now being done every day, along with the studies done in the United States for clinical approval of the Visx laser, are showing that it is a viable option.

Pinelli: After 2 years of presby-LASIK trials and another 2 years of adjustments of the nomograms, we have stable results. Ninety percent of patients achieve bilateral 20/20 distance vision and J2 near vision, 5% achieve 20/20 and J3 bilateral, and 2% require retreatments. We have treated approximately 1,000 eyes (500 patients).

We believe that PML is a good option because it preserves the crystalline lens. We think that lens surgery can be considered as a second option (obviously in patients without any opacity of the lens), and consequently, it is clear that presbyopia surgery can be developed in steps, not managed definitively in one operation. PML will be available soon.

What advantages are provided by presby-LASIK? How does it compare with multifocal IOLs?

Alió: We may experience unpredictable results with multifocal IOLs in many patients, despite careful patient selection. And so, even though I am very fond of multifocal IOLs, and in my practice about 25% of my patients have multifocals, I acknowledge the limitations of the technology. I do not think that multifocal IOLs will be the final step in presbyopia correction. Rather, they are a transitory step.

Presby-LASIK is my current preference for most myopes and presbyopes with errors up to 4.00 D and early-to-intermediate presbyopia. Multifocals can have a role in myopes and hyperopes with advanced presbyopia, where patients have a loss of more than 2.00 D of accommodative amplitude. In these patients my current preference is for a pupil-independent, diffractive multifocal IOL that can fit through a sub–2-mm incision. This currently describes the Acri.Tec Acri.LISA IOL (Carl Zeiss Meditec AG, Jena, Germany).

Gordon: It is not necessarily a choice of one or the other (ie, presby-LASIK or multifocal IOLs). Again, we need to determine which patient gets which procedure. Once patients get into the age range of 55 to 60 years and above, we will lean more toward lens extraction and multifocal IOL implantation. But for younger patients, presby-LASIK is ultimately a safer procedure. Any time we do not have to enter the eye, it is safer.

Tamayo: I strongly believe that we cannot go inside the eye for lens-exchange surgery in patients under 55 or 60 years of age. Therefore, we have to offer a variety of options to be able to correct presbyopia in all of our patients.

Presby-LASIK is noninvasive, so it does not carry the risks of multifocal lenses. Also, it is more easily reversible than multifocal lenses. That is, if multifocal IOLs have to be exchanged, that requires another intraocular surgery. With presby-LASIK, we can erase the multifocality of the cornea with a wavefront laser treatment. So I think that presby-LASIK with a multifocal cornea is a better option than multifocal lenses in younger patients, unless of course the patient already has some opacity in the lens, in which case I prefer to implant multifocal IOL.

Avalos: The advantages I have found for presby-LASIK include the following: It is an effective procedure with a stable long-term result; it can be performed bilaterally; surgery time is short and is low cost; it allows retreatment or reversal; there is a small incidence of retreatment; it causes few undesirable optical effects; and good visual results are achieved the day after the surgery.

Pinelli: The advantages of presby-LASIK certainly are many. One of the most important is the use of a tissue-saving nomogram. With this type of nomogram a small amount of tissue is removed (only 25–30 µm), leaving the possibility to enhance if needed. PML is my preferred technique for emmetropes from 45 to 60 years old. After that age, I consider lens surgery, but in the absence of a cataract we prefer PML also in later years. Multifocal IOLs are not my favorite option, but we actually implant IOLs in 20% of our presbyopic patients.

What do you think is the correct presbyopic solution for baby boomers? I will relate our own experience first. The baby boomers include a large group of emmetropic presbyopes. We can clearly see that 50% of our presbyopic patients are candidates for presby-LASIK, and this percentage is growing as the baby boomers age.

We think that, in this age group, presbyopia should be managed not with one operation but by providing different refractive solutions for patients over time—more like a presby-project.

For example, suppose we perform presby-LASIK in a 48-year-old man, and 10 years later he develops a cataract. We can continue the presby-project, exchanging the crystalline lens for an IOL and still maintaining his multifocality.

The challenges will be to establish this approach to the management of presbyopia in the near future, as this group of patients reaches the appropriate age, and to identify the specific technologies that make the approach work refractively.

Tamayo: The right solution, at the present moment for these patients, has to be creating a multifocal cornea with presby-LASIK. Baby boomers, who only started turning 60 years old in 2006, are mostly still too young for IOLs, unless they have some opacity in their lens.

The corneal multifocality can be erased with a second CustomVue treatment (Advanced Medical Optics, Inc.). Therefore, we can later erase the multifocality of the cornea and insert a multifocal IOL if needed. We have already done this in some patients.

Avalos: Young presbyopes are frequently looking for a solution to their new-found visual deficiency. I agree, they generally prefer an extraocular, less-invasive LASIK procedure rather than intraocular surgery. Additionally, with presby-LASIK, the progressive evolution of presbyopia can be retreated if needed several years after the initial surgery.

Pinelli: I agree, Guillermo. We are also retreating some patients after several years with good results.

Alió: For baby boomers, my current choice for emmetropes, myopes up to -4.00 D, and hyperopes up to 4.00 D with early to intermediate presbyopia is presby-LASIK with PresbyMax. For surgeons who do not have access to this software, my recommendations vary depending on the refraction and accommodative status of the patient. In many cases my recommendation—given the currently available treatments—is monovision.

Presby-LASIK is currently best for patients between 40 and 50 years old—the second decade of the baby boomers—with up to 2.00 D of accommodative loss. These patients are very happy if properly selected and treated. If they have a greater demand for near vision, or if they previously had presby-LASIK and their accommodative deficit has increased with age, monovision plus presby-LASIK works well. The patient who needs an accommodative add of 2.50 D will still need glasses for near function (eg, reading the newspaper). With a multifocal cornea, a refraction of -0.75 D in the other eye tremendously increases the near-vision depth of focus, so the patient is much happier in that situation. This mixed presby-monovision works well in advanced presbyopes and is an alternative for those who had presby-LASIK and have become more presbyopic.

Gordon: I think the preferred procedure for baby boomers will change over time. As others mentioned, we will see patients who have one procedure when they become presbyopic, whether it be presby-LASIK, corneal implants, conductive keratoplasty, or something of that nature. When they get to an older age range, they will start having refractive and multifocal IOL implants.

Pinelli: The discussion is getting more interesting now. Do you find that patients are receptive to this procedure?

Gordon: We do not offer presby-LASIK yet, but patient acceptance will be a significant factor when it does become available. When you present surgical options to a 40- or 45-year-old and say that: (1) presbyopic lens exchange means removing the natural lens of the eye, which still has some accommodative ability, (2) one of the potential complications is retinal detachment, and (3) if you get an infection in the eye it is more serious than getting one on the cornea. These factors weigh against the intraocular approach. Then when you introduce the idea of a corneal procedure, which does not negate the possibility of having a lens procedure later on, I think patient acceptance will be high. Cost and other factors will also enter into the patients decision.

Avalos: In my practice, I never advertise. Patients come to my office requesting presbyopic LASIK surgery through word of mouth. One patient recommends it to another, and the new prospective patient knows from his friends example that we can achieve good vision for distance and reading.

Alió: Patients come to me because they want spectacle independence. If they are presbyopes as well, with 1.50 to 2.00 D loss of accommodation, they have never used glasses. Suddenly, they need glasses all the time and they depend on them for every activity. They hate this, and they are happy to have an option to decrease their need for glasses.

I am very careful, however, with patient selection in advanced presbyopic emmetropes. These patients are not happy with the decrease in distance vision that they sometimes experience with multifocal correction—whether through an IOL or through a multifocal LASIK correction—and conversely they are not happy either if there is some near vision deficit so that they still have to use reading glasses. This is a good group of patients in which to do nothing or to try monovision.

Tamayo: Patient acceptance of presby-LASIK is good. Patients still experience some visual symptoms similar to multifocal IOLs, such as glare and halos at night. Those patients will complain for 3 to 4 months, and after that, the symptoms start to slowly disappear. Despite the complaints, most patients are very happy because they can see well at distance and do not need glasses for near.

Pinelli: We find that LASIK is highly appreciated, and patients are happy to undergo presby-LASIK, which does not involve exchanging the crystalline lens.

Philosophically, I have nothing against inserting multifocal IOLs, but personally, I think that if we exchange the lens in a 50-year-old emmetrope without any cataract we lose an opportunity to have another chance for his future.

For instance, I am a LASIK patient with a monovision correction. Theoretically, I should be a presbyope, but I am not because of my monovision. As I do not have any cataract symptoms currently, at 48 years of age, if I develop problems with near vision, I will ask for retreatment with the presby-LASIK nomogram rather than a lens exchange.

Lets now discuss what techniques can be used to encourage patients to accept this option?

Avalos: It will depend on the patient. For young presbyopic patients, we must explain the benefits of this option compared to an intraocular procedure, and I think that with the laser procedure the acceptance will be greater.

Pinelli: Patients will accept this option if we give them correct information with an honest approach, engage in continuous research to improve our knowledge and skills, and perform excellent surgery.

Gordon: One thing you can do is put the patient in a multifocal contact lens and say, "This is somewhat like the vision you will get with the laser procedure. Walk around with it and see what you think." That is probably the only demonstration that can give patients an idea of what they are going to experience. There are some less effective gimmicks, so to speak, that we have in the office, such as computer displays and CD-ROMs.

Pinelli: Good suggestion. So, if presby-LASIK becomes available, will you perform it? Why or why not?

Gordon: Absolutely I will perform it, for reasons already enumerated. It is safer than a lens procedure. The younger patient retains his lens, which still has some accommodative ability.

Alió: I am already performing presby-LASIK as my preferred technique in many patient populations. But I look forward to the next generation of presby-LASIK, which I believe will able to correct patients with larger refractive errors; patients who are already pseudophakic, such as those who have already had cataract surgery; and indeed also patients in whom LASIK has been performed. In these patients, we will lift the flap and use the PresbyMax software to perform a multifocal ablation. All of this makes me optimistic about presby-LASIK.

But surgeons should be aware that not all presby-LASIK technologies are the same. Some of them provide only moderately acceptable results, and at the cost of slow visual recovery for distance vision. These modes are not going to be successful, in my opinion, because these active patients cannot afford to have inadequate vision for distance. Our presby-LASIK techniques should provide acceptable to good vision on day 1 after surgery for both distance and near, even if the vision continues to improve later.

Avalos: I have been doing presbyopic LASIK since 1998, using my personal presbyopic Avalos-Rozakis method (PARM). Why do I do it? Because it works. Patients are happy with it, and so am I.

Pinelli: I hope presby-LASIK will be available soon. Some nomograms are already available. We are working now with the Bausch & Lomb laser. My opinion is that presby-LASIK will be routine within the next 5 years. We need more publications to support the scientific basis of the technique.1

Last question: Do you think this technique has a future? Personally, I do not think that it will be the only solution for presbyopia, but it is still a great option.

I think that the future of presbyopic surgery will include a sort of menu; the solution will differ from person to person. A variety of options, whether corneal surgery, scleral surgery, or lens surgery, will be chosen based on patients ages, refractive conditions, and lifestyle needs.

Avalos: I am sure presby-LASIK has a future. Its effectiveness, its long-term stability, its low cost, the possibility of retreatment, the low incidence of complications, the low degree of optical side effects, the fact that it can be done starting at the onset of presbyopia, and that it will be available in the future on any excimer laser. For all these reasons, I think it will be the surgery of choice for correction of presbyopia in years to come.

Tamayo: Presby-LASIK undoubtedly has a future. In the future, we will have a complete portfolio of treatment options for patients. We will have multifocal and accommodating IOLs, corneal inlays, and also multifocality of the cornea as options for our patients.

Right now, because the clinical studies in Canada are advanced, I believe that we may have this option to offer our patients within 6 months. It will be easy for surgeons to adopt presby-LASIK once it becomes available because it is based on surgeries that they have done for many years, LASIK, LASEK, or epi-LASIK. Surgeons will be able to use the presby-LASIK nomogram with any excimer laser vision correction technique. It requires only a software change in the laser system; for the surgeon, it will be the same as any other LASIK or LASEK procedure. Also it works very well with IntraLase (Advanced Medical Optics, Inc.). I think the results are even better with IntraLase than with other options. So it is going to be very easily adopted.

Regarding which patients will be appropriate candidates, it will be used in presbyopic baby boomers and also in those patients who do not desire to have intraocular surgery.

Alió: In the future, I think presby-LASIK will replace monovision, and corneal inlays will also substitute for monovision in some cases. Inlays are attractive to surgeons because they can be replaced, and they may find a niche in the market. Multifocal IOLs will be replaced by accommodating lenses. These changes will not be completed for at least 5 years.

In my opinion, presby-LASIK will definitely have a role in the future. Presby-LASIK is already performed, and ongoing studies will show how effective it is for presbyopic correction. We need to wait for the results of these studies and others to see whether presby-LASIK will be able to achieve full presbyopic correction.

Pinelli: I believe the panel has touched all the key points. Thanks to the expert participants. This technique will have a solid future, and it will soon be considered and applied as a routine in institutes of vision worldwide.

Roberto Pinelli, MD, Moderator, is the Scientific Director of the Istituto Laser Microchirurgia Oculare, Brescia, Italy. Dr. Pinelli states that he has no financial interest in the products or companies mentioned. He may be reached at pinelli@ilmo.it.

Gustavo Tamayo, MD, practices at the Bogot& Laser Refractive Institute, Bogotá, Colombia. He states that he is a paid consultant to Advanced Medical Optics, Inc. and Moria, and he has a patent ownership or part ownership and a royalty agreement with Advanced Medical Optics, Inc. He may be reached at gtvotmy@telecorp.net.

Michael Gordon, MD, is a partner at the Gordon Binder Vision Institute, San Diego. He states that he is a consultant to Alcon Laboratories, Inc., and an investigator for WaveLight Laser Technologie AG. Dr. Gordon may be reached at +1 858 455 6800; mgordon786@aol.com.

Jorge L. Alió, MD, PhD, is Professor and Chairman of Ophthalmology, Miguel Hernandez University, Alicante, Spain and Medical Director of Vissum Corp. Professor Alió states that he is a clinical investigator for Schwind-eye-tech-solutions. He may be reached at +34 96 515 00 25; jlalio@vissum.com.

Guillermo Avalos, MD, practices at the Clinica Laser Oftalmico, Guadalajara, Mexico. Dr. Avalos states that he has no financial interest in the products or companies mentioned. He may be reached at +52 33 36410972; guavalos@infosel.net.mx.