feature
The
New Multifocals: Better
Sight, RIGHT NOW
How the next generation of IOLs will impact
your patients and practice.
BY
JERRY HELZNER, SENIOR EDITOR
If ophthalmology had something similar to the Chinese calendar, 2005 would surely go down as the Year of the Multifocal.
The year just past saw FDA approval for two long-awaited next-generation multifocal lenses the AcrySof ReSTOR apodized diffractive IOL and the ReZoom. These approvals were soon followed by a landmark decision by CMS to initiate so-called "patient-share" billing for Medicare-covered cataract surgery patients. The ruling allows those patients to elect to pay the difference for implantation of any of the three more costly presbyopia-correcting lenses they now have the option to choose the ReSTOR (Alcon, Fort Worth, Texas), the ReZoom (Advanced Medical Optics, AMO, Santa Ana, Calif.) and the crystalens (eyeonics, Aliso Viejo, Calif.).
The result of these actions promises to create the ultimate "win-win" situation, offering the potential of spectacle-free vision for many patients and increased profitability for cataract surgeons who have experienced years of declining reimbursement for the basic Medicare-covered cataract procedure performed under CPT code 66984. Approval of the new multifocals is also expected to greatly enhance the popularity of refractive lens exchange (RLE) for individuals above the age of 45 who do not have cataracts, but desire better vision without glasses.
The potential benefits of the new multifocals have not been lost on cataract surgeons. Spurred by the excellent results of visual improvement and patient satisfaction reported in clinical studies, thousands of surgeons have either completed training, or are now being trained, to implant one or both of the new lenses. For example, Alcon reports that 3,300 U.S. surgeons have completed ReSTOR training, with almost half of them now implanting the lens regularly in patients. Advanced Medical Optics reports similar heavy participation in ReZoom training.
Given this level of interest in the next-generation multifocals, Ophthalmology Management surveyed by phone and e-mail more than 20 leading cataract surgeons who have experience implanting one or both of the new lenses. This article will provide a range of insights into how they are using the ReSTOR and ReZoom and the importance of patient selection and accurate eye measurement. It will also highlight certain perceived differences between the two lenses. Some of the statements by surgeons about the lenses are opinions based on their own personal experience with patients.
How Big an Advance?
Before moving on to more specific pointers on using the new multifocals, it might be instructive to look at several diverse opinions as to how big an advance the ReSTOR and the ReZoom represent in the overall evolution of the IOL.
R. Bruce Wallace III, M.D., medical director of Wallace Eye Surgery in Alexandria, La., clinical professor of ophthalmology at LSU New Orleans, and associate clinical professor of ophthalmology at Tulane University, has as much experience as any surgeon in the United States in implanting multifocal lenses. Dr. Wallace performed numerous procedures using the Array lens (AMO), the only previously approved multifocal.
"I consider the new multifocals a step
in the right direction," says Dr. Wallace. "The evolution from the Array to the
ReZoom is obvious. However, these multifocals still represent somewhat of a compromise
in vision because you are losing contrast sensitivity by splitting light. A lot
depends on the needs of the patient. These lenses may be an excellent solution for
many cataract and precataract presbyopes, especially hyperopes who may not drive
much at night and who are going to be very
appreciative of being able to read without
glasses. Overall, presbyopia-correcting lenses can provide good uncorrected multifocal
vision to these people right now, but I do believe that all aspects of IOLs will
continue to improve."
Richard Mackool, M.D., a clinical investigator for the ReSTOR and senior attending surgeon at the New York Eye and Ear Infirmary, has implanted the ReSTOR in approximately 200 patients. He says that about 95% of his bilaterally implanted ReSTOR patients never wear spectacles.
"I believe that history will recognize the ReSTOR lens as a truly groundbreaking advance in both cataract and refractive surgery. There is no comparison between the abilities of the ReSTOR and the Array lenses."
Asim Piracha, M.D., of the John-Kenyon Eye Center, Louisville, Ky., has implanted both the ReZoom and ReSTOR lenses.
"I am excited about the ReZoom," says Dr. Piracha. "It gives good near, intermediate and distance visual acuity. It is distance-dominant, which is important to most patients, and is a significant improvement over the Array."
Richard L. Lindstrom, M.D., of Minnesota Eye Consultants, notes that 95% of his ReZoom patients are satisfied with their vision, but provides this succinct observation.
"The current generation of lenses is useful but not ideal. The ultimate goal is an accommodating IOL with at least 4 D of accommodative amplitude. This will give a full range of vision with minimal night vision symptoms."
And I. Howard Fine, M.D., of Drs. Fine, Packer and Hoffman in Eugene, Ore., who also has implanted the ReZoom, says the new multifocals "represent an interim solution that will be here until something better supersedes them. I see that happening within the next 5 years. To me, the ideal solution would be an accommodative lens with an amplitude of 8 D of vision."
Interestingly, Both Dr. Lindstrom and Dr. Fine give high marks to the crystalens for the intermediate and distance vision the lens provides with fewer night vision symptoms than multifocals. Indeed, Dr. Lindstrom has advocated "mixing and matching" the crystalens, ReZoom and ReSTOR in various combinations under specific conditions for certain select patients. He advocates implanting the ReZoom or crystalens in one eye and then evaluating the patient's satisfaction level to determine if the same or a different lens should be used for the second eye. But more on mixing and matching later in this article.
Using the Multifocals
Because the Array lens never achieved widespread acceptance in the United States, most surgeons who have recently completed ReSTOR and/or ReZoom training will be implanting multifocals for the first time. They will be going through a learning curve that could take 6 months or longer, according to surgeons who have wide experience implanting multifocals.
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The ReZoom IOL |
The actual implantation procedure is not difficult. The foldable ReZoom can be inserted through a 2.8 mm incision using the Emerald T Unfolder insertion device (AMO). The ReSTOR can be easily inserted through the normal-size phaco incision used for the AcrySof SA-60 lens (Alcon).
But be aware that multifocal lenses require highly accurate centration. Surgeons who have experience with the lenses usually will not implant them in patients with severely compromised capsular bags. In addition, surgeons note that implantation of multifocals can increase the visual symptoms of dry eye. It is important to obtain a complete history from all multifocal candidates because some diseases, such as AMD and glaucoma, can rule out the use of multifocals, and other conditions, such as dry eye, may make the use of multifocals problematic if the dry eye is not treated aggressively.
High Patient Expectations
All of the surgeons Ophthalmology Management surveyed agree that two key aspects of achieving patient satisfaction with multifocals are careful patient selection and accurate eye measurement.
Farrell Tyson, M.D. of Cape Coral Eye Center in Cape Coral, Fla., serves a patient base consisting mostly of retirees. Many of his patients are relatively affluent and have opted to pay the difference for the new multifocals. Thus, Dr. Tyson has already achieved extensive experience with both the ReSTOR and the ReZoom.
Because Medicare cataract patients are paying thousands of dollars out of their own pockets for the ReZoom and ReSTOR, and RLE patients are paying the entire cost, Dr. Tyson is aware that expectations can be high and that one dissatisfied patient can hurt a surgeon's practice in a close-knit community of retirees.
"I spend a lot of time with patients upfront to determine their visual needs and learn about their daily activities," he says. "I want to find out what their expectations are and if they are good candidates for multifocals. If they drive a lot at night, I don't give them multifocals."
He also notes that implanting multifocals requires an investment in technology.
"To do multifocals right, you need to know how to use an IOLMaster (Carl Zeiss Meditec, Dublin, Calif.), you should know how to do immersion A-scans, you should be comfortable performing limbal relaxing incisions, and you might have to do some explants," asserts Dr. Tyson. "Multifocals might be beyond the realm of some smaller practices."
Dr. Wallace says he does almost all of his eye measurements for multifocals with the IOLMaster and a corneal topographer. The corneal topographer is useful in the important area of astigmatism control.
In selecting patients for the ReSTOR and ReZoom, Dr. Tyson tends to favor the ReZoom for patients who require very good intermediate vision.
"If they are heavy computer users or work at a cash register, I give them the ReZoom," says Dr. Tyson. "Bifocal wearers who require cataract surgery tend to do well with the ReSTOR. I find that both lenses work better binocularly. I will do the ReSTOR only as a binocular implant."
Dr. Tyson will often give plano polarized sunglasses or prescribe antireflective plano driving glasses for his multifocal patients who have problems with glare, halo or simply the strong Florida sun.
Noted California cataract surgeon David Chang, M.D., says he is using both the ReZoom and the ReSTOR.
"The ReSTOR effective add is about +3.00. The ReZoom effective add is closer to +2.25 and there is some intermediate focus produced by the blending of the refractive zones. This means that compared to ReSTOR, ReZoom is better for intermediate focus but doesn't provide the same power up close," says Dr. Chang. "With average pupil sizes, I tend to use ReZoom more in hyperopes because of the better intermediate focus. These patients have never had good uncorrected near vision and are delighted with what they get with ReZoom. I tend to use ReSTOR in myopes because they are used to seeing very well without glasses up close. However, optimal pupil size is more important with ReZoom. Too small (pupils) means poor reading ability and too large means more halos. Therefore, with small or large pupils, or with patients who may be more sensitive to halos because of frequent night driving, I tend to favor ReSTOR."
Dr. Chang estimates that he is implanting ReSTOR in two thirds of his multifocal patients and ReZoom in one third.
Dr. Piracha is also selective in his choice of multifocals.
"I prefer ReZoom for younger and more active individuals and in those who use a computer. The lens provides good quality of distance vision, especially in bright light, and better intermediate vision," says Dr. Piracha. "I use the ReSTOR in older, less active patients who primarily desire reading vision. I also use ReSTOR in patients with small pupils in photopic conditions. I like the ReSTOR's consistently good near vision and the fact that it is less pupil-size dependent."
Interestingly, Dr. Chang says that only about 3%-5% of his multifocal patients are RLE, while Kevin L. Waltz, M.D., of Eye Surgeons of Indiana, says that about half of his multifocal patients are RLE. Generally, surgeons report that approximately 10%-20% of their multifocal patients are RLE.
Vision Improves
Almost all of the surgeons surveyed for this article agree that most, if not all, of the initial glare and halos experienced by some multifocal recipients tend to disappear over
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The ReSTOR IOL |
6 to 12 months as the brain adjusts to the new lenses. Clinical studies have shown that only about 5% of ReSTOR patients ever experience significant glare or halo.
"It's like putting on a ring or a watch for the first time," says one surgeon. "Initially, you're aware of it and then gradually you forget that it's there. With multifocals, the brain usually learns to ignore the glare and/or halos."
"I do believe there is a learning curve for the patients (in adjusting to multifocals)," says David Hardten, M.D. of Minnesota Eye Consultants.
If there is one salient complaint about the new multifocals, it is loss of contrast sensitivity. Dr. Lindstrom, for example, says that the crystalens produces fewer night vision symptoms than either of the new multifocals. Michael Korenfeld, M.D., of Comprehensive Eye Care in Washington, Mo., will not use either multifocal because he believes the loss of contrast sensitivity, particularly in regard to night driving, is too big an issue to overcome.
David Evans, Ph.D., who has written extensively on the importance of contrast sensitivity in determining quality of vision, has this to say about the issue.
"The multifocal lens is creating multiple focal planes on the back of the eye. These multiple planes overlap each other and cause aberrations and light scatter, thus reducing contrast sensitivity. It would be a good clinical practice to test multifocal candidates before surgery, but most of these individuals are cataract patients and will have reduced contrast sensitivity before surgery due to the cataract. However, for those patients who are considering multifocal IOLs for refractive purposes, measurement of contrast sensitivity before surgery would be a must. If the patient has low contrast sensitivity before surgery, then he or she would not be a good candidate, unless, of course, the patient spends no time in low-contrast environments.
"Also, the point about driving at night or under other low contrast conditions is a good one," Dr. Evans continues. "Doctors should screen patients' quality of vision after surgery with the multifocal IOLs. If the quality of vision
is reduced, then the patients should be advised of this. This is particularly true for cataract patients, who had such poor vision before surgery, any improvement seems like perfect vision. But, they may still have reduced contrast sensitivity due to the multifocal optics."
Though Alcon asserts that most patients' ability to drive at night should be enhanced after surgery, the company does not recommend the ReSTOR for patients who do significant night driving as part of their occupation. Advanced Medical Optics prefers a customized evaluation, suggesting that the issue should be considered on a patient-by-patient basis, with a ReZoom in one eye and a Tecnis monofocal lens in the other as a possible solution for those patients who drive at night.
Alcon and AMO also differ on the issue of mixing and matching IOLs. Alcon does not recommend the practice because the ReSTOR has been studied and was approved by the FDA as a binocular implant and the company is concerned that mixing the technologies may lead to dissatisfied patients. In addition, the company notes that there are no clinical studies to establish the safety and efficacy of implanting any presbyopia-correcting IOL in one eye with a different one in the other eye. AMO again offers surgeons some latitude, suggesting that "the patient's personal needs and lifestyle need to be taken into consideration when making a technology decision."
Advanced Medical Optics follows Dr. Lindstrom's lead in recommending initial implantation of the ReZoom in one eye "for solid intermediate vision" and then working with the patient to select the best option for the fellow eye.
If one can draw a consensus from all the surgeons this magazine surveyed, it is that they generally believe that, used correctly and with motivated patients, both the ReZoom and the ReSTOR are useful additions to a cataract surgeon's armamentarium and that both lenses have the ability to provide both cataract and RLE patients with improved vision and a high level of satisfaction right now. Surgeons agree that the new multifocals represent a step forward in the evolution of the IOL.
ReZoom and ReSTOR: How They Were Designed |
Certain that they could improve on the design
of the original Array multifocal, both AMO and Alcon spent years working on the
next generation of multifocal lenses. The result was AMO's ReZoom and Alcon's ReSTOR. Though some industry observers have characterized the ReZoom as a "new and improved" version of the Array, Ron Bache, vice president of worldwide marketing, AMO refractive group, differs strongly with that description. "The ReZoom is an optimized optic placed under an acrylic surface," says Bache. "The lens is a next-generation refractive multifocal that improves distance, intermediate and near vision with significantly reduced halos and glare." Bache says that the ReZoom is a result of examining "the good points and bad points" of the Array. "The Array is a silicone lens. The ReZoom is an acrylic lens," says Bache. "In dealing with the halos caused by the Array, we knew that they were primarily being caused by the near ad of the lens. We took the fourth near zone, which was causing most of the halos, and made it 57% smaller. We also made the third zone, for distance, 70% larger. The result is that, with the ReZoom, more light is going to distance, reducing halos and glare at night." The ReZoom also has AMO's Opti-Edge design, which Bache says is another element in reducing glare. One of the most eagerly awaited products to come out of the Alcon pipeline is the AcrySof ReSTOR lens, an acrylic, foldable multifocal IOL that uses apodized diffractive technology to provide patients with a full range of near, intermediate and distance vision (with studies showing the best visual acuity at near and distance). The FDA clinical studies indicate that 80% of the individuals in the trial did not need to wear eyeglasses at all after they received the ReSTOR lens. Unlike accommodative IOLs such as the crystalens, the ReSTOR does not depend on contraction of the ciliary muscle to move the lens to create a range of vision. Instead, it combines the complementary technologies of apodization, diffraction and refraction in an optical design that allows appropriate amounts of light to focus on the retina for images at various distances without mechanical movement of the lens. Apodization gradually blends the diffractive step heights, managing the light energy delivered to the retina. Alcon says this technology distributes the appropriate amount of light to near and distant focal points, regardless of the lighting situation. The apodized diffractive optics of the ReSTOR are designed to improve image quality while minimizing visual disturbances. More simply stated, when the pupil is constricted, incoming light is equally divided between near and distance vision. When the pupil is enlarged, as in low lighting conditions, the light distribution becomes distance-dominant. |