Chang: I thought we would start by having everyone describe their personal experiences with presbyopia-correcting IOLs.
Nichamin: Most of my experience is with the Crystalens (Eyeonics, Inc., Aliso Viejo, CA), and I am just beginning to implant the Acrysof Restor (Alcon Laboratories, Inc., Fort Worth, TX) and Rezoom (Advanced Medical Optics, Inc., Santa Ana, CA) multifocal IOLs. Overall, I am happy with my results thus far. As others have observed, if there is a shortcoming with the Crystalens (which is terrific in that it does not degrade the quality of vision), it is the lack of near function it achieves. In my experience, patients’ reading ability can vary considerably, but their intermediate vision is definitely better than we would expect with a standard monofocal implant. For my refractive lens exchange population who depend on their computers, I find that the Crystalens represents an excellent option, because it provides an extra 1.50D of function over that of a standard lens.
Lindstrom: In our clinical practice, we currently use the Crystalens, the Rezoom IOL, and the Acrysof Restor lens. We use the Tecnis diffractive IOL (Advanced Medical Optics, Inc.) in clinical trials. In the previous 20 years, I have implanted the 3M (St. Paul, MN) diffractive lens, the Nuvue lens (IOLab), the Acrysof Restor lens, the Storz three-zone lens, and the Array lens (Advanced Medical Optics, Inc.), in addition to a large series of monofocal monovision implants.
Lane: Most of my experience is with the Acrysof Restor lens. I have minimal experience with the Rezoom lens and with the Array lens before that. I have very limited experience with the Crystalens.
Bucci: For the 7 years preceding 2005, I made select but steady use of the Array lens. In the past 4 to 6 months, I have implanted approximately 230 Acrysof Restor lenses and about 20 Rezoom IOLs.
Packer: I have used the Array lens since 1997, the Crystalens since 2000 in clinical trials, the Rezoom lens during the last 6 months, and the Tecnis Multifocal IOL (Advanced Medical Optics, Inc.) currently in clinical trials.
Kohnen: My experience goes back to the diffractive 3M design when Dick was involved in a study started in Europe.1 Currently, most of my experience is with the Acrysof Restor lens, because I was involved in the European trials for that IOL. I have implanted the Array lens, of course, during the last 10 years, but my use of it is decreasing. I have not used the Rezoom lens yet. As for accommodative IOLs, I have only used an experimental design, and I am starting to see a couple of complications.
Chang: Currently, I am using all three (the Acrysof Restor, Rezoom, and Crystalens implants), although I think I probably implant significantly more multifocal IOLs than Crystalens IOLs.
Now that US ophthalmologists are allowed to implant presbyopia-correcting IOLs in Medicare patients, I would ask each of you to tell me what percentage of your cataract patients are choosing to pay the extra premium for these lenses.
Nichamin: I am probably the novice in the group at integrating this technology into practice. In rural western Pennsylvania, at this point, we are probably implanting fewer than 10% of refractive lens exchange patients with premium presbyopia-correcting lenses and perhaps as low as 5% for the cataract population.
Lindstrom: Right now, our practice is at about 10%.
Lane: Yes, that is the number I would choose. Dick and I practice in the same kind of community, but I have clearly seen a trend upward now, even in the last month. Although I might have been at the 10% level that Skip was talking about, it is certainly, now, in the 15% to 20% range with all the publicity and advertising for these lenses.
Bucci: My number is probably 25% of patients. It is interesting that more are choosing a multifocal option at the time of cataract surgery now than when the multifocal IOL was paid for by Medicare. I tell patients that, because the lenses are so expensive, Medicare will not cover them. I then explain that this type of surgery in patients who do not have cataracts costs approximately $4,000 per eye. I tell them that, because they have cataracts, they can undergo the surgery for approximately $1,700 per eye, and their perception is that they should not pass up this opportunity to receive advanced technology.
Packer: Approximately 10% of the Medicare patients in our practice receive presbyopia-correcting IOLs. That percentage is slightly higher for younger cataract patients with commercial insurance. We implant the majority of these IOLs during refractive lens exchange.
Kohnen: We do not have a premium in Europe, so I only use presbyopia-correcting IOLs in clinical trials for my social security patients. For patients whose private insurance will cover the cost of the lenses, I have seen an increase of maybe 30% to 40%. Of course, I use these IOLs for refractive lens exchange more and more.
A DIFFERENT MINDSET
Chang: The fact that patients pay something out of pocket is probably key to their understanding and differentiation of the service provided. There was never much patient demand for the Array lens, because it was difficult for patients to determine whether they saw well due to cataract surgery or to the multifocal lens implant. In contrast, patients are now requesting that new multifocal IOL or the Crystalens. Steve, which lenses are you primarily using, and what are the pros and cons you have observed?
Lane: I mainly use the Acrysof Restor refractive, apodized, multifocal lens. The advantages of this particular IOL are that it provides excellent near vision in addition to distance vision. The Achilles’ heel of this diffractive IOL is intermediate vision, which, although not as good as distance or near vision with this lens, is more than satisfactory for most intermediate tasks. The problem that needs to be emphasized with any multifocal technology is that you have to give up something someplace; it is not an accommodating technology.
It is also important to define what is meant by intermediate vision. What we measure and call an intermediate range might not be the same for every patient. It depends on the person’s activities. You must discuss with patients what they really want of the technology. If patients’ main daily tasks are in the intermediate range, then you probably should give them a lens that stresses intermediate vision. If what they really want is something for good near vision, then you probably should choose the optimal lens for that goal. A true accommodating lens that covers all ranges of vision is the Holy Grail. I just do not think that we have one at this moment.
Bucci: I want to re-emphasize several points. The transition from a LASIK surgeon to a refractive lensectomy surgeon is very different than the transition from a cataract surgeon to a refractive lensectomy surgeon. The expectations of patients undergoing refractive lensectomy are like those of a LASIK patient, not a cataract surgery patient. Cataract surgeons who have never performed refractive surgery think they can simply start implanting presbyopia-correcting IOLs. We must manage patients’ expectations preoperatively and develop a relationship with them. It is a whole different culture.
Nichamin: I agree strongly with Frank. We can talk as much as we want about the different qualities of these lenses. At the end of the day, however, it is the refractive mindset of the surgeons and their entire practice that is paramount. Surgeons adopting this type of technology have to be versed in bioptics or be able to partner with a surgeon who can perform enhancements such as LASIK and conductive keratoplasty. Implanting presbyopia-correcting IOLs is a big undertaking. I think Steve’s point is excellent: we will need to spend a lot more chair time educating our patients.
Packer: Yes, I completely agree. It is a very different relationship that you have with these patients, whether they be cataract patients who are paying the extra premium or refractive lens exchange patients. You have a real physician/patient relationship as opposed to a relationship mediated by a third-party payer, where you are really doing government work. Implanting presbyopia-correcting IOLs is very similar to refractive surgery, as Frank said.
In refractive surgery, we tell patients we want to achieve their goals, if possible. Our efforts may include enhancements, astigmatic correction, an investment in biometric technology, and topography. They are not part of the skill set of the average cataract surgeon. To me, patients are paying me to do all that I can to help them achieve spectacle independence. Now, if there is something I cannot do, they have to accept that as a limitation of the technology. We can usually fix residual refractive error.
Bucci: You have to be prepared to correct astigmatism. I correct astigmatism of 0.75D or higher. We know that 1.00D of astigmatism means 20/30 UCVA, and these patients are not going to be happy with that visual acuity.
Lindstrom: I said in the past that 20/happy is 20/30 and J3, but, really, it is becoming more like LASIK now. We really have to be within 0.50D of emmetropia and 0.50D or less for astigmatism, and that is 20/20 and J1 vision. I am aggressive about enhancements in this group of patients.
Lane: Dick, you coined the phrase 20/happy. What you want is a happy patient. It really does not matter which plus or minus number you choose. As with any keratorefractive procedure, you want a patient who is (1) happy and (2) spectacle independent. Usually, you do not get one without the other.
Bucci: The added cost of the lens increases the price of the surgery. A cost of $7,000 to $10,000 for two eyes means patients have higher expectations. People who can afford this surgery want to be happy. They expect not to use glasses. You have to be able to solve that problem.
Lane: I think the surgery we perform for patients receiving presbyopia-correcting IOLs must be more meticulous than in the past with monofocal lenses. We must perform thorough cortical cleanup, size the capsulorhexis exactly right, and center the lenses well. Posterior capsular cleanup is particularly important, because anything on the posterior capsule is going to have a more significant effect on a multifocal than a monofocal lens. We should do as much as we can to prevent posterior capsular opacification (PCO) or anything else that would diminish the patient’s vision early postoperatively. That includes preventing even mild degrees of cystoid macular edema (CME).
Chang: You are saying that it is more than just delivering a premium IOL. It is premium lens removal surgery. You have to have perfect biometry, a perfect capsulorhexis, an intact posterior capsule, good cortical cleanupessentially flawless surgery.
Kohnen: It is not only premium surgery; it is premium diagnostics. We need accurate corneal topography in order to place our incisions correctly to reduce astigmatism.
Nichamin: I would point out the corollary to Steve’s point. To optimize the result, we have to have a perfectly positioned IOL. If the lens does decenter just a little bit, we may find that the patient’s vision is significantly worse because of induced higher-order aberrations, particularly with multifocal optics.
Bucci: With refractive lensectomy, you cannot tolerate CME. Using nonsteroidals with steroids after surgery should be almost standard. The CME may last a few weeks and reduce visual acuity to 20/25 or 20/30. Most of the time, this CME resolves, but these patients want to see well fast.
Chang: May I see a show of hands for how many of you are using a topical nonsteroidal routinely in your cataract patients? I see that it is everyone. Dick, how would you compare and contrast the presbyopia-correcting IOLs?
Lindstrom: I have had a chance to examine and talk to patients who have received all of these lenses. One way to think about it is to look at what patients do not like about each lens. They want to have good distance, intermediate, and near vision, and they would like to have high-quality vision, including at night, with no dysphotopsia. We do not have such a lens yet. The primary complaint I hear from patients who receive the Crystalens is that their near vision is inadequate. From my perspective, the Crystalens provides the weakest near (see sidebar: The Crystalens: Pros and Cons).
With the Acrysof Restor and Tecnis Multifocal lenses, intermediate vision is weaker, and some patients complain about reduced quality of vision and night vision symptoms. With the Acrysof Restor lens, some patients also describe difficulty reading in a dim environment, because the near function of the lens depends on pupillary size. They either need more light, or they must have someone else read the menu to them, so to speak, in a dark restaurant. Patients who receive the diffractive Tecnis Multifocal IOL actually do not have that problem.
With the Rezoom lens, my patients’ primary complaints have been of night vision symptoms and somewhat weaker near vision. My colleagues and I used the Array lens for years, and, like everyone else here, many of our patients were dissatisfied with their near vision and experienced more night vision symptoms than we wanted. We have found the Rezoom lens to be better at providing near vision and to perform a little better at night. Still, a patient may complain about night vision symptoms and, occasionally, about weak near vision. So, here I am comparing the lenses according to their shortcomings.
Packer: Turning it around, you can look at the relative strengths of the lenses and say patients who have more activities that are distance or intermediate dominant will be happier with the Crystalens, if they do not mind possibly needing a 1.25D or 1.50D pair of reading glasses. Patients who read a lot will be happier with a diffractive multifocal IOL (Acrysof Restor or Tecnis Multifocal IOL), which has a +4.00D add at the IOL plane. Dependence on pupil size is interesting, because it is the reverse with the Acrysof Restor and the Rezoom lenses. With the Rezoom IOL, patients need a larger pupil to read, because the near does not start until past 2.5mm. With the Acrysof Restor IOL, a bigger pupil decreases the patient’s ability to read, because the lens becomes more distance dominant. I actually have Rezoom patients who say, “I can read, but I have to turn down the lights.”
Bucci: I have bilaterally implanted 56 Acrysof Restor IOLs, and I was very pleased with patients’ reading vision (see sidebar: The Acrysof Restor Lens: Pros and Cons). It was everything they did not have with the Array lens. The night vision problems were minimal, but a significant number of patients have had pronounced problems with their intermediate vision.
The older cataract patients who do not use computers often and who are thrilled just to read a book tolerate the Acrysof Restor lens better than younger people who spend more time in front of the computer. I started a study in which I implant the Rezoom lens in patients’ nondominant eye and the Acrysof Restor lens in their dominant eye. When the pupil is small, the Acrysof Restor IOL provides good reading vision. As the pupil dilates, the Rezoom lens takes over, so there is a reading synergy. So far, I have performed 30 of these procedures and have at least 8 weeks’ follow-up for 21 patients.
Chang: For those of you who have tried or are using both, do you see a difference between the Rezoom and Acrysof Restor IOLs as far as nighttime halos and visual symptoms?
Packer: In the FDA data, the IOLs performed almost identically, which is fascinating. It is about 30% moderate and severe combined. The study of the Acrysof Restor lens began with the three-piece platform and went to the single piece, and there are actually slightly fewer halos with the three-piece platformperhaps, one might speculate, because of better centration.
Bucci: You can get different numbers depending on how you ask about nighttime images. It is difficult for people to explain what they see, categorize that information, and make an apples-to-apples comparison.
Chang: Imagine that you are counseling a young, somewhat demanding patient with big pupils. He is interested in reducing his dependence on spectacles for near tasks, but he is really worried about halos. Which lens are you going to implant?
Bucci: The engineer would expect to be independent of spectacles. He is definitely going to be in front of a computer. I have not yet implanted the Rezoom lens bilaterally, so I am unfamiliar with how patients may describe the pattern of halos with it. I would be confident about placing the Acrysof Restor lens in a patient’s dominant eye and the Rezoom lens in his nondominant eye. I think that the patient would adapt to slightly more halos perceived by his Rezoom eye versus fewer rings and halos in his Acrysof Restor eye. He would have excellent near, intermediate, and distance vision, and he would depend less on his pupillary size for excellent reading. He would be able to read under almost any circumstance.
Lindstrom: For a truck driver at night, I would probably choose an aspheric monofocal lens, or I would implant a Crystalens for blended vision. I probably would not choose a multifocal IOL, although a multifocal lens in one eye could be an option.
Lane: I would agree with Dick. I am wary of implanting multifocal IOLs in a person who has significant night vision duties such as a pilot or a truck driver. My experience with the Acrysof Restor IOL is based on implanting several hundred lenses and my role as a monitor of the clinical trial. It is unusual for someone in my patient population to complain of nighttime symptoms. I have never even considered explanting a lens from the eye of any of the Acrysof Restor patients who have reported night vision problems. For the rare patients who experience significant nighttime glare, I put a -3.00D lens in front of them to demonstrate what their vision would be like. In every instance, the patients said they would rather put up with the glare than give up their ability to read without correction.
Kohnen: The European trial of the Acrysof Restor lens reported more glare symptoms than the US trial (approximately 8% vs 4%). Our experience was with the three-piece design, which was in the European more than in the US trials. I never had a patient request an explant. In the European trial, there were two explants, one due to an incorrect IOL power calculation and one because of disturbances. Like Dick, I would probably avoid multifocal implants and choose a monofocal IOL in eyes with large pupils. Monovision may be the best option.
Lindstrom: I think the likelihood of explants will be slightly higher with multifocal versus standard lenses. A few patients will not achieve the outcomes they want and will have unwanted night vision symptoms. During the Array era, I had patients who accepted unwanted nighttime symptoms to achieve excellent near vision. Patients who had night vision symptoms but not good near vision asked, “I’ve got all these problems at night for what?”
Kohnen: I had the same experience as Dick. I was really frustrated with some of the Array lenses, because I had to take them out. Then came the Acrysof Restor lens with its apodized diffractive optics and then the Tecnis Multifocal IOL. From a clinical standpoint, however, results are even better than in the trials.
Packer: Even so, the engineer and the nighttime driver have always been on our watch list for multifocal implants. As Steve said, there is always a compromise with multifocality, and people who have high demands and who want to read their micrometer scopes may be better off with monovision or with binocular vision and reading glasses. If quality of vision is what they are after and spectacle independence is secondary, it is a different sort of person than the one who really just wants to be free of glasses and will put up with the slight blur or reduced contrast that multifocality always engenders.
Bucci: Effective preoperative communication with patients is critical. If I assess a patient’s personality and realize that I will never make this individual happy, I practically talk him out of multifocal IOLs. If he begs me to implant this lens type, I can always remind him that I said he might have halos.
Packer: Especially because they are spending so much, they need to know the truth about the technology and what its limitations are.
Bucci: I inform them that there can be astigmatism in either their cornea or their crystalline lens. I point to a cross-section diagram of the eye at the time of this discussion, and they see that light passes through both of these anatomic entities. I make clear that we are removing the crystalline lens but that there is still a 35% chance that they will have enough residual astigmatism in their cornea to require an enhancement. I explain that this procedure is necessary for them to achieve the maximum outcome with these implants and that, if they are unwilling to undergo the enhancement, the multifocal IOL is probably not a good option for them. Usually, patients are receptive to the straightforward explanation and are willing to pay extra for the additional procedure.
CATARACT VERSUS REFRACTIVE LENS EXCHANGE
Chang: Have you seen a difference in the tolerance or intolerance of halos between your refractive lensectomy patients and your cataract patients? Presumably, cataract patients are already having nighttime images due to the cataract.
Lindstrom: Most of the Array lenses that I implanted were in cataract patients, and they did not hesitate to complain. I am not sure I can tell the difference. I think perhaps cataract patients have more to gain, so they may be more accepting. They still notice the negative side effects, however.
Kohnen: We have a different population, because refractive lens exchange is usually for high myopes or high hyperopes, at least in my practice. We are not yet treating presbyopic emmetropes.
Lane: People who have cataracts are obviously disabled by them. People who are coming in for refractive lens exchange are disabled by their refractive error. The people who are -1.00, -2.00, -3.00D are usually opting for LASIK when they are younger, or they are getting along pretty well if they are in the presbyopic age group.
Packer: I have infrequently treated the mildly hyperopic (+0.50D) presbyope. The low myopes, I think, are very happy. I tell patients who are 50 years old with
-0.75D that they already have what I would consider a successful result from refractive surgery.
Lindstrom: We perform a lot of monovision LASIK on those patients, maybe not for -0.75D but for -1.25 to
-1.50D. What do you do for a -1.50D 50-year-old? I do not perform a refractive lens exchange. If I do something, I only treat one eye for distance with the excimer laser.
Chang: What about an emmetrope who really hates his glasses. Are any of you using presbyopia-correcting IOLs in these patients?
Bucci: I tell them that I am very conservative and respectful of intraocular surgery and the 20/20 eye. I really do not want to perform two refractive lensectomies. If they are adamant about undergoing treatment, I may agree to operate on one eye, but I insist on waiting 6 months to see if they adapt to any light phenomena and if they are happy with their reading vision.
Lane: If they were good candidates with monovision contact lenses, I would try that modality first. Then, I would not hesitate to try conductive keratoplasty, LASIK, or PRK. I think that is the way to go with that patient.
Packer: Just to make the IOL power calculations more difficult when they have their cataract surgery?
Lindstrom: There are a lot of presbyopes. What if a 44- to 55-year-old patient loved his monovision contact lenses but was becoming contact lens intolerant? Would you be willing to duplicate that approach with surgery? I would.
Kohnen: I might, but this is not a concept that is very popular in Europe.
Nichamin: I think your point is well taken in the context of the multifocal discussion. If a patient was successful with monovision, why broach multifocality? Why not go with monovision?
Lindstrom: I usually do.
IMPACT ON CLINICAL PRACTICE
Chang: For those of you who have busy LASIK practices, how have these new IOLs changed your approach to patients between 50 and 60 years of age who request LASIK for their refractive error?
Nichamin: We rarely perform LASIK as a primary procedure on patients older than 55. The hyperopes, I believe, should lose their crystalline lens. They are in a healthier state as pseudophakes. It is so disappointing to perform successful LASIK, for example, on a 54-year-old myope and have him return 2 years later complaining about his quality of vision. One might think that perhaps it is induced higher-order aberrations from the LASIK procedure. Instead, the problem more often is a change in the crystalline lens that then must be removed to alleviate his symptoms. In such a case, of course, one faces the additional task of a challenging IOL power calculation because of the patient’s previous refractive surgery.
Approximately 7% of our total implants now are refractive lens exchanges, and the number is slowly growing. Although I realize that we are probably more aggressive than most, we track our data, and I truly believe that the risk/benefit ratio favors lenticular surgery in many presbyopic ametropes. As we continue to see improvements in IOL technology, this trend will continue, and I believe it to be the wave of the future. I think the age range of our LASIK population is definitely shrinking.
Lane: I would agree. I discuss the possibility of restored near vision with all presbyopic 45- to 55-year-old patients who come in asking about LASIK. They were unfamiliar with this kind of lens technology, and most walk out having decided that they really want refractive lens exchange, which will give them more than they had hoped for LASIK alone.
Additionally, we all have patients on whom we would not operate, because they have an unusual looking cornea. We may even be nervous about PRK for that group. They come back year after year with no change in topography. If you perform refractive lens exchange on those patients, they love you.
Kohnen: The complications of IOL surgery are currently low compared to laser surgery on a cornea with potential pathologies. I am not really sure. I agree that, if we had patients who have this corneal problem or potential corneal problems, then I am always more inclined to use phakic IOLs or refractive lens exchange.
Lindstrom: I do not have an exact age cut-off, but the closer the patient gets to having cataracts, the more logical it is to perform cataract surgery. Another issue that we are facing is at what point can we write cataract in the chart? When do we have to write incipient cataract, which is a difference of a couple of thousand dollars per eye for the patient. They can pay for the procedure now, or they can wait 2 to 3 years to see if their insurance will cover the surgery. It is an awkward discussion.
Chang: How does mild age-related macular degeneration (AMD) or the possibility of AMD affect your decision to implant a presbyopia-correcting IOL in a cataract surgery patient?
Lindstrom: I implanted my first multifocal IOL in 1985. AMD was always a concern. I have some patients now who have developed meaningful AMD who had none at the time of surgery. My clinical impression is that receiving a multifocal implant was not a bad thing for them. When they look through the top of a standard bifocal spectacle, they have their standard multifocal vision. When they look through the bottom, they more or less have a built-in low-vision aid. I do not think I have harmed anyone’s near visual function; if anything, I think I have helped them. I do believe, however, that a few of these patients will lose their driving privileges a little earlier than if they had not received a multifocal IOL. I do not put multifocal IOLs into the eyes of patients who have frank macular degeneration, but I feel comfortable that I am not harming those who later develop AMD.
Lane: I think it is a controversial subject and will continue to be until we get some good studies. The bottom line is that we do not know for sure, but I do not believe that a multifocal IOL is contraindicated in a patient who has some drusen and/or maybe a little pigmentary mottling but still has vision consistent with his level of cataract or good vision because of refractive lens exchange.
The issue, of course, is that there is some splitting of light that occurs with any multifocal system, and patients with AMD need as much light as possible to maximize their vision. Realize, however, that there is some loss of energy even going through the optical system of a monofocal IOL.
As Dick just mentioned, the near portion of a multifocal lens may actually give a telescopic effect that aids patients with AMD. I do not think we are doing a disservice to patients with early macular changes whose decrease in vision is consistent with their cataract.
Lindstrom: If a patient with AMD and 20/30 visual acuity strongly desired to maintain his independence and ability to drive, I would be uncomfortable putting in a multifocal IOL and possibly costing him his driver’s license. I would select an aspheric monofocal IOL. If a person has already given up driving, I can argue that the multifocal IOL would be beneficial.
Lane: The concern I have is for the patient who has some macular changes but is not yet symptomatic. Some people would not want to implant a multifocal IOL, because the patient may develop macular degeneration somewhere down the line. Although studies need to be performed, I do not think the implant would be detrimental.
Packer: Even in the clinical trials, patients with slight changes in the retinal pigment epithelium or atrophic changes who had a potential acuity of 20/20 were considered candidates. I think that is fair. There is no way of knowing whether or not these people are really going to suffer in their driving later or not. If it is a huge benefit now to be free of spectacles, maybe that is a reasonable tradeoff.
Lindstrom: As a clinician, I have learned that these patients are not unhappy with you later when they get macular degeneration.
Bucci: I am not extremely worried about these patients. If they have macular changes, I diligently document a potential acuity meter (PAM) reading of 20/20, if they can achieve it. It is somewhat harder to get reliable PAM readings in patients with dense cataracts, because the PAM is not quite as accurate through more severe nuclear sclerosis. If the patients have heard about multifocal lenses, it is somewhat of a judgment call as to the true health of their retinas.
Chang: For those of you using the Crystalens, do you see a difference in its performance between the younger and older patients?
Packer: I think there is a greater difference with various refractive errors when using the Crystalens. I have found that long eyes tend to do very well, which is counter to what we would have expected had we thought the lens’ actual mechanism was movement. I think this observation comes together, Dick, with what you said and with what Jack Holladay, MD, has said about how the Crystalens may increase the depth of focus in a standardized fashion.2 Then, in a long eye with the posterior placement of the optic and small optic diameter, it will be more forgiving; you will get a much longer depth of focus. I had the opportunity to implant the Crystalens bilaterally in an ophthalmologist who confirmed that impression. He was a high myope and is now spectacle independent. He said, “I don’t get the idea I am changing my focal distance. I just feel like everything is in focus all the time.” I found that high myopes do exceptionally well with the Crystalens, better than I would have expected.
Lindstrom: The clinical trials confirmed that the hyperopes did not do better than the myopes. In addition, a higher powered lens, if this IOL works primarily through forward movement of the optic, should work much better. A +30.00D lens should work better than a +10.00D, but that has not been found. It is clear to me that the Crystalens does not primarily shift focus by having the optic move forward and backward. It is also clear to me, however, that, with the Crystalens, we get greater depth of focus than a monofocal IOL and better