American Academy of Ophthalmology Web Site: www.aao.org
Cataract Poll Exclusive: Results Now In
For the second year running, EyeNet brings you exclusive results of the audience response poll during the popular Spotlight on Cataract Surgery Session at the Academy’s Annual Meeting.
This past November, the Spotlight on Cataract Surgery Session at the Academy’s Annual Meeting in Las Vegas was entitled Pseudophakic IOLs—Where Are We Now? Where Are We Going? This, the fifth annual Cataract Spotlight Session, covered aspheric, blue-blocking and toric IOLs, as well as presbyopia-correcting IOLs, future refractive IOL designs and challenging IOL cases and complications. In all, 30 different speakers addressed controversial topics ranging from mixing presbyopia-correcting lenses to IOL fixation in the absence of capsular support. Howard Gimbel, MD, MPH, concluded the four-hour symposium by delivering the second annual Charles Kelman Lecture, entitled “Capsule Openings and Evolving Strategies for IOL Fixation.”
For the second straight year, an audience response poll was conducted throughout the symposium. Following each lecture, audience members weighed in with their preferences and opinions using electronic rapid response keypads. The voting results were immediately tabulated and projected on large screens during the symposium and are now reprinted in this issue of EyeNet. The results are particularly interesting given the anonymity guaranteed by this polling method and the fact that each question immediately followed a lecture on the topic. Read on for the questions and results, as well as a post-meeting commentary offered to EyeNet from each of the session speakers.
Q1-Your preferred IOL platform
No surprises. We confirm that most surgeons have moved toward hydrophobic acrylic material (81 percent). Use of silicone IOLs has dropped significantly. An important caveat: Surgeons in the United States have not yet used the modern hydrophilic acrylic IOLs, which can be inserted through very small incisions (i.e., 1.6 to 1.8 mm). These are used in increasing numbers in several foreign markets and some will be FDA approved. It will be interesting to see if these may be added to the list of commonly used IOL materials in the future.
Q2-How often do you implant minus spherical aberration IOLs?
The trend in cataract and refractive surgery is to focus on improving not only Snellen visual acuity but also quality of vision. Multiple independent studies, including an FDA trial conducted using the Tecnis lens, show that aspheric IOLs can reduce the spherical aberration of the eye and improve quality of vision parameters. The importance of implanting an aspheric IOL goes beyond improving Snellen acuity and quality of vision and translates into improved safety for the patients especially while driving at night.
Q3-How often do you implant zero spherical aberration IOLs?
Although the audience poll answers reveal that most surgeons do not implant zero spherical aberration IOLs, perhaps that may change once they have been informed about the benefits of this type of IOL. It is a “do no harm” IOL. It eliminates the added spherical aberration caused by a standard implant and offers visual benefits to all types of cataract patients. It is the ideal lens in cases of pseudoexfoliation or zonular instability, such as trauma. It should be in the armamentarium of IOLs for all surgeons.
Q4-Is there a medical benefit to blue-blocking chromophore?
Based on the audience response, the majority are convinced that there probably is such evidence with a significant minority thinking there probably is not sufficient evidence. There is indeed a great deal of evidence to support that blue light may be toxic to the retina and that filtering blue light in its toxic range has no negative clinical impact. Color vision, contrast sensitivity, etc., have been shown not to be meaningfully interfered with. I predict that the majority of IOL manufacturers in the near future will all incorporate some form of blue filter in their IOLs.
Q5-Would you choose a blue-blocking IOL for yourself today?
Blue-blocking IOLs have been around now for many years, and the debate has raged unabated. The most interesting part about the audience response is that while 54 percent said there probably is a medical benefit to blue-blocker lenses, only 34 percent stated that they would personally use it. Considering the number of years that this lens has been available, it seems to represent a hesitancy on the part of many surgeons. This probably means that the possible benefit is not perceived as very great, or that the concerns outweigh the benefits. Now, 14 percent state that if they were going to block some visible light it would be the violet range, which is a relatively new part of this debate. A full 19 percent still have not decided either way. It would appear that without a prospective, randomized trial to prove or disprove the medical benefit—which seems unlikely at this point—we will continue with a lot of uncertainty.
Q6-In the future, for 1 to 2 D of astigmatism, I will usually
As the use of toric IOLs increases and surgeons become better educated about how they work and about techniques for implantation, I predict that the percentage of use will sharply increase. Toric IOLs offer the most predictable and accurate correction of astigmatism available. I think it is still unclear and confusing to many surgeons how best to implement these IOLs in their practices. Astigmatism control—even more than the correction of presbyopia—is the first frontier that must be conquered in what we call refractive cataract surgery. I expect these percentages to change in the coming years as surgeons see how easy these IOLs are to use, how straightforward the calculations are in determining lens power and axis positioning, and, most important, how excellent the results are for their patients.
Q7-Can most emmetropic patients tell a difference between aspheric and spherical IOLs?
The differences between aspheric IOLs and spherical IOLs can be difficult for patients to detect. While a reduction in ocular spherical aberration can be easily detected by the physician using a wavefront aberrometer in the clinic, detecting differences in contrast sensitivity measurements usually requires a specialized instrument in a controlled testing environment. As we learn more about optical aberrations and how to better quantify them, we may see IOLs that are customized not only based on axial length measurements but also on parameters like spherical aberration.
Q8-Main reason I don’t routinely use negative spherical aberration aspheric IOLs
It has been just over four years since the FDA-monitored clinical investigation of the first modified prolate aspheric IOL was completed. Double-masked, randomized night driving simulation testing revealed significantly better functional vision with the Tecnis aspheric IOL. On that basis CMS designated Tecnis a New Technology IOL, eligible for a $50 additional reimbursement when implanted at Ambulatory Surgery Centers (Feb. 27, 2006, through Feb. 26, 2011); subsequently, CMS granted the same status to the SN60WF IOL (Alcon). A recent review of articles in the peer-reviewed literature found 24 reports that suggested varying degrees of superior contrast sensitivity and/or reduced spherical aberration with the Tecnis IOL as compared with a variety of spherical control IOLs.
Given the naturally conservative inclination of most cataract surgeons,it is gratifying to see that almost one out of three has adopted this new technology. The skeptical and cost-conscious among them may yet find reason to join the trend.
Q9-For biometry, I primarily use
The IOLMaster has proven itself to be the most accurate and reproducible method for axial length measurement in many clinical situations. And it now appears to be the method of choice for many ophthalmologists. However, optimizing just one part of the total IOL power calculation process, such as axial length, is not all that’s required to dramatically improve postoperative refractive outcomes. An IOL power calculation is a multipart process that contains a pitfall. Doing one part perfectly, such as measuring the axial length, is not all that’s required for a perfect result. But doing one part poorly may result in an unpleasant refractive surprise. To consistently hit the postoperative refractive target, every component part of the entire IOL power calculation process must be optimized.
Q10-Do you usually charge for limbal relaxing incisions?
Of the surgeons who perform LRIs, the majority do not charge for this service. However, the salient finding in the responses was that half of those polled do not perform LRIs at all. Performing LRIs is one of the most important steps that must be mastered for improving uncorrected visual acuity following cataract surgery. As patients continue to demand improved uncorrected visual acuity, this skill must be learned to perform refractive IOL surgery. LRIs provide a significant service and involve the purchase of instrumentation, physician expertise, additional testing, risk and additional surgical time. The decision to charge for LRIs rests with the physician, but in an era of declining reimbursement, it seems more than reasonable to charge for the service.
I am surprised that there are so few keratorefractive-only surgeons (1 percent). I had a distorted view of their prevalence, I guess, because I am friends with so many of them! I am also surprised that 43 percent of our colleagues do both cataract and keratorefractive surgery; this is quite impressive, as it is challenging to stay up-to-date in both areas.
Q12-Your Crystalens experience
The poll tells us that the Crystalens story has not been told; 91 percent of our colleagues have never even used it. Although the Crystalens was the first lens approved by the FDA for presbyopia, and the only one labeled for accommodation, market penetration is low. I believe this is largely due to small size, lack of track record and the single-product nature of the parent company, Eyeonics. Perhaps we have seen a similar situation in the past when LASIK was championed only by Chiron, a relatively small company, and depended upon the merits of the product and word of mouth to grow.
I predict that lenses with accommodative technology will play a significant role in our clinical practices in the future. Let’s watch this poll next year and in years to come.
Q13-Your ReZoom experience
Recent reports show that the ReZoom multifocal IOL is gaining market share over last year. However, presbyopia-correcting IOLs in general are in an early phase of adoption, and it is likely that we will see increased interest in this technology once surgeons and their patients learn about the benefits of multifocal and accommodative IOLs.
Q14-Your ReStor experience
It is interesting to note the relative popularity of the ReStor multifocal IOL among the roughly 600 attendees who responded to this question. Of those responding, 27 percent indicated that it was their presbyopia-correcting IOL of choice, as compared with 7 percent for ReZoom and only 3 percent for Crystalens.While it is interesting to speculate whether the data reflect superior clinical performance of the ReStor, it remains possible that other factors account for this observation. These may include popularity of the one-piece, blue-blocking, hydrophobic acrylic template design; the manufacturer’s (Alcon) overall high market share; or other design features of the IOL.
SPEAKER: Samuel Masket, MD
LECTURE TOPIC: ReStor, top 10 clinical pearls for success.
Q15-Were Tecnis multifocal available, it would likely be
The very interesting poll results show that 40 percent would use the Tecnis multifocal, 41 percent are not sure and 19 percent would not use it. The number of physicians who would not use the Tecnis multifocal IOL is less than 20 percent despite the fact that the IOL is not on the U.S. market yet. This shows a shifting interest to multifocal lenses.
Q16-If you implant multifocals, have you mixed designs?
There are three questions in succession dealing specifically with mixing multifocal or presbyopia-correcting IOLs. The trend observed from the answers is extremely interesting. The first question (this one) asked how many surgeons have mixed presbyopia-correcting lens designs, and the response was 29 percent if you disregard those who don’t use multifocals. When asked in Question 17 what was the most common bilateral presbyopia-correcting IOL strategy, only 9 percent chose “Mixing presbyopia-correcting IOLs.” However, after the audience heard three presentations that offered a significant amount of data about mixing presbyopia-correcting IOLs (both for and against), the change in opinion was remarkable. The surgeons were asked what they would choose if they were a patient getting multifocals (Question 18), and 66 percent chose the ReZoom/ReStor combination vs. only 5 percent ReZoom/ ReZoom and only 13 percent ReStor/ ReStor.
It was impressive to see the surgeons responding to credible data regarding mixing and matching multifocal IOLs. The synergistic and complementary aspects of mixing technologies exploded the myth that different optical systems would be antagonistic.
Q17-My most common bilateral presbyopia-correcting IOL strategy
An increasing number of ophthalmologists are addressing presbyopia in their cataract surgery, and at present only 25 percent do not offer this option. It is interesting that although 66 percent of cataract surgeons themselves would choose a mix of multifocal IOLs for themselves (see next question), only 9 percent perform a mix of any of the presbyopia-correcting IOLs for their own patients. Perhaps this discrepancy reflects the difference in what surgeons have been doing thus far, vs. what they now plan to do going forward. It will be interesting to see whether future surveys reveal a change in presbyopia-correcting IOL use.
Q18-Assuming you are getting multifocals, which would you choose today?
Market research has shown us that the vast majority of ophthalmologists do not mix IOL technologies. This was also the case with the ophthalmologists who responded here (Question 17). Looking only at those who do implant presbyopia-correcting IOLs, 88 percent use the same type of lens in both eyes, while 12 percent of respondents mix technologies.
Yet when asked what IOL they would want for themselves today, 66 percent responded that they would want to be mixed with one ReStor and one ReZoom lens compared with 18 percent who would want the same IOL technology implanted, and 16 percent who don’t know. Clearly the ophthalmologists are looking for the best possible outcome for themselves, and the respondents believe mixing technologies offers them advantages over matching technologies in spite of the practice pattern of what they or their colleagues are routinely performing.
Since the ideal presbyopia-correcting IOL has not yet been designed, ophthalmologists are continuing to look for new and innovative ways to improve upon what we have today.
Q19-Regarding contrast sensitivity and functional vision, I think the companies are
It is interesting to see that 66 percent have the impression that IOL manufacturers are being less than perfectly candid. Only 4 percent believe companies accurately portray the advantages and disadvantages of their products. It remains critical to the advancement of the science of ophthalmology that surgeons evaluate technology independently and provide honest feedback to industry.
Q20-Would you yourself have a multifocal IOL?
Those who would personally have bilateral multifocals make up 41 percent of respondents. The remainder are primarily concerned about nighttime halos and the loss of contrast, and some don’t mind wearing readers. The 41 percent is much higher than is seen in practice but may be a forecast of the increased use of multifocals.
Q21-Most common reason your presbyopia-correcting IOL patient is unhappy
Half of surgeons use presbyopia-correcting IOLs and half do not. Presumably, the half not using presbyopia-correcting IOLs do not use them for fear of the reasons listed. What we do not know is the proportion of patients who are happy with presbyopia-correcting IOLs. Residual refractive error is a predictable and fixable postop problem. No one expects to always achieve a perfect refractive result after implanting a presbyopia-correcting IOL, but everyone needs a plan to fix a suboptimal refractive result.
Q22-Do you routinely tell cataract patients (reasonable candidates) about presbyopia-correcting IOLs?
It is encouraging to see that roughly three-fourths of surgeons are routinely discussing presbyopia-correcting IOLs with reasonable candidates. Since none of these technologies is perfect, the challenge will be to appropriately inform patients of the optical compromises inherent in all of these lenses. The concept of increased quantity of vision at the expense of quality of vision must be explained to these potential candidates.
Q23-Percent of your cataract patients receiving presbyopia-correcting IOLs?
With any new technology, there will be early adopters, followed by more conservative surgeons who want to see the results from the early adopters. And some will never embrace new technology. The important finding in the responses is not that 45 percent of surgeons do not use presbyopia- correcting IOLs, but that the majority of surgeons do. This suggests that presbyopia-correcting IOLs have moved beyond the early adopters and are entering mainstream cataract surgery.
Q24-Of Crystalens, ReStor and ReZoom
Since no current presbyopia-correcting IOL meets all four requirements for achieving full patient satisfaction—1) near, to read a newspaper, 2) intermediate, to use a computer, 3) excellent distance vision, and 4) acceptable light phenomena at night—I mix the refractive ReZoom, with the diffractive ReStor about 70 percent of the time.
My second choice is bilateral ReZoom, which provides excellent distance vision, excellent intermediate vision and adequate reading more than 80 percent of the time. If the nondominant eye is made a –0.5 D, the reading is almost always adequate. Patient neuroadaptation to the halos is much quicker than I had anticipated, and I have had zero explants after implanting more than 250 ReZoom lenses.
I’m greatly looking forward to mixing the ReZoom with the Tecnis multifocal diffractive IOL since I believe it has a higher-quality distance vision and less pupillary dependence with near compared with the ReStor lens. I may try the new Crystalens in the very near future but have not used it to date.
Q25-60-year-old, contact lens-intolerant man wants refractive lens exchange
It is surprising that 71 percent of respondents would offer refractive lens exchange for this patient, either by operating on the patient themselves or by referral elsewhere. I believe this represents a major shift in thinking over the past several years.
The presence or absence of a posterior vitreous detachment would substantially alter the risk profile of this procedure, and this would figure in my thinking. When evaluating statistics regarding retinal tears in refractive lens exchange patients, it is important to consider that the risk of refractive lens exchange at this time must be gauged against the risk of cataract surgery in the relatively near future in a patient such as this.
IOL CHALLENGES AND COMPLICATION
Q26-Post-LASIK IOL calculation (no available records). I would
Interestingly, the most common response as to what method is used to calculate IOL power in LASIK corneas is “Use another method” (27 percent). Unfortunately, that doesn’t tell us what they are using.
There are many other methods that have been proposed over the years, and Dr. Giacomo Savini and I have presented a new Excel spreadsheet tool that calculates almost all the methods that have been proposed in the past decade and allows all the data collected to be kept in one place. It allows the surgeon to analyze all the results calculated automatically and make a decision based on that. This tool is available for free to anyone who requests it by e-mailing me at KHofferMD@aol.com.
Q27-To surgically correct a spherical –3 D surprise at two months (cornea and posterior capsule are OK), I’d perform
The audience clearly feels comfortable with keratorefractive surgery because of the high accuracy and low complication rate of this procedure, especially in the range of the –3 D myope. Keratorefractive surgery is also preferred in patients with cylinder, or low hyperopic corrections.
For high corrections, though, piggyback IOL or lens exchange are preferred options, despite being an intraocular procedure. In patients with an open capsule and enough room in the sulcus, piggyback IOL implantation is preferred, and in patients with quality-of-vision issues related to the IOL in addition to ametropia, IOL exchange would be preferred.
Q28-Have you personally explanted presbyopia-correcting IOLs?
This response indicates that one-fifth of the audience has had to exchange a presbyopia-correcting IOL, a procedure that can be safely performed utilizing contemporary explantation techniques.
Of the surgeons using presbyopia-correcting IOLs, 63 percent have not needed to remove a lens, which underscores the importance of accurate biometry, meticulous surgery and appropriate patient selection. The fact that nearly one-half of the polled audience has yet to use a presbyopia-correcting IOL will certainly change. Regardless of the type of IOL the surgeon selects, he or she should be prepared to remove and exchange it when necessary.
Q29-Have you ever explanted an opaque IOL?
It is not surprising that 75 percent of the respondents have never explanted an opaque IOL. The majority of IOLs that opacified postoperatively were hydrophilic acrylic lenses, and these lenses never attained widespread use in the United States. Therefore, the number of opacified lenses in this country is relatively small. In spite of this fact, 25 percent of respondents have either explanted an opaque IOL or have seen and referred one for treatment.
Q30-Iris suture fixation of a posterior chamber IOL
The ability to insert and suture fixate an IOL through a 3.5 mm incision gives the surgeon greater flexibility in treating patients with no capsular support. This technique permits secondary IOL insertion in aphakic patients who are contact lens intolerant, facilitates the management of IOL problems after surgery that require IOL exchange, and allows the surgeon to properly treat patients who develop loss of capsular support at the time of cataract surgery. I am pleased that 40 percent of the audience has performed the procedure and an additional 36 percent plan to do so.
Q31-Routine secondary IOL/anterior vitrectomy in 60-year-old. I prefer
A majority of surgeons use anterior chamber IOLs in the absence of adequate capsule for fixation. The literature supports this practice. Modern ACIOLs are technically easier to implant and have no demonstrated inferiority to sutured posterior chamber IOLs. Perhaps new technology such as anterior segment OCT, by measuring true anterior chamber diameter, will further improve results with ACIOLs.
Q32-Have you seen glistenings in hydrophobic acrylic IOLs?
Almost one-half of the respondents have seen glistenings in hydrophobic acrylic IOLs, but these were not noted to be visually significant. This is in line with the experience of most surgeons who use these IOLs—that glistenings are seen commonly but it is rare that they are visually significant. In fact, it is surprising that 17 percent of the respondents feel that they have seen glistenings that have some visual significance. Almost one-third of the respondents report that they have never seen glistenings in the hydrophobic acrylic IOLs.
Q33-Have you ever aborted a presbyopia-correcting IOL implantation?
It is important to have a back-up plan with presbyopia-correcting IOLs. They are unforgiving. It is appropriate to not place a presbyopia-correcting IOL in an eye with unstable capsular fixation. It is an unusual situation that needs to be recognized and managed. Ideally, the patient will be aware of this possibility preoperatively.
New IOL Designs
Q34-If the light adjustable IOL were available now, I’d prefer to treat residual refractive error using
With more than 95 percent of cases within 0.25 D of the intended result following IOL surgery, it is not surprising that 68 percent of the audience would select the light adjustable lens as their IOL of choice when adjustment of the result may be needed.
Q35-If a dual-optic accommodating IOL were available (same cost), for what percent of your presbyopia-correcting IOL practice would you use it?
The audience response poll indicates that roughly one-fourth of respondents would still (for whatever reason) not be implanting presbyopia-correcting IOLs of any kind.
Interestingly, for those who are implanting presbyopia-correcting IOLs, about one-half would choose the accommodating IOL for the majority of their candidates, while the other half would not. Given the strong theoretical appeal of an accommodating IOL, I presume that half of the refractive IOL surgeons would need to review more clinical data and experience before adopting this as their primary presbyopia-correcting IOL technology.
Q36-Predict the most successful presbyopia-correcting IOL design 15 years from now
I am not surprised that many in the audience chose the SmartIOL as the most promising presbyopia-correcting IOL technology because it most resembles the human crystalline lens. In order for this IOL to be successful, though, several things to need to be true. First, the lens has to be the proper power, or, alternatively, the surgeon must be able to adjust it postoperatively. Second, we have to assume that the capsule’s elasticity will persist indefinitely—that fibrosis, and any resulting movement of the IOL, or a change in the capsule’s ability to alter its shape will not take place.
I, myself, believe that deformable optic IOL technology holds the most promise because it will have the largest amplitude of accommodation.