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The state of the art in cataract surgery
International participants herald the shrinking of the cataract incision and caution that a step forward in IOL technology may equal two steps back.
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Introduction
Ocular Surgery News convened a round table at this year’s American Society of Cataract and Refractive Surgery meeting in Philadelphia. We gathered together editorial board members from the the U.S. Edition, the Europe/Asia-Pacific Edition and the Latin America Edition of Ocular Surgery News.
 | Philippe Sourdille, MD, |
The topic was cataract surgery, a look at current trends and future developments. Moderator Philippe Sourdille, MD, strove to bring the participants to a consensus on as many issues as possible. The result, as you will see, is an international snapshot of the state of the art in cataract surgery in 2002. It is our pleasure to present it to you here.
Philippe Sourdille, MD: It is a great honor to moderate this prestigious roundtable discussion. It is critically important that Ocular Surgery News has sponsored this roundtable because there is so much information coming up about cataract surgery, new lenses, smaller lenses, accommodating lenses, changes in surgical technique, while we are still faced with major problems such as endophthalmitis, breakdown of the blood-aqueous barrier and so on.
We will first discuss our operative techniques and preferences for surgery. In the second part of our discussion we will cover issues in IOL choice. We begin at the beginning, with anti-infective prophylaxis.
Symposium
Anti-infective prophylaxis
Dr. Sourdille: Anti-infective prophylaxis is a major problem because we are still confronted with the possibility of endophthalmitis. Because we come from different countries and different parts of the world, I think we can cover worldwide experience with endophthalmitis, uveitis and related problems.
 | Kenneth J. Rosenthal, MD, |
Kenneth J. Rosenthal, MD: Rather than address antibiotic prophylaxis first, I’d like to mention detection, recognition. I’m not familiar with worldwide statistics, but in the U.S. the incidence of endophthalmitis is something on the order of 1 in 4,000 or 5,000 cases of cataract surgery in most institutions. So it’s gotten to be rather low. And yet, because it’s such a devastating illness, it certainly deserves our attention.
One of the major necessities for good treatment is prompt recognition. Patient education needs to be better, and we as surgeons have an obligation to schedule patient visits at times, for example, that we’re most likely to discover endophthalmitis.
For many years I have seen patients on day 1 and then either day 3 or 4, so that I’m seeing patients during the peak incidence of acute endophthalmitis, rather than waiting the "traditional" one week and then I see them again at a month.
I think studies would be helpful to show us what would be the best technique for detection. And then having done early detection and advising patients what to look for, we’re likely to catch them at so early a stage that the vast majority of them would be treatable.
Dr. Sourdille: We have different protocols in different countries. I know that in the United States the cause of endophthalmitis is verified by bacteriological examination, which I think does not cover all the possibilities for detection of endophthalmitis.
Since we have to instruct our patients in what to look for, what do we tell them are the symptoms that are most likely to happen in cases of endophthalmitis? What are the symptoms of endophthalmitis that should be explained to the patient so that he can come immediately to the surgeon if he feels these symptoms.
Tadeu Cvintal, MD, |  |
Tadeu Cvintal, MD: I am in charge of a residency program, and there is a rule in our service that if the operated patient feels pain in the immediate postop, he has endophthalmitis until proven otherwise. So this patient is seen as an emergency at any time.
Pain is the first symptom, in our experience. Then comes vision loss, and then other signs as endophthalmitis grows more serious.
Dr. Sourdille: Do we all agree that pain is a very frightening symptom? Are there other symptoms?
Lucio Buratto, MD: Blurred vision is one.
Dr. Sourdille: Pain and blurred vision. Do we all agree that sudden blurred vision and pain are the two major symptoms? (Show of hands.) We agree.
Now, coming to prophylaxis, what can we do to prevent endophthalmitis? Do you treat patients before surgery or at surgery, and do you use antibiotics in the infusion?
Virgilio A. Centurión, MD: At the end of the 1980s I read an article by James Gills about prevention of endophthalmitis by using antibiotics in the infusion fluid. From that time until 2 years ago I worked with antibiotics in my infusion system. But recent studies about endophthalmitis have recommended not to use vancomycin prophylactically during surgery, and so I stopped this use.
During those 10 years I didn’t have a single case of endophthalmitis. I stopped using vancomycin and I have had two cases in 2 years, and I didn’t change anything else in my operative technique. For that reason, nowadays I have returned to using vancomycin.
Fernando C. Trindade, MD: A good preoperative examination is very important. You have to look for the presence of blepharitis, problems in the lacrimal sac. These things should be analyzed and treated before every single surgery.
I think a good prophylaxis is through 5% povidone iodine, three times before surgery with intervals of 10 minutes. I have been doing this and I haven’t had any problems. A case of endophthalmitis in a routine surgery case is extremely seldom.
Dr. Sourdille: Do you think something else should be added to topical povidone iodine?
Francisco Contreras, MD: We use a topical povidone in advance. Of course, with this treatment the eye is in safe condition, but in addition we use Ciloxan (ciprofloxacin, Alcon) five or six times before the surgery.
Dr. Centurión: It is important to note that with ambulatory surgery centers we must be careful about the biological control of the operating room. The control of air conditioning and these types of things is very important.
Dr. Sourdille: Does anyone want to add something to that, topical treatment before surgery?
Dr. Rosenthal: Just a philosophical issue. Because endophthalmitis has such a low statistical incidence, it’s extremely difficult to discern what constitutes good prophylaxis. The philosophy I’ve taken is that I would use any modality that’s available, pre- and postoperatively, to ensure the best possible antibiotic coverage, as long as it’s benign. So, therefore, I would include all of those modalities and more.
Preoperatively for three days a fluoroquinolone, povidone iodine at the time of the surgery, the draping of lashes (although it’s never been proven to be effective), examination and treatment of blepharitis. And then frequent use of antibiotic drops both immediately postoperatively on the table, in order to ensure that any inoculum that was about to get in would not, and then frequently that day and in diminishing doses.
And I also use vancomycin in the bottle, which again has not been proven effective, but my empirical result has been similar to Dr. Centurión’s in that it has been effective for me.
So you put five modalities together and you’ve done pretty much everything you can.
Dr. Sourdille: But, as you know, there are criticisms of prophylactic vancomycin because people say that today it is the only antibiotic that can be used in severe general infection, and that it shouldn’t be used so that we do not create resistance.
Dr. Rosenthal: In cataract surgery, vancomycin is used in a small anatomic area, in a small concentration, for a brief exposure. Epidemiologists and infectious disease experts generally will consider that to be a minimal risk towards development of resistant organisms.
One has to look at the public health issue, which would suggest that it’s beneficial in the long run. There have not been strains of vancomycin-resistant bacteria, and vancomycin has been around for many years. Development of resistance certainly would not be likely to come from the small doses we use inside the eye during surgery.
Dr. Sourdille: I take your point, but this does not reflect unanimous agreement on the use on vancomycin. So we can only conclude that we have to use as many precautions as we can for topical treatment and leave the use of vancomycin or not in the infusion an open topic. We cannot conclude positively because it is so difficult to reach the status of statistical significance in the field of endophthalmitis.
Anesthesia
Dr. Sourdille: Now we move to the next topic, anesthesia. Who will speak in favor of general anesthesia, local anesthesia, topical anesthesia?
 | Lucio Buratto, MD, |
Dr. Buratto: General anesthesia is used for certain indications. For children and mentally retarded patients.
Richard Packard, FRCOphth: I agree with Lucio. I think that there are specific groups for which general anesthesia is used. I still use it in certain types of patients.
If we require general anesthesia, we use total intravenous anesthesia with a laryngeal mask, which is fairly minimal in approach. We use it in patients that can’t have topical, and it’s as simple as that.
Dr. Sourdille: So we all agree on that, general anesthesia for certain patients. Local anesthesia. Who does it today?
Dr. Buratto: I think that we still need about 5% to 10% local anesthesia by injection, because some difficult patients, unreliable patients, a very nervous patient really can give you problems during surgery if you don’t keep the eye stable and soft.
Dr. Sourdille: Again, agreed. Now topical. Is there unanimous agreement to say that topical anesthesia is the anesthesia of choice today for cataract surgery?
Dr. Packard: I’d like to talk about the type of topical, because not all topical is the same.
For instance, mine is a regimen which involves lidocaine gel, the same jelly that is used by urological surgeons for doing a catheterization, and the reason I use that is because if adequately anesthetized at the conjunctiva, it’s well tolerated by the patients, and it lasts much better than drops.
And I top it off with a little bit of intracameral. I’m not yet convinced as to whether or not that is absolutely necessary, but certainly in my experience it works much better than drops. Has anybody else in the room used this approach?
Dr. Sourdille: Two things about that. First, a paper published in the Journal of Cataract and Refractive Surgery 2 years ago, in which laser flaremetry was performed after intracameral anesthesia was added to topical anesthesia, proved that it was not harmful to the blood-aqueous barrier. So it is a practice that can be accepted.
Second, another recent article has showed that by modifying the pH of these topical anesthetics, by moving them from a pH of 5 to 7, you can increase the transcorneal penetration of the drops. So we should be aware of that.
Dr. Trindade: I would like to just make the comment that most topical anesthesias are not topical because they have sedation. So they’re not strictly topical.
Dr. Packard: I disagree with that entirely. We don’t use any intravenous sedation.
Fernando C. Trindade, MD, |  |
Dr. Trindade: That may so be in your practice, but I’ve seen a lot of surgeons that say they do topical, but it’s not plain topical. It’s topical plus sedation. So the patients can’t even walk out of the operating room.
I must say that I frequently use topical anesthesia but I still today feel much more comfortable using peribulbar.
Dr. Packard: We do not routinely use any sedation for patients. In fact, when the patients ask me for sedation I say that I prefer you do not have sedation. I say I would rather that you were terrified out of your wits but still than if you were half sedated and went to sleep and woke up and moved all over the place. Most patients accept that readily, and if you talk through with them what is going to happen, most patients are frightened about the needle. If they don’t have a needle you’re halfway home.
You explain exactly what you’re going to do in the procedure, what sensation they are going to feel. All my patients are told specifically that they will feel things. I never say to them that they will feel nothing. I say that this is part of the procedure, you are supposed to feel something. If you do that, they don’t complain about it.
You do, however, say to them, "You won’t feel pain."
Dr. Rosenthal: In reference to Dr. Packard’s comment, my approach is exactly the opposite for exactly the same reason. It’s tomato/tomahto. Intravenous sedation is designed to calm patients and make them feel comfortable, not to obtund them. I’m talking about a limited dose, somewhere between 0.5 mg and 2 mg of Versed, to keep the patient calm but cooperative. The local anesthetic is applied to the end organ, that is, the eye, to produce anesthesia at the operative site. So sedation is for patient cooperation and comfort, and anesthesia is for removing sensation in the eye.
I use anesthetic sponges, a technique that I published in 1995, in which the anesthetic is placed on the sponge in the lower and upper fornices, and dilating drops can be added to that sponge for a good effect.
The concept of balance in this technique does not preclude a patient who is fully cooperative and street-ready by the time he or she gets to the recovery room. Most of our patients are going home within 20 to 30 minutes after their operation.
Dr. Sourdille: The second question about topical is, do you use topical with or without an anesthesiologist? That’s a major question, especially for medicolegal matters. Who uses an anesthesiologist in the OR today? (Show of hands.) Okay, we all do. So we all think that the presence of an anesthesiologist is mandatory.
Incision size, design, location
Dr. Sourdille: We come to the size, design and location of the incision.
Dr. Cvintal: I use a clear corneal approach, very close to the limbus, for most cases that need only cataract surgery. Routine size is 3 mm, and 2 mm of depth. Then I always have an astigmatism-neutral incision. That’s my routine.
Dr. Buratto: I use a temporal approach, a tunnel incision, corneal location, and the size is 2.7 mm.
Dr. Cvintal: Do you operate on the temporal steepest meridian?
Dr. Buratto: I do some relaxing incisions, limbal incisions if there is astigmatism.
Dr. Contreras: I use a two-plane limbal incision, 2.8 mm by 2 mm in depth.
Dr. Packard: The size of the incision I use depends on which phaco hand piece I am using. With the AMO Sovereign phaco with WhiteStar I use a very tight incision. With that 20-gauge needle I use a 2.5-mm incision. If I am using the Alcon Legacy with the 21-gauge MicroTip then I will use a 2.75-mm incision. I personally make my incisions a little bit longer, in that I like to have them 2.5 mm in length, although people say that if you have a longer incision you’re likely to have difficulty with distortion of the cornea. I also use a Kelman-type curved phaco tip quite often, which gets you over most of these problems because of the curve.
Dr. Buratto: I do the same. I agree with that. I agree with the longer incision too.
Dr. Sourdille: Does what has been said about incision reflect a consensus here? (Show of hands.) Yes.
Capsulorrhexis
Dr. Sourdille: We move on to capsulorrhexis. First, size and method of performing, which are closely related. As Richard just indicated, many things change now because we are using two-port phaco, This is familiar to posterior segment people but not so much to the anterior segment.
Dr. Buratto: There is a tendency to reduce the size of the capsulorrhexis because of new lenses — for example, accommodative lenses — that need to have a smaller capsulorrhexis. That is because of a general concept that keeping the capsulorrhexis smaller than the size of the lens will reduce capsular opacification. So a few years ago we used a large capsulorrhexis, and now we do it much smaller.
We prefer to perform capsulorrhexis under viscoelastic. We use thin coaxial forceps now because we need to have a small incision for cataract surgery, and sometimes regular forceps are not thin enough to do the capsulorrhexis.
 | Virgilio A. Centurión, MD, |
We need good illumination and high magnification to achieve a well-done, well-centered capsulorrhexis, because if we do a small capsulorrhexis in decentered position it will not accommodate the larger lenses.
Dr. Centurión: I prefer to perform capsulorrhexis with a cystotome. I make it about 5 mm, but it’s easier with a smaller incision.
Dr. Sourdille: Who else uses a cystotome? (Show of hands.) So, four of us and the rest prefer forceps.
Dr. Trindade: Viscoelastic is very important in order to maintain the chamber, especially in pediatric cataracts. I use a dispersive agent, such as Viscoat (sodium hyaluronate, chondroitin sulfate, Alcon).
Dr. Contreras: I use the Arshinoff soft-shell technique.
Francisco Contreras, MD, |  |
Dr. Rosenthal: I use a Utrata type of forceps on a vitrectomy-style long handle for better maneuverability. My capsulorrhexis size is small enough to cover the edge of the optic but large enough to provide a provision against later capsular contraction. I do my capsulorrhexis with impeccable control, under a modified Arshinoff ultimate soft-shell technique, which is Healon5 (sodium hyaluronate, Pharmacia) with a layer of fluid under it. This compresses and flattens the anterior capsule and allows you tear exactly where you’re going, not peripheral and not central to where you want to go. I use capsular dye in appropriate cases.
Dr. Sourdille: That was my next question. What about the use of capsular dyes and recent remarks and publications on the fact that these dyes might influence the transparency of the IOL? What are your indications for using a dye, and which dye do you use? And have you ever noticed problems related to the dye?
Dr. Centurión: I prefer trypan blue that is made in Brazil. We have it very cheap, different from the United States. I normally use it in white cataract.
Dr. Buratto: Not only in white cataract, we also use it in brunescent cataracts and in all cases where there is not a good red reflex.
I use trypan blue more and more because it can really help. In several cases I have found myself in trouble for not having used it at first. I have to inject it when the viscoelastic is already inside the eye, and then it’s not the same.
I have seen no complications with the dyes not cleaning out, because we wash the capsular bag and the anterior chamber very well.
Dr. Cvintal: I have seen complications presented in which, if you inject the dye in the classical way, sometimes you not only put the dye on the capsule but on the vitreous, too. Then you cannot see what you’re doing because the vitreous gets very dark with the blue color. So instead of injecting, a safer way of doing it is just painting the capsule with the tip of the cannula that has a little bit of the dye at the tip.
By doing this you don’t put the dye on the vitreous, and you don’t put the dye in the hydrophilic lenses, if you’re using them. A hydrophilic lenses can become stained by the dye, and then it becomes completely blue. If it turns blue, the patient’s vision can drop to 20/200.
Dr. Sourdille: This we can discuss later because not all hydrophilic IOLs are the same.
Dr. Buratto: Can we talk about the posterior capsulorrhexis? Sometimes it’s useful to have a posterior capsulorrhexis. This can be difficult, especially when you can’t see the capsule and you need to have a well-done, well-centered capsulorrhexis. Also, we need to clean the capsular bag before performing the capsulorrhexis and before placing the lens.
Dr. Sourdille: What are your indications for creating a posterior capsulorrhexis?
Dr. Buratto: In a child, when there is posterior fibrosis on the capsule. Sometimes you find plaques.
Dr. Sourdille: What about in senile cataracts? Are they an indication for posterior capsulorrhexis? Not only to treat an unintended capsular rupture, which is a good way to go, but I mean planned posterior capsulorrhexis. Who does that in adults? (Show of hands.) No, none of us.
 | Richard Packard, FRCOphth, |
Dr. Packard: We would do it in eyes where there was a posterior capsular plaque, but as a routine procedure I doubt anybody in this room would do a posterior capsulorrhexis if it was a clear capsule.
Dr. Sourdille: This is the case mainly because, apart from the technical difficulty and the increased risk of vitreous prolapse, it does not improve anything in terms of posterior capsule clarity because there is still some remaining capsular support for the growth of epithelial cells with the remaining posterior capsule.
Lens removal
Dr. Sourdille: So the capsulorrhexis is done, and now we come to lens removal. Who uses lasers and which lasers do you use?
Dr. Buratto: I have used two of the available lasers on the market. In the end, I didn’t see any advantage in laser over phaco for removal of cataract. First, they are not able to remove medium and hard cataracts, only soft. Second, they increase the surgery time. Third, they don’t reduce complications. I had a couple of ruptures, one on the posterior capsule, a couple of capsulorrhexis extensions, because of the longer time manipulating the lens removal.
Also, some of these machines don’t have good irrigation and aspiration systems, so it makes the procedure more unstable because the chamber is deepening and shallowing. So I really don’t see any real advantage with the laser machines.
Dr. Rosenthal: One advantage of lasers, which may be overcome with other technologies, is the ability to operate through very small incisions, so that when lenses are available that will go through those incisions we’ll have minimized our incision. Whether that’s important or not is another subject.
Dr. Sourdille: I have used the Dodick laser, and I have done extensive work with the erbium:YAG. I always say that the nice thing with the lasers is that they do not prevent mechanical fracture and aspiration to remove the lens. This is a pro for the lasers, and the other pro is nothing. It doesn’t help and I think it reflects the consensus here, a unanimous consensus anyway around this table, that there is no indication today, for the time being, to use lasers to remove cataracts.
Dr. Packard: I agree entirely, although my experience with lasers is limited. But we have to look at why the lasers for phaco were ever created. Essentially, they were to overcome what could perceived as the problems with ultrasound, which is largely generation of heat in the eye and excess energy. What we have now available to us with a number of different technologies is the ability to use ultrasound in a way that we couldn’t before. So that we can do everything that was previously thought to be done with a laser much more efficiently and effectively on any cataract.
Ultrasound power
Dr. Sourdille: That leads nicely into our next topic, options in lower ultrasound power, smaller tips, and improvements in fluidics. It seems to me difficult to separate all these items. I think we must have a comprehensive approach in this discussion because you can’t talk of fluidics without talking of these other factors.
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So what are the main recent improvements in fluidics, tips, smaller incisions and options in lower ultrasound power.
So I think here we have time to do a real roundtable discussion and take every single participant’s opinion, trying to summarize those three things: options in lower ultrasound, smaller tips and improvements in fluidics.
Dr. Rosenthal: To explain my approach I use the pneumonic PANDA, a gentle technique. PANDA stands for Phaco-Assisted Nuclear Disassembly and Aspiration, and the philosophy that I’ve embraced is one in which phaco is beside the point. Phaco is your energy of last resort.
The technique is dominated by the use of mechanical disassembly of the lens and then aspiration of the lens with assistance from phacoemulsification, which reduces the most damaging type of energy in the eye, ultrasonic energy.
The evolution of this technique is largely due to the availability of better machines that are able to sense changes of pressure in the eye, allow us to use high vacuum due to microprocessors that can sense in microseconds changes and allow us to maintain a stable anterior chamber without trampolining of the nucleus and zonular or capsular donesis.
With regard to smaller tips, I don’t today consider that terribly important, although, as been alluded to by other speakers, the prospect of smaller lenses is enticing. Perhaps we ought to be looking at that technology towards the future.
With respect to use of phacoemulsification energy per se, we now have technologies that reduce the amount of energy that’s needed to emulsify the lens. Primarily by the use of those other modalities, we’ve already disassembled and aspirated what we can, and are left with only harder particles that are lesser in number and smaller in size. The ability to grasp a nuclear piece so that it can be phacoemulsified successfully with a minimum use of energy is part of the fluidics, but impacts on our ability to use less phaco energy.
And finally, we have the development of technologies that increase those efficiencies. The one that Dr. Packard referred to, WhiteStar, a segment of the Sovereign instrument, has been useful in reducing phacoemulsification times, improving energy utilization at the tip. Because it’s rapidly turned on and off during the cycle there is less chatter. And it seems to offer the reduction of the hazard of heat damage, specifically wound burns because the rapid on-and-off duty cycle of the Sovereign prevents the generation of significant heat at the tip.
Dr. Contreras: The tendency now is the better control of pressure in the eye, less ultrasound, and therefore less energy. I think that’s what we are all looking for.
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Dr. Centurión: I am working with the Alcon Legacy System, with a MicroTip 0.2-mm flare tip, with the NeoSoniX handpiece, and I use a lower rate of phaco power and a high rate of vacuum. All of this seems to contribute, to add together, and you have a smaller tip improving fluidics and concentration of flow.
Dr. Packard: I have to declare an interest. I am an ad hoc consultant for AMO. But despite that, I have been using WhiteStar and have been very impressed with the way that this technology behaves. You were talking about getting incisions smaller. I now have the ability with this technology to do phaco on any cataract through a 1-mm incision. I have used this on black cataracts without increasing surgery times, with the same phaco times I would have achieved with conventional phaco. Since we have this technology available in any cataract, I believe that, as Ken Rosenthal said, we now need to look very closely at the new IOL technology (which we’ll discuss later), and the ability to put a lens through a very small incision.
Dr. Cvintal: I have used the Bausch & Lomb Millennium for many years. With this machine I can separate very well the aspiration and the phaco to perform bimanual phaco. So I can really appreciate what Ken Rosenthal is saying. I try to do most of the work with this advantage of having the aspiration separate, breaking the nucleus with the two instruments and using minimal phaco energy.
Dr. Trindade: I use the Alcon Legacy. My incision is 2.8 mm. I use a divide-and-conquer technique. Most phacos are done through just one incision. I use a delicate cross-action nucleus cracker to consistently break the nucleus in four fragment. Under viscoelastic assistance, I use a Kelman microtip, high vacuum and low ultrasound power.
I think this technique is nice because there is less turbulence, less manipulation, the anterior chamber is deeper, and it’s possible, say in 90% of the cases, to do the phaco with just one 2.8 mm incision, in a safe and consistent way. That’s my routine.
Dr. Buratto: More and more we use less and less energy for phaco. This is first of all because we have fewer hard cataracts in Europe now, but mainly because we have better machines. Better machines mean that we have more control of fluidics, we can work with higher vacuum and more smoothly. We have more control, we can better protect the endothelium. And we have these new technologies that really have a part in providing the ability to destroy the nucleus more easily. These new technologies all help in controlling the phacoemulsification.
With smaller phaco tips we can be aggressive against the nuclear material or the nucleus. And with the new designs of tips and new phaco machines, we have less heating, and this also is very helpful in keeping the procedure safe and under control. But mainly what we really have is safe and reliable transmission of ultrasound with well-controlled fluidics. That really keeps the surgery stable and under control.
Dr. Rosenthal: It seems to me the primary advantage of bimanual is the ability to use smaller incisions. Other than that, I don’t see any mechanical advantage. In fact, using current tip designs there may be a disadvantage in not having a sleeve around the phaco tip. At this meeting, William Fishkind has showed the sleeve to influence the direction of phaco energy. Therefore, in current tips designs there may be more scatter of phaco energy without a sleeve. When tips are redesigned, I think it’s an interesting and a good idea to consider.
Dr. Packard: In relation to the use of ultrasound in that situation, the fluidics are enhanced because the wound is so tight. And as far as the question of cavitation going awry, what you actually do is leave the hub of the phaco sleeve on the needle and just pull the sleeve off. If you do that, you don’t get the spray and you don’t get the misdirection of cavitation.
Dr. Sourdille: Another important factor is control. We have detailed the importance of control of fluidics with the loss of inertia, and we now have systems that respond very rapidly. The control of fluidics is important for techniques such as mechanical nuclear disassembly.
Many companies now have controlled ultrasound delivery at the tip of the probe, not on the handle of the machine but at the tip, and with systems that use feedback to control this, the machine has as little as possible real ultrasound energy at the tip of the probe.
There is another factor that in my mind has not been solved. We did some work years ago, and published it in the Journal of Cataract and Refractive Surgery, using the ocular coherence tomography (OCT) to measure macular thickness after uncomplicated phaco. We found that 20% of these patients had some macular thickening after uneventful phaco. Some of them had not just angiographic but clinical CME. A recent publication reports that 40% of cataract patients have macular thickening postoperatively.
I think this is related to the rupture of the blood-aqueous barrier, which itself is related to traction on the zonular system. This is why I think that the divide-and-conquer, which was the first approach to mechanical disassembly of the nucleus, should be reconsidered. By rotating the lens in the capsular bag, especially when it is intact, or just after the hydrodissection, you create zonular traction, which in turn can disrupt the blood-aqueous barrier. This is an underestimated threat, the consequence to the blood-aqueous barrier of zonular traction.
Dr. Rosenthal: I offer a counterpoint to your discussion of CME. I’m simply speculating in another direction and offering another point of view.
The theories about CME abound. No one knows what causes it, and we don’t even really know how to treat it. It’s always been my view that CME is primarily an inflammatory disease, not a mechanical one, in uncomplicated cases.
However, of course, we know that in complicated cases there is a greater likelihood of CME. So mechanical force may play a part. So I agree with you that trampolining of the capsular-zonular complex, if you will, as the final barrier to vitreous, would constitute a potential hazard for the development of CME.
However, a properly done phaco chop technique, with a pure vertical chop particularly, has very little if any downward motion. On the other hand, sculpting or divide-and-conquer has a great deal of posterior pressure.
So my philosophy would be that after a thorough hydrodissection, when rotating the nucleus there’s little if any tractional force on the zonules. A good embedding or lollipopping of the nucleus is done at the beginning of the crack, pulling up slightly as one cracks, so that there’s no pressure on the zonules or the capsule. Then the rest of the phaco is done at iris plane or slightly above. Using those parameters one may actually have less manipulation of the capsule.
Dr. Sourdille: I totally agree with you, Ken. I’m sure that phaco chop is far better than divide-and-conquer, and rotating, and rotating, and rotating.
Another thing regarding inflammation. In the study in which we looked at the macula with OCT, we also studied the anterior chamber with a laser flare and cell meter, and we did not find a close relationship, even in though this has sometimes been noted, between macular thickening and elevation of flare in the anterior chamber. One of these patients developed a clinical CME at 2 weeks with a flare never greater than 12 photons/mm3, which is very low.
So this is still an open subject, but in our surgical technique we should keep in our mind to try to avoid, by any means, traction on the zonular system, which is still a very fragile part of the eye, even with one or two very small incisions.
Dr. Rosenthal: I think a lot of our attention on surgical technique over the next few years will be centered less on how to remove the nucleus and more on how to preserve the capsular-zonular complex, which we’ve now come to understand is at least as significant, if not more so, as what lens we put in or how we take the nucleus out.
Dr. Sourdille: To summarize, it’s a trend, it’s more than a trend. Bimanual phaco helps us with cleaning up, removing all that we have to remove. Since most surgeons are two-handed, we should use our two hands. This is useful not only for intraocular maneuvers but also to orient the eye and to be in a better situation to treat any potential complication.
IOLs
Dr. Sourdille: Before starting our discussion of IOLs, we should keep in mind that sometimes a step forward is two steps backwards. For instance, if a small-incision IOL uses such materials and design that it brings us back 10 years in terms of PCO due to the design or the material, what is the advantage of having 0.12 D less induced astigmatism, when what we have today with a 2-mm or even 3-mm incision is clinically insignificant?
Our first topic is minimizing PCO. I would like everyone to give his opinion on how we minimize PCO. Is it done by design, by material, or by a combination of design and material?
Dr. Buratto: To reduce capsular opacification we have first to select the right design of the lens, second, the right material, and after these consider the surgical procedure. The surgical procedure includes creating a capsulorrhexis of the right size, well centered, and cleaning the posterior capsules and the posterior surface of the anterior capsule adequately.
Regarding lens design, the most important factor for PCO prevention seems to be the posterior edge of the lens. It should be squared off.
Regarding material, the most effective is the acrylic hydrophobic; the AcrySof (Alcon) is the best lens for that.
The size of the capsulorrhexis should be a little bit less than the diameter of the lens, well centered in a way to keep the lens covered by the capsulorrhexis.
Cleaning of the posterior surface of the anterior capsule is helpful. Cleaning the posterior capsule is helpful also, but the first three topics are more important in my opinion.
Dr. Trindade: I agree. It’s a combination of factors, not solely cortical cleanup. Complete cleanup, removal of anterior capsule cells and also the equatorial cells is very important.
For the lens, the hydrophobic acrylic nowadays is the material of choice. I’m using now the 6-mm AcrySof Single-Piece SA60AT, which enters into an incision usually of less than 3 mm, using the injector.
I had a bad time in terms of opacification using a single-piece silicone STAAR lens. I think it was the least satisfactory lens I have ever used in terms of PCO.
Dr. Cvintal: I agree with what has been said before. We’re now using routinely a square-edged lens, both the silicone Pharmacia lens and the acrylic by Alcon, and we believe that we get the same amount of opacity with either lens.
Beside the material and shape, the other thing I think is important is to clean very well, as much as you can, the epithelium of the anterior lens capsule.
Dr. Packard: I must declare interest. I’m a consultant for Alcon IOLs. I’ve been using the AcrySof lens longer than anybody, it’s nearly 12 years now. My current lens of choice is the SA60AT, which is a one-piece 6-mm optic lens. It works extremely well. I have no reason to suppose that, with its square edge, it will have a different PCO rate from any of the other Alcon AcrySof lenses.
I’ve been involved in many, many studies which have shown that the one-piece, the SA30, and the MA30 and MA60 are really very similar. I’ve been using the one-piece AcrySof now for 4 years, and I have to say to date I have not done one capsulotomy in any of these patients.
Dr. Centurión: The only thing to add is that in my technique I to try to perform a perfect cortical cleaving hydrodissection, and this makes a difference in the opacification rate. I’m working with the SA60, the same kind.
Dr. Contreras: I also use a one-piece acrylic, 6 mm in diameter, and I think it’s important to clean not only the posterior capsule very well but the anterior capsule.
Dr. Rosenthal: If I could just take a step backward, I think the lenses that exist in the year 2002 represent a Rube Goldberg — a lens that tries to do everything and does nothing perfectly. The lens, in my view, should do only one thing, it should refract light as well as possible. I think that the Tecnis lens, for example, from Pharmacia shows promise in that respect in that it’s aspheric and corrects some of the spherical aberrations in the eye.
With the truncated edge, we have improved PCO, but we have increased dysphotopsia. It’s a losing proposition to use the edge of an IOL to try to prevent PCO. Rather, I like the approach that has been studied in Europe and in Japan of a device such as the Nishi-Menapace capsular bending ring, placed way in the periphery of the capsule outside of the area of light refraction.
Dr. Packard’s elegant studies in the areas of PCO, by the way, have helped us tremendously in understanding that process.
I agree that posterior capsule polishing is worthwhile. With respect to anterior capsule polishing I am less certain. There have been studies on both sides of the equation, some showing that capsular polishing reduces the rate of PCO and some that show that it actually increases. In keeping in mind that the lens epithelial cells have tight junctions at the equator, it seems to me a waste of time to polish the anterior capsule, although I don’t disagree with those who do it.
The IOL that I use primarily today is silicone, unless there is a contraindication such as a vitreous case that may need silicone oil. I think acrylic is a perfectly good material, but it does require a larger incision. Since all of the acrylic lenses now have truncated edges on them, I have tried to avoid them, feeling that I’d rather see PCO than dysphotopsia requiring a lens exchange, even though it has a low incidence. In fact, the silicones, such as the AMO SI-40, have an acceptably low rate of YAG capsulotomy.
Dr. Sourdille: My first comment is on the lack of proper evaluation of PCO. We have tried at the ESCRS to adopt a standard protocol that could be used by a large number of colleagues. A number of software systems have been used in Europe: by David Spalton at St. Thomas, the German group led by Manfred Tetz and Gerd Auffarth, the AQUA system in Vienna. There is yet another system coming up in London. Yet we still lack a reproducible method to document the transilluminated pupil, and to know what we want to look for.
Another missing part of the protocol is the focus on anterior capsule. If we have a good lens and a densely opacified anterior capsule with only a 4-mm opening, that precludes forever a careful examination of a pseudophakic retinal detachment. And, as you know, there is still today a difference between the incidence of good results in pseudophakic retinal detachments as compared to phakic retinal detachments. So we should think of the posterior segment, even if we are anterior segment surgeons.
Another area where we have lack of agreement is in how to measure contrast sensitivity. Obviously from what has been said here and what we are hearing here in Philadelphia, the field of IOLs is moving rapidly today. You have noted the improvement in optical properties, in creating aspherical surfaces instead of spherical surfaces. This improves both depth of field and contrast sensitivity, and yet it’s interesting to note that we do not agree on how we evaluate contrast sensitivity. The way to evaluate it changes from place to place. So we still have a lot of work to do.
We have also noted the IOL edge effects, and there has been very interesting work done by Allergan on trying to decrease the influence of edge effects by working on the anterior edge of the lens, not having a sharp edge on the anterior part of the optic, which seems optically and clinically to improve the situation.
Regarding surgical factors, I agree with those who suggested that cortical cleanup is not the most important thing to do. There is a lot of controversy in the literature. People at the University of Vienna have demonstrated that it does not help in the long term in terms of IOL fixation and prevention of fibrosis. The effect of the implant in this is still open to discussion.
Hydrophobic materials have many advantages, especially in terms of capsular adherence, which I think is their major property. Certainly they are beneficial in terms of PCO. But the problem of glistenings, so-called microvacuoles, have been underestimated and can lead to explanation of these lenses. And recently we have reports of the edge effect that causes temporal visual field decrease with some of the acrylics, which I think has to be mentioned.
Multifocal, accommodating IOLs
Dr. Sourdille: In discussing the next topic, accommodating lenses and multifocality, we should keep in mind that if we are talking of recreating accommodation after removal of cataracts, the ultimate lens, as the Japanese said 15 years ago and Jean-Marie Parel 20 years ago, should be a soft material so that the lens could be as soft as a juvenile or even infantile lens.
Dr. Buratto: I think the multifocal lens has not achieved the results that we hoped for from these lenses. Most of our patients are happy with their results, but there have been complaints about glare and night problems. So multifocality probably is not the right solution for patients.
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The newer lenses, the accommodative lenses, offer something more. We still need to improve our knowledge of these lenses, but from the first results we have from the C&C Vision lenses and HumanOptics, they seem to work well in improving near vision. So it looks to me like we’re going to correct presbyopia. They offer really a new era in IOL research.
But when we are choosing a lens for our patients we have to really keep in mind what we want to obtain. If we want to keep a low level of capsular opacification, we have to retain our current IOL designs because all the lenses now are much better in avoiding capsular opacification and improving the quality of vision.
These new lenses are made in a smaller size, like the C&C, or with a material that is not able to reduce capsular opacification, like the HumanOptics lens, and we find in our experience that these lenses are getting early capsular opacification. So we are offering to the patient something more from one point of view, in the sense that we are opening up their vision for far and near. But from another point of view we are offering less because we are having more YAG laser and more posterior segment problems, and more problems related to the capsular opacification rate.
Dr. Sourdille: This is what I meant at the beginning by saying one step forward can also mean two steps backwards.
Dr. Trindade: I have no experience with the accommodating lens, but I think this issue is overhyped. I hope that it works, but I have my doubts.
I basically use monofocal lenses, and my patients are very happy. If patients end up with –0.5 D sphere or even with –1 D, with against-the-rule-astigmatism bilaterally, these patients are extremely happy with their uncorrected vision for far and near. So I don’t think this is a major issue.
Dr. Sourdille: Do you mean that correcting intermediate and near vision, whatever the method is, is not important to you?
Dr. Trindade: No, not at all. Obviously it’s extremely important, but it is important to say that the overwhelming majority of the patients are happy with a low myopic refraction postoperatively, as we all know. And I’m not predicting the future, but I have the impression that these lenses may work in the beginning but after a certain amount of time the effect will decay. That’s my impression.
Dr. Cvintal: I just solve the problem of accommodation by using monovision. I find this is a very easy and efficient solution, and very few patients I know are dissatisfied with this solution. I did try multifocals, but there were problems with night vision and glare, and I was not very impressed. I didn’t find much good in multifocal IOLs, and today I remove them most frequently from patients.
Dr. Sourdille: Why are the patients unhappy?
Dr. Cvintal: Errors in distance correction, and sometimes slight decentering of the lens that causes aberrations, usually this kind of complaint. They are not happy with the quality of their vision.
Dr. Packard: I have some experience with both multifocality and accommodating lenses, and I think the most important thing in relation to multifocal lenses is what you tell the patients, what they expect from the procedure. I don’t think by any means that the Allergan Array lens, which is the multifocal most often used, is an ideal lens. But for some patients it works extremely well, particularly the ones that want it to work, and I think this is vitally important.
When I use multifocal lenses on patients I do bilateral, simultaneous surgery because it is so important that the neural adaptation should start to work immediately and that both eyes should start working with the brain at the same time. I haven’t done huge numbers, I’ve probably done about 50 or 60 patients. In most patients, the results have been good. I haven’t done it on any myopes. I have done it on hyperopes almost exclusively.
As far as the accommodative lenses are concerned, my experience is limited. I have done a couple of patients so far with the HumanOptics lens. Both of my patients, who are only 2 months postop, are seeing 20/15 and J1 unaided. I have yet to see where the problems will come, but at the moment this is exciting technology, and if we are supposed to look forward these are the things we should be looking at.
In relation to the question of going forward only to go backward, I agree entirely. We do have some lenses at the moment that work very well for our patients as monofocal lenses for distance vision, or whatever we choose.
The problem of monovision is another issue. It works well for some patients, but again, it’s a compromise because not only are we degrading their distance and reading vision by separating it, but we are also degrading their stereopsis. This may not be a major issue for some patients, but certainly for drivers it can be a problem.
I think we are at a watershed now. There are so many new technologies coming upstream. We as ophthalmologists want them to happen because we find them exciting, but we also have to look very carefully at what we’re doing and what in the long run is going to be the best for our patients.
Dr. Centurión: I have no experience with the accommodative lens, but I have a lot with the multifocal Array, and I have had excellent results. I don’t perform bilateral simultaneous surgery, but within two or three days, and I always try to put these patients slightly in the hyperopic level.
Dr. Contreras: I don’t have experience with these types of IOLs.
Dr. Rosenthal: I agree with Richard Packard’s assessment that patient expectation is crucial to multifocal IOL implantation and that the Array does require that education. It also requires careful patient selection, and impeccable surgical technique to determine that the lens stays well centered.
It also requires impeccable biometry. I believe that the No. 1 reason for failure of the Array multifocal is small degrees of ametropia that create a lot of blur circles and, therefore, very symptomatic patients. As was alluded to earlier, patients who are not emmetropic do not do well with them.
I also agree with Dr. Packard that surgery should be done bilaterally in proximity to each other. I do them a week apart, as that’s the closest we’re allowed to do. I would do them the same day if it were feasible. I agree that the visual adaptation is crucial.
I don’t have any direct experience with the accommodative lenses. The C&C is being investigated in the U.S. My concern is a theoretical issue. Although it looks like a promising design concept, any lens that both moves and depends on the integrity of the capsular-zonular complex may fail in a number of patients in which subsequent capsular phimosis, zonular weakness, and decentration or limitation of the movement of the lens may occur. While it’s not likely to happen in most patients, I’m concerned about the long-term follow-up with regard to that
I can tell you that U.S. patients have high expectations of having a complete refractive solution, and we ought to exert our energies in this direction. Again, this should not be at the expense of other quality-of-vision issues, but we ought to be spending time to develop those technologies.
Dr. Sourdille: I have the same remark regarding these technologies as for PCO, the lack of reproducible proper evaluation. With the development of refractive surgery, we have become familiar with aberrometry, and there are some instruments on the market now that can both measure the global aberration of the eye and at the same time pupillometry, which is critical for the evaluation of these multifocal or accommodative system.
In this field, as in others, it is of critical political importance to address both the public and the health authorities to say that we are in a rapidly developing world where companies need support from their governments in terms of pricing, certainly for the betterment of our patients. But we cannot say today, especially in terms of multifocal IOLs or the accommodative lenses in development, that this or that material or design is the best.
I shall try to summarize what we have said about new types of IOLs. We should not compromise the good results we have with today’s lenses in terms of optical quality of the IOL and PCO prevention for the sake of multifocality or accommodation.
Postop regimen
Dr. Sourdille:Now before concluding, a few words about postoperative drug regimens. Do we all agree that this is mainly based on a combination of antibiotics for a given period of time, cortisone for a longer period of time and nonsteroidal anti-inflammatory drugs for the rest of the time, which means months?
Dr. Rosenthal: I don’t use steroids except in complicated cases. I use a fluoroquinolone and an NSAID starting three days preoperatively four times a day. I use it every 2 hours on the day of surgery, and then four times a day. I discontinue the antibiotic a week later, and I continue the NSAIDs twice a day for an additional 6 weeks, with a view to reduce incidence of CME. With uneventful surgery, with minimal postoperative cell and flare and inflammation, probably no anti-inflammatory is needed in a large percentage of patients.
Dr. Trindade: In an uneventful case I use steroids with antibiotics, and I taper in two weeks’ time. And that’s it.
Dr. Contreras: In the normal cases I use and antibiotic and a steroid four times a day for 15 days. If I have some problems I add NSAID drops.
Dr. Packard: Preoperatively I use nonsteroidals the day or so before surgery, and postoperatively depending on how the surgery has gone. If it’s a brunescent cataract then obviously there will be more disturbance in the eye. I will use more NSAIDs and steroids and taper it generally over 3 weeks.
Dr. Sourdille: Miotics, intraoperatively or postoperatively?
Dr. Rosenthal: I use miotics, yes.
Dr. Sourdille: You seem to be the only one here.
Dr. Rosenthal: I use the miotic primarily to dull the postoperative intraocular pressure rise, not for contraction of the pupil.
Dr. Packard: One brief thing on miotics during surgery, you have to warn the patient. It causes pain.
Dr. Rosenthal: Yes, it does. Absolutely.
Dr. Sourdille: Regarding postoperative inflammation we have data, thanks to this wonderful invention the laser flare cell meter that we have already mentioned several times. It is interesting to note that even when flare is low, it takes months — months — to come back to the preoperative level, even in non-complicated cataract cases. It takes five times longer to come back to preoperative levels compared to nonpenetrating trabecular surgery for instance.
Thank you all for participating. It has been a lively and informative discussion.
For Your Information:
- Philippe Sourdille, MD, can be reached at Clinique Sourdille, 3 Place Anatole France, F-44000 Nantes, France; (33) 251-83-32-00; fax: (33) 251-83-87-19; e-mail: philippe.sourdille@wanadoo.fr.
- Kenneth J. Rosenthal, MD, can be reached at Suite 102, 310 East Shore Rd., Great Neck, NY 11023; (516) 466-8989; fax: (516) 466-8962.
- Tadeu Cvintal, MD, can be reached at Rua Maria Figueiredo, 396-16 São Paulo SP 04002-002, Brazil; (55) 11-884-3475; fax: (55) 11-283-4878.
- Lucio Buratto, MD, can be reached at Piazza della Republica 21, 20124 Milan, Italy; (39) 02-636-1191; fax: (39) 02-659-8875; e-mail: office@buratto.com.
- Virgilio A. Centurión, MD, can be reached at IMO Instit de Molestias Oculares, Av Ibirapuera São Paulo SP 04028-000, Brazil; (55) 11-5084-2770; fax: (55) 11-5084-1584; e-mail: centurión@imo.com.br.
- Fernando C. Trindade, MD, can be reached at Rua Manaus 595 Belo Horizonte MG 30150-350, Brazil; (55) 31-241-1318; fax: (55) 31-241-4021; e-mail: fct@gold.com.br.
- Francisco Contreras, MD, can be reached at Clinica Ricardo Palma, Piso 10, Av Javier Prado Este 1038, Lima 27, Peru; fax: (51) 11-224-1603; e-mail: oftcont@infoweb.com.pe.
- Richard Packard, FRCO, can be reached at HRH Princess Christians Hospital, 12 Clarence Road, Windsor, England SL45AG; (44) 175-382-92204; fax: (44) 175-38-31-185; e-mail: eyequack@vossnet.co.uk.