March 2008

 

CATARACT/ IOL

 

Comparing the cataract challenge


by Vanessa Caceres EyeWorld Contributing Editor

 

ABOUT THE PARTICIPANTS

Moderator

David F. Chang, M.D., is clinical professor, University of California, San Francisco, and chair, ASCRS Cataract Clinical Committee. Contact him at 650-948-9123 or dceye@earthlink.net

Lisa Arbisser, M.D., is adjunct clinical associate professor, John A. Moran Eye Center, University of Utah, Salt Lake City. Contact her at 563-323-2020 or drlisa@arbisser.com

I. Howard Fine, M.D., is clinical professor, Casey Eye Institute, Oregon Health & Science University, Portland. Contact him at 541-687-2110 or hfine@finemd.com.

Kevin M. Miller, M.D., is Kolokotrones professor of clinical ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles. Contact him at 310-206-9951 or kmiller@ucla.edu.

Tom Oetting, M.D., is clinical professor of ophthalmology, University of Iowa; Chief, VA Eye Service; and ophthalmology residency program director. Contact him at thomas-oetting@uiowa.edu.

Ken Rosenthal, M.D., is an associate adjunct in ophthalmology, New York Eye & Ear Infirmary. Contact him at kenrosenthal@ eyesurgery.org.

 

A few leading ophthalmologists discuss their management strategies for complicated cataract cases

Iris prolapse to phaco and side port incisions in patient with IFIS Source: David F. Chang, M.D.

Malyugin pupil expansion device in tamsulosin patient with IFIS.

Source: David F. Chang, M.D.

Oblique cut with capsule scissors is made to initiate a secondary enlargement of the capsulorhexis

Flap is re-torn with capsule forceps to enlarge the capsulorhexis in a patient with pseudoexfoliation.

Source: David F. Chang, MD

D

avid F. Chang, M.D. (moderator): Surgeons are continually looking for better ways to approach complicated cataract cases. Today, we have invited a panel of experienced cataract surgeons to discuss their pearls for patients with posterior polar cataracts, intraoperative floppy iris syndrome, pseudoexfoliation, and Fuchs dystrophy. Before we open the general discussion, let me ask one of our experts to first introduce and summarize the challenges posed by each of these four risk factors.

Posterior polar cataracts

I. Howard Fine, M.D.: Posterior polar cataracts generally are present at the time of birth. Many patients live with posterior polar cataracts relatively well until they reach an age in which they are driving, and then glare and difficulties with night vision is what finally brings them to the ophthalmologist. On occasion, we see people that wait until they are quite old before they actually come, but in my experience, many of the patients are young and are just now beginning to feel bothered enough that they seek treatment. The real issue with posterior polar cataract is a fact that is described in the peer-reviewed literature by both Robert Osher [M.D., Cincinnati] and Abhay Vasavada [M.D.] about a 35% incidence of the effective posterior capsules are associated with those cataracts, so there is a very high possibility of posterior capsule rupture. My first concern is to stabilize the anterior segment. I don’t want to over-pressurize the eye because you can force the lens into the vitreous cavity if there is a badly compromised posterior capsule. On the other hand, if the chamber shallows, the lens may lift out of the posterior capsule and come forward, and it will be followed by vitreous. With a posterior polar cataract, we make side-port incisions and then fill the anterior chamber with viscoelastic material, being very careful to not overfill it, because again we don’t want to pressurize it. The great advantage of bimanual microincision is that we can keep the irrigator in the eye throughout the case and therefore never shallow the chamber. We do minimal hydrodelineation, and then we remove the endonucleus, usually by chopping horizontally rather than vertically. If the lens is very hard and we are afraid to rotate it, we can actually take the phaco instrument out of the eye, add viscoelastic material, take the irrigator out, and switch hands. We can actually mobilize the pie-shaped segments from chopping with either hand. After we remove the endonucleus, we keep the irrigator in, and we viscodissect the epinucleus by lifting the anterior capsule and injecting viscoelastic material carefully. We try to elevate it, and therefore, end up with some viscoelastic under the epinucleus in the area of the posterior capsule. If there is a defect, we have some protection against some nuclear material falling into the vitreous cavity. We then mobilize the epinucleus peripherally towards the center so that we try to keep that central floor of epinucleus covering the posterior capsule. When the peripheral epinucleus is gone, we take the central portion ... the floor of the epinucleus. We keep the irrigator in, and we then use Viscoat to viscodissect the cortex, and we do the same thing there basically. We really move around peripherally, bringing cortex out of the eye, trying to leave the posterior portion of the cortical envelope intact as the last portion to take out. Usually by the time the cortex is out, we still have viscoelastic under it, and we have some idea as to the status of the posterior capsule. I try hard to not polish the posterior capsule because it have been burned on occasion with the capsule being intact but very weak. So I may polish a little bit the periphery of the capsule but never the central portion. Then again, we keep the irrigator in the eye and fill the bag with viscoelastic, being careful to not overfill again. This is something that you can do visually; you can see that it’s not stressing, the capsulorrhexis is not enlarging, and then we put the IOL in, and then we can use our aspirator to remove the residual viscoelastic. We have done a number of cases this way. They work very well, and I think the advantage of bimanual microincision cycle is that it’s possible to keep the eye pressurized throughout the procedure, with stability of the anterior chamber.

Lisa Arbisser, M.D.: I agree about keeping the chambers stable, and I will do that by never removing an instrument until I fill through the pieces with my chopper. Viscoelastics might not be enough to maintain the paracentesis. I exchange viscoelastic for the chopper just like you would in the setting of vitreous loss. When you withdraw, it will behave as though there was vitreous present. I use a cohesive viscoelastic before irrigation and aspiration (I/A) so that I don’t fill the chamber with dispersive. I don’t know if my number is not up yet, but I have yet to find an open capsule on a posterior polar case.

In a couple of recent cases, rather than remove lens material from the periphery and bring it into the center, I first removed the central material—releasing the capsular cortical adhesion because I think that’s what it actually is. In other words I think a posterior polar defect is a capsular cortical adhesion that is axial, and there is no elasticity within that area to allow for deformation without rupture. In my opinion, the only time we have open capsules preoperatively is if there is trauma or concussion, but it’s way more likely that causes the posterior capsular rupture occurs due to the lack of elasticity or give in that area. During surgery I believe we cause this area to rupture early by any rotation, delineation or gross chamber depth variation. As soon as you release that cortical capsular adhesion, you no longer have a problem. That’s how I think of it rather than a defective capsule. Perhaps it is a variant of the continuum of PHPV and Mittendorf dot pathology. It’s a slightly different but important perspective.

Kevin Miller, M.D.: It’s not that the capsule spontaneously ruptures. The reason the cataract is there in the first place is that there is a problem in the embryogenesis of the lens. It doesn’t pinch off from the surface ectoderm properly. As a result, he capsule doesn’t form properly and a posterior polar cataract develops secondarily. Because the lens capsule is weak or absent at the central posterior location, the surgeon is usually not at fault for rupturing it. He or she lifts off the piece of cataract plugging the hole and exposes the break. I would like to address what Dr. Fine said. I have a different approach in that I don’t perform bimanual phacoemulsification. I don’t like the anterior chamber instability I see with this procedure. I perform microcoaxial and standard coaxial phacoemulsification instead. I do not think anterior chamber shallowing is a problem during removal of the first half of the lens. When the surgeon gets close to the bottom, however, he or she should not remove the irrigating line from the eye without first pressurizing it with OVD. If at this point the chamber is allowed to shallow, the cataract will suddenly pop out of the capsule hole and then you have problems. I agree 100% with the other thing Dr. Fine said. There is always a little bit of capsule debris after successful cataract removal. If the surgeon is fortunate enough to get through nucleus and cortex removal and the capsule is still intact, stay away from the posterior capsule debris. If you try to polish the capsule you will rupture it!

David Chang, M.D.: How many of you have had a situation where you successfully complete the phaco or cortical cleanup and pull your instruments out, and it’s at that moment that the central posterior capsule ruptures as the chamber shallows?

Dr. Fine: I had it when I was doing live surgery. Of course, we did it here in our own surgery center. I thought it was a posterior subcapsular cataract. It was actually a posterior polar, and I took the instrument out and there was vitreous and I had to tell everybody in the audience that some eyes have too much vitreous.

Dr. Chang: Using the surgical strategies discussed, I think that the posterior capsule rupture rate with posterior polar cataracts is probably less than 5 to 10%.

Tom Oetting, M.D.: The only thing I would like to add is that I like to lower the bottom height, lower the vacuum, and first sculpt out a bowl prior to hydro-delineation. Clearing away some of the central nucleus allows the remaining nuclear material to collapse into the central sculpted out area during hydro-delineation which relieves some of the tension that could cause posterior capsular rupture during this step. For me, this also makes it easier to not mistakenly hydro-delineate rather than hydro-dissect as the sculpted out area allows one to more easily find this plane. And finally if you do get a posterior capsular rupture during either hydro-dilenation or inadvertent hydo-dissection at there is less nuclear material in the vitreous when you sculpt out a bowl first!

IFIS

Dr. Oetting: IFIS, or intra-operative floppy iris syndrome, is a very important and timely topic. While this syndrome was described by Drs. Chang and Campbell along with its association with Flomax (tamsulosin), IFIS is really a problem that we have been mystified by for years but we didn't understand: “why this case, why me?, is it the phase of the moon?”. Until their paper came out, we had no way to predict who would have iris prolapse and who would not. Now we know that we must be ready for IFIS in all patients on Flomax and other alpha antagonists used primarily for benign prostatic hypertrophy particularly if they have a small pupil at the start of surgery. We know to plan our surgery with the possibility that the iris may behave in this manner and work to prevent iris prolapse and possible loss of iris tissue. There are a variety of techniques that have been described to help manage the iris during this condition, and they involve pharmacologic agents such as, pre-operative atropine, intracameral agents such as epinephrine and phenylephrine, and then a variety of devices such as pupil rings and iris hooks. The real emphasis, I think, with surgery on patients with IFIS is to preserve the iris. The horrible complication that can occur with IFIS patients is loss of iris tissue from iris prolapse which may require further surgery or cause glare. As such I think that prevention of iris prolapse is the primary goal of any technique for IFIS so we can remove the cataract and not remove the iris in the process.

If the pupil is big (>7 mm) and the patient is on Flomax, then I tend to place a single sub-incisional iris hook, to prevent iris prolapse. If the pupil dilates poorly, I tend to use four iris hooks in a diamond configuration with one of the hooks under the main incision. My practice may be skewed a bit as I do a lot of teaching with longer cases and have had less luck with pharmacologic agents. Lately, I have also been using the Malyugin Ring with good luck.

I would also like to get the panel’s opinion on another observation: I think that patient’s with IFIS also have a weaker zonular apparatus (now I’m really getting paranoid?). I wonder if anyone else has noticed this?

Dr. Fine: I think my experience with pharmacologic agents is not the same as others have described. I do use atropine pre-operatively, and sometimes it works and sometimes it doesn’t. If the patient comes to the OR with more than a mid-dilated pupil we use shugarcaine, and it will hold the pupil. In my experience with a floppy iris, Shugarcane will not dilate it. The second thing that we do is that we try to dilate and expand the pupil with Healon5, and then we use a little Viscoat in the center. It’s a great advantage to use bimanual microincision techniques because if you have an irrigator in the anterior chamber above the iris, the iris will never billow. The irrigation high in the anterior chamber will tamponade the iris and actually hold it back. In some cases, we will prolapse the lens; we do hydrodissection and hydrodelineation and prolapse the lens into the plane of the capsulorrhexis, and then we actually just hold the irrigator high in the chamber and carousel the endonucleus in the plane of the capsulorrhexis. When the endonucleus is gone, we have a fully intact epinucleus holding the iris back in addition to the fluids that are above, and then we remove the endonucleus. In other cases, where we have very hard lenses, we do a slightly larger capsulorrhexis; we use Healon5 and Viscoat in the same way. We do one and only one endolenticular chop and from that point on, after the first chop, we bring material out of the endolenticular space up to the chopper in the anterior chamber to further disassemble it. We are always irrigating from above. We try to keep the phaco tip occluded, and if we have a clearance of occlusion we go directly to position one so we are not mobilizing viscoelastic, and that stays in the eye. We will bring the material up to chop it and remove it and then bring the epinucleus out and frequently, bringing the epinucleus out it’s hard to keep the tip occluded. We lose some of the Healon5, so we redilate the pupil and then we bring cortex out by doing the same thing. We keep this irrigator occluded and move circumferentially around the rim of the capsulorrhexis just bringing cortex out of the capsular fornix, we are not bringing it out of the eye and that way we can keep the tip occluded and not mobilize viscoelastic material. We end up with a big clump of cortex in the posterior segment of the capsule, and then we remove that and go ahead and do our IOL. In some cases, we can’t hydrodissect or hydrodelineate. In those cases in which we have minimal hydrodissection and hydrodelineation, I found that I can create very small pie-shaped segments with vertical chopping, and if I remove two or three of those without rotating the lens, I then have enough room to mobilize more lens material, but if I haven’t been able to hydrodissect or hydrodelineate at all, I would bowl out the center of the lens and then do inside out hydrodelineation and then chop the periphery of the endonucleus and remove the epinucleus in the same way. These are things that I found to be useful using bimanual microincision techniques, and it’s keeping the irrigating chopper high for tamponing the iris and you don’t get any billowing. In cases in which I just don’t have an adequately dilated pupil, I like the Morcher pupil expander ring best. I have to use coaxial phaco then because it takes a 2.5-mm incision to put that in. I found that if I am careful at the end of the procedure, I can lift the Morcher ring out of the pupillary space, move it to the right side of the anterior chamber, and then have the leading edge of that ring directly facing the incision. I can then go in with the injector forthe Morcher pupil expander ring and remove the ring with the injector. Now if that ring is angled and you try engage it with the injector, you break off a segment of the rim of the first positioning hole and then you have a transparent intraocular foreign body. It’s real hard to recover that. These are some of the techniques that I’ve used, and I get as many as four of these a day, so I am starting to think of myself as a specialist. Recently, we have used the Malyugin ring successfully.

Dr. Arbisser: Here are a couple of things I would like to add to these comments. First of all I think Tom, it’s really interesting that you think that there is some difference in the zonular apparatus as well because I thought so also and I was sort of told by several people that there was no evidence to that effect though I too had that impression. Of course so many of these people are elderly and you know, may have other reasons for zonular issues. We can’t do a really good hydrodissection sometimes because we may draw out the pupil and we have to sort of do multidirectional hydrodissection so they act in a sense like a case with poor zonular integrity in that we can’t rotate the nucleus easily. I personally haven’t yet become comfortable with the pupil expanders because I want that pupil be normal the next day and I found when I’ve tried them that they can be a little traumatic on placement and removal. I most often use an ophthalmic visco device in this setting and the concept of using the soft shell; laying down the peripheral Healon 5 [Advanced Medical Optics, Santa Ana, Calif.] and then packing this in with Viscoat [Alcon, Fort Worth, Texas] allows you to use a little bit higher vacuum and aspiration flow rate than you would working with 5 Healon alone. The other thing we haven’t stressed is that you really want to be very careful to make excellent tunnels in your cornea both paracentesis as well as your main incision. I wouldn’t go near- clear but would stay more truly corneal in these cases. If incisions are tight and a lot of attention is paid to lowering that sub-incisional iris away from the Descemet’s window with Viscoat multiple times as needed and any time I am going to go in or out with an instrumentI it’s so gentle that you don’t get any thermal change or loss of pigmented epithelium. By using viscoelastic as a true OVD, I rarely resort to hooks in these cases.

Ken Rosenthal, M.D.: I have had some limited experience; it’s fairly new and I think, Lisa, that answers some of the issues that you have with pupil expanders. First I want to preface by saying that I, like Howard, am a big fan of the bimanual technique for all the reasons you mentioned. In these cases where stability is important, Boris Malyugin’s pupil expander is extremely easy to insert. It isn’t inserted in the tradition of a capsular tension ring inserter so it’s externally manipulated: you grab the ring, pull it into the inserter, and then you inject it back into the eye and it gradually pulls the pupil open in a very, very gentle and dramatic way. It’s extremely easy to place but it grasps the iris on each side. If you have seen what it looks like when it’s opened in the eye it creates a square pupil and at each junction point there is a loop which reminds you of the bottom of a safety pin. Each loop fits on each side of the iris of the pupil so not only does it expand the pupil but it also stabilizes it in an anterior posterior direction if you combine that with Healon 5 and then with bimanual. As Howard says if you keep the infusion anterially with your chopper when you are not actively chopping, you can actually use that and generally place that on the ring to stabilize it. The interesting thing is that it almost prevents all the billowing as well because it’s stabilizing in an anterior posterior direction as well. If you combine that with Healon 5, you have a very easy case that would otherwise be very challenging. The ring is likewise very atraumatic to remove; you can either cut it and pull it out or what I do is simply grasp it with the inserter slice and withdraw it back into the vitreal cartridge and take it out of the eye. I would say that probably 75% of the time that I do floppy iris cases I use Healon 5 alone and I find that continually or repeatedly instilling the Healon 5 gives a tremendous stability along with bimanual technique. So, it depends on the individual. The other thing is that before I start any manipulation, I just use epinephrine at a mixture of 1:4000 rather than the usual one to 6000 to 7000. That seems to create a very stable dilation and tends to (increase) the pupil where we wanted. So, epinephrine and the Malyugin expander along with some Healon 5.

Dr. Oetting: Ken, have you had the experience where you come and the pupil is pretty small and you use epinephrine and the pupil actually dilates?

Dr. Rosenthal: Well, I would have to say sometimes. Mostly it holds when it does dilate.

Dr. Chang: There are certainly many IFIS cases with a medium starting pupil diameter where injecting intracameral epinephrine magically expands the pupil, and it doesn’t hurt to try it for this reason. If it doesn’t dilate enough, you can always then add Healon 5, to push the pupil open further. However, even if it doesn’t dilate the pupil any further, epinephrine still can provide a major advantage —that of increasing iris rigidity by stimulating iris dilator muscle contraction. By reducing or preventing iris billowing and prolapse, there is much less likelihood that the pupil will constrict during the course of surgery. For this reason, I believe that epinephrine is an excellent approach for the mild to moderate IFIS cases. Thanks to the work of Joel Shugar, [M.D., Perry, Fla.] we know that the acidic pH of the commercial epinephrine solution can be elevated to a physiologic range by a 1:3 dilution with either BSS or BSS Plus (Alcon).

On the other hand, Howard is right. If you have a very small starting pupil, which usually predicts severe IFIS in my experience, then simply injecting epinephrine alone is not going to solve the problems. I think it is also important that surgeons have a strategy for these cases, such as using a pupil expander ring or iris retractors. Tom Oetting’s idea of placing iris retractors in a diamond configuration solves many of the problems associated with the typical square configuration.

We have probably all had cases where we have over-stretched the pupil with hooks causing significant damage to the iris sphincter. Inadvertently creating an atonic pupil is one risk of iris retractors, and it is more likely to happen after overstretching a fibrotic pupil. With IFIS, however, the pupil is quite elastic, and you can usually maximally expand it with retractors. It is impressive how quickly the IFIS pupil springs back and constricts as soon as the hooks and OVD are removed. I prefer 4-0 Prolene iris retractors because they are stiffer and easier to handle and maneuver. They are also reusable, which makes them very cost effective.

Many surgeons are not experienced with using Healon 5, or prefer to use higher vacuum and flow parameters, particularly with denser nuclei. In addition, Healon 5 or intracameral epinephrine may achieve a marginal dilation that some surgeons are comfortable with, but others are not. Fortunately, with iris retractors you can use your usual OVD and phaco settings and still have maximal pupil dilation with no risk of sudden miosis during surgery. Surgeons should not be soured by prior experiences using costly and floppy disposable 6-0 nylon iris retractors in a square configuration with fibrotic pupils. Reusable 4-0 Prolene retractors with the diamond configuration are a 100% reliable way to manage the most severe of IFIS cases. As others have mentioned, the Malyugin pupil expansion ring (Microsurgical Technologies, Redmond, Wash.) recently became available and this is the easiest pupil expansion ring to use. It works very well for severe IFIS cases, and I think it is going to be a very popular strategy.

Clearly, there is no one single best solution for all surgeons and all IFIS cases, and I think we all become better surgeons by becoming adept at using different strategies for IFIS that can be staged or combined according to the variable severity of the condition.

Pseudoexfoliation

Dr. Rosenthal: Let’s take a step back and say that the two most important problems that we face surgically are pupil dilation problems and instability of capsular apparatus. The two very often work against each other in terms of a surgical strategy. Let’s talk about the pupil that’s worked from the front to the back and think about our strategy. Here, I agree with Dr. Fine on the issue of bimanual phaco any time when you have a case in which there are challenges in creating stability. In my hands, this has been one of the best ways and particularly with the electronic circuits and feedback mechanisms of the current phaco machine, the ability to maintain a stable chamber, and additionally, the opportunities to manipulate tissues inside the eye by a variety of ports or ports rather than paracenteses. So, you can make four or six or even eight paracenteses all around in cases where you need to gain access in a direction you wouldn’t normally take.

Let’s go back to the pupil again. I think the techniques that we just discussed are useful in pupil expansion and particularly the pupil expanders, rings and hooks, and so on. The Malyugin expander works beautifully here in my limited experience with it. For some people working on in quadrants other than the quadrant closest to them is a challenge and so, any of these devices that can be inserted through the incision without having to place, for example, hooks have to be placed radially around the eye, for some surgeons poses some challenges. Being able to go through one incision and place the device easily is a virtue. Of course, the difference here too is the pupil needs to be stretched very often and here we don’t worry about it as much. I am wondering if anybody has an experience of an IFIS patient with pseudoexfoliation.

Dr. Arbisser: It is necessary to resist stretching the pupil as it will only become more floppy with IFIS. These are cases where I will consider using iris hooks in a diamond pattern with one hook subincisionally located. However pseudoexfoliation is another condition entirely in which the iris is strong, or even fibrotic but the muscle structure is otherwise normal. Stretching of the pupil here can be quite beneficial and could be done I think more liberally. In my hands with my vertical chop technique I only require a 5 mm pupil for a perfect rhexis of 5 to 5.5 mm and it is always easy to get the pupil to this size with some combination of two point stretch, viscomydriasis and microsphinctorotomies if necessary. The biggest challenge, of course, with the pseudoexfoliation eye is handling the propensity for zonules to be weakened and brittle. Then of course for us, it’s like a box of chocolates because we never know what we are going to get from the preoperative exam. We could see extensive pseudoexfoliation in the anterior capsule and even in the angle or on the corneal endothelium and have very little trampolining during surgery and vice versa. I think if we know the patient has pseudoexfoliation, we go in prepared for the most challenging case. Here again, capsulorrhexis size is controversial, I think. I tend to make a capsulorrhexis of normal size. Some people like to make a larger one with the idea that phimosis may occur, but I initially want the rhexis smaller than the optic one because in a minority of cases I will actually electively use a sulcus implantation with optic capture or even a buttonhole technique through a planned posterior rhexis with in the bag implantation. If the rhexis is too large we lose that option. My theory is that the lens supports the bag and the bag supports the lens preventing phimosis with the physical barrier of the optic and possibly saving the patient a decade hence from a bag lens dislocation. Time will tell. If the case is routine of course I implant in the bag I can always enlarge the rhexis to barely cover the optic edge which is were I would choose to leave it.

In my experience when a capsular tension ring is indicated, I have tried to place the ring as late in the case as possible and as early as necessary.

Dr. Rosenthal: If I see an extensive amount of instability, I’ll place the ring early, and the strategy for placing the ring early in the case to avoid entrapment of the cortical fibers. It’s pretty simple and it consists of evacuation, but we are using the irrigation and aspiration (I/A) handpiece, so we are using bimanual I/A of the anterior and equatorial cortex first before removal of the nucleus.

Placing a retentive viscoelastic material, I do like to use C15 in these cases. Inside the capsular bag under the anterior capsular rim and pressing the nucleus and residual cortex backward and then placing the ring, the capsular tension ring jerks on the anterior capsule so that it dials free of any of the remaining contents of the capsular bag. Now we have a ring that’s in place that helps us to stabilize the capsule and that is non-entrapping cortex so then we can go ahead and continue the case and remove the lens. Whatever residual cortex that needs to be evacuated is completed and then generally put away pretty easily. I am going to avoid the rather lengthy topic of how we handle profound zonular weakness, for example, that requires suturing of the rings and things like that. Suffice it is to say that there are cases which do require more than just a capsular tension ring and, in a small minority of cases, I think where the capsular just needs to come out. But one of very useful adjuncts I have found to this is that it will miss still profound zonular weakness is that and as I mentioned before is that I will use rather than place the lens in the capsular bag and then rely on that complex to hold itself I will prolapse the optic by, capture the optic in the anterior capsulorrhexis leaving the haptic and sulcus and then when I place the suture through one or both of those haptics and actually suture the IOL in the posterior iris. What I have done there is created a belt and suspenders to stabilize the IOL even if the capsular bag later is to the center. The other beauty of that technique is it almost always avoids profound capsular phimosis because you know that even with one or two capsular tension rings, capsular phimosis can progress because these capsular tension rings—the ones we have available in the United States—aren’t strong enough to withhold the progressive capsular lens metaplasia that it can contract our forces that occur post-operatively. We need to actually put something in the way to prevent this, this capsular contraction now. If I have done this and there is, if I have done this smaller capsulorrhexis and I find that I can put the lens in the bag but there is not that much I will then go ahead and repair my anterior capsular at the end of the case to make it slightly larger and forego the luxury of preventing posterior capsular classification by allowing that rhexis to go slight just to the edge of the IOL if I need it. I find that almost all these, in cases like that, it does end up over the next few weeks to months to contract down a little bit and cover the edge of the IOL. I think that anterior chamber stability during the case is very important as tamponing tends to progressively weaken the zonules. Dr. Fine, I know you have been a big proponent of capsular tension rings in every patient with pseudoexfoliation.

Dr. Miller I think I agree with you. I can’t say I put CTRs in every pseudoexfoliation patient, but I put them in many, particularly if the zonules are notable weak.

Dr. Chang: Dr. Fine, are you still using CTRs routinely in pseudoexfoliation patients?

Dr. Fine: I use them 100% of the time. First of all, I think it helps to have that in place during the procedure because it transmits any force on the capsule to the entire zonular apparatus, rather than just to the adjacent zonules, so I think you are less likely to unzip zonules. The second thing, I do cortical cleaving hydrodissection gently before I put the ring in, and I can put the ring in through a 1.1-mm microincision by holding the injector outside of the eye and let the ring go in. I use my left hand to push the plunger, and I lift it up with a Lester hook in the right hand to control the forces on the bag as it goes in. There was a paper written recently by Ike Ahmed, M.D., showing that you shouldn’t put it in early because you can damage the zonules, but in my experience, if you control the forces on the zonule by pushing or pulling with the Lester hook, it goes in easily in every case. The cortical cleaving hydrodissection is usually peripheral to the cortical capsular connections, and then mobilization of cortex is much easier if you strip circumferential tangential to the capsulorrhexis because you tend to be pulling those strands of cortex around the ring rather than if you pull them directly centrally. You sometimes can capture anterior and posterior edges of cortex, and you end up pulling on the ring itself. One of the things that we should keep in mind also is that you probably shouldn’t use a silicon lens in pseudoexfoliation because they stimulate anterior subcapsular cells to produce extracellular matrix. It has many precursors of contractal elements, and it participates in creating phimosis of the capsule, so we use only acrylic lenses in pseudoexfoliation.

Dr. Rosenthal: I also want to mention the technique which I think is helpful when inserting the ring, in particular early in the case, where one is more concerned about the eccentric force of the capsular tension ring as it goes in.

The typical technique is to inject the ring, get it under the capsule, and then get it under the capsule and then push it so that it dials itself around the circumference of the capsule inside, underneath the anterior rhexis.

That is the best way to create eccentric capsular forces, so what I do very often, I use the 1.1-mm incision and just put the ring in, but what I do is, I inject the ring anterior to the anterior capsule. I place it as far as I can, and I tend to inject the ring so that it moves clockwise. So, if we picture that I move it as clockwise as possible and then as I am injecting I am it in to the eye, so I have actually extended it all the way, on. I have pushed the plunger almost all the way down, extended the ring almost all the way in to the eye before I even place it in to the capsular bag. Wrest it down into the capsular bag and then with a Sinskey hook pulled the trailing hole, the fixation hole off of the inserter and then tuck it down under the capsule. What I have done is rather than dial the capsular tension ring in, I have actually compressed it and placed it into the capsule so there is absolutely no dialing there.

Dr. Chang: How often are the rest of you using a CTR in pseudoexfoliation patients, particularly when there is no evidence of significant zonular laxity during the case?

Dr. Arbisser: Whenever I sense that there is zonular abnormality and otherwise I don’t, I don’t base it on the presence of pseudoexfoliation alone.

Dr. Chang: I want to underscore an earlier point. With pseudoexfoliation, it is very important not to leave the capsulorrhexis diameter too small, because this will create greater centripetal contractile forces that further strain the zonules. To lessen the potential for capsular contraction I prefer a 3 piece acrylic IOL because of the stiffer expansile haptic forces and to avoid the greater capsular fibrosis associated with silicone material. I have also always advocated doing a secondary enlargement of the capsulorhexis. It is actually easier to do if you have a three-piece IOL and/or CTR in place, because you have made the anterior and posterior capsule more taut.

With pseudoexfoliation cases, including those with no clinical signs of zonular weakness, I actually try to re-tear the capsulorhexis out to or beyond the edge of the IOL, with the goal of minimizing the capsulorhexis contraction forces. In cases of delayed bag-IOL dislocation, the capsulorhexis is often small. Like the chicken and egg question, is this because there is insufficient zonular tension to prevent the purse string-like constriction of the capsulorhexis, or does the contracting rhexis actually weaken the zonules further? I think that both factors are at play in a continuing vicious cycle. In this case, enlarging the capsulorhexis diameter should help, or alternatively, we could make several radial slits in the capsulorhexis edge. I certainly don’t have 10-year follow-up for this approach, but by one month postoperatively, you can already see how much quieter and inactive the anterior capsule looks when it is this large.

Dr. Miller: I routinely polish the undersurface of the anterior capsule in virtually all of my patients. The only exception is patients with small pupils where visualization is difficult. I use Shepherd–Rentsch capsule polishers. It is possible to remove most of the lens epithelium with the sharp anterior edges of these devices. You can get out almost to the equator and clean almost 360 degrees, including subincisionally. It’s a real eye opener to run these polishers beneath the capsulorrhexis and see how much lens epithelium comes off. These polishers are much better than any other devices I have used. I have been polishing the anterior capsule all of my career and, as a result, I never see anterior capsule fibrosis or capsulorrhexis phimosis. I polish all my patients, and pseudoexfoliation cases are no exception. I may polish even more aggressively in pseudoexfoliation. And so I don’t have to worry about progressive capsulorrhexis contraction in these patients. Now, there will be some age related loss of zonules unrelated to lens fibrosis, but there is nothing I can do about that.

Dr. Arbisser: I think that’s probably one of the as a single most important things we can do thing—that you can polish the capsule and polish it pretty aggressively. The downside is that these are the same patients we are talking earlier Ken was mentioning with small pupils so. A lot of timetimes you are doing this capsule polishing a little bit in the dark. I listen for the occlusion tone as well as, but I think you can still do it. I think you still need to do it pretty well-just by feel. Adequate rhexis size and cleaning the capsule flaps is my priority. I use a That’s probably my single peril and I use CTR about half the time in these patients. For the extremely unstable bag I optic capture as I mentioned earlier and have found these eyes to be extremely stable over time. The ultimate of course is to use a sutured Cionni modified tension ring in an eye with focal as well as diffuse zonular pathology.

Dr. Oetting: I am changing my practice in this area. Until recently, I didn’t use capsule tension ring if everything was going really well. However, like others, we have been getting PXF patients that we did years ago that with beautiful intact capsules around their single piece of acrylics floating in the vitreous. This really gives us a problem because we have a single piece acrylic that’s not easy to suture to the iris or sclera and we don't have a capsular tention ring (CTR) to which we could potentially suture as Howard said. So I have rethought my strategy a little bit and either place a single piece acrylic with a CTR or use a 3 piece IOL to allow suturing later in PXF which is clearly a progressive zonular disease.

Dr. Chang: Three piece haptics are stiffer and should better resist capsule contraction, and just as your case points out, you at least later have the option of suturing the haptics to the sclera if the IOL does subluxated. To summarize everyone here is trying to think of ways to decrease the risk of delayed bag-IOL dislocation.

Fuchs’ dystrophy

Dr. Miller: Fuchs’ dystrophy is the most common endothelial corneal dystrophy. There is a spectrum of presentation, from asymptomatic corneas that don’t require a whole lot of attention to corneas that are completely decompensated. I think the cataract surgeon’s approach should vary depending on the extent of the dystrophy. I think it’s helpful to divide eyes into those that will benefit from just from a cataract operation alone, with perhaps with the few extra steps, to those eyes that will benefit from combined or staged procedures. I’ll limit my initial comments to eyes that have mild to moderate Fuchs’ dystrophy, where it’s most appropriate to perform a cataract operation alone, see how the cornea fares, and do a DSEK or PK if it doesn’t come back.

In Fuchs’ dystrophy there is an age-related acceleration of loss of endothelial cells, perhaps starting from a lower than normal count. Fuchs’ dystrophy is a dominant condition with variable penetrance, and it’s common in women and common after age 50. When performing phacoemulsification, the cataract surgeon should do everything possible to protect the corneal endothelium. There is typically a 2 to 3% endothelial cell loss with carefully performed cataract surgery. If surgery is not clean, the sky is the limit on cell loss. I think the things that traumatize the endothelium the most are high or turbulent flow, and things that bump into it, such as pieces of cataract. Heat is also traumatic. In my opinion the single most important technique I employ to protect Fuchs’ patients is Steve Arshinoff’s soft-shell technique. I like a dispersive agent up against the corneal endothelium such as Viscoat (Alcon, Fort Worth, Texas) and a highly cohesive agent like Healon GV (Advanced Medical Optics, Santa Ana, Calif.) beneath it. Lately, I have been using DisCoVisc (Alcon) as the second agent. I replace the dispersive agent as often as necessary to maintain a nice endothelial coating. I also stay away from the endothelium and try to minimize the amount of aspiration flow. I keep Fuchs’ patients on corticosteroid eye drops as long as necessary to quiet all postoperative inflammation. I tell the patients that it may take two weeks, three weeks, two months, or three months for their corneas to recover fully. I also tell them I’ll wait six months before I consider a DSEK or PK if their cornea doesn’t recover.

Dr. Fine: I think one of the most important things about Fuchs’ dystrophy is to use bevel-down phaco tips. Because then, all of the energy is going toward the lens, and none is going to the endothelium or the trabecular meshwork. I like a bent tip; a bent tip allows you to work with less lifting of the incision, it allows you to go more posteriorly, and it puts the tip against the nucleus in such a way that you can easily occlude the tip and achieve vacuum quickly. I like to use power modulations on all cases, but I try for as little phaco energy in the eyes as I possibly can get. I think cortical cleaving hydrodissection is very important here so that you can minimize the amount of fluid that goes to the eye with cortical clean up.

Dr. Chang: Any thoughts on the use of OVDs in Fuchs patients?

Dr. Miller: It’s very important to remove all of the viscoelastic to keep the intraocular pressure down.

Dr. Arbisser: I was just going to say I always use Diamox (acetalzolamide, Wyeth-Ayerst, Pearl River, N.Y.) or other hypotensives in sulfa allergic patients to avoid that little pressure rise in addition to trying to remove the viscoelastic. , but I will leave a little bit of viscoat under the endothelium rather than use really aggressively aspiration in the interest of minimizing turbulence and using as little fluid as possible to spare the endothelium further trauma

Dr. Miller: The clinical appearance of these eyes is way more important than any laboratory test you can perform. Endothelial cell counts are not terribly predictive. Cell counts can be 600 cells per square mm, and the corneas can look really good. I have seen patients with counts of 3,200 that look terrible. The counts don’t really mean that much. Corneal pachymetry can be more helpful, but even with that test you can have corneas that are thick that do well and corneas that are thin that do poorly. I think clinical appearance is more predictive of how Fuchs’ corneas will do post-operatively than any test I can perform.

Dr. Fine: My comment on viscoelastic is simply to just use a lot of it. Coincidentally, a lot of these Fuchs’ patients tend to have advanced nuclear sclerosis, because surgeons have not wanted to work with them until it’s going to make an obvious difference. I think that a dispersive ophthalmic viscosurgical device (OVD); right now, this means Viscoat which I feel is the best.

Dr. Chang: The other thing that happens when we have a dense lens is that as you get to the last few remaining fragments, the exposed posterior capsule starts to trampoline because of the absence or lack of a substantial epinuclear shell. As a result, the surgeon tends to emulsify the final fragments closer to the cornea in order to increase the distance from the exposed and mobile posterior capsule. Roger Steinert had the excellent idea to use a dispersive OVD to expand the posterior capsular bag when the epinucleus is absent. By using OVD to restrain the posterior capsule from trampoling forward, you can safely emulsify the last pieces within the iris plane rather than closer to the cornea. A dispersive OVD better resists aspiration, and is the logical choice for this application.

Editors’ note: Dr. Chang has financial interests with Advanced Medical Optics (AMO, Santa Ana, Calif.) and Alcon (Forth Worth, Texas), and his consultant fees are donated to the Himalayan Cataract Project. Dr. Fine has financial interests with AMO, Bausch & Lomb (Rochester, N.Y.), and Alcon, among others. Dr. Arbisser has financial interests with AMO and Alcon.Dr. Miller has financial interests with Alcon. Dr. Oetting has no financial interests related to his comments. Dr. Rosenthal has no financial interests related to his comments.

Comparing the cataract challenge Comparing the cataract challenge
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