This month, Review is debuting a new type of article. "Face-off" is designed to foster lively discussion about the reasons why surgeons do what they do. The articles center on a real-time debate between two colleagues, either in person or via the telephone. It's our hope that by listening to their opinions, you confirm that your technique is sound, question your tactics or learn new ones. Dr. Blecher is Chief Medical Editor at Review	Dr. Masket is in private practice in Los Angeles, and is a clinical professor at the Jules Stein Eye Institute, UCLA Center for Health Sciences.	Dr. Van Meter is an associate professor of ophthalmology at the University of Kentucky, and is also in private practice.

Dr. Blecher: In cases of pseudoexfoliation or subluxated or dislocated IOLs, is your preference to implant an anterior chamber lens or a sutured, posterior chamber lens?

Dr. Van Meter: I think an anterior chamber lens is easier to implant if the iris and angle are normal and there are no other extenuating circumstances like corneal edema or glaucoma. This was borne out by a prospective, randomized study by Baltimore surgeon Oliver Schein, MD.¹ He performed a prospective, randomized comparison of anterior chamber lenses, iris sutured lenses and trans-sclerally sutured lenses in penetrating keratoplasty patients. There wasn't much of a difference between the groups, except for a slightly higher incidence of glaucoma with the trans-sclerally sutured lenses and a slightly higher incidence of cystoid macular edema with iris sutured lenses, neither of which were statistically significant.

There's a caveat, though, with anterior chamber lenses: I think most of them are made in three sizes, small, medium and large. An accurate white-to-white measurement for implantation can be challenging, so here's a recommendation for implanting anterior chamber lenses. Some eyes are small and hyperopic and would do better with a small lens, while others are large and would do better with a larger IOL. Since it can be very difficult to get a truly accurate white-to-white measurement, I think the medium-sized lens is preferable to start with for most patients. If, during surgery, it proves to be the wrong size, you can exchange it for a larger or smaller one. Unless there are obvious corneal size or refractive parameters, or other extenuating circumstances that are known preoperatively, this strategy works very well in most patients.

Dr. Masket: I prefer a sutured posterior chamber lens in this type of situation. Although it's important to individualize surgery based on the patient's finding, even in the case of an ideal candidate for an anterior chamber lens--the hyaloid face is intact, it's not necessary to perform a vitrectomy, the angle is open and normal, the cornea is healthy and there's no glaucoma--there would still be a problem with the sizing of the lens. As you mentioned, anterior chamber lenses can be either too large or too small. The other issue is that they're not foldable, so the surgeon will need to create a larger incision. Anterior chamber IOLs are excellent in the appropriate situation, but they do have limitations.

Case 1

Dr. Blecher How would you respond, then, to the following patient presentation? The patient is 70 years old with pseudoexfoliation. The capsule is torn, but the lens material has been removed. You think you can finish the surgery successfully, but you can't. The bag is gone, so there is no possibility of using a capsular tension ring. After performing a vitrectomy and cleaning up, the rest of the ocular anatomy is normal.

Dr. Van Meter: I would use an anterior chamber lens, since the other anatomical features are normal.

Dr. Masket: With the incision being at 3 mm, I am likely to suture fixate a foldable lens to the iris. My opinion is based on recent experiences with iris-fixation of malpositioned posterior chamber IOLs.

"Although it's important to individualize surgery based on the patient's finding, even in the case of an ideal candidate for an anterior chamber lens ... there would still be a problem with sizing." -- Dr. Masket

A few years ago, I began receiving referrals of patients with dislocated IOLs and employed McCannel suturing of the IOLs to the iris. I learned that one can use the iris well to support a PC IOL. Interestingly enough, I've now adopted this method as a primary procedure for sewn-in posterior chamber lenses at the suggestion of my colleague, Gary Condon, MD, of Pittsburgh. I think that this method is somewhat easier and perhaps a little less risky than sewing to the sclera.

Dr. Blecher: Why, then, did sutured iris lenses, used frequently for a time about 15 years ago, get such a bad reputation?

Dr. Van Meter: I think you're referring to the Medallion IOL with a prolene suture through the iris. It really had to do with the IOLs and not the fact that they were sutured to the iris. If you go back to Dr. Ridley's initial lens, he used a PMMA lens in the posterior chamber, so he got two features of modern IOLs right. The problem was that his lens wasn't accurately affixed in the eye and was too big. The same goes for suturing to the iris 15 years ago. This lens was kind of big, and the loops in the posterior pole probably caused iris chafe. There may also have been trauma to the iris or the cornea during implantation through a large incision or associated with intracapsular cataract surgery.

Dr. Masket: The Medallion was a tri-planar lens requiring a large incision. If the two posterior loops weren't long enough, dislocation occurred frequently. The suture would keep the lens from falling out of the pupillary plane. The rate of decentration was about 5 percent; corneal decompensation occurred in another 5 percent. The lens was also too mobile.

Dr. Van Meter: Aside from my preference for implanting an anterior chamber lens, I also think it's sometimes reasonable to close the eye, leave the patient aphakic for a few days or weeks and then return for a secondary procedure to implant the lens. This gives the eye a chance to heal and for me to confirm that the status of the vitreous and retina is OK. When I do a vitrectomy combined with a cataract extraction, I'm always concerned about the risk of subsequent retinal holes, detachment or CME. Performing the implantation as a secondary procedure works well, but the patient is aphakic during that time period between procedures and can be frustrated from the unfulfilled expectation of having improved vision following cataract surgery.

Dr. Masket: I have very rarely left a person aphakic, mainly because of difficulty in dealing with his or her postop disappointment. I always try very hard to ensure that the patient leaves with a lens, but, more importantly, that it's the appropriate lens for his or her eye. However, when under some unusual circumstances, wisdom may dictate that the surgeon stop and temporize.

Dr. Blecher: Do you think suturing to the iris results in less tilt? Because one of the problems people have when suturing to the sulcus, not having direct visualization of where they're placing their sutures, is a lot of tilt and induced cylinder.

Dr. Masket: As with any procedure, outcomes are technique dependent. With the appropriate tension on the sutures, one can anticipate excellent centration and an absence of tilt. It's quite true, though, that with asymmetric scleral fixation one can induce a significant amount of tilt. One of the other difficulties of scleral fixation is making sure that the sutures are oriented appropriately with respect to the suture eyelet on the loop. We've all seen demonstrations where the surgeon thinks that the suture is correctly placed, only to find that the lens rotates 90 degrees to stand on end when the suture is drawn tightly.

Dr. Blecher: How long do these sutures last?

Dr. Van Meter: I think there is some light degradation of the prolene over time in addition to metabolic degradation of the suture in the eye. They probably last 20 years, longer than most patients need, but they don't last forever. In the anterior chamber, if you have a prolene suture through the iris, I think you have to admit that it would be subject to more light degradation than a suture that is buried under a scleral flap.

Dr. Masket: I think it's a combination of UV light degradation and a metabolic hydrolytic process. When viewing scanning electron microscopy of polypropylene sutures, degradation is evident, even in the buried material. What also concerns me is that I have seen sutures that support Medallion lenses that have metabolized or broken. Of course, Dick Lindstrom, MD and others have presented cases with scleral fixated lenses that have revealed suture degradation after about eight to 10 years.

Dr. Blecher: Do you think there's a difference in degradation time of iris vs. sclerally sutured lenses?

Dr. Van Meter: I think there's perhaps less light degradation of a buried scleral suture, but there are so many other things that figure into the degradation process, such as trauma from crimping to the suture, that it's hard to say how much degradation is due to UV radiation alone.

Dr. Masket: These sutures do undergo hydrolysis. It's a slow process, but my sense is that it does occur. The only question is, does it occur quickly enough in our young patients that we're going to get burned down the road?

Dr. Blecher: Dr. Masket, is there any situation in which you would implant an anterior chamber lens?

Dr. Masket: Yes, there is. One can take advantage of the temporally oriented 6-mm incision to help with astigmatism control in cases with against-the-rule astigmatism. I've operated on any number of people in their 80s and 90s who were long-standing aphakes, had intact hyaloid faces, had lost their ability to wear contact lenses, had cataract surgery years ago and had against-the-rule astigmatism. In them, I can use the
6-mm incision that the anterior chamber lens requires, although I'll need to place sutures. These patients must live with some transient augmentation of the astigmatism postop, but, by the time the sutures are out, I will have significantly reduced the against-the-rule astigmatic shift that they got from their original cataract surgery.

The other scenario where anterior chamber IOLs are useful is to protect and maintain an intact hyaloid face. While a surgeon can push the vitreous back with viscoagents like Healon5 or Viscoat, there's still the risk of disrupting the hyaloid when suturing the IOL. And so, when an eye has an intact hyaloid face, one can avoid damaging it by implanting an anterior chamber lens.

Case 2

Dr. Blecher: What would your strategy be for a relatively young patient, 35 or 40 years old, who, after cataract surgery, has no capsular support? Otherwise, the anterior chamber anatomy is normal, and there is no glaucoma. It's a 2.7-mm incision. There's not enough capsule to implant a sulcus-fixated lens.

Dr. Van Meter: I would close the eye in the young patient if there were vitreous present in or near the pupil and wait. Then, I'd go back in a secondary procedure and implant an anterior chamber lens. I say this because I wouldn't want to extend my 2.7-mm clear corneal incision at the time of cataract extraction. I would try to alleviate the patient's disappointment by saying I did what was in the best interest of his eye.

Dr. Masket: Many surgeons may say, "Now, we wouldn't want to put an anterior chamber lens into a 20- or 30-year-old, because we don't know how long that lens is going to do well." One nice feature, however, about a well-manufactured, high molecular weight, solid one-piece, open-looped, PMMA anterior chamber lens is that a surgeon can implant one in a patient, observe him over a long period of time, and remove the IOL should the patient develop iris distortion, an inflammatory syndrome or CME. There is a distinction between current and previous models of anterior chamber lenses; the latter are off the market. The old ones had extruded closed PMMA loops and a high monomer content. The loops would often fibrose in the angle and become problematic. The high molecular weight, single-piece, open-looped, PMMA lenses are less likely to induce problems.

If I felt that an anterior chamber lens was the most appropriate for the patient at the time of surgery, and I didn't wish to extend the 3-mm temporal clear corneal incision, I would move superiorly, open the conjunctiva and make a sclero-corneal tunnel for lens implantation at the same sitting. I'd want to leave the patient with a lens implant after one surgery, if at all possible. But, if I could bring the pupil down, then I'd use my technique for suture fixating the lens to the iris. The problem is that, in the primary cataract situation, the pupil is often widely dilated, and making the pupil small enough to use the iris-suture technique isn't possible in every case.

Case 3

Dr. Blecher: How would you respond to a patient with aphakic corneal edema who had intracap 20 years ago?

Dr. Van Meter: A patient like this would probably be having a corneal transplant, so if the iris and angle were normal I'd implant an anterior chamber lens, because it doesn't require external knots or flaps and is easier, takes less time and hasn't been shown to be less effective than an iris-sutured or trans-sclerally sutured IOL.

Dr. Masket: In my experience, the corneal grafts that I've seen or done with anterior chamber lenses are less likely to be successful than those using posterior chamber lenses, though the literature doesn't reflect that concept. Studies indicate that a well-positioned anterior chamber lens is tolerated by the graft. Peripherally, however, the cornea develops some puckering or flattening as a result of the suturing process, and there's an opportunity for the anterior chamber IOL to touch the graft.

Dr. Van Meter: It's hard to generalize about procedures in scenarios such as this. Almost every patient that needs a corneal transplant and a lens implant has a different history. The Schein paper to which I referred had 75 patients with different preop diagnoses, suturing techniques and ocular histories. In the end, you've got to individualize the surgery.

If the iris and the angle are normal and there's no capsular support, I have no qualms about putting in an anterior chamber lens with a graft. A well-sized anterior chamber lens seems to be well-tolerated and is technically easier to implant. If there are iris or angle abnormalities, however, I would use a trans-sclerally sutured IOL. In that procedure, I bury the prolene knot into the sclera below a partial thickness scleral flap to eliminate the risk of knot erosion. I believe that trans-scleral suture fixation is more versatile than iris fixation of a posterior chamber lens, because, if there's iris damage or a large section iridectomy, iris fixation may not be possible.

Dr. Masket: Most of the eyes that require surgery of this nature have a variety of issues. It's rare to find them with a lens that doesn't have a problem, either the natural lens or an implant. Frequently, the iris and other structures are involved, and there may be glaucoma, iritis and cystoid macular edema. The number of eyes that I recall that have required triple procedures and would have also been good candidates for an anterior chamber lens are very few.

The rule that I've followed is that, in performing a graft in a patient who has an anterior chamber lens where CME or chronic inflammation are absent, I leave the anterior chamber lens in place and perform the graft. By and large, the eyes that do come to surgery almost always have pathology in addition to corneal opacification. RO

1. Schein OD, Kenyon KR, Steinert RF, Verdier DD, Waring GO 3rd, Stamler JF, Seabrook S, Vitale S. A randomized trial of intraocular lens fixation techniques with penetrating keratoplasty. Ophthalmology 1993;100:1437-43.

Best Practices Cataract Surgery This month, we continue our periodic series providing pearls and other successful innovations that surgeons have implemented to improve outcomes and efficiency. This month's focus: cataract surgery. I recommend a maximum of three grabs for the rhexis. The fewer times you have to re-grasp the anterior capsule, the better. I make the capsulorhexis in the shape of a three-pointed star. I grab it once and tear it about 120 degrees. Then I grab it again and tear another 120 degrees, and then grab it again and finish it up. Grabbing the capsule a dozen times just stirs up the cortex and makes the view difficult.     Inserting the intraocular lens with an injector, in this case the Bausch & Lomb LI61U lens with the M-port injector. Consistent 10-minute cases are feasible if you load your own lens into the injector, says Uday Devgan, MD. I think the chopper is the single most effective instrument for increasing efficiency and decreasing phaco and surgical time. I prefer my "pop-and-chop" technique. I hydrodissect until the distal nucleus pops out of the bag, and hook it at the equator with a chopper. Next, I impale the nucleus with a second of phaco. I bring the two instruments together and then pull them apart to give a complete chop, resulting in two halves. I then phaco each half with smaller chops.   Don't underestimate the importance of the postop regimen of drops, precautions like not rubbing the eye, and follow-up appointments. I use Lotemax (loteprednol 0.5%), and I've never seen a steroid-induced pressure spike from it. Uday Devgan, MD Los Angeles Let the patient learn everything he needs to know about you and the procedure in advance. Before he ever meets me and walks into the exam room, we show him a 15-minute video of me talking to him about what I am going to do for him and what he can expect with a cataract procedure. Be sure it's you talking and not a canned film on cataracts. This saves you valuable time and removes the common problem of an anxious patient impeding routine and flow with questions best addressed at an earlier time. I schedule my cases by probable duration, dividing them into three categories so surgical complications don't affect the entire process. "A" will be the routine cataract cases. "B" is for cases that may take longer, such as pseudoexfoliation or extremely dense cataracts. "C" is the probable marathon, such as a case in which I know I am going to be suturing a posterior chamber lens. That way I don't have 10 patients and my staff waiting around because I got hung up for an hour for one difficult case. I schedule A and B cases on separate days, with C cases given more time later in the day. The routine cases are complete, and my staff can leave, except for those needed for the C case. I don't make grooved incisions. Rather, I go straight in with the keratome. With the incisions so small now, we do the phaco and insert the IOL through a 2.75-mm incision, and that's with the largest flare tip and the Acrysof lens and Monarch II injector. It's very efficient to be able to inject the IOL through the same incision that you did the phaco through. A 90-degree I/A tip, in the place of a straight I/A tip, saves a lot of time. You can get sub-incisional cortex really quickly, and you don't have to be flipping around to bimanual instruments and going through two sideports with two hands. This also helps in efficiently removing the viscoelastic from under the IOL at the end of the case. You can get right underneath the implant easily, lift it up, take the viscoelastic out in 5 to 10 seconds and hydrate the incision. Richard Mackool, MD Astoria, N.Y.   A good hydrodissection is a critical step of the cataract operation. Be certain of a good nuclear rotation before moving to the next step, says Elizabeth A. Davis, MD. The success of the procedure hinges on preop preparation. I discuss with all my patients what they wish for their refractive goal. Most patients want distance correction in both eyes, whereas some want monovision or a multifocal IOL. The decision becomes more complex if the patient has a significant refractive error and a unilateral cataract. In the situation where the -6 D myope has a unilateral cataract, he may desire distance vision, but this may entail his wearing a contact lens or undergoing refractive surgery in the other eye to prevent intolerable anisometropia. David R. Hardten, MD Minneapolis Construct a well-fashioned clear corneal incision. The length of the incision is critical. Too long an incision will result in striae that impair visualization when the phaco probe is inserted. Too short an incision results in leakage of irrigating fluid with loss of anterior chamber stability and a wound that may not be self-sealing. I use a single-planed, 2.5-3.0 mm incision fashioned with a trapezoidal diamond blade. I insert the blade into clear cornea 1-2 mm anterior to the limbus, parallel to the iris. I aim for anterior chamber entry to occur when the shoulders of the blade begin to enter the wound exteriorly. This creates a 2.0-2.5 mm tunnel that does not need to be enlarged for most injectable IOLs. If possible, I prefer to make a large 5.5-6.0 mm capsulorhexis. This facilitates nuclear fragment removal. In cases of very soft nuclei or very deep anterior chambers, I have the option of prolapsing the nucleus into the iris plane for a supracapsular approach. Capsular phimosis is far less likely with this size capsulorhexis. A good hydrodissection is critical. I rarely proceed to the next step until I am certain of good nuclear rotation. I use a bent hydrodissection cannula to go beneath the anterior capsular edge above cortex. I tent up the edge of the capsule and then slowly and steadily inject balanced salt solution while observing the fluid wave. Once the wave has completely traversed the posterior aspect of the nucleus, I use the back of the cannula to depress the nucleus. This forces the fluid that has collected posteriorly to move anteriorly, breaking cortico-capsular connections.   Postop, I maintain patients on a fluoroquinolone, steroid and non-steroidal anti-inflammatory regimen twice a day for approximately three weeks. I then see patients at one day, two weeks and three and six months. Elizabeth A. Davis, MD Minneapolis We have our surgery center on the same floor as my office, and we use two exam rooms for preop maintenance. I place a pledget soaked in Ciloxan, Phenylephrine 10%, Tropicamide 1.0% and Acular in the inferior cul-de-sac for approximately 10-15 minutes. My staff then helps the patient, still in his street clothes, on to the preop bed. I insert an IV, if needed, and give a block or Xylocaine jelly. I give 5 cc of Xylocaine 2% without epinephrine subconjunctivally, superior to the 12 o'clock limbus to all topical patients. I find that this avoids the need for occasional intraocular Xylocaine, which delays surgery and is expensive. Prior to bringing the patient back to the OR, I check his intraocular pressure with a Tonopen to prevent surgical surprises. Postop, I use prednisolone acetate 1% q.i.d. for one month and Ciloxan q.i.d. for two weeks. I see patients at one day and at two-and-a-half weeks, and I arm them with thorough instructions about the signs and symptoms of healing problems. Minimizing the number of appointments is more efficient, and no patient wants to keep going back and forth to the doctor's office. Jeffrey Whitman, MD Dallas