Match Makers
Top-level surgeons share how they use today's IOL options for the best outcome in each patient.
By Frank Celia, Contributing Editor

IOL selection can make or break your cataract or clear lens procedure, more so today than ever. Not only must you maximize the safety and predictability of your surgery, often in the face of co-existing conditions, but you must contend with a newer concept as well: Cataract surgery is refractive surgery.

You need a refractive result that fits each patient's lifestyle. Some want near vision; others want distance; and increasingly, they want it all. Because no one has yet invented a "one-size-fits-all" lens, and all lenses are not created equal, selection can be somewhat confusing. However, on the positive side, the wide assortment of high-quality lenses that are now available, when matched with the right patients, can lead to significant patient satisfaction.

To help you make those matches, the following pages contain highlights from interviews with several leading surgeons. They reveal which lenses they use for the majority of their cases and which they use in special situations. Understanding their choices should help you to evaluate, and perhaps improve, your own.

Robert P. Lehmann, M.D.
Nacogdoches, Texas

"Workhorse" lens: Dr. Lehmann's lens of choice for the largest number of his patients is the single-piece Acrysof SA60AT. "The lens has a bi-convex, 6-mm optic. It's available in higher powers now, too. The haptics, which have an overall length of 13 mm, are open-looped. They provide a broad arc of contact within the capsular bag, allowing me to obtain excellent centration in the short- and long-term, and to be precise in terms of my predictability with my A constants and axial lengths. The SA60AT is made of the same acrylic material as its multipiece predecessors, the MA30 and the MA60, and, in my experience, has a long track record of excellent biocompatibility and a low posterior capsule opacification rate."

Co-existing conditions: For patients with glaucoma, cystoid macular edema and uveitis, he also prefers the Acrysof single-piece acrylic lens. "It produces less post-op inflammation than silicone lenses. It's an ideal lens for patients with uveitis because it's a less reactive material. It's truly a single-piece material, not a bicomposite. With a bicomposite, you're staving a haptic into the optic, so there's an area there where debris can accumulate.

"In patients who've had or are likely to need vitreoretinal procedures, or for those who are more likely to have a detached retina post-op, retinal specialists are much happier to see an acrylic lens than a silicone lens. In the event that they have to use silicone oil, silicone lenses impede visualization."

With pupil problems, "It depends on what type I'm dealing with, but for the most part I still use the SA60AT. For small pupils, my PhakoKinesis technique works well with occasional pupil stretch or lysis of synechiae. And the Monarch II injector allows me to implant the SA60 through a sub-3-mm corneal incision. It's well designed for small-pupil implantations. With a fixed or large, poorly reactive pupil, I might choose the MA50, which has a 6.5-mm overall optic with PMMA haptics."

Refractive considerations: Until recently, for high hyperopes outside the LASIK range, Dr. Lehmann would usually consider stacking acrylic lenses. However, "When Acrysof lenses were stacked within the capsular bag, a phenomenon of interlenticular membrane, or secondary membrane, became well documented, so I abandoned that practice. However, it's still possible to put one implant in the capsular bag and a subsequent implant in the ciliary sulcus. I think it should be noted that the single-piece acrylic lens is designed for use in the bag. So, if I have a patient who's over 33D or 34D, I implant a single-piece lens in the bag and a multipiece MA60 or MA30 lens in the sulcus. The single-piece lenses are now available in high powers. I'm also performing more and more clear lensectomies for these patients."

For astigmatic patients, "If a patient has more than 1D of astigmatism, I use the Arcuate blade, which is designed to cut to a depth of no more than 600 microns, to make the initial step of the incision, and that takes care of it. If the patient has more than 2D of cylinder, I make paired arcuate incisions, placing the second one 180 degrees opposite the incision. I'm looking forward to the introduction of an acrylic toric lens."

In the case of a significant compromise of the posterior capsule, "I don't think the single-piece lens should be placed within the eye if I'm going to leave the haptic in the sulcus and not in the bag. So, in that situation, I prefer the multipiece MA60 Acrysof. I say that because of long-term stability. I like to capture the optic. In other words, I put the haptics in the sulcus and use the capsule to capture the optic.

"If I'm going to potentially put a lens within the capsular bag, if I'm dealing with a round posterior capsule or a very small opening in the posterior capsule, then I think the SA single-piece Acryosof is appropriate."

Roger F. Steinert
Boston, Mass.

"Workhorse" lens: "I employ the Allergan SI40NB posterior chamber IOL as my standard lens because it has beautiful optical performance, doesn't require wound enlargement when used with the injector, and has highly stable fixation in the capsular bag."

Co-existing conditions: "With co-existing glaucoma, my choice remains the SI40NB. Lens choice for patients with pupillary abnormality depends on the specifics of the abnormality. In many cases, I perform some sort of iris reconstruction. In two cases, I implanted a Morcher IOL with a peripheral opacity, having obtained special approval both from our Institutional Review Board and from the FDA to import this IOL on a compassionate basis. I wish we had more open access to these lenses.

"When presented with uveitis or cystoid macular edema, consideration should be given to the causes for these conditions prior to cataract surgery. In any case prone to anterior segment inflammation, if a large incision isn't a major problem, I switch from my most-used lens to the Pharmacia heparin surface-modified IOL. In most cases, when maintaining a small incision is preferable, I use the Allergan Sensar AR40."

Refractive considerations: "For high hyperopes outside the LASIK range, whether the surgery represents cataract removal or clear lensectomy, my choice remains the SI40NB.

"High myopes outside the LASIK range are also sometimes outside the range of most of the foldable IOLs, other than the STAAR 3-piece AQ5010.

"For astigmatism of 1.75D or higher, I shift from simple limbal relaxing incisions to the STAAR Toric. In my experience, approximately 25% of these lenses rotate and require repositioning post-op, but we have a straightforward mechanism for managing this, and our patients understand that repositioning isn't considered an unusual step or a complication.

"In patients younger than 40, whose fellow eye would retain accommodation, I choose the SA40 Array multifocal."

James P. Gills, M.D.
Tampa, Fla.

"Workhorse" lens: "I'm quite comfortable with the STAAR AA4203 silicone plate lens and have experienced very few complications related to it. The design distributes the forces on the circumference of the capsular bag, so wrinkles and lines in the capsule are minimized. I also like that the lens can be inserted through a 2.5-mm incision. By placing the injector on the outer lip of the incision, rather than completely into the wound, I can insert the lens with little or no incision stretch. I do, however, reserve the use of this lens for patients who've had no compromise of capsule integrity. I occasionally experience problems with the lens splitting as it passes through the injector, but overall I'm happy with it."

Co-existing conditions: When he's operating on patients who have pupil problems, Dr. Gills typically uses a three-piece lens along with iris hooks to hold the iris back. "When you can't see the capsular bag around a small pupil, single-plate lenses are dangerous. That's why a three-piece is safer here."

He also prefers a three-piece lens -- silicone -- for diabetic patients, unless they have significant retinopathy and might require future retinal surgery. In that case, PMMA is his first choice because retinal surgeons don't like to perform surgery through a silicone lens.

"For glaucoma patients, especially African Americans, I typically use silicone lenses, but collamer lenses may be preferable. Although it's yet to be conclusively proved, collamer seems to produce less of a reaction. For that reason, I also prefer a collamer lens for patients with a history of uveitis."

Where there is a history of cystoid macular edema, "I make sure the patient receives plenty of topical steroids before and after surgery. I also use NSAIDs at the time of surgery. I think for these patients, the lens type isn't as important as the topical steroids and NSAIDs."

Refractive considerations: Dr. Gills recommends clear lens replacement for all hyperopes who are presbyopic, regardless of whether they're in the LASIK range. "I prefer clear lens replacement for several reasons, the chief one being that I believe these patients have better and more predictable outcomes with an intraocular lens. My first choice is the STAAR AA4203. But when a patient requires more than a 30.5D lens, I use PMMA or a piggyback IOL. I feel the PMMA optics are superior to the acrylic, and I see a much lower incidence of interlenticular opacification.

"For astigmats with less than 2D of cylinder, I use the STAAR plate lens and perform relaxing incisions. I reserve Toric lenses for those with more than 2D of astigmatism, and add limbal relaxing incisions as needed. For patients with high amounts of astigmatism, two Toric lenses can be sutured together and inserted through a 6-mm incision. When I use this technique, I factor 1D of surgically induced astigmatism from the incision into the surgical plan.

"I also apply the principle of surgically induced astigmatism to those who require a PMMA lens for one reason or another. By making a 5.5- to 6-mm incision at the steep meridian, I can correct mild amounts of astigmatism.

"My top lens choices for high myopes are the STAAR AQ2003, AQ2010 or AQ5010, depending on the power required. These lenses have been a valuable contribution to the safety of cataract surgery for high myopes. Because the scleras of these patients tend to be thinner than normal, implanting a foldable lens through a small incision means a better seal. For this reason, I avoid using lenses that require large incisions for these patients."

For patients younger than 40 who can accommodate, Dr. Gills uses the STAAR AA4203. But he offers monovision to those who are motivated to be as independent of glasses as possible. That's about 33% of his cataract patient population.

I. Howard Fine, MD, P.C.
Eugene, Ore.

"Workhorse" lens: "I don't really have a workhorse lens because I'm always customizing and am always in the process of investigating. At any one time, we have seven or eight FDA-monitored studies going on at our practice. I mix and match almost randomly if patients don't require a specific lens. I have an interest in all foldable IOLs, and I want to use all that are available. I do all of my own post-op care, so I'm always looking at the patients and evaluating how they're doing."

Co-existing conditions: "For patients in whom we have a history of uveitis or chronic inflammation, I often use the STAAR Collamer lens, either the three-piece or the plate haptic. It's an unusually biocompatible material. However, for these patients we also use the Acrysof because of its track record with respect to posterior capsule opacification. Also, for the same reason, we're beginning to use the Pharmacia CeeOn square-edged lens more frequently.

"With a history of cystoid macular edema, I don't know that one lens has any benefit over others. I typically choose the Collamer just because I have a feeling that it's the most biocompatible. Is acrylic better than silicone? I don't think there's any documentation that that's true. I want to see more data and more studies.

"We can implant the silicones through slightly smaller incisions. But I'm not sure that matters. We've got some new data in our office that show that we may be just as well off making a 3-mm incision with a keratome as we are making a 2.5-mm incision and stretching it to 2.8 mm. In terms of ultimate astigmatism, there's not much difference. Although we do like the fact that a smaller incision is more likely to be stable and less likely to leak.

"For glaucoma patients, we choose the Collamer plate haptic. Again, because it has very low reactivity and is highly biocompatible. Plus, it won't be impacted by filtering surgery.

"For patients in whom I break the capsule or use a capsular tension ring, or who have zonular weakness, I like the 6-mm Acrysof single-piece IOL with its Monarch inserter. I can place that by folding it upside down with the haptics underneath the optic, injecting it into the capsule as a very small mass (it goes into the bag as a 6-mm by 3-mm rectangular object). It unfolds nice and slowly. So it isn't like any other injectable lens, where I need to dial in a second haptic, or retract it and drive it in with the injection system. That can put stress on the zonules or even the capsule."

Refractive considerations: "For patients who have a strong desire for independence from spectacles, I use the AMO Array multifocal.

"For high hyperopes outside the LASIK range, our best lens is the Collamer because it goes up to a plus 34. Also, we frequently do piggybacking, putting one lens in the bag and one in the sulcus. We prefer silicone lenses for that.

"For high myopes, we frequently use the STAAR AQ5010. It's a large, foldable, silicone lens. I can implant it through a 2.5-mm incision. It has a 6.3-mm optic and a large loop. The polyamide haptics are stiff. We also use the AQ5010 for almost every patient who's on the myopic side of emmetropia, for any myopic surprises I get. I like it as a secondary piggyback IOL, too, because going through the same incision and implanting it in the sulcus is very atraumatic.

"For patients with astigmatism, particularly high levels, we use the Toric IOL, sometimes in conjunction with limbal relaxing incisions."

New technology IOLs: As Dr. Fine mentioned above, he implants many Array multifocal lenses. "Thirty percent of our cataract patients get an Array. We also do a lot of refractive lens exchanges with the Array, and our data is spectacular."

Dr. Fine also implants the STAAR Toric frequently. "I'm not affected by price. I try to give my patients the absolute best surgical result they can get. If I give them a good result, they'll send other patients to me, and that takes care of my financial concerns."

David C. Brown, M.D.
Fort Myers, Fla.

"Workhorse" lens: For most cases, Dr. Brown uses the STAAR Surgical AQ2010. "I choose this lens because it goes through a 2.5-mm incision, has a 6-mm optical zone, and flexible polyamide haptics with good memory that result in excellent centration. The AQ2010 also comes in a broad range of powers so it fits almost all primary procedures, and is also useful as a secondary implant."

Co-existing conditions: He implants the AQ2010 for patients with pupil problems. Also, "Patients with glaucoma are good candidates for the AQ2010, particularly if a complication could compromise the integrity of the anterior capsule during the rhexis or phacoemulsification. The polyamide haptics ensure good centration, even when the anterior capsule is irregular. I haven't found inflammation or pigment deposits to be a significant factor with silicone lenses. A thorough cleaning of the capsule fornices and removal of all lens material help to keep the eye free of pigment or inflammatory deposits."

For cases when uveitis, diabetes, or a history of cystoid macular edema are factors, Dr. Brown uses the STAAR Collamer lens. Because his retina surgeon prefers working around a plate lens, Dr. Brown also chooses the Collamer for eyes undergoing cataract surgery prior to a vitrectomy procedure.

Refractive considerations: Because he's participating in the clinical trials of the STAAR implantable contact lens, Dr. Brown is able to use the ICL for high hyperopes. For clear lens extraction patients, he implants either the AQ2010 or the Collamer.

He uses the AQ2010 in high myopes as well because, "Even in large eyes, the haptics traverse the posterior capsule and ensure centration."

He uses the STAAR Toric for astigmatic patients undergoing lens extraction. If additional correction or modification of the astigmatism is needed, he makes limbal relaxing incisions 6 to 8 weeks postoperatively.

New technology IOLs: Dr. Brown sometimes implants the AMO Array multifocal, but doesn't expect to increase his current percentage because of patient complaints of glare. He implants the STAAR Toric as frequently as indicated.

Arturo Chayet, M.D.
Tijuana, Mexico

"Workhorse" lens: Dr. Chayet prefers to use the three-piece Acrysof in just about every situation. "The lens works excellently in the bag and in the sulcus. The 6-mm optic is effective."

Co-existing conditions: Dr. Chayet also uses the Acrysof in diabetics, patients with glaucoma, pupil problems, and a history of uveitis or cystoid macular edema.

Refractive considerations: For high hyperopes, outside the LASIK range, he prefers a single-piece lens, either the Acrysof or one made of polymethylmethacrylate.

For astigmatic patients, he implants the Acrysof and uses limbal relaxing incisions. For high myopes, outside the LASIK range, he prefers the Acrysof. 

Louis Nichamin, M.D.
Brookville, PA.

"Workhorse" lens: For the majority of his cases, Dr. Nichamin prefers the 3-piece, silicone Bausch & Lomb LI61U. "I prefer today�s advanced silicone materials to acrylic. In my experience, silicone is as biocompatible as any material available. I believe a misconception exists that all silicone lenses are the same. Actually, the newer lenses made of the latest generation silicone perform very well. They�re more compressible than acrylic lenses, and they�ve lent themselves nicely to advanced injector designs. That being said, many acrylic lenses are now catching up with regard to injector delivery systems. I happen to think that all lenses will eventually be implanted with injectors.

"I also like the way silicone manipulates in the intraocular environment; it�s facile for me, and there�s little tissue drag. We also get beautiful optical performance, with no reflections.

"Matching lenses to patients is all about sorting through the particular design and material aspects, and making sure not to confuse whether it�s a lens�s design or material that�s responsible for certain performance attributes. For example, the decreased rate of posterior capsular opacification we�ve seen with truncated-edge lenses is due to that truncated edge, not, for the most part, to the acrylic material as was once thought. I think that eventually all implants will have a truncated edge."

Co-existing conditions: For patients with glaucoma, Dr. Nichamin stays with the LI61U. "The work of Dr. Thomas Samuelson and others has shown that silicone lenses haven�t contributed to increased cellular aggregation or post-op inflammation."

Dr. Nichamin also uses the LI61U in patients who have a history of uveitis or cystoid macular edema. "There�s certainly an argument to be made for using a heparin surface-modified PMMA lens, but in my experience, second- and third-generation silicone has worked well. Independent of the material issue, these patients have a higher proclivity for posterior capsular opacification, and a lens with a square edge might help to inhibit that. So, I�ve begun to implant and will be looking at results with Pharmacia�s new squared-edge silicone lens, the 911.

He also uses the LI61U in most patients with pupil problems, although may switch to a lens with a larger optic diameter in a very unusual condition, such as corectopia.

In diabetic patients whose disease is well-controlled or whose retinopathy isn�t significant, he stays with silicone. In cases of advanced disease, he switches to an acrylic lens to allow better fundus visualization for the retina surgeon.

Refractive considerations: In high myopes and hyperopes, Dr. Nichamin uses his workhorse lens in all cases where the available power is sufficient. Above +30D, he uses a variety of piggyback techniques, including placing two silicone lenses in the capsular bag or placing one acrylic lens in the bag and one acrylic lens in the sulcus.

"New technology" IOLs: For astigmatic patients, he uses limbal relaxing incisions. "I�m comfortable with my abililty to correct astigmatism with incisions. The concept of a toric IOL is wonderful, but at the present time, we only have two sizes to work with, and I don�t think the first-generation plate lens is our best design."

With patients younger than 40 who can still accommodate, Dr. Nichamin does discuss the multifocal IOL option, and 35 to 50% of those patients have chosen that route. Overall, multifocal implants account for about 10% of his cases, but he expects that percentage to increase as he examines his data on bioptics -- lens surgery with multifocal implant combined with LASIK. He�s been using the technique for more than a year with his clear lens exchange patients and for close to a year on his cataract patients. "So far it�s working great. Multifocal patients need to be emmetropic to enjoy the full benefits of the IOL, and adding LASIK gets them there. We do have some concerns about denervation and epithelial problems from creating flaps in older patients. We do create flaps in many patients prior to the time of lens surgery, but have only used the laser in a couple of dozen cases. We�ll be reporting on the technique in September."

Calvin Roberts, M.D.
New York, N.Y.

"Workhorse" lens: "My workhorse is the CIBA Vision 232 Memory Lens.  I like this lens because:

• It�s a hydrophilic acrylic with PMMA attributes.  So it has the rigidity and the refractive optical surface of PMMA. I haven�t seen any other silicone or acrylic lens match that optical surface. However, unlike PMMA lenses, there is no adhesion of inflammatory cells and products, so the material acts inertly in the eye.
• It�s pre-folded, so I�m not dependent on an experienced assistant to fold and prepare the lens for me.  The lens is ready to be inserted right out of the bottle.
• I can insert the lens through a 3.1-mm incision, so I never have to place a suture post-op.  I have no concerns about wound stability, and the incision is astigmatically neutral.
• The lens unfolds slowly. I like to do a complete viscoelastic removal, and all other lenses require me to maneuver under the optic to remove trapped viscoelastic.  This isn�t necessary with the CIBA 232.
• The square-edge design acts as a barrier to epithelial migration, resulting in a low rate of posterior capsular opacification."

Co-existing conditions: "The CIBA 232 is my lens of choice for all patients with concurrent medical disease because the material is so inert, and inflammatory products don�t adhere."

"New Technology" IOLs: Dr. Roberts uses the Allergan Array multifocal in patients who:

• are highly motivated not to rely on reading glasses post-op
• are hyperopic or who have low levels of myopia
• have less than 1 diopter of corneal astigmatism, or are willing to undergo post-op LASIK for astigmatism correction
• have binocular vision and are likely to have both eyes operated on within 3 months
• do limited night driving
• aren�t obsessively critical of their vision.

R. Bruce Wallace, III, M.D.
Alexandria, LA.

"Workhorse" lens: "We like the Allergan SI40, which is a foldable silicone lens in powers of 6D to 30D. It provides us with quality optics, a long track record of success, great centration, ease of insertion with the Unfolder, and relatively low YAG rates. For patients, it provides a cosmetically appealing pupil after surgery with little unnatural glinting."

Co-existing conditions: Dr. Wallace says that many surgeons consider using an acrylic lens for glaucoma patients, but "We�ve implanted many SI40s successfully, with very few adverse effects post-op. We�ve found that cataract surgery alone, without a filtering procedure, will result in a lowering of the intraocular pressure for many glaucoma patients."

For patients who have unusually miotic pupils, Dr. Wallace uses pupil stretching, but when encountering small pupils, he cautions, "Use of the Array multifocal may be less effective, although the lens will generally perform like a monofocal. Sometimes, laser pupilloplasty can help these patients postoperatively if their near acuity is less than desirable. Patients with elliptical pupils or unusually large sector iridotomies might benefit from lenses with larger optics, such as the 7-mm lenses that generally come in PMMA varieties."

The Allergan Sensar AR40 comes into play for Dr. Wallace in cases where there is a potential for uveitis or cystoid macular edema. "For CME suspects, I use nonsteroidal anti-inflammatories, pre- and post-op for an extended period of time, along with topical steroids and oral steroid therapy when necessary." He usually uses the SI40 in diabetic patients, unless there�s a history of significant diabetic retinopathy or if there�s a risk of developing proliferative disease or a condition that might require a vitrectomy. In those cases, he again prefers the acrylic AR40.

In another special circumstance, where patients require a secondary IOL implantation but don�t have sufficient capsular bag support, he uses Alcon�s anterior chamber lens, the MTA4UO.

Refractive considerations: In hyperopes, Dr. Wallace commonly uses the Allergan Array multifocal (SA40). "Hyperopes tend to be the happiest patients after Array implantation. We consider these patients presbyopic lens exchange (Prelex) patients. Fortunately, hyperopes are less likely than myopes to experience retinal detachment with refractive lensectomy.

"However, with our high myopes, after careful peripheral retinal examination with the assistance of a vitreoretinal specialist, we generally recommend either the Array or Allergan�s monofocal SI40, depending on the patient�s understanding of the need for visual cortical adaptation after Array implantation. Some of our happiest patients are high myopes who�ve elected to undergo a Prelex procedure."

Dr. Wallace performs limbal relaxing incisions for astigmatism in approximately 20% of his lens surgeries. "We assess each eye preoperatively to determine if, after standard phaco incisions, the patient would likely still have more than 1D of astigmatism. If so, a limbal relaxing procedure is performed."

And, finally, on the challenge of patients younger than 40 who can still accommodate, Dr. Wallace says: "I discuss with the patient the fact that monofocal IOLs don�t provide near acuity in patients who are prepresbyopic. Therefore, lens surgery might produce unwanted presbyopia. For these patients, I�ve found the Array to be a good choice."

New technology IOLs: "We�ve been increasing our implantations of the Allergan Array. A year ago, we were implanting it in 10% of our cataract patients. Today, we�re at 20%. The percentage is likely to increase as we continue to examine our long-term results, which at this point are very favorable."

Richard J. Mackool, M.D.
New York, N.Y.

"Workhorse" lens: Dr. Mackool most often chooses a single-piece Acrysof lens. "I turned to this lens as my main lens shortly after it was introduced because it has some distinct intraoperative and postoperative advantages, which in combination make it unlike any other lens I�ve used.

"Intraoperatively, it allows for an atraumatic insertion. The soft, jellylike haptics fold up onto the optic, and release slowly and gently. That�s a huge advantage. The more fragile the eye, the zonule, whatever the situation, it�s better. The second big intraoperative advantage is the small incision. (Silicone lenses can be injected into small incisions, too.) I can inject either the SA30 or the SA60 through an incision as small as 2.6 mm. When I�m done, the incision measures between 2.8 and 2.9, but I don�t have to enlarge my phaco incision to insert it. And while the benefits in the area of astigmatism are probably all equal below 3 mm, the smaller the incision, the quicker it seals. So I don�t have to wait 2 to 3 minutes for an incision to seal.

"I should note that I don�t use forceps to inject these lenses. I use the Monarch II injector. (The Monarch I requires a bigger incision.) I don�t insert the cartridge tip all the way into the eye. The tip of the leading edge of the bevel gets into the anterior chamber. That�s easy to do with this kind of implant because it comes out in one plane. That plane may not be the same plane that the cartridge is in. It can be a little anterior or a little posterior, but it�s one plane. So it�s easy to direct the single-piece lens into the posterior chamber and deliver it into the capsular bag all at once. With a multipiece, the haptic comes out in one direction, and the optic in another, so you really have to get the cartridge tip into the eye so you can manipulate the direction of the IOL.

"Postoperatively, with the acrylic material, I never see significant deposits. It�s also extremely rare that I see posterior synechia, which tend to develop between the iris and the edges of the capsulorhexis. For that to happen, the capsulorhexis has to be pretty close to the iris, and a fairly thick optic has to be pushing the capsule into the iris. So, it may be that the thinness of the acrylic optic prevents that. Or it may be a product of the material, but I suspect it�s both.

"Another post-op advantage that I see is that acrylic is easier to YAG than silicone. When you YAG an acrylic lens, you get little or no pitting. If a YAG pulse strikes a silicone IOL, a large pit will be created. I rarely use a contact lens when using a YAG laser if the patient has an acrylic lens, but I commonly have to use a lens when a silicone IOL is in the eye."

Co-existing conditions: The single-piece Acrysof is Dr. Mackool�s lens of choice for patients with glaucoma. "Glaucoma patients are more likely to experience anterior synechia, so a thin IOL is an advantage. Furthermore, the lens has to be well-tolerated. Otherwise, cellular deposits recur on the surface of the IOL, requiring repeated YAG laser treatments. When that happens, glaucoma patients need topical steroids, which can raise their intraocular pressure."

Dr. Mackool sticks with a single-piece Acrysof for patients with diabetes, pupil problems or a history of uveitis or cystoid macular edema. "I suspect that the single-piece acrylic lens is the least likely to induce CME. Some autopsy eye studies suggest that the haptics in a multipiece lens, even in the capsular bag, can press against the ciliary body, and this may cause inflammatory changes in the ciliary body over time."

He will switch from the single-piece Acrysof if he�s dealing with an open posterior capsule, or any time he needs to put a lens in the sulcus. "A single-piece lens, in my opinion, isn�t designed to go there. The haptics have sharp edges and shouldn�t be touching vascularized tissue. So, I implant an MA60 in the sulcus, and assuming the opening of the capsulorhexis is still intact and at least .75 mm smaller than the optic, I push the optic through the capsulorhexis, capturing the optic. This provides additional insurance that the lens will remain centered."

Refractive considerations: Dr. Mackool�s treatment choice for high hyperopes depends on whether any accommodation remains. If not, he prefers to perform a clear lensectomy, implanting a single-piece Acrysof. If the patient has some accommodation, he likes to preserve it by using a phakic IOL. He�s an investigator in the trials of two phakic IOLs.

"You have to consider the wishes of the hyperope. Some patients don�t want to use reading glasses. In those cases, you�re getting into multifocal implants, where you must consider a whole new set of advantages and disadvantages."

For many high myopes, Dr. Mackool chooses a single-piece acrylic lens, or a multipiece because they�re available in low powers now. But "For refractive procedures outside the LASIK range, I�m going to a phakic IOL, especially if the patient is male. Clear lensectomy is OK if the patient is female and doesn�t have accommodation. Myopic females have a low rate of retinal detachment after cataract extraction. Males have a much higher rate, so I�ve got to believe that�s true after clear lens extraction as well. I think males have stronger vitreoretinal attachments, and when they get a posterior vitreous detachment they�re much more likely to get a tear in the retina and/or a retinal detachment. When women suffer a posterior vitreous detachment, they�re less likely to get a tear and less likely to get a retinal detachment.

"That�s what I found when I did a retrospective study of retinal detachment after cataract extraction in 1,000 high myopes several years ago. Since then, one or two other surgeons have confirmed that."

For astigmatic patients, "I�m not one to do limbal relaxing incisions at the time of surgery. At most, you get about a half diopter of change with a small clear-corneal incision. I�m comfortable performing the surgical procedure on-axis. I wait and see how the patients tolerate any astigmatism they have left. If they�re having trouble, then, in most cases, I perform a limbal relaxing incision, assuming that the spherical equivalent of doing the limbal relaxing is what the patient wants. Sometimes it isn�t. Sometimes I want to change the spherical equivalent also. Then, I do either LASIK, PRK, LASEK, or combine the limbal relaxing incisions with some form of RK.

"I�m careful with limbal relaxing incisions for another reason, too. Some patients have astigmatism on their K readings that isn�t present in their manifest refraction. I think these patients, especially the high myopes, have a slanted, for lack of a better word, posterior pole. So they actually can have astigmatism based on that. I�ve seen this a lot in eyes with an axial length of 25 mm or more. So, in that patient population, I�d rather avoid limbal relaxing incisions because I�m not quite sure what I�m going to wind up with."

New technology IOLs: "I occasionally use a toric IOL for patients who aren�t high myopes but who clearly have a lot of astigmatism, 3D or more. For the patient who really wants to correct his astigmatism with one procedure, the toric does work. I implant with some trepidation, however, because in my opinion the plate-haptic IOLs are our least reliable foldables. In my experience, the toric also rotates out of position and requires repositioning in about 10% of cases and has a decentration rate of about 1%. I suspect that we�ll see single-piece lenses in toric form soon. I�m hoping for an acrylic.

"My percentage of toric implants will increase only when we have one that doesn�t rotate and is something other than a silicone plate haptic. When that happens, I anticipate using a toric IOL in as many as 20% of my cases."