Eyeworld

Visit us at AAO Booth #1221 isit us a V Booth #1221 O A t A isit us a Booth #1221 EW FEATURE 56 waits to do LASIK or PRK enhance- ments until the refractive outcome is stable, usually at the 2- or 3-month post-surgery mark. There are excep- tions, however. "If you have a big miss, sometimes you find yourself fixing it right away, with an IOL ex- change or a piggyback, or with small incision cataract surgery." He pointed out that practitioners can actually do a LASIK or PRK retreat- ment quite early these days because of the use of self-sealing IOL wounds. Weighing enhancements options The length of time that has passed since the original LASIK procedure can alter the challenges that a practi- tioner may face in doing an en- hancement. For example, practitioners can always lift a flap physically, even if it has been 20 years, Dr. Durrie finds. "I've done these 17 years later, but we find out that the longer it has been, the higher the risk of complications to lift that flap—mainly epithelial in- growth," he said. "There was some good work that came out with retro- spective analysis that showed that if you lift a flap within the first year, the incidence of epithelial ingrowth was 1-2%, but if it was over 3 years the incidence went up to 10%." In these late cases, Dr. Durrie thinks that it may even be a little higher than that. When it comes to lifting flaps he has his own rule-of-thumb. "If patients are within the first year I lift the flap," he said. "If they're over 3 years I do PRK." As far as the cases that fall in between he uses his clini- cal judgment on what is the best way to go. Dr. Goldman lifts flaps in cases where he made the cut himself origi- nally and he can still see the edge. In other cases, however, he'll opt for a recut using the IntraLase (Abbott Medical Optics, AMO, Santa Ana, Calif.). "If it's a flap that I know is a large flap but it's really scarred down hard and I know that it's going to be a myopic ablation, then we can recut using a ring cut," Dr. Goldman said. "We'll put the patient under the IntraLase and we'll set it to do a ring cut but at a smaller dimension than the original flap and we'll set it to go deeper." This helps to ensure that the thickness and depth of the original flap are incorporated. "It's just a matter of having the IntraLase cut all the way around the original dimensions of the flap," Dr. Goldman said. Essentially this is a new flap within the original. However, if there are any con- cerns about being able to get the flap up appropriately, Dr. Goldman will move to a surface ablation in- stead to avoid a higher risk of ep- ithelial ingrowth. He also won't consider using a microkeratome on these patients. "I would have too many concerns about dislodging the original flap," he said. Dr. Lindstrom will consider lift- ing flaps for up to 2 years. After the 2-year mark, Dr. Lindstrom recom- mended PRK retreatments. He ex- plained that at this late stage patients face a 5% chance of epithe- lial ingrowth versus a 0.5% or less chance of this before the 2-year mark. He never considers doing a recut on any patients. "Recut enhance- ment for us is zero," he said. "It's ei- ther a flap lift or a surface ablation because we have had complications with both microkeratomes and IntraLase with recuts." At one point, Dr. Lindstrom tried the concept of creating a new side cut with the IntraLase but was dismayed to find that he had a very high incidence of epithelial ingrowth. "The ones that worked well were fantastic," he said. "It's possible that maybe I have something to learn about different side-cut angles." With this retreatment technique he found that he had a 30% inci- dence of epithelial ingrowth. "I don't recommend that approach, but remain willing to have someone teach me how to do it right because the 70% that did well were wonder- ful," Dr. Lindstrom said. He also avoids the use of the mechanical microkeratome because of concerns of getting a sliver of tissue that would result in irregular astigma- tism. Overall, Dr. Durrie urged practi- tioners to do what they can to avoid enhancements. "Your happiest pa- tients are the ones that you do once and then never need to do again," Dr. Durrie said. He pointed out that while an enhancement is nothing serious to the practitioner, patients consider this a failure, and they are not inexpensive. "In our practice when we look at what it costs us, it's around $1,200 to do an enhance- ment out-of-pocket, including em- ployee time, chair time, and factoring in lost opportunity," Dr. Durrie said. "Anything that you can do to lower the enhancement rate improves patient satisfaction, im- proves referral rates, and lowers your costs." EW Editors' note: Dr. Durrie has financial interests with AMO and Alcon (Fort Worth, Texas). Dr. Goldman has no financial interests related to his com- ments. Dr. Lindstrom has financial in- terests with AMO, Alcon, and Bausch & Lomb (Rochester, N.Y.). Contact information Durrie: ddurrie@durrievision.com Goldman: 561-515-1543, dgoldman@med.miami.edu Lindstrom: 952-567-6051, rllindstrom@mneye.com February 2011 Challenging refractive cases October 2011 Up continued from page 55 Scraping of the epithelium for surface ablation. This technique can be used to avoid a high risk of epithelial ingrowth Source: Steven C. Schallhorn, M.D. Now available online EyeWorld.org/replay 52-67 Feature_EW October 2011-DL33_Layout 1 9/29/11 4:51 PM Page 56

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