SEP 2013

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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September 2013 Refractive challengesFebruary 2011 and innovations toric IOL would be and what the residual refractive error calculates to be," he said. "If you slide it all the way to the other side it would tell you where the LRIs need to be and how long they need to be." Meanwhile, when positioned anywhere in between, it will indicate what the result of a toric lens and incisions would be. "Let's say that the patient would have a good result with a toric intraocular lens of a T4, but have some residual astigmatism and would be overcorrected with a flipped axis if a T5 was used," Dr. Lane said. "It will also tell you that if you put a T4 in and limbal relaxing incisions in a certain position and of a certain length, you could attain an even better result." Femtosecond link After this preparation comes the actual surgery with the Verion, which integrates its preoperative diagnostic measurements to the LenSx femtosecond laser. Here it is able to capitalize on the laser's accuracy in conjunction with the preoperative registration system. "You are able to more precisely make the incisions in the cornea with the LenSx femtosecond laser to do your LRIs and other incisions," Dr. Lane said. Using the preoperative photograph to first register the eye, the LenSx laser can accurately create the capsulorhexis and any needed corneal relaxing incisions, he noted. With the aid of the preoperative registration, the LenSx laser can lock onto the eye with those reference measurements that were made, Dr. Lane explained. "You are able to seamlessly compensate for cyclotorsion, and you can then put the incisions right where they need to be," he said. The upshot, he pointed out, is to more precisely correct astigmatism and be able to place your capsulorhexis, limbal relaxing and other incisions with greater precision. Dr. Nichamin likewise sees the incorporation of the LenSx system as a natural segue that's going to more accurately allow the femtosecond laser to position its LRIs, adding it will no longer be a matter of the practitioner positioning LRIs on a screen. The system will know precisely where the meridian is located. "The patient could be misaligned underneath the laser," Dr. Nichamin said. "The laser will automatically place the incisions at the accurate meridian, as predetermined when the patient was in an upright position." He explained that for the surgery, the preoperative digital image is transferred into the operating room for real-time analysis. "It can be either on a separate monitor or it can project this image into the microscope, almost like a heads-up display, and one can then identify the needed landmarks," Dr. Nichamin said. "With a high degree of veracity and accuracy, one can identify these important landmarks, and if the patient moves during surgery, there is a tracking system that can adjust in a real-time manner," Dr. Nichamin said. As a result of this preoperative registration, Dr. Lane pointed out that it is no longer necessary to use ink for alignment because the photograph has done that. "You can throw all of your markers that you use intraoperatively away," Dr. Lane said. "This lays down a reference line and with that you would be able to place the lens in the proper position." He thinks that practitioners will more accurately be able to correct cylinder than they could previously, and that this will be more accurate, reproducible, and repeatable from one surgeon to another. Dr. Nichamin said that the use of such preoperative registration is more accurate than relying on even the best manual technique. He pointed to the problem of parallax, which arises when a technician or the doctor is marking the limbus. "It's hard to come in absolutely straight," he said. For example, right-handers attempting to ink the 6 o'clock position tend to come in at 5:30 while left-handers tend to mark 6:30, Dr. Nichamin explained. In addition to indicating where the steep axis in need of correction is and making it easier to line up toric lenses or center relaxing incisions, Dr. Nichamin sees other potential surgical benefits to the new system. He pointed to steps such as centering an implant with the patient's pupil or with the visual axis and to use of overlays during surgery. For example, you can photograph the patient's pupil in either an undilated or dilated state, and this can be shown on an overlay, he explained. This image can be projected into the microscope and the practitioner can use this to center the IOL. "Similarly, an overlay of a 5.5 mm perfectly round circle can be used as your capsulorhexis stencil," Dr. Nichamin said. "There are EW FEATURE 55 all kinds of digital overlays that we can use real time during surgery to help refine the accuracy of these important surgical steps." Ultimately, he sees this technology as an incremental advance that is going to result in a significant improvement to overall outcomes. Going forward, Dr. Lane thinks the future for surgeons is tied to being able to improve their ability to hit the refractive target. "I think that any surgeon who is not striving to his/her utmost to hit a refractive target is not giving patients the opportunity to have their best vision," he said. "Verion becomes a part of the solution to help us better hit our refractive targets." He stressed that it's no longer enough for surgeons to be satisfied with removing a cataract, putting in an implant, and giving patients vision with spectacles similar to what they had prior to cataract development. "I think that it's now the obligation of surgeons to offer these patients the potential opportunity to have vision better than they've ever had before," Dr. Lane said. "I think that we now have technologies that allow that, and we need to offer those technologies and opportunities to our patients." EW Editors' note: Dr. Lane has financial interests with Alcon. Dr. Nichamin has no financial interests related to this article. Contact information Lane: 651-275-3000, sslane@associatedeyecare.com Nichamin: 814-849-8344, Nichamin@laureleye.com Poll size: 163 EyeWorld Monthly Pulse EyeWorld Monthly Pulse is a reader survey on trends and patterns for the practicing ophthalmologist. Each month we send a four-question online survey covering different topics so our readers can see how they compare to our survey. If you would like to join the hundreds of physicians who take a minute a month to share their views, please send us an email and we will add your name. Email daniela@eyeworld.org and put EW Pulse in the subject line; that's all it takes. Copyright EyeWorld 2013

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