Eyeworld

EW FEATURE 60 Toric IOLs June 2015 by EyeWorld Staff correction may not be in patients' best interest. You can't assess that accurately without topography." "If you are doing limbal relax- ing incisions or toric lenses, the first thing you need is topography," he added. The following are the responses given when surgeons were asked how they align the preoperative axis assessed with the diagnostic tools with the intraoperative axis where they are placing the toric IOL: • Ink marking with the aid of manual instruments: 48% • Ink marking at the slit lamp with no additional instruments: 31% • Anatomical landmarks without preoperative marking: 6% • Digital image registration: 5% • Intraoperative wavefront aberrometry: 5% • Other: 5% "More than one-third of survey respondents use only anatomic or simple ink marking alone to estab- lish the intended position of a toric IOL. This may have been adequate in the past, but patient expectations of excellent uncorrected vision re- quire a more controlled approach," Dr. Vukich added. He also noted that digital systems make toric IOL placement easier and help achieve more accu- rate results. "For that reason alone, we can expect to see growing use of this technology," he said. However, Dr. Hovanesian thinks that while these systems offer some advantages, such as greater preci- sion, they are not absolutely neces- sary. "Before we had formal digital tracking mechanisms … we used ink marks placed at the slit lamp. We found that we had very good accuracy with our [limbal relaxing incisions]. If you are careful and you mark preoperatively, you are going to get fairly good results even if you don't use a digital registration system." "The real advantage of these digital systems is that they make it easier to measure and then translate that information accurately into the operating room to put the toric lens or the limbal relaxing incisions in the correct location. Anything we can do to automate and systematize our refractive treatments is likely to improve accuracy, so I'm definitely in favor of these systems," Dr. Hovanesian said. However, the cost of these systems can be a significant barrier for practices. Therefore, surgeons will need to consider their surgical volume and other factors before deciding to buy. "The necessary volume depends somewhat on the price structure of the practice for premium IOL use. In general, if a practice is doing 10 or more toric IOLs a week, the use of a digital system starts to make sense," Dr. Vukich said. EW Editors' note: Dr. Hovanesian has financial interests with Alcon (Fort Worth, Texas), Abbott Medical Optics (AMO, Abbott Park, Ill.), and Bausch + Lomb (Bridgewater, N.J.). Dr. Vukich has financial interests with AMO and STAAR Surgical (Monrovia, Calif.). Contact information Vukich: javukich@facstaff.wisc.edu Hovanesian: johnhova@gmail.com Preoperative and intraoperative planning for implanting toric lenses: What is your protocol? ASCRS members weigh in F or cataract patients with astigmatism, toric IOLs are a great option for achieving optimal uncorrected visual acuity. However, lens po- sitioning is key because even small errors in a toric IOL's position have the potential to significantly affect a patient's vision. In fact, for every 1 degree of error in a toric IOL's rotational alignment, there is a 3.3% decrease in astigmatism correction. In the 2014 ASCRS Clinical Survey, ASCRS members were surveyed about their preoperative and intraoperative practices when implanting toric IOLs. When asked about the prima- ry preoperative measurement that drives their astigmatism axis deci- sions when implanting these lenses, 11% of respondents said that they use manual or automated keratom- etry measurements to drive their astigmatism axis decisions, and 45% said they use topography. "Obtaining the best result from the use of a toric IOL requires fastidious attention to detail," said John Vukich, MD, Madison, Wis. "Topography is a critical part of the evaluation, not only to determine the axis, but also to spot irregular astigmatism from corneal asymme- try. Forty-five percent, or close to half, of ASCRS members are using topography, but as awareness of the value of topography increases, we can expect that more surgeons will incorporate this into their evalua- tion plan." John Hovanesian, MD, Laguna Hills, Calif., agreed. "You really need topography, and the reasons are multiple," he said. "First, we want the most accurate representation of the axis, and topography tends to provide the most accurate location of the axis of astigmatism. "The second reason is that you need to identify corneas that are ab- normal, such as those that have ker- atoconus or other irregularities," he said. "In these patients, astigmatism The 2014 ASCRS Clinical Survey asked, "What is the primary preoperative measurement that drives your astigmatism axis decisions when implanting a toric IOL?" Global Trends in Ophthalmology ™ Copyright © 2015 Global Trends in Ophthalmology and the American Society of Cataract & Refractive Surgery. All rights reserved.

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