SEP 2013

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

Issue link: https://digital.eyeworld.org/i/176967

Contents of this Issue


Page 47 of 98

September 2013 How can you hit a moving target? Eyes move. Eyes rotate. Pupils shift. Shouldn't your LASIK treatment keep up? Advanced Control Eye Tracker (ACE) for the TECHNOLAS 217z100 Excimer Laser Platform is the most comprehensive eye tracker available in the US. ® ble," he said. In cases where little history is available, he looks at the level of asymmetry of the cornea using 3 D topography, and he talks to the patient about his or her use of glasses in the past and ascertains how long the keratoconus has been stable. In addition, he contacts patients' optician to get a history of their refractions and visual acuity. Only then, he said, is he comfortable proceeding with cataract surgery or refractive lens exchange. Overall, in Dr. Trattler's view, patients with keratoconus now have a plethora of refractive opportunities. "I think that patients with keratoconus have more options and avenues for improving vision than they ever had before," Dr. Trattler said. "Surgeons should be aware of the many options for their patients, especially those who have difficulty tolerating contact lenses." EW Editors' note: Dr. Daya has financial interests with Bausch + Lomb (Rochester, N.Y.), Carl Zeiss Meditec, TearScience (Morrisville, N.C.), PRN (Plymouth Meeting, Pa.), and SARcode Bioscience (Brisbane, Calif.). Dr. Trattler has financial interests with with CXLUSA and CXLO. Dr. Lee has financial interests with Allergan (Irvine, Calif.) and Bio-Tissue (Miami). Complete compensation of rotational errors, both static and dynamic, from diagnostics to the very end of the ablation. Instantaneous adjustment of the ablation profile as the eye rotates. Increased precision through iris recognition for all treatments – wavefront-guided, cylinder, or sphere only. Contact information Daya: +44 1342 306020, sdaya@centreforsight.com Lee: 646-342-5546, jimmylee@montefiore.org Trattler: 305-598-2020, wtrattler@earthlink.net Peace of mind for you and your patients. ACE has you covered. How continued from page 42 values by definition are poorer predictors of the disease and should not be used individually in the screening process. The reason that five (of 9) of the most heavily weighted values are shown on the BAD is to help the clinician explain the final result value, not predict ectasia. It is also important to remember that even the best predictor BAD Final D value is not 100% accurate. Pentacam BAD Final D is a multivariate regression. Each univariate variable is weighted according to its own individual predictive value. Each variable is compared to a large known database of normal patients and patients with keratoconus then plotted on ROC curve plots showing sensitivity vs. specificity allowing comparison of individual variables' predictive nature. So Final D is not a percentage predictor of ectasia or a standard deviation but a predictor of true/false positives vs. true/false negatives based on a normative database population. I recommend additional factors to consider when trying to diagnose keratoconus (see tables). Ultimately, the question that needs to be answered is not "Does this patient have keratoconus?" but "Can this patient's cornea safely tolerate laser vision correction?" In order for us to better predict if a patient's cornea can "survive" LVC, I think we need to look closer at corneal biomechanics. Most of the current biomechanical studies in progress involve the identification of "at risk or keratoconus suspect." There are no large scale studies in publication on LVC effects on biomechanical changes of the cornea. I believe every cornea is at risk if the "wrong" collagen fibrils are compromised. A first step would include collecting biomechanical data before and after we alter corneas with laser vision correction, which could lead to a better understanding of this dynamic process, ultimately allowing us to perform more surgery and offer a better safety profile for all our patients. Therefore if topography and tomography can only show keratoconus once it begins, the addition of corneal biomechanical analysis should further improve our ability to predict a patient's relative risk of ectasia based on corneal thickness, viscosity, IOP, and tissue removed by surgery. The near future for laser vision correction patient screening is likely to include a combination of advanced tomography and corneal biomechanical analysis to push our ability to provide the safest form of refractive surgery for our patients. EW Editors' note: Dr. Tullo is vice president of clinical services, TLC Laser Eye Centers, Princeton, N.J. Dr. Tullo has financial interests with Oculus. Contact information Tullo: William.Tullo@tlcvision.com Some of the products and/or specific features as well as the procedures featured in this document may not be approved in your country and thus may not be available there. Design and specifications are subject to change without prior notice as a result of ongoing technical development. Please contact our regional representative regarding individual availability in your respective market. The trademarks (™ and ®) and logos used in this document are the property of Bausch & Lomb Incorporated or its afliates. kbcomunicacion. Ref. TPV-001/01-2013 © 2013 Technolas Perfect Vision GmbH. All rights reserved. Technolas Perfect Vision Inc 3365 Tree Court Industrial Blvd. St. Louis, MO, 63122 USA Customer Service 1-888 704 3601- Domestic / Customer Service 636-226 3600 - International TECHNOLAS Perfect Vision GmbH – A Bausch + Lomb Company Messerschmittstr. 1+3, Munich, Germany www.technolas.com – www.bausch.com

Articles in this issue

Links on this page

Archives of this issue

view archives of Eyeworld - SEP 2013