EyeWorld Asia-Pacific September 2017 Issue

wavefront-guided treatments is that normal eyes do not usually have higher-order aberrations. Therefore, it would not make sense to employ wavefront-guided treatment, which could induce higher order aberra- tions due to capture and/or delivery error,” said A. John Kanellopoulos, MD , professor, New York University, and medical director, Laservision.gr Institute, Athens, Greece. “Potential parameters that may induce higher order aberrations include the LASIK flap, decentration of the excimer ablation, and irregularities in the ablation.” The use of the femtosecond lasers for flap creation has reduced wavefront deviations for most LASIK patients. The reduction in flap-related aberrations may be the strongest indication for the use of femtosecond lasers in flap creation in LASIK. Laser centration is also a con- cern. The latest laser trackers have higher frequencies and therefore faster response times. “Centration, especially for myopic ablations, has been more important than match- ing pupil size in determining quali- ty of vision in mesopic and scotopic pupils. A decentration of more than 100 μm in myopic ablations starts to become significant and may induce mesopic and scotopic aberra- tions,” Dr. Kanellopoulos said. Conventional laser treatments Wavefront-guided and wavefront- optimized treatments are not ideal for all patients, so there is still a place for conventional laser treat- ments. “One of the challenges is that in patients who are pseudophakic or who have irregular corneas, it is sometimes difficult to capture a high quality wavefront measure- ment. It depends on the wavefront technology,” Dr. Trattler said. “For example, the original VISX device, called WaveScan, has difficulty obtaining a high-quality cap- ture in pseudophakic patients. In comparison, a newer technology called iDesign [Johnson & Johnson Vision] measures five times more points, so it provides higher density of measuring. The iDesign can capture higher quality wavefront images, and can provide an accurate measurement, as well as a non-sub- jective refraction, in patients who are pseudophakic.” “It’s nice for surgeons to have a lot of tools in their toolbox so that they can fit the technology to the patient rather than fitting the patient into the technology,” Dr. Greenwood said. “For most eyes, both treatments are going to be good. For patients who have a lot of preexisting higher-order aberra- tions, wavefront-guided treatment is a better option. But in general, they both provide good outcomes with minimal induction of higher- order aberrations, which means good quality of vision following the procedure.” EWAP Editors’ note: Dr. Gordon and Dr. Kanellopoulos have financial interests with Alcon. Dr. Trattler has financial interests with Alcon, Bausch + Lomb (Bridgewater, New Jersey), and Johnson & Johnson Vision. Dr. Greenwood has no financial interests related to his comments. Contact information Greenwood: Michael.greenwood@van- cethompsonvision.com Gordon: mgordon786@gmail.com Kanellopoulos: ajkmd@mac.com Trattler: wtrattler@gmail.com Wavefront-guided – from page 51 “ Wavefront-guided and wavefront-optimized are two different algorithms for trying to provide the best quality vision to patients desiring laser vision correction with LASIK and PRK. ” – William Trattler, MD 52 EWAP REFRACTIVE September 2017 Watch for our weekly emails every Saturday, broadcasting recorded live cornea presentations Learn from the experts @ http:// Video Ed .CorneaSociety.org Copyright ©2017 Cornea Society. All rights reserved. The Cornea Society portal features cornea presentations and expert interviews from educational events throughout the year Now playing ... 2017 Cornea Day LOS ANGELES Video Ed .CorneaSociety.org Watch, Learn & Share! Available on all mobile devices, tablets, and desktops All content is archived for future reference Watch, Learn, and Share! Video Ed