EyeWorld Asia-Pacific December 2015 Issue

47 EWAP REFRACTIVE December 2015 high-tech alternative to manually marking the eye is not for all candidates undergoing cataract extraction surgery. Since the technology is designed to capture an image of the eye when the patient is upright and looking ahead, and that image is critical because it can then overlay onto a live image in the operating room, patient cooperation is key. “If the patient doesn’t stay still or the surgeon is not able to capture a large enough area, it will not be a good image,” Dr. Ahmed said. “There are concerns about registration errors or registration failures.” Ophthalmologists may view markerless IOL systems as emerging technologies that are cost- prohibitive, and that may initially slow down the adoption of these systems into clinical practice, Dr. Ahmed said. To date, there have been some studies comparing digital markerless IOL alignment technologies to traditional ink mark approaches, and they have concluded the digital markerless systems are more accurate, but the studies have been largely non- randomized with cases from a single center. Personally, Dr. Ahmed has found markerless systems to yield similar results to those he gets with manual marking techniques, but workflow and consistency are improved. EWAP Editors’ note: Dr. Ahmed has financial interests with Alcon and Carl Zeiss Meditec. Contact information Ahmed: ike.ahmed@utoronto.ca Views from Asia-Pacific Rick WOLFE, MD Medical Director, Peninsula Eye Centre 937 Nepeal Hwy Mornington, Victoria 3931 Australia Tel. no. +61-3-5975-9999 Fax no. +61-3-5975-987 A hmed discusses the use of digital markers and points to increased accuracy, improved workflow and a reduction in reduced errors. I have experience with Alcon’s system: Verion. It has reduced the complexity of the surgical process with control through the Centurion foot pedal is easy and quick without the need to take eyes from the microscope. Verion can provide an overlay to guide capsulorhexis creation. I have not found this feature particularly useful other than to confirm the size and centration of my capsulorhexis was regularly good. We have come a long way with astigmatic control in IOL surgery. My view is that it can now be considered a complication if astigmatism is 0.75 D or greater. This represents a new paradigm: astigmatism elimination rather than reduction. The two contributors are IOLs with 1.00 D cylinder correction at the IOL plane (approximately 0.68 D at corneal plane) and the understanding for the need for compensation for the posterior cornea with, say, the Barrett Toric Calculator. A problem however remains with the correction of higher cylinders. To my surprise, I have found the digital axis and my estimated marked axis can differ by 10 degrees. Such an error can cause errors of 2.00 D or more with higher toric corrections. This is where the digital marker appears to have its strength. It is clear to me that low or no residual astigmatism can be a normal result even with the highest of cylindrical corrections. When there is residual cylinder postop often IOL rotation will solve the problem. Rotation of an IOL by 10 degrees is simple with Verion, but can be difficult to mark and do manually. Of course we need to investigate digital markers and if they are indeed superior, by how much. The most practical way is to assess astigmatism as aligned by the device, comparing with the prediction error were alignment by marks. We are currently studying this. Is the digital marker simply an expensive technology that does little for us? I am starting to think not. Editors’ note: Dr. Wolfe declared no relevant financial interests. Index to Advertisers Haag-Streit Page: 33 www.haag-streit.com Moria Page: 55 www.moria-surgical.com OCULUS Optikgeräte Page: 37 www.oculus.de Ziemer Page 64 www.ziemergroup.com ASCRS Page 15, 23, 31, 39, 43 www.ascrs.org APACRS Page 5, 7, 19, 21, 45, 60, 63 www.apacrs.org EyeWorld Page 2, 17, 29 www.eyeworld.org WOC 2016 Page: 58 www.woc2016.org