EyeWorld India December 2014 Issue

57 EWAP NEWS & OPINION December 2014 Royal College of Ophthalmologists of Thailand (RCOPT), Asia Cornea Society (ACS), American Society of Cataract and Refractive Surgery (ASCRS), the European Society of Cataract and Refractive Surgeons (ESCRS), and the Latin American Society of Cataract and Refractive Surgery (ALACCSA-R/LASCRS). In the lamp lighting ceremony, the light represented knowledge, while darkness represented ignorance, and knowledge removes ignorance just as lightness removes darkness. The lighting of the lamp signified the commencement of the meeting. The 2014 APACRS Awards were also presented. , Singapore read the citation presenting Dr. Vasavada with the 2014 APACRS Gold Medal Award. He spoke of Dr. Vasavada’s achievements and also of his friendship. “We are nothing without our patients, and his dedication to his patients is a testimony to the character of the man,” Dr. Yeoh said. Prior to the APACRS LIM Lecture by Warren Hill, MD , Mesa, Ariz., U.S., Dr. Barrett then read the citation for the introduction of Dr. Hill. More than anyone else, he has devoted his career to helping fellow surgeons to obtain more accurate outcomes, Dr. Barrett said APACRS LIM Lecture highlights the latest innovations in IOL calculations Dr. Hill talked about the benefits of technology transfer and its impacts on ophthalmology in the 2014 APACRS LIM Lecture. Innovation often comes from having a network of friends, acquaintances, and colleagues that allow you to take things to the next level, Dr. Hill said, and IOL calculations are one example of that type of collaboration. “So many things that we do in ophthalmology come from other places,” Dr. Hill said. “It’s not so much that we have to be smart enough to know exactly what to do, but sometimes [we have to be] smart enough to know who to talk to.” A new IOL power calculation method, developed by Dr. Hill and colleagues both within and outside of ophthalmology, integrates aspects of established calculation methodologies from unrelated fields to offer better patient safety and physician confidence in refractive outcomes. Dr. Hill began by discussing current refractive outcomes achieved by cataract surgeons. Less than 1% of individual surgeons achieve accuracies of half a diopter or less more than 92% of the time, he said. The vast majority of surgeons achieve half diopter accuracies around 78%, he said, so there is a vast need for innovations in power calculation formulas. Fear of having a refractive surprise or an unhappy patient pushes many cataract surgeons in the direction of maintaining familiarity, Dr. Hill said, but improving refractive outcomes requires surgeons to be innovators who readily embrace and seek change. Borrowing technology is not a new concept in ophthalmology— optical biometry is based on the Michelson interferometer used to measure the diameter of stars, and Charles Kelman introduced phacoemulsification after seeing an ultrasonic probe in his dentist’s office during a teeth cleaning. Dr. Hill’s IOL calculation method borrows engineering-based interpolation methods that are used in facial recognition software, modeling oil well behavior, diesel engine calibration, and even financial forecasting. “This is not new technology,” Dr. Hill said. “It is pervasive, it’s just never been used in ophthalmology.” The method utilizes a radial basis function (RBF), a sophisticated pattern-recognition algorithm. RBFs are able to deal with non-linear factor relationships—such as the relationship between axial length and central corneal power—and provide better outcomes with l ess data. The advantage of RBFs is that they utilize adaptive learning—the ability to learn how to perform a task (or calculation) based on data, independent of what is already known, Dr. Hill said. With the RBF model, surgeons will have to input only 3 measured variables—axial length, corneal power, and anterior chamber depth—dropping effective lens position and vergence calculation inputs. Based on several studies of the model’s refractive results, RBF formulas have been shown to deliver power calculation accuracy on par with, or better than, the most advanced theoretical models in use today. Half diopter accuracy has consistently been between 92% and 96%, Dr. Hill said, far better than he or his colleagues anticipated. The RBF model will open up a brand new era of IOL power calculation, Dr. Hill said, making tailored IOL selection possible for large population groups with previously ignored anatomical differences. “One of the ironies of all the lens power calculation formulas we’ve had to date is that they’re based on eyes of European ancestry,” he said. “And anybody who lives in Hong Kong will tell you that some of the formulas we love in Europe and North America don’t work for southern Chinese.” The RBF formula will allow surgeons to make IOL calculations more specific and sensitive for these ethnic groups that have ocular anatomical differences such as shorter anterior chambers and longer vitreous cavities. RBF power calculations represent a robust approach based on pattern recognition and data continued on page 58