EyeWorld India March 2016 Issue

March 2016 14 EWAP FEATURE Tips for using topographic ablation by Ellen Stodola EyeWorld Staff Writer Physicians discuss which patients are strong candidates for topographic ablation A s topographic ablation becomes more popular worldwide, it’s important for physicians to know which patients may be the best candidates, which patients are not the best candidates, and when it will benefit them most to use this technology. Karl Stonecipher, MD, Greensboro LASIK, Greensboro, NC; Allon Barsam, MD, AB Vision, London; and Daniel Durrie, MD, Durrie Vision, Overland Park, Kan., discussed when they would use topographic ablation, pearls to ensure a good topography, and when topographic ablation may be used with certain conditions. When to choose a topographic over a wavefront or optimized ablation Dr. Durrie was a clinical investigator for the topography- guided study in the U.S. “One of the most important things Topographies, pre and post topography-guided PRK. Prior to the procedure, the patient had moderately severe keratoconus with 5 D of irregular astigmatism. After topography-guided PRK with theWaveLight system (Alcon), the astigmatismwas halved and is more regular. The patient had improvement in both unaided and best spectacle-corrected visual acuity. Source: Allon Barsam, MD AT A GLANCE • Currently in the U.S., the indications for topographic ablation are only for treating virgin eyes with asymmetric topography. • It’s important for surgeons to be able to capture a high quality image and realize that this is different from using topography as a diagnostic tool. • Optimizing the ocular surface prior to treatment is key. about this new system is for surgeons to understand that this is different from doing diagnostic topography,” he said. Topography helps in diagnostics to make decisions, he said, but if there’s a bad test, it won’t hurt anyone as a diagnostic tool. However, using it now as a therapeutic tool, Dr. Durrie’s worry is that physicians will think they already know how to use it, even though there are different considerations. You need to pay a lot more attention to the quality of the image, he said. Be sure that it’s a high quality topography before using the data. Patients who have asymmetric topography do well because the topography will drive the asymmetric ablation pattern, he said. However, Dr. Durrie said it’s important to note that all of the patients in the U.S. clinical trial had virgin eyes, so there were no enhancements or touch-ups. “It’s approved for treating virgin eyes who have asymmetric topography,” he said. One worry, he said, is that some patients may not be the best candidates for this procedure, and if these patients don’t get good results, the procedure could get a bad reputation. Topographic ablation could work for patients who have had previous surgery, but it’s important to remember that there is currently no U.S. data on this. Dr. Barsam currently only uses topographic ablations on diseased corneas that also have an irregular corneal shape and poor quality of vision as a result of this. He uses wavefront-optimized ablations in routine cases. “I find wavefront scanning to be somewhat unpredictable on diseased corneas and therefore do not do wavefront- guided treatments on diseased corneas,” he said. “It goes without saying that either with Contoura [Alcon, Fort Worth, Texas] treatments or wavefront-guided treatments, you must first be able to capture an accurate, reproducible, and continued on page 16