EyeWorld Asia-Pacific March 2016 Issue

21 March 2016 EWAP FEATURE Figure 2 Figure 1 Laser vision correction in patients with irregular corneas by EyeWorld staff ASCRS members weigh in N ew advances in wavefront technology and topography have improved the management of irregular corneas in laser vision correction patients. “While we still do not have a laser ablation technology that will completely treat highly irregular corneas, it is exciting to see the incremental improvements in technology that are being approved,” said John Hovanesian , MD , Laguna Hills, Calif. “Particularly, the approval of the first topography-guided laser ablation in the United States is great progress. There can be a disconnect, though, between correcting topography and correcting vision. How often have we seen patients with keratoconus and maybe 8 D of fairly regular astigmatism undergoing cataract surgery? We can correct at best 4 D with current toric IOLs, but for many of these patients, that undercorrection still provides excellent uncorrected acuity. Fully correcting all corneal aberrations in all patients may not be necessary or even desirable. That means even if they were available, we should be careful not to apply laser correction to all measured corneal aberrations. Just because we can correct an aberration doesn’t mean we should.” In the 2015 ASCRS Clinical Survey, ASCRS members were surveyed about their use of new technology in these patients. Here are the results. Ablations Ophthalmologists were asked, “What category of ablations are the majority of your corneal refractive procedures currently and in the next 2–3 years?” Currently, 81% of U.S. respondents use wavefront- guided ablations, with 52% using customized ablations and 29% using optimized ablations. Non- U.S. surgeons’ responses were evenly split, with 26% using customized wavefront ablations, 27% using optimized wavefront ablations, and 27% using standard ablations. When asked what they thought they would be using in 2–3 years, 79% of U.S. surgeons said that they would be using wavefront ablations, with 44% saying they would be using customized wavefront ablations, and 34% saying that they would be using optimized wavefront ablations. The number of non- U.S. surgeons who expect to use topography-customized ablations in 2–3 years was 18%, up from 11% who currently use topography- customized ablations. Additionally, the number of non-U.S. surgeons who expect to use femtosecond intrastromal lenticule extraction in 2–3 years was 16%, up from 5% who currently use this method (Figure 1). Impact on corneal biomechanical properties When asked which treatment option has the least impact on the corneal biomechanical properties, the most common response was surface ablation (with 58% of surgeons giving this response). This response was much more common among U.S. surgeons (74%) compared to non-U.S. surgeons (42%). Additionally, 20% of non-U.S. surgeons said femtosecond flap LASIK had the least impact on corneal biomechanical properties, and 3% of non-U.S. surgeons said femtosecond lenticule extraction (Figure 2). “There’s no question that PRK has the least impact on corneal biomechanics and dry eye. Naturally, more patients and surgeons choose LASIK because of its faster visual rehabilitation. In general, the more patient- friendly procedure wins out in any contest between techniques,” Dr. Hovanesian said. EWAP Editors’ note: Dr. Hovanesian has financial interests with Abbott Medical Optics (Abbott Park, Ill.), and Alcon (Fort Worth, Texas). Contact information Hovanesian: drhovanesian@harvardeye.com