EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/357599
EW FEATURE 41 can offer a customizable UV pattern that can be tailored in correlation with the cornea topography pattern. Preliminary data presented at the 2013 American Academy of Ophthalmology meeting and the 2014 ASCRS•ASOA Symposium & Congress suggest the ability to obtain predictable refractive changes along with epi-on CXL without the use of an excimer ablation. Topographic treatment of irregular corneas In addition to traditional PRK and crosslinking, a topographic- guided approach is being used. Dr. Kanellopoulos pioneered what is known as the "Athens Protocol." With this approach there is very "frugal" topography-guided normalization of irregular corneas combined with high-fluence collagen crosslinking, he explained. This procedure entails laser epitheli- al removal with PTK mode, followed by another PTK designed to treat the cornea, in conjunction with topog- raphy-guided software by Alcon (Fort Worth, Texas). Some of the treatment is done over the peak of the keratoconus cone. Simultaneous- ly, a partial hyperopic treatment is done at the diametric opposite side of the cone that normalizes the part of the cornea that is flat, superior to the cone. The combination of these 2 principles results in a remark- able normalization of the anterior corneal surface, Dr. Kanellopoulos explained. He emphasized that while some of these patients may have their myopic refractive error increased with the procedure, this is a marked improvement as it enables an improvement in best spectacle corrected visual acuity. Dr. Kanellopoulos encourages prac- titioners not to think of this as a refractive procedure but rather as an "elegant" customized topographic procedure aimed at improving corneal regularity. Raymond M. Stein, MD, medical director of the Bochner Eye Institute, and associate professor of ophthalmology, University of To- ronto, finds that pairing topography PRK and crosslinking can improve the quality of a patient's vision. "With the laser we do a series of topographic maps," he said. From there a laser treatment protocol is designed to flatten steep areas and steepen flat areas to make the cornea more symmetric. Dr. Stein likens it to taking a football that has warped from being left out in the rain and turning it back into a normal foot- ball. With keratoconus, he finds that crosslinking will halt the progression in 98.99% of cases and can improve vision in more than 70% of patients. In addition to keratoconus, Dr. Stein finds that topographic treatment can benefit those with pellucid marginal degeneration, post-LASIK ectasia, RK irregularities, those with central islands, patients with decentered ablations or small optical zones, and those with irregular astigma- tism, among others. "I see this as a breakthrough technology and that the indications will be expanded with time," Dr. Stein said. EW Editors' note: Drs. Donnenfeld and Stein have no related financial inter- ests. Dr. Kanellopoulos has financial interests with Alcon. Dr. Maloney has financial interests with Abbott Medical Optics. Contact information Donnenfeld: ericdonnenfeld@gmail.com Kanellopoulos: ajkmd@mac.com Maloney: 310-208-3937 Stein: rstein@bochner.com August 2014 Keratorefractive surgery