EyeWorld India December 2013 Issue

38 EWAP CORNEA December 2013 Corneal collagen crosslinking still hot topic in U.S. by Ellen Stodola EyeWorld Staff Writer The procedure continues to advance as it seeks U.S. FDA approval C orneal collagen crosslinking continues to be a hot topic in ophthalmology. Still seeking FDA approval in the U.S., the technology has been showing promising results in an Avedro (Waltham, Mass., USA) clinical trial currently in the process of seeking FDA approval and other investigational Institutional Review Board (IRB) trials, leading more and more physicians to get on board with it. In addition, combinations of crosslinking with other therapies have begun to emerge, and studies are being undertaken to determine results of crosslinking with Intacs (Addition Technology, Des Plaines, Ill., USA), LASIK, and other procedures. Roy S. Rubinfeld, MD , Washington Eye Physicians & Surgeons, Chevy Chase, Md., USA; Eric Donnenfeld, MD , clinical professor of ophthalmology, New York University Medical Center, New York, NY, USA; and Peter S. Hersh, MD , the Cornea & Laser Eye Institute, Teaneck, NJ, USA, commented on the current state of crosslinking, trials and findings, and expectations for the future. Additionally, David Muller, PhD , president and CEO of Avedro, Waltham, Mass., USA, spoke about the company’s clinical trial, which is going through the FDA submission process, and other endeavors and advancements in crosslinking. Cobalt blue slitlamp appearance after 15 minutes of epithelial on loading with proprietary epi-on riboflavin solution from CXLO White light slitlamp photo of well-loaded corneal stroma after 15 minutes of epithelium on loading using the same proprietary formulation in a 20-year- old patient with keratoconus. The yellow arrow shows that the epithelium is intact and is relatively free of riboflavin loading, thus permitting UVA penetration for good crosslinking to occur using CXLO’s proprietary corneal strengthening technology. Note AC flare with epithelium intact (epi-on CXL). Case results from epi-on crosslinking Source (all): Roy Rubinfeld, MD Current state of crosslinking “There are a plethora of studies that are ongoing right now, and it’s very easy to get into these studies so that patients do have access to crosslinking,” Dr. Donnenfeld said. Discussions on crosslinking bring up two main issues, he said, which are how the riboflavin is applied and the duration of the treatment. Advancements as studies progress have allowed for shorter treatment times and less invasive transepithelial procedures. “Crosslinking worldwide has been around for several years now, and I think that the consensus in the field is that it’s something that is a very useful technique for the treatment of keratoconus and corneal ectasia with the goal of decreasing the progression of these disease processes, as well as in some cases actually improving vision,” Dr. Hersh said. “In the U.S. there was an original multicenter clinical trial, and that currently is sponsored by Avedro,” he said. This trial has been completed and is currently going through the FDA submission process. “This is occurring now,” Dr. Hersh said. “The hope is that this would ultimately lead to FDA approval.” The results in safety and efficacy were “quite encouraging,” Dr. Hersh said. Though the actual clinical trial was completed several years ago, it took some time to complete the data analysis and move on to the submission stage. Dr. Hersh indicated that the study is proceeding at an expected pace. Dr. Muller said that Avedro is the only company so far in the U.S. that has a trial that is expected to produce some sort of approval for crosslinking. He said Avedro expects to submit the data from its clinical trial to the FDA sometime in September. “With a little luck, we hope that approval will be within six months of that submission,” he said. Though this approval could come as early as the first quarter of next year, Dr. Muller noted that it would just be for the first generation protocol of crosslinking, based on data from some years ago. Current crosslinking being done around the world and trials starting now in the U.S. are much more advanced than that, he said. Newer protocols include shorter procedure time with more effective parameters. Dr. Hersh said Avedro has completed another clinical trial of accelerated crosslinking, which is currently conducting follow- up with patients. In addition to Avedro’s work, he indicated that there is a multicenter study with transepithelial crosslinking being conducted by CXLUSA. Dr. Rubinfeld is currently working with CXLUSA, which he started because the rest of the world seemed to have access to a treatment for keratoconus that was not available in the U.S. “With a group of excellent physicians and a lot of regulatory advice from professionals and some significant personal funds, I started a physician-sponsored, IRB-approved, clinical study in the U.S., and we