Eyeworld

70 | EYEWORLD | DECEMBER 2022 C HOT TOPICS IN OPHTHALMOLOGY ORNEA by Ellen Stodola Editorial Co-Director About the physicians John Berdahl, MD Vance Thompson Vision Sioux Falls, South Dakota Matthew Giegengack, MD Associate Professor of Ophthalmology Wake Forest University School of Medicine Greensboro, North Carolina Edward Holland, MD Professor of Ophthalmology University of Cincinnati Cincinnati, Ohio Elizabeth Yeu, MD Virginia Eye Consultants Norfolk, Virginia W hen treating endothelial dys- function, surgeons have several options. The current standard of care is endothelial keratoplasty, DSAEK and DMEK, said Edward Holland, MD. "These transplant procedures have been a tremendous surgical advancement," he said. "However, there are issues that can be problematic. Patients are required to lie flat on their back for 1–2 days postoperatively. Graft detachment is an issue especially in DMEK. And despite a successful procedure, the endothelial cell count can be low, resulting in a shorter life of the graft." There has been very little innovation in transplantation in decades, said Elizabeth Yeu, MD. However, she noted that rejection rates have improved in the last 10–15 years because of advances in allograft techniques. "That's great, but at the same time, that does not allow us to do more than a one-to-one ratio," she said. "That's not enough to cure global blindness." One new therapy that has been getting a lot of attention is corneal endothelial cell therapy, and Dr. Holland said there has been excellent progress in the last 18 months. This technology was developed by Shigeru Kinoshita, MD, PhD, and colleagues at Kyoto Prefecture University of Medicine in Japan. "Dr. Kinoshita published key findings of his first 11 patients at 2 years postop in the New England Journal of Medicine 1 and at 5 years postop in Ophthalmology. 2 Those publi- cations were met with tremendous enthusiasm by corneal specialists throughout the world," Dr. Holland said. "In total, Dr. Kinoshita and colleagues have treated 65 patients in research and clinical studies. Dr. Kinoshita's exciting innovation was to create a method to reproduce corneal endothelial cells in vitro." Dr. Yeu said this is a form of harvesting and culturing, so it allows for one donor to help up to 200 patients. The reason this is so exciting is there is less antigenicity with the greater cell lines that are harvested, she said. In 2021, the technology was acquired by Aurion Biotech, which has continued to inno- vate with cell manufacturing advances and treated a total of 67 patients in the last 18 months in OUS trials. Dr. Holland was part of a team of U.S. surgeons who treated those patients. "I think that the preliminary results for safety and efficacy are largely consistent with patients treated in Japan," he said. "I have high confidence in the technology and its exciting potential." Dr. Yeu, John Berdahl, MD, and Matthew Giegengack, MD, also have experience working with the new technology. Compared to DSAEK and DMEK, Dr. Hol- land said there are several benefits of corneal endothelial cell therapy: Postop endothelial cell counts are significantly higher than EKs; there is an improved surgical experience for the patient (surgery takes less time, and there is no prolonged positioning); and there is a lower complication rate, as there is no risk of graft detachment. Dr. Holland added that there is also a shorter postop patient recovery. "Corneal endothelial cell therapy involves a single injec- tion," he said. "Once the procedure is complete, patients lie face down for a couple of hours. Then they are free to go home and live relative- ly normally. Within weeks, vision recovers." Another potential benefit of this new thera- py is the number of patients it could treat. "The ability to manufacture corneal endothelial cells will ultimately enable ample supply for patients in need. This, along with the benefits of a sim- plified surgical procedure, has the potential to dramatically increase accessibility for patients," Dr. Holland said, although he stressed that this cell therapy is not yet available commercially, and Aurion Biotech must go through clinical trials in the U.S. "We are lucky in the U.S. in that we have very good treatment options for endothelial dys- function, DSAEK and DMEK, both of which set a high bar for cell therapy," Dr. Giegengack said. "For patients in the U.S. who qualify for DMEK/ DSAEK procedures, increasingly we are opting for DMEK since patients are generally able to see better and recover more rapidly than with DSAEK. But due to the complexity of surgery, we cannot perform DMEK on all patients, so DSAEK is still a viable option." Dr. Giegengack said that for cell therapy to be a viable treat- ment option, it would need to be at least as good as DMEK. "In my experience with the cell therapy patients I've treated (and who I've observed my Innovations in the treatment of endothelial dysfunction

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