EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/76185
July 2012 EW CORNEA Surgeons hope "holy grail" is near for macular degeneration patients by Matt Young EyeWorld Contributing Editor Stem cells are being tested in clinical trials for Stargardt's disease and dry AMD N ow that clinical trials of embryonic stem cell treatment for dry age- related macular degenera- tion (AMD) and Stargardt's disease are underway, ophthalmologists—from involved researchers to many others across America—are hoping for excellent results from what is touted to be a very promising therapy for these devastating diseases. Back in July 2011, Advanced Cell Technology (ACT, Marlborough, Mass.) announced that retinal pig- ment epithelial (RPE) cells derived from human embryonic stem cells (hESCs) are being used to treat the first patients with dry AMD and Stargardt's macular dystrophy. The Stargardt's trial and dry AMD trial have enrolled 12 patients each and are expected to determine the safety and tolerability of this treatment. Results will depend on outcomes at 12 months. In the meantime, ophthalmolo- gists eagerly await the results, as do many of their patients. Unleashing stem cell potential Steven Schwartz, M.D., Ahmanson Professor of Ophthalmology, David Geffen School of Medicine, UCLA, and retina division chief, Jules Stein Eye Institute, UCLA, is the studies' principal investigator. "Early indications are that the patients tolerated the surgical proce- dures well," Dr. Schwartz said. "The primary objective of these Phase I/II studies is to assess the safety and tolerability of these stem cell-derived SimLC continued from page 30 need an adjunctive treatment because of thinner corneas or steeper cones. For those patients, both SimLC and Keraflex are effective solutions. EW References 1. Kanellopoulos AJ. Comparison of sequen- tial vs. same-day simultaneous collagen crosslinking and topography-guided PRK for treatment of keratoconus. J Refract Surg. 2009;25(9):S812-8. 2. Kanellopoulos AJ. Collagen crosslinking in early keratoconus with riboflavin in a fem- tosecond laser-created pocket: Initial clinical results. J Refract Surg. 2009;25(11):1034-7. 3. Kanellopoulos AJ, Binder PS. Management of corneal ectasia after LASIK with combined, same-day, topography-guided partial transep- ithelial PRK and collagen crosslinking: the Athens protocol. J Refract Surg. 2011;27(5):323-31. 4. Krueger RR, Kanellopoulos AJ. Stability of simultaneous topography-guided photorefrac- tive keratectomy and riboflavin/UVA cross- linking for progressive keratoconus: case re- ports. J Refract Surg. 2010;26(10):S827-32. 5. Marshall J, Angunawela R, Tengroth J. Wound healing and biomechanics of corneal flap creation. Keynote address. XXIV Congress of the European Society of Cataract and Re- fractive Surgeons. London: Sept. 9-11, 2006. 6. Marshall J. Sub-Bowman's keratomileusis (SBK) vs. PRK. 11th European Society of Cataract & Refractive Surgeons Winter Refrac- tive Meeting. Athens, Greece: Feb. 2-4, 2007. Editors' note: Dr. Cummings practices at Wellington Eye Clinic and UPMC Beacon Hospital, Dublin, Ireland. He has financial interests with Alcon. Contact information Cummings: abc@wellingtonclinic.com transplants. We will be carefully monitoring our patients over the course of the trials." The first dose given to patients involved 50,000 cells of fully-differ- entiated RPE cells, considered to be a relatively small dose. Robert Lanza, M.D., chief scientific officer, ACT, suggested that it's about time for stem cells to be put to good use for visual purposes. "Thirteen years after the discov- ery of human embryonic stem cells, the great promise of these cells is fi- nally being put to the test," said Dr. Lanza. "While we will continue writ- ing research papers and carrying out more research, it's time to start mov- ing these exciting new stem cell therapies out of the laboratory and into the clinic. We hope these cells may provide a treatment option not only for degenerative eye diseases, but for a wide spectrum of other debilitating conditions, ranging from diabetes to vascular and autoimmune diseases." According to ACT, RPE cells support, protect, and give nutrients to light-sensitive photoreceptors. Meanwhile, human embryonic stem cells differentiate into any cell type, including RPE cells. With this new treatment, researchers are hoping to improve the conditions of patients with Stargardt's disease and dry AMD, both of which involve thin- ning of the RPE layer in a patient's macula. Waiting in the wings Meanwhile, George H.H. Beiko, M.D., assistant clinical professor of ophthalmology, McMaster Univer- sity, St. Catharines, Ontario, Canada, said many patients are waiting with bated breath for the results. "Patients who are affected by atrophic age-related macular degen- eration are following these studies closely," Dr. Beiko said. "They are interested in the rudimentary results from these studies because they are desperate to try the treatment as soon as they can. The main reason for this is because there has been such good success treating wet mac- ular degeneration. They have colleagues who get treatment and have improved vision. But there is nothing they can do [for their own dry AMD]." Dr. Beiko suggested results don't even have to be that good yet for there to be a major impact on pa- tients. "Even if there is a small, limited degree of improvement, a huge number [of patients would benefit]," Dr. Beiko said. "This topic comes up in my office once or twice a day with questions like, 'Is this viable?' and 'Is this something I have access to?' The general population is eagerly awaiting the results. Patients are more aware of stem cell research than anything else." William B. Trattler, M.D., director, Cornea, Center for Excellence in Eye Care, Miami, agreed that the treatment is sorely needed. "Advanced vision loss [like dry AMD] is not responsive to current treatments," Dr. Trattler said. "One would hope that this new treatment will be promising for patients with macular degeneration, a major cause of vision loss in patients over 65. Any therapy is going to be tremen- dous." Terry Kim, M.D., professor of ophthalmology, Duke University School of Medicine, and associate director, Duke Eye Center, Durham, N.C, said he used to perform stem cell treatments for diseased corneas, but no longer does. "It's a tough surgery," Dr. Kim said. "It's a labor-intensive process. I don't perform those any more at Duke. I refer a lot of mine. The treat- ment is for patients who have no other options—for sick eyes—but there are very rewarding results for some of them." Douglas Katsev, M.D., Sansum Clinic, Santa Barbara, Calif., said that he thinks embryonic stem cell treatment is "the holy grail" of visual rehabilitation. "It's for lost vision that we don't have a hope to get back," Dr. Katsev said. Currently stem cells are being used to help corneal epithelium regenerate, Dr. Katsev said. Still, there's much more work that needs to be done, he said. "That would be the ultimate treatment for ophthalmologists," he said. "I don't know if I will see it in my lifetime. But I have been sur- prised by what I have seen in my lifetime in ophthalmology already." EW Editors' note: Drs. Beiko, Katsev, Kim, and Trattler have no financial interests related to their comments. Dr. Lanza is chief scientific officer of ACT. Dr. Schwartz is the principal investigator for the clinical trials. Contact information Beiko: 905-687-8322, georgebeiko@hotmail.com Katsev: 800-472-6786, katsev@aol.com Kim: 919-681-3568, kim00006@mc.duke.edu Lanza: 310-576 0611, bill@gothamcomm.com Schwartz: 310-206-7474, schwartz@jsei.ucla.edu Trattler: 305-598-2020, wtrattler@gmail.com 31