Subretinal prosthesis advances toward clinical trial

Fort Lauderdale, FL-The 256+ channel Boston subretinal prosthesis is on track for in vivo validation of function and an FDA investigational device exemption application within the next 9 months, according to Joseph F. Rizzo III, MD.

Dr. Rizzo, a neuro-ophthalmologist at Massachusetts Eye & Ear, is leading the retinal prosthesis team. Development of the wireless, subretinal, neurostimulator is nearly complete, he said. Milestones expected by late 2012 or early 2013 will include completion of bench testing and preclinical testing in Yucatan mini-pigs.

Dr. Rizzo and co-inventors of the prosthesis described recent steps in the development and testing of the device, focusing on the implant itself rather than the entire system. Advances in circuit design, packaging, array design, surgical tools, and techniques have been achieved as the team inches closer to the ultimate goal of restoring vision to the blind.

Three progressively better versions of the stimulator’s computer chip have been fabricated, and although one more round of modification may take place soon, the current generation should be suitable for animal trials, said John L. Wyatt, PhD, professor of electrical engineering and computer science, Massachusetts Institute of Technology, Cambridge.

Douglas B. Shire, PhD, Boston VA Medical Center, described the hermetically sealed package that contains the electronics, protecting them from the saline environment in which they will be implanted; this package has been welded and leak tested. This sophisticated packaging technology is necessary to produce an implantable device that contains the large number of receivers and electrodes required to produce high-quality vision.

For more articles in this issue of Ophthalmology Times Conference Briefclick here.