ABSTRACT
Purpose: To date, reviews of retinal prostheses have focused primarily on devices undergoing human trials in the Western Hemisphere and fail to capture significant advances in materials and engineering research in countries such as Japan and Korea, as well as projects in early stages of development. To address these gaps, this systematic review examines worldwide advances in retinal prosthetic research, evaluates engineering characteristics and clinical progress of contemporary device initiatives, and identifies potential directions for future research in the field of retinal prosthetics.
Methods: A literature search using PubMed, Google Scholar, and IEEExplore was conducted following the PRISMA Guidelines for Systematic Review. Inclusion criteria were peer-reviewed papers demonstrating progress in human or animal trials and papers discussing the prosthetic engineering design. For each initiative, a description of the device, its engineering considerations, and recent clinical results were provided.
Results: Ten prosthetic initiatives met our inclusion criteria and were organized by stimulation location. Of these initiatives, four have recently completed human trials, three are undergoing multi- or single-center human trials, and three are undergoing preclinical animal testing. Only the Argus II (FDA 2013, CE 2011) has obtained FDA approval for use in the United States; the Alpha-IMS (CE 2013) has achieved the highest visual acuity using a Landolt-C test to date and is the only device presently undergoing a multicenter clinical trial.
Conclusion: Several distinct approaches to retinal stimulation have been successful in eliciting visual precepts in animals and/or humans. However, many clinical needs are still not met and engineering challenges must be addressed before a retinal prosthesis with the capability to fully and safely restore functional vision can be realized.
Acknowledgments
The authors would like to acknowledge Dr. Joseph Rizzo (Massachusetts Eye and Ear, Boston Retinal Implant Project) for his help in identifying the most current updates in the rapidly expanding field of retinal prosthetics as well as Jimmy Xia (Brown University) for providing illustrations.
Funding
This work was sponsored in part by the Defense Advanced Research Projects Agency (DARPA) BTO under the auspices of Dr. Doug Weber through the [Space and Naval Warfare Systems Center, Pacific OR DARPA Contracts Management Office] Grant/Contract No. D15AP00112, the International Research in Paraplegia Foundation (IRP, P152), and the Brown Program in Liberal Medical Education.
Disclaimer
The views expressed in this article are those of the authors’ and do not necessarily reflect the position or policy of the Department of Veteran Affairs of the United States government.