A review and update on the current status of retinal prostheses (bionic eye)

INTRODUCTION/BACKGROUND: The Argus® II is the first retinal prosthesis approved for the treatment of patients blind from retinitis pigmentosa (RP), receiving CE (Conformité Européenne) marking in March 2011 and FDA approval in February 2013. Alpha-IMS followed closely and obtained CE marking in July 2013. Other devices are being developed, some of which are currently in clinical trials. SOURCES OF DATA: A systematic literature search was conducted on PubMED, Google Scholar and IEEExplore. AREAS OF AGREEMENT: Retinal prostheses play a part in restoring vision in blind RP patients providing stable, safe and long-term retinal stimulation. AREAS OF CONTROVERSY: Objective improvement in visual function does not always translate into consistent improvement in the patient's quality of life. Controversy exists over the use of an external image-capturing device versus internally placed photodiode devices. GROWING POINTS: The alpha-IMS, a photovoltaic-based retinal prosthesis recently obtained its CE marking in July 2013. AREAS TIMELY FOR DEVELOPING RESEARCH: Improvement in retinal prosthetic vision depends on: (i) improving visual resolution, (ii) improving the visual field, (iii) developing an accurate neural code for image processing and (iv) improving the biocompatibility of the device to ensure longevity.