Bionic eye review - An update.

Purpose: To date, reviews of bionic eye have concentrated on implants which were used in human trials in the developed countries. This is the main restriction of this systematic review examines, however this review discusses worldwide advances in retinal prosthetic research, assesses engineering features and clinical progress of recent implant trials, and identifies potential future research areas in the field of bionic implants.

Methods: A literature review searching PubMed, Google Scholar, and IEEExplore was performed using the PRISMA Guidelines for Systematic Review. We included peer-reviewed papers in the review which demonstrated progress in human or animal trials and papers with described innovative bionic eye engineering design. For each trial, a characteristic of the device, engineering solution, and latest clinical outcomes were presented.

Results: Eleven prosthetic projects fulfilled met our inclusion criteria and were ordered by stimulation location. Four have recently finished human trials, three are having conducted multi- or singlecenter human trials, and three are in preclinical animal testing stage. FDA has approved Argus II (FDA 2013, CE 2011); the Alpha-IMS (CE 2013) has been approved and obtained BCVA with Landolt-C test has taken into a multicenter clinical research. New approaches will be presented using alternating magnetic fields, low-intensity focused ultrasounds, optogenetics, implementing ionic gradients across neural cell membranes or influencing neurotransmitter levels will be presented in the review.

Conclusion: Several bionic eye have successfully achieved visual perception in animals and/or humans. However, many things need to be improved and engineering difficulties are to be resolved before bionic eye will be capable of fully and safely bring back vision functions. New approaches could improve medical outcome of future bionic eye.