Implantation and explantation of a wireless epiretinal retina implant device: observations during the EPIRET3 prospective clinical trial.
OBJECTIVE
Visual sensations in patients with blindness and retinal degenerations may be restored by electrical stimulation of retinal neurons with implantable microelectrode arrays. A prospective trial was initiated to evaluate the safety and efficacy of a wireless intraocular retinal implant (EPIRET3) in six volunteers with blindness and RP.


METHODS
The implant is a remotely controlled, fully intraocular wireless device consisting of a receiver and a stimulator module. The stimulator is placed on the retinal surface. Data and energy are transmitted via an inductive link from outside the eye to the implant. Surgery included removal of the lens, vitrectomy, and implantation of the EPIRET3 device through a corneal incision. The clinical outcome after implantation and explantation of the device was determined. The implant was removed after 4 weeks, according to the study protocol.


RESULTS
Implantation was successful in all six patients. While the anterior part was fixed with transscleral sutures, the stimulating foil was placed onto the posterior pole and fixed with retinal tacks. The implant was well tolerated, causing temporary moderate postoperative inflammation, whereas the position of the implant remained stable until surgical removal. In all cases explantation of the device was performed successfully. Adverse events were a sterile hypopyon effectively treated with steroids and antibiotics in one case and a retinal break in a second case during explantation requiring silicone oil surgery.


CONCLUSIONS
The EPIRET3 system can be successfully implanted and explanted in patients with blindness and RP. The surgical steps are feasible, and the postoperative follow-up disclosed an acceptable range of adverse events.
Departments of Ophthalmology, RWTH Aachen University, Aachen, Germany.
Gernot
G
Roessler
Thomas
T
Laube
Claudia
C
Brockmann
Thomas
T
Kirschkamp
Babac
B
Mazinani
Michael
M
Goertz
Christian
C
Koch
Ingo
I
Krisch
Bernd
B
Sellhaus
Hoc Khiem
HK
Trieu
Joachim
J
Weis
Norbert
N
Bornfeld
Harald
H
Röthgen
Arthur
A
Messner
Wilfried
W
Mokwa
Peter
P
Walter
D001766:Blindness / Q000534:rehabilitation*; D020878:Device Removal; D004558:Electric Stimulation; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004596:Electroretinography; D005240:Feasibility Studies; D005451:Fluorescein Angiography; D006801:Humans; D008839:Microelectrodes; D011446:Prospective Studies; D019919:Prosthesis Implantation; D012160:Retina / Q000601:surgery*; D012174:Retinitis Pigmentosa / Q000534:rehabilitation*; D013685:Telecommunications; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests