Experimental implantation and long-term testing of an intraocular vision aid in rabbits.
OBJECTIVE
To develop an intraocular vision aid to provide artificial vision in severely traumatized eyes, where neuroretinal function could be preserved but irreversible anterior segment opacification resulted in blindness.


METHODS
The basis of an intraocular vision aid is in principle a telemetric circuit to bridge the opaque cornea and to allow for artificial light stimulation of the retina. The visual prosthesis comprises an external high-dynamic range complementary metal oxide semiconductor camera and digital signal processing unit and an intraocular miniaturized light-emitting diode array to project the image onto the retina. For in vivo testing of long-term function and biocompatibility, silicone-encapsulated active photodiodes were implanted in 13 pigmented rabbits and were followed up for up to 21 months.


RESULTS
Lens extraction and stable fixation of the device in the ciliary sulcus were successful in all cases. For up to 21 months inductive energy transmission and wireless stimulation of the implants could be maintained. Electrophysiologic data and histology demonstrated a good tissue biocompatibility in the long-term follow-up.


CONCLUSIONS
The results demonstrate the general feasibility and biocompatibility to implant and fixate an intraocular light-emitting diode prosthesis. Inductive energy transmission to the intraocular device and wireless light stimulation are assured in the long term but depend on meticulous water-impermeable encapsulation of the delicate microelectronic components. Clinical Relevance An intraocular vision aid compound system with a high-resolution light-emitting diode matrix might be a future treatment option to restore vision in blind eyes with severe anterior segment disorders.
Szurman
Peter
P
Department of Ophthalmology I, Eberhard-Karls University of Tuebingen, Schleichstrasse 12, 72076 Tuebingen, Germany. peter.szurman@med.uni-tuebingen.de
Warga
Max
M
Roters
Sigrid
S
Grisanti
Salvatore
S
Heimann
Uta
U
Aisenbrey
Sabine
S
Rohrbach
Jens M
JM
Sellhaus
Bernd
B
Ziemssen
Focke
F
Bartz-Schmidt
Karl U
KU
D000818:Animals; D001672:Biocompatible Materials; D004567:Electrodes, Implanted; D004596:Electroretinography; D008839:Microelectrodes; D010775:Photic Stimulation; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D011817:Rabbits; D012160:Retina / Q000601:surgery*; D012666:Semiconductors; D012682:Sensory Aids; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D014785:Vision, Ocular / Q000502:physiology
D001672:Biocompatible Materials