The artificial silicon retina microchip for the treatment of vision loss from retinitis pigmentosa.
OBJECTIVE
To determine the safety and efficacy of the artificial silicon retina (ASR) microchip implanted in the subretinal space to treat vision loss from retinitis pigmentosa.


METHODS
The ASR microchip is a 2-mm-diameter silicon-based device that contains approximately 5000 microelectrode-tipped microphotodiodes and is powered by incident light. The right eyes of 6 patients with retinitis pigmentosa were implanted with the ASR microchip while the left eyes served as controls. Safety and visual function information was collected.


RESULTS
During follow-up that ranged from 6 to 18 months, all ASRs functioned electrically. No patient showed signs of implant rejection, infection, inflammation, erosion, neovascularization, retinal detachment, or migration. Visual function improvements occurred in all patients and included unexpected improvements in retinal areas distant from the implant.


METHODS
Subjective improvements included improved perception of brightness, contrast, color, movement, shape, resolution, and visual field size.


CONCLUSIONS
No significant safety-related adverse effects were observed. The observation of retinal visual improvement in areas far from the implant site suggests a possible generalized neurotrophic-type rescue effect on the damaged retina caused by the presence of the ASR. A larger clinical trial is indicated to further evaluate the safety and efficacy of a subretinally implanted ASR.
Chow
Alan Y
AY
Optobionics Corporation, Naperville, Illinois, USA. alanykc@aol.com
Chow
Vincent Y
VY
Packo
Kirk H
KH
Pollack
John S
JS
Peyman
Gholam A
GA
Schuchard
Ronald
R
D000368:Aged; D001766:Blindness / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019919:Prosthesis Implantation; D012160:Retina / Q000601:surgery*; D012174:Retinitis Pigmentosa / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D012449:Safety; D012666:Semiconductors; D012825:Silicon; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
D012825:Silicon