Abstract
Abstract: :
Purpose: To evaluate the moderate-term safety, feasibility and efficacy of subretinal microphotodiode-based silicon chip retinal prostheses in patients with retinitis pigmentosa (RP). Methods: Six patients, five men and one woman, with RP and visual acuities of count-fingers to bare light perception were each implanted, under general anesthesia, with a 2-mm diameter Artificial Silicon RetinaTM (ASRTM) and followed for 6 to 18 months with subjective interviews, ETDRS, automated visual fields, fundus photography / angiography and electrophysiology. The ASRTM chips, 25 microns thick, contain approximately 3500 independent microphotodiodes and were implanted successfully in all patients approximately 20 degrees superior and temporal to the macula. Results: No patient expressed discomfort after surgical recovery. In all subjects, the ASRsTM continued to function electrically without signs of migration, degradation, rejection, infection, inflammation, erosion or retinal detachment. Subjective and objective improvements in visual function have occurred in all patients postoperatively and have persisted. Conclusion: ASRTM retinal prostheses can be implanted into the subretinal spaces of RP patients for at least 18 months and produce improved visual function. The longer-term durability of the ASRTM and its safety, feasibility, efficacy and suitability for the treatment of RP, are yet to be determined.
Keywords: 568 retinitis • 385 degenerations/dystrophies • 607 transplantation