Subretinal implantation of Okayama University-type retinal prosthesis(OURePTM) in canine eyes by vitrectomy

[摘要] Okayama University-type retinal prosthesis (OURePTM) is a photoelectricdye-coupled polyethylene film which generates electric potential in response to light andstimulates nearby neurons. This study aims to test surgical feasibility of subretinalimplantation and functional durability of dye-coupled films in the subretinal space. Thedye-coupled films were implanted subretinally by 25-gauge vitrectomy in the right eye of11 normal beagle dogs 2 dogs served for film removal after 5-month film implantation, 3dogs for film removal after 3-month film implantation, 3 dogs for 3-month filmimplantation and pathological examination, and 3 dogs for sham surgery. The surfaceelectric potential of the removed dye-coupled films in response to light was measured bythe Kelvin Probe system. At surgery, rolled-up dye-coupled films in 5 × 5 mm square sizecould be inserted into subretinal space of retinal detachment induced by fluid injectionwith a 38-gauge polyimide tip. Retinal attachment was maintained by silicone oil injectionin vitreous cavity. At autopsy, the retina in all dogs maintained the ganglion cell layer,inner and outer nuclear layers while it lost the outer segments in some part. All 5 sheetsof removed dye-coupled films maintained the dye color. One sheet of the 5-month implantedfilm showed proportional increase of surface potential in response to increasing lightintensity. Subretinal implantation of OURePTM by vitrectomy was technicallyfeasible in canine eyes, and OURePTM maintained the function of generatinglight-evoked surface potential after 5 months in subretinal implantation.

[学科分类] 兽医学

[关键词] 38-gauge polyimide tip;vitrectomy;dog;dye-coupled thin film retinal prosthesis;photoelectric dye