Visual evoked potential in rabbits’ eyes with subretinal implantation byvitrectomy of Okayama University-type retinal prosthesis(OURePTM)

[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 for subretinalfilm implantation and to examine functional durability of films in subretinal space.Dye-coupled films were implanted subretinally by vitrectomy in the right eye of normalwhite rabbits 8 rabbits for 1 month and 8 rabbits for 6 months. The implanted films wereremoved by vitrectomy in 4 of these 8 rabbits in 1-month or 6-month implantation group.The films were also implanted in 4 rhodopsin-transgenic retinal dystrophic rabbits. Visualevoked potential was measured before film implantation as well as 1 or 6 months after filmimplantation, or 1 month after film removal. The films were successfully implanted insubretinal space of retinal detachment induced by subretinal fluid injection with a 38Gpolyimide tip. The retina was reattached by fluid-air exchange in vitreous cavity, retinallaser coagulation, and silicone oil injection. The ratios of P2 amplitudes ofvisual evoked potential in the implanted right eye over control left eye did not showsignificant changes between pre-implantation and post-implantation or post-removal (pairedt-test). In Kelvin probe measurements, 4 pieces each of removed filmswhich were implanted for 1 or 6 months showed proportional increase of surface electricpotential in response to increasing light intensity. The film implantation was safe andimplanted films were capable of responding to light.

[学科分类] 兽医学

[关键词] dye-coupled thin film retinal prosthesis;rabbit;retinal dystrophy (retinitis pigmentosa);visual evoked potential;vitrectomy