BACKGROUND: The fixation of polyimide stimulator foils as the basic substrate of epiretinal prostheses by using retinal tacks may cause retinal or choroidal alterations such as retinal proliferations or choroidal neovascularizations. During the prospective trial for the semichronical testing of a wireless intraocular retinal implant (EPIRET3) we investigated alterations in angiographic findings during implantation and after explantation of the device, to detect potential vascular pathologies at the fixation site or elsewhere. METHODS: As the final step of the implantation surgery in six blind patients, the stimulator was placed on the retinal surface using retinal tacks. For the detection of possible morphological or vascular alterations committed by the implant fluorescein angiography (FA) was performed 1 day before and 4 weeks after implantation surgery, as well as at the final visit 5 months after explantation. RESULTS: Following implantation surgery funduscopy and FA did not reveal any evidence of either vascular pathologies or choroidal neovascularisations (CNV), in addition, no cystoid macular edema (CME) occurred after 4 weeks. At the 6-month follow-up visit, we found a mild epiretinal gliosis formation in four patients. In one patient a retinal break occurred during explantation, requiring a temporary silicone-oil endotamponade. At the final visit, we observed a focal proliferative vitreoretinopathy (PVR) reaction without activity, while there was no evidence for a CNV formation in that area. CONCLUSIONS: The FA findings confirm our previous results on the safety of the EPIRET3 system, which was tolerated in all patients but revealed a certain risk profile in regard to the stimulator fixation. While there was no evidence for newly occurred CME or CNV during the follow-up visits, nevertheless gliosis or even PVR reaction at the tack's fixation site suggests the need to develop alternative fixation procedures of epiretinal stimulators.
BACKGROUND: The fixation of polyimide stimulator foils as the basic substrate of epiretinal prostheses by using retinal tacks may cause retinal or choroidal alterations such as retinal proliferations or choroidal neovascularizations. During the prospective trial for the semichronical testing of a wireless intraocular retinal implant (EPIRET3) we investigated alterations in angiographic findings during implantation and after explantation of the device, to detect potential vascular pathologies at the fixation site or elsewhere. METHODS: As the final step of the implantation surgery in six blind patients, the stimulator was placed on the retinal surface using retinal tacks. For the detection of possible morphological or vascular alterations committed by the implant fluorescein angiography (FA) was performed 1 day before and 4 weeks after implantation surgery, as well as at the final visit 5 months after explantation. RESULTS: Following implantation surgery funduscopy and FA did not reveal any evidence of either vascular pathologies or choroidal neovascularisations (CNV), in addition, no cystoid macular edema (CME) occurred after 4 weeks. At the 6-month follow-up visit, we found a mild epiretinal gliosis formation in four patients. In one patient a retinal break occurred during explantation, requiring a temporary silicone-oil endotamponade. At the final visit, we observed a focal proliferative vitreoretinopathy (PVR) reaction without activity, while there was no evidence for a CNV formation in that area. CONCLUSIONS: The FA findings confirm our previous results on the safety of the EPIRET3 system, which was tolerated in all patients but revealed a certain risk profile in regard to the stimulator fixation. While there was no evidence for newly occurred CME or CNV during the follow-up visits, nevertheless gliosis or even PVR reaction at the tack's fixation site suggests the need to develop alternative fixation procedures of epiretinal stimulators.
Authors: Gernot Roessler; Thomas Laube; Claudia Brockmann; Thomas Kirschkamp; Babac Mazinani; Michael Goertz; Christian Koch; Ingo Krisch; Bernd Sellhaus; Hoc Khiem Trieu; Joachim Weis; Norbert Bornfeld; Harald Röthgen; Arthur Messner; Wilfried Mokwa; Peter Walter Journal: Invest Ophthalmol Vis Sci Date: 2009-05-06 Impact factor: 4.799
Authors: Eyal Margalit; Mauricio Maia; James D Weiland; Robert J Greenberg; Gildo Y Fujii; Gustavo Torres; Duke V Piyathaisere; Thomas M O'Hearn; Wentai Liu; Gianluca Lazzi; Gislin Dagnelie; Dean A Scribner; Eugene de Juan; Mark S Humayun Journal: Surv Ophthalmol Date: 2002 Jul-Aug Impact factor: 6.048
Authors: J Menzel-Severing; T Laube; C Brockmann; N Bornfeld; W Mokwa; B Mazinani; P Walter; G Roessler Journal: Eye (Lond) Date: 2012-03-16 Impact factor: 3.775
Authors: David A X Nayagam; Ceara McGowan; Joel Villalobos; Richard A Williams; Cesar Salinas-LaRosa; Penny McKelvie; Irene Lo; Meri Basa; Justin Tan; Chris E Williams Journal: J Vis Exp Date: 2013-08-02 Impact factor: 1.355