Takashi Fujikado1, Motohiro Kamei2, Hirokazu Sakaguchi2, Hiroyuki Kanda3, Takao Endo2, Masakazu Hirota4, Takeshi Morimoto1, Kentaro Nishida2, Haruhiko Kishima5, Yasuo Terasawa6, Koji Oosawa6, Motoki Ozawa6, Kohji Nishida2. 1. Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan 2Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan. 2. Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan. 3. Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan 3Nidek Co., Gamagori, Aichi, Japan. 4. Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan. 5. Department of Neurosurgery, Osaka University Graduate School of Medicine, Osaka, Japan. 6. Nidek Co., Gamagori, Aichi, Japan.
Abstract
PURPOSE: To determine the feasibility of a 49-channel suprachoroidal-transretinal stimulation (STS) retinal prosthesis that was implanted for 1 year. METHODS: Three patients with advanced retinitis pigmentosa (RP) and with less than or equal to hand motion (HM) vision were studied. A 49-channel STS system was implanted in a scleral pocket, and the stability of the prosthesis, adverse events, and its efficacy were investigated. RESULTS: The electrode array was implanted in a scleral pocket located under the parafoveal area through a scleral incision at 14 mm in patient (Pt) 1, 16 mm in Pt 2, and 18 mm in Pt 3 from the sclerocorneal limbus. No complications occurred during surgery in all cases. During the follow-up period, iridocyclitis developed in Pt 2 and Pt 3, which was successfully treated with topical medications. The implanted devices continued functioning and elicited phosphenes in all cases. The results of localization tests (P < 0.05) and table tests (P < 0.05) were significantly better with the prosthesis turned on than turned off in Pt 3. The deviations of the walking tests were smaller with the prosthesis turned on than off in Pt 2 and Pt 3 at multiple times after the implantation. CONCLUSIONS: The 49-channel STS retinal prosthesis was able to elicit phosphenes in all patients with advanced RP for the entire 1-year experimental period without major complications. Better results on visual tasks were found in the eyes in which the electrode array was implanted closer to the fovea centralis.
PURPOSE: To determine the feasibility of a 49-channel suprachoroidal-transretinal stimulation (STS) retinal prosthesis that was implanted for 1 year. METHODS: Three patients with advanced retinitis pigmentosa (RP) and with less than or equal to hand motion (HM) vision were studied. A 49-channel STS system was implanted in a scleral pocket, and the stability of the prosthesis, adverse events, and its efficacy were investigated. RESULTS: The electrode array was implanted in a scleral pocket located under the parafoveal area through a scleral incision at 14 mm in patient (Pt) 1, 16 mm in Pt 2, and 18 mm in Pt 3 from the sclerocorneal limbus. No complications occurred during surgery in all cases. During the follow-up period, iridocyclitis developed in Pt 2 and Pt 3, which was successfully treated with topical medications. The implanted devices continued functioning and elicited phosphenes in all cases. The results of localization tests (P < 0.05) and table tests (P < 0.05) were significantly better with the prosthesis turned on than turned off in Pt 3. The deviations of the walking tests were smaller with the prosthesis turned on than off in Pt 2 and Pt 3 at multiple times after the implantation. CONCLUSIONS: The 49-channel STS retinal prosthesis was able to elicit phosphenes in all patients with advanced RP for the entire 1-year experimental period without major complications. Better results on visual tasks were found in the eyes in which the electrode array was implanted closer to the fovea centralis.
Authors: Jan Lestak; Jiri Chod; Jozef Rosina; Karel Hana Journal: Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub Date: 2022-06-14 Impact factor: 1.648
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