Transcorneal electrical stimulation for the treatment of retinitis pigmentosa - a multicenter safety study of the OkuStim® System (TESOLA-study) by Jolly, J, Wagner, S, Martus, P, Maclaren, R, Wilhelm, B, Webster, A, Downes, S, Charbel Issa, P, Kellner, U, Jägle, H, Rüther, K, Bertelsen, M, Bragadóttir, R, Prener Holtan, J, Van Den Born, I, Sodi, A, Virgili, G, Gosheva, M, Pach, J, Zündorf, I, Zrenner, E, Gekeler, F