Electrical stimulation of anterior visual pathways in retinitis pigmentosa
| Autor: | J, Delbeke, D, Pins, G, Michaux, M C, Wanet-Defalque, S, Parrini, C, Veraart |
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| Přispěvatelé: | Laboratoire de Neurosciences Fonctionnelles et Pathologies (LNFP), Université de Lille, Droit et Santé-Centre National de la Recherche Scientifique (CNRS), Institut de génétique et biologie moléculaire et cellulaire (IGBMC), Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire des systemes Thermiques Industriels - UMR 6595, Université de la Méditerranée - Aix-Marseille 2-Université de Provence - Aix-Marseille 1-Centre National de la Recherche Scientifique (CNRS), Wartel, Anny |
| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
Adult
Male genetic structures Phosphenes Sensation Blindness MESH: Psychophysics MESH: Blindness Psychophysics Humans Visual Pathways [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] Aged MESH: Aged MESH: Visual Pathways MESH: Humans MESH: Middle Aged MESH: Visual Perception MESH: Sensation MESH: Mathematics MESH: Electric Stimulation Optic Nerve MESH: Adult MESH: Optic Nerve Middle Aged Electric Stimulation MESH: Male MESH: Phosphenes Visual Perception MESH: Retinitis Pigmentosa Female [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] MESH: Female Mathematics Retinitis Pigmentosa |
| Zdroj: | Investigative Ophthalmology & Visual Science Investigative Ophthalmology & Visual Science, Association for Research in Vision and Ophthalmology, 2001, 42 (1), pp.291-7 Investigative Ophthalmology & Visual Science, 2001, 42 (1), pp.291-7 |
| ISSN: | 0146-0404 1552-5783 |
| Popis: | International audience; PURPOSE: To explore electrically induced phosphenes in blind patients with retinitis pigmentosa (RP) in comparison with healthy subjects and to develop a screening test for candidates for an optic nerve visual prosthesis implantation. METHODS: Phosphenes are obtained by charge balanced biphasic pulse stimulations through a surface cathode over the closed eyelids and an anode near the opposite ear. The resulting strength-duration relationship for somatosensory, phosphene, and pain threshold has been recorded in five RP patients as well as in 10 healthy volunteers. RESULTS: In sighted subjects, the average rheobase and chronaxy for phosphene perception are 0.28 mA and 3.07 msec, respectively. For pulse durations longer than 2 msec, phosphenes are usually obtained at current strengths below the level giving rise to any other electrically generated sensation. In RP patients, however, phosphenes are not so easily obtained. One in five had no visual response at all. Another patient reported a flash perception for the longest pulse durations only. Spontaneous phosphenes interfered heavily with the stimulation in a third person. Finally, despite the higher threshold, two patients displayed normally shaped strength-duration curves. CONCLUSIONS: The surface stimulation has proven harmless, adequate, and very helpful to ascertain that the optic nerve can be electrically activated in completely blind individuals. Long-duration stimulation pulses yield very low phosphene thresholds in healthy subjects. Anterior visual pathways activation requires higher currents in RP patients. |
| Databáze: | OpenAIRE |
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