Journal Article

Alternating Current Stimulation for Vision Restoration after Optic Nerve Damage: A Randomized Clinical Trial

Gall, Carolin, Antal, Andrea, Paulus, Walter, Ambrus, Géza Gergely, Dannhauer, Moritz, Mante, Alf, Michalik, Romualda, Bola, Michal, Lux, Anke, Brandt, Stephan A., Kropf, Siegfried, Schmidt, Sein, Sabel, Bernhard A., Schittkowski, Michael P.

2016

Overview

Vision loss after optic neuropathy is considered irreversible. Here, repetitive transorbital alternating current stimulation (rtACS) was applied in partially blind patients with the goal of activating their residual vision. We conducted a multicenter, prospective, randomized, double-blind, sham-controlled trial in an ambulatory setting with daily application of rtACS (n = 45) or sham-stimulation (n = 37) for 50 min for a duration of 10 week days. A volunteer sample of patients with optic nerve damage (mean age 59.1 yrs) was recruited. The primary outcome measure for efficacy was super-threshold visual fields with 48 hrs after the last treatment day and at 2-months follow-up. Secondary outcome measures were near-threshold visual fields, reaction time, visual acuity, and resting-state EEGs to assess changes in brain physiology. The rtACS-treated group had a mean improvement in visual field of 24.0% which was significantly greater than after sham-stimulation (2.5%). This improvement persisted for at least 2 months in terms of both within- and between-group comparisons. Secondary analyses revealed improvements of near-threshold visual fields in the central 5° and increased thresholds in static perimetry after rtACS and improved reaction times, but visual acuity did not change compared to shams. Visual field improvement induced by rtACS was associated with EEG power-spectra and coherence alterations in visual cortical networks which are interpreted as signs of neuromodulation. Current flow simulation indicates current in the frontal cortex, eye, and optic nerve and in the subcortical but not in the cortical regions. rtACS treatment is a safe and effective means to partially restore vision after optic nerve damage probably by modulating brain plasticity. This class 1 evidence suggests that visual fields can be improved in a clinically meaningful way. ClinicalTrials.gov NCT01280877.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Acuity / Adult / Aged / Alternating current / Biology and Life Sciences / Biometrics / Brain / Brain damage / Brain injury / Brain stimulation / Care and treatment / Causes of / Clinical trials / Cortex (frontal) / Double-Blind Method / EEG / Electric currents / Electric Stimulation Therapy - methods / Electric stimuli / Electrical currents / Electrical stimuli / Electricity / Electroencephalography / Ethics / Female / Flow simulation / Follow-Up Studies / Glaucoma / Health aspects / Health informatics / Humans / Male / Medicine and Health Sciences / Middle Aged / Nerve degeneration / Neurology / Neuromodulation / Neuropathy / Optic nerve / Optic Nerve - physiopathology / Optic Nerve Diseases - physiopathology / Optic Nerve Diseases - therapy / Optic Nerve Injuries - physiopathology / Optic Nerve Injuries - therapy / Optic neuropathy / Patients / Prospective Studies / Quality of Life / Randomization / Reaction time / Research and Analysis Methods / Restoration / Self Report / Sensory stimulation / Social Sciences / Time Factors / Treatment Outcome / Vision / Vision disorders / Vision Disorders - therapy / Vision, Ocular / Visual Acuity / Visual cortex / Visual field / Visual Field Tests / Visual Fields / Visual plasticity / Visual thresholds