Trial of Alternating Current Stimulation in Optic Neuropathy

University of Magdeburg22 enrolled

Overview

Non-invasive brain stimulation can increase cortical excitability in the visual system, but it is not known if this is of clinical value. The investigators now assessed if repetitive, transcranial alternating current stimulation (rtACS) can improve visual field size in patients with optic nerve damage. The investigators hypothesized that rtACS would improve visual functions within the defective visual field sectors of the visual field (primary outcome measure).

In a prospective, double-blind, randomized, placebo-controlled clinical trial 22 patients with optic nerve damage were randomly assigned to a rtACS- (n=12) or placebo-group (n=10). Visual field measures, visual acuity and EEG-recordings were collected before and after a daily 20-40min treatment for 10-days and at a 2-months-follow-up. Primary outcome measure was detection accuracy (DA) in defective visual field sectors of computer-based high resolution perimetry (HRP). Secondary outcome parameters included DA in static and kinetic perimetry, reaction time (RT) in HRP, visual acuity (VA), contrast vision, and EEG power spectra.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Optic Nerve Diseases Optic Nerve Injuries Optic Neuropathies

Interventions

Repetitive transorbital alternating current stimulationDEVICE

Repetitive, transorbital alternating current stimulation (rtACS) was applied with a multi-channel device generating weak current pulses in predetermined firing bursts of 2 to 9 pulses. The amplitude of each current pulse was below 1000µA. Current intensity was individually adjusted according to how well patients perceived phosphenes, i.e. any sensation of flickering light in response to the rtACS stimulation.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria * patients with optic nerve lesion * stable visual field defect with residual vision * lesion age at least 6 months Exclusion Criteria * heart pacemakers and any metal artefacts in head and truncus * epileptic seizure within the last 3 years * photosensitive epilepsy as determined by EEG * mental diseases (schizophrenia etc.) * unstable diabetes, diabetes causing diabetic retinopathy * macular degeneration, maculopathy with decimal visual acuity below 0.4 * high blood pressure * instable or high level of intraocular pressure (i.e. \>27 mmHg) * presence of an un-operated tumor anywhere in the body * total blindness * primary or secondary glaucoma * pathological nystagmus

Locations (1)

Institute of Medical Psychology

Magdeburg, Germany

Outcomes

Primary Outcomes

Detection Accuracy (DA) Change in Percent Over Baseline Within Defective Visual Field Sectors

Central visual fields were assessed with computer-based high-resolution perimetry (HRP). Based on such plots, areas of the visual field were characterized as intact, partially damaged or absolutely impaired (blind). Detection accuracy (DA) change in percent above baseline within defective visual field sectors was defined as the primary outcome criterion.

Time frame: Outcome measures were assessed at initial diagnostics (baseline) and after 10 days stimulation at post diagnostics

Secondary Outcomes

Other Visual and EEG Parameters

Secondary outcome parameters included DA in static and kinetic perimetry, reaction time (RT) in HRP, visual acuity (VA), contrast vision, and EEG power spectra.

Time frame: Nov 2006 - Dec 2010

Data from ClinicalTrials.gov

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