Paraorbital-Occipital Electric Stimulation in Patients With Optic Neuropathy (BCT_optnerve)

University of Magdeburg40 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 with the defective visual field sectors of the visual field (primary outcome measure).

exploratory, randomized, controlled study

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Visual Impairment

Interventions

rtACS (verum condition)DEVICE

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 1000 microA. 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.

placebo stimulationDEVICE

a clicking sound was presented and the same electrodes montage set-up was used during rtACS and placebo stimulation, except that placebo patients received no current (stimulator turned off).

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: * residual vision * patients with optic nerv lesion * lesion age at least 6 months * stable visual field defect Exclusion Criteria: * electric or electronic implants such as pace maker * any metal artefacts in head and truncus * epilepsia * photosensitive epilepsy as determines by EEG * autoimmune illnesses in acute stage * mental diseases such e.g. schizophrenia etc. * diabetes causing diabetic retinopathy * addiction * high blood pressure * unstable or high level intraocular pressure (i.e. \> 27 mmHg) * retinitis pigmentosa * pathological nystagmus * presence of an un-operated tumor or tumor recidive

Locations (2)

Klinik für Neurologie, Charité Campus Mitte, Universitätsmedizin Berlin

Berlin, Germany

Institut für Medizinische Psychologie, Leipziger Str. 44

Magdeburg, Germany

Outcomes

Primary Outcomes

Detection accuracy (DA) change in percent over baseline within defective visual field sectors

Central visus 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).

Time frame: between baseline and 60 days after stimulation