This trial is active, not recruiting.

Conditions complete hemianopia, incomplete hemianopia, scotoma, quadrantanopia, stroke, hemorrhage, brain trauma
Treatments verum stimulation, placebo stimulation
Phase phase 2/phase 3
Sponsor University of Magdeburg
Collaborator EBS Technologies GmbH
Start date March 2011
End date December 2013
Trial size 32 participants
Trial identifier NCT01418820, EBS-PP-2011-02-16-001


Visual field areas, which are not absolutely blind, are hypothesized to have some residual capacities that constitute their potential for vision restoration. Vision restoration can be achieved by varies methods including behavioral training and electrical brain stimulation such as transcranial direct current stimulation (tDCS) and repetitive transorbital alternating current stimulation (rtACS) which are able to influence the excitability and activity of cortical areas.

It is hypothesized that transorbital alternating current stimulation (tACS) can improve the residual field of vision in patients with post-chiasmatic lesions.

United States No locations recruiting
Other countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification efficacy study
Intervention model parallel assignment
Masking double blind (subject, investigator, outcomes assessor)
Primary purpose treatment
repetitive transorbital alternating current stimulation (rtACS)
verum stimulation
10 days (2x 5 working days), daily transorbital alternating current stimulation (rtACS) is applied with a device generating weak current pulses in predetermined firing bursts of 2 to 9 pulses. The amplitude of each current pulse is below 1000 µA. Current intensity is individually adjusted according to how well patients perceived phosphenes, e.g. any sensation of flickering light in response to the rtACS stimulation. Stimulation frequencies were between the individual alpha frequency peak and below flicker fusion.
(Sham Comparator)
compared to verum stimulation the same electrode montage set-up is used during placebo stimulation, except that placebo patients receive a minimal stimulation
placebo stimulation
10 days (2x 5 working days), daily sham-stimulation with the same electrode montage set-up that is used for verum transorbital alternating current stimulation (rtACS). Minimal sham-stimulation was performed with single bursts (approx. one per min) of electrical currents at a given frequency of 5Hz and individually adjusted current amplitude.

Primary Outcomes

detection accuracy (%) in visual field measures over baseline
time frame: baseline to 8 weeks after stimulation

Secondary Outcomes

detection accuracy (%) in the intact visual field over baseline
time frame: baseline to 8 weeks after stimulation
visual acuity (LogRAD)
time frame: baseline to 8 weeks after stimulation
EEG parameters
time frame: baseline to 8 weeks after stimulation
conventional perimetry
time frame: baseline to 8 weeks after stimulation
reaction time (ms)
time frame: baseline to 8 weeks after stimulation

Eligibility Criteria

Male or female participants at least 18 years old.

Inclusion Criteria: - lesion of the tractus opticus or of the visual cortex - lesion age > 6 months - stable visual field defect with residual vision Exclusion Criteria: - electric or electronic implants, e.g. heart pacer - any metal artefacts in the head - Epilepsy - Auto-immune diseases in acute stage - mental diseases, e.g. schizophrenia etc. - diabetic retinopathy - addictive diseases - blood pressure above 160/100 mmHg - instable or high level of intraocular pressure above 27 mmHg - retinitis pigmentosa - pathological nystagmus - presence of an un-operated tumor or tumor relapse (patients with non-progressive tumor are eligible if study participation is recommended by medical authorities) - focal findings in EEG or photosensitivity (patients with single seizure more than 10 yrs ago may participate) - recurrent transitional ischemic attacks after stroke - arteriosclerosis of large blood vessels with stenosis >75% - severe coronary heart disease (CHD) - unstable angina pectoris - diabetes with blood glucose level > 9 mmol/l - myocard infarct/ cardiomyopathy - ventricular fibrillation - risk of vascular thrombosis - pregnant or breast-feeding women

Additional Information

Official title Paraorbital-Occipital Alternating Current Stimulation Therapy of Patients With Post-Chiasmatic Lesions
Principal investigator Bernhard A Sabel, Ph.D.
Trial information was received from ClinicalTrials.gov and was last updated in November 2013.
Information provided to ClinicalTrials.gov by University of Magdeburg.