Classical repetitive transorbital alternating current stimulation (rtACS) or rtACS with individually optimized stimulation protocol with a predefined fixation paradigm will give a greater improvement in the threshold visual field than sham stimulation. Patients with significant optic atrophy in primary open-angle glaucoma (POAG). Key inclusion criteria: age > 40 years fulfilling the EGS (European Glaucoma Society) criteria for POAG, significant visual field impairment (>5dB), typical glaucomatous optic disc damage, and visual field loss in one eye, and either visual field loss or typical glaucomatous optic disc damage, or both, in the fellow eye, "experienced" patients who are familiar with visual field testing (at least five examinations prior to this study), intraocular pressure <22 mmHg (topically treated or untreated), signed informed consent, willingness to participate. Key exclusion criteria: any glaucoma other than POAG,
age > 80 years, visual field defect > 22dB, variation in MD > 2dB between screening and first
(-5 days) and/or second (-3 days) visit, visual acuity below 0.2, media opacity (i.e. cataract or corneal scars which would interfere with the detection of any sudy effects during follow-up), laser or filtering surgery in the previous three month, and/or use of >2 topical (or any oral) IOP-lowering products at the baseline visit, other ophthalmological reason for impaired vision (e.g. age-related macular dageneration), refractive error: spherical equivalent worse than +6 or -6 (cylinder value worse than 3 dpt), seizures, cerebral implants, pregnancy, substance abuse, uncontrolled arterial hypertension rtACS will be applied in patients with significant optic atrophy due to primary open- angle glaucoma with the aim to activate their residual vision. We will conduct a prospective, randomized, double blind, sham-controlled trial in an ambulatory setting with daily 30 min rtACS sham stimulation sessions in two series of five consecutive days separated.
