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

Area of Science:

• Neuroscience
• Ophthalmology
• Neuromodulation

Background:

• Vision loss from optic neuropathy is typically irreversible.
• Repetitive transorbital alternating current stimulation (rtACS) was investigated to activate residual vision in partially blind patients.

Purpose of the Study:

• To evaluate the efficacy and safety of rtACS in restoring vision in patients with optic nerve damage.
• To assess the impact of rtACS on visual fields, reaction time, visual acuity, and brain activity.

Main Methods:

• A multicenter, prospective, randomized, double-blind, sham-controlled trial was conducted.
• 45 patients received daily rtACS, while 37 received sham stimulation for 10 weekdays.
• Primary outcome was super-threshold visual fields; secondary outcomes included near-threshold visual fields, reaction time, visual acuity, and EEG.

Main Results:

• The rtACS group showed a significant mean visual field improvement of 24.0% compared to 2.5% in the sham group.
• Improvements in visual fields persisted for at least 2 months.
• rtACS also improved near-threshold visual fields, reaction times, and altered EEG patterns, indicating neuromodulation.

Conclusions:

• rtACS is a safe and effective treatment for partially restoring vision after optic nerve damage.
• The treatment likely works by modulating brain plasticity.
• Class 1 evidence supports clinically meaningful improvements in visual fields.