Transpalpebral Microcurrent Therapy Improves Vision in Dry AMD

Transpalpebral microcurrent therapy — a treatment that uses cutaneous electrodes placed on a patient’s temples to deliver low current electrical stimulation to nerve fibers — can improve visual measures for patients with non-neovascular (dry) age-related macular degeneration (AMD) and vision loss, according to research published in the International Journal of Retina and Vitreous. Those treated gained visual acuity (VA), converted to 8.2 in number of letters read (NLR) vs control participants, who lost 2.2 letters in 30 weeks.

Trial investigators (ClinicalTrials.gov NCT02540148) randomly assigned 62 patients (3:1) to receive the microcurrent treatment (n=43) or a sham treatment (n=19) that used a battery-operated device with signal lights, but no current delivery. Treated participants underwent pulsed waveform, 1 to 50 Hz varying frequency pattern electrical stimulation through closed eyelids with MacuMira^TM System I (MacuMira Medical Devices Inc.) connecting eyecup-formed electrodes to a headset.

All participants underwent 30-minute sessions with the transpalpebral microcurrent device or sham 4 times during the first 2 weeks, and 2 more sessions at weeks 14 and 26.

Data for the 43 patients (43 eyes) who underwent the transpalpebral microcurrent treatment shows a mean baseline NLR of 19.6 [SD, 8.9] increasing to 27.6 [9.1] after 4 weeks, sustained at 27.8 [8.4] after 30 weeks. Nineteen individuals (19 eyes) who received sham therapy presented initial NLR of 24.2 [7.1], similar at 4 weeks, 24.2 [7.2], and decreasing to 22.1 [7.4] by study’s end. Thus, groups differed at 4 weeks by 7.7 NLR (95% CI 5.7, 9.7, P <.001), with final difference of 10.4 letters (95% CI 7.8, 13.1, P <.001).

Repeated measures analysis of variance (RM-ANOVA) revealed change of contrast sensitivity was also better for transpalpebral microcurrent vs sham: a mean difference of 0.11 (95% CI 0.04, 0.17, P =.002) immediately before the second session, to 0.25 (95% CI 0.16, 0.34; P <.001) by 30 weeks.

“Mitochondrial senescence from mitochondrial DNA damage, reduced ATP production, and altered cellular autophagy provide other targets of therapy for the highly metabolic retinal pigment epithelia, all potentially impacted by microcurrent,” investigators explain. Previous research has also demonstrated more letters gained than with placebo. “This data provides cautious optimism that microcurrent can improve vision, at least over 30 weeks for dry AMD.”

Social distancing requirements during the COVID-19 pandemic may have increased possibility for bias, which could limit this study. However, a 3:1 ratio and the treated group’s steady trend toward better NLR compared with control individuals’ letter loss indicates less chance for regression to the mean.

Disclosure: One study author declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.