Retina Society 2026: Non-invasive electrical stimulation therapy for intermediate dry AMD: improved retinal health and visual acuity

Non-invasive electrical stimulation delivered through closed eyelids improved retinal structure and photoreceptor function and was linked to meaningful visual acuity gains in some patients, based on the results of a randomized, sham-controlled pilot study (i-SIGHT) (NCT05447650) of intermediate dry age-related macular degeneration (iAMD). This treatment may fill a gap, in that treatments are limited for that stage of the disease. Michael David Ober, MD, reported the findings at the Retina Society 2026 meeting in Los Angeles.

Study design

The trial tested the efficacy of transpalpebral microcurrent stimulation (MCS) delivered using the I-Lumen AMD device (i-Lumen Scientific, Inc.)

and compared the results to those with sham stimulation in patients who lost vision as the result of iAMD.

The randomized, sham-controlled, double-masked feasibility trial enrolled participants age 50 or older who had both lost vision as a result of iAMD and had distance best-corrected visual acuity (BCVA) between 0.3 and 1.0 on the logarithm of the minimum angle of resolution scale in the study eye. Active MCS was delivered at stimulation amplitudes 550 to 1,000 µA and compared with sham stimulation of 0 µA. Treatment consisted of monophasic and biphasic waveforms delivered through closed eyelids in sessions over five days, followed by single treatment days at months 1 and 2. A total of 30 participants were enrolled, 21 underwent active MCS treatment and nine received sham treatment.

The investigators collected optical coherence topography (OCT) imaging and measured the photoreceptor function based on central ring N-wave latency (crNWL) on multifocal electroretinography (mfERG) over 12 months of follow-up. The imaging and mfERG data were independently graded by the Voiant Reading Center.

The effects of MCS

Compared with sham stimulation, Ober reported, active MCS was associated with fewer defects in the retinal ellipsoid zone (EZ) on OCT images. Specifically, the EZ defects decreased more with active MCS than with sham at both early and later follow-up time points. At week 2, the EZ defects decreased by 1.3 mm² in active-treated eyes versus 0.82 mm² in sham-treatedeyes; at month 3, the gap widened, with active-treated eyes decreasing by 1.1 mm² compared with 0.13 mm² in sham-treated eyes.

The results also showed greater improvement in photoreceptor function. The crNWL improved more with active treatment than with sham treatment. At week 2, the crNWL improved by 1.2 msec in active-treatment eyes versus a 0.20 msec worsening in sham-treatment eyes. At month 6, active-treatment eyes improved by 1.7 msec versus 0.24 msec in sham-treatment eyes. At month 12, active-treatment eyes improved by 0.5 msec, while sham-treatment eyes worsened by 5.3 msec.

In the active-treatment eyes that gained eight or more letters of BCVA, the improvements in the crNWL were more pronounced than in the eyes that were non-responders. This was a relationship that was not observed in the sham group.

Specifically, the responders showed greater crNWL improvement than non-responders at the three time points: week 2 (-3.4 msec vs +1.7 msec; sham: none); month 6 (active responders: -2.5 msec; non-responders: -0.3 msec; sham: -0.4 msec), and month 12 (responders: -1.7 msec; non-responders: +1.4 msec; sham: -0.6 msec). This trend was not observed in sham-treatment eyes.

A look ahead

The authors concluded both that active transpalpebral MCS may improve photoreceptor crNWL and EZ integrity in patients with iAMD, and that these improvements in retinal function may be associated with meaningful gains in visual acuity. The study provides objective evidence that transpalpebral MCS may improve retinal function. While the findings require confirmation in further studies, the authors suggested this non-invasive approach may represent a new treatment option for patients with iAMD.

Ober reinterated, “The i-SIGHT trial yielded very exciting proof of concept findings for transpalpebral microcurrent stimulation in patients with intermediate dry AMD. It is most promising that visual acuity improvements were echoed by anatomic and functional results without significant side effects.”

Ober was joined in this study by co-authors Veeral Sheth, MD, MBA, Timothy L. Jackson, PhD, FRCOphth, and Sophie J Bakri, MD.