Transpalpebral electrotherapy for dry age-related macular degeneration (AMD): An exploratory trial

Abstract

Purpose: To evaluate the effect of transpalpebral electrotherapy on patients with dry age-related macular degeneration (AMD). Methods: 22 patients were randomized in two groups to either receive therapy (n = 12) or placebo (n = 10). There was no statistically significant difference for age and initial visual acuity (VA) between the two groups (p = 0.6; ANOVA). Treatment was performed on 5 consecutive days. On each day two sessions were applied. Every session included 8 spots (40 sec/spot) around the eye globe. The current applied (changing frequency 5–80 Hz) varied individually between 150 and 220 μA. Patients were examined before treatment, at the end of the 5-day treatment period, after 4 weeks and at 6 months. Examinations included a standardized VA testing, using ETDRS letters, contrast sensitivity, macular sensitivity and fixation stability using microperimetry and measurements with SD-OCT. Results: At the end of week 1, mean VA improved markedly (p = 0.001; T test), with 7 out of 12 patients showing an improvement of more than 5 letters. After 4 weeks, there was an improvement of more than 10 letters in 3 patients (mean + 5.7 letters; p = 0.001; T test) whereas at 6 months a loss of 1.6 letters was observed. Only 4 (33%) of our patients did not show any improvement at all. Contrast sensitivity displayed a similar pattern. Within one week after treatment, there was a rapid improvement (+4.4 optotypes; p = 0.006; T test). After 6 months, contrast sensitivity declined again (+1.5 optotypes; p = 0.2; T test). Compared to the placebo group changes on VA failed statistical significance (p = 0.1 at 4 week; T test) whereas changes on contrast sensitivity were statistically significant (p = 0.01 at week 4; T test). No adverse events were seen or reported during the study period. Conclusions: To the best of our knowledge, this is the first report of a transpalpebral electrostimulation in patients with dry AMD that demonstrates a temporary increase in visual function in some of these patients; results that seem to justify further research on this potential treatment option for dry AMD.