Abstract
Purpose :
A previous small scale randomized controlled trial conducted by our group found that 57% of retinitis pigmentosa (RP) subjects who received 6 weekly sessions of Transcorneal Electrical Stimulation (TES) developed significant improvements in visual acuity (VA) and/or quick contrast sensitivity function (qCSF) within a month of completing this short course of therapy. Our next goals were to longitudinally monitor these participants for declining visual function due to natural RP progression without TES to determine the duration of these responses and administer retreatments.
Methods :
Following significantly improved VA and/or qCSF after an initial course of 6 weekly 30-minute TES sessions using DTL electrodes and the microcurrent setting on a Trio Stim unit (Mettler Electronics Corp), 3 RP subjects completed follow-up ETDRS VA and qCSF tests over 18-22 months and received a retreatment course of 6 weekly TES sessions when measurable decreases in VA and/or CS occurred.
Results :
A 44 y/o female had 1.52 logMAR VA in the worse eye at baseline, which improved to 0.52 logMAR following the initial course of TES, but 10 months later her VA had diminished to 1.22 logMAR, at which time she was retreated and regained VA of 0.62 logMAR at 2 months post-retreatment. Follow-up visits at 6 and 9 months post-retreatment revealed a slight decline to 0.78-0.80 logMAR, then VA improved again to 0.50 logMAR a month after receiving a 2nd course of retreatment. A 47 y/o male had baseline 1.62 logMAR VA and 0.20 logCS at 1.5 cpd in the worse eye, which improved to 1.20 logMAR and 0.46 logCS a month after the initial course of TES; then 11 months later his VA was relatively stable at 1.24 logMAR, but qCSF declined back to baseline (0.22 logCS). Then 14 months after initial TES, VA declined to 1.40 logMAR, at which time he was retreated and improved to 1.32 logMAR and 0.66 logCS at one-month post-retreatment. A 34 y/o female improved binocularly from 1.12 to 1.00 logMAR VA and 0.33 to 0.65 logCS at 1.5 cpd after initial TES, then after slight declines every 3-4 months, she received 3 retreatment courses, which maintained her VA and CS improvements over 18 months.
Conclusions :
Following encouraging improvements in VA and qCSF after 6 weekly TES sessions that lasted for several months, it appears possible to restore slowly diminishing vision over time by retreating with TES.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.