Article
Transcorneal electrical stimulation for patients with retinitis pigmentosa – a randomized, partially-blinded, Sham-controlled pilot study
Search Medline for
Authors
Published: | June 15, 2011 |
---|
Outline
Text
Background: Electrical stimulation using low currents was shown to be beneficial for various retinal degenerations in animal models and humans. Aim of this study was the assessment of efficacy of transcorneal electrical stimulation (TES) in patients suffering from retinitis pigmentosa (RP).
Methods: Twenty-four RP-patients in this prospective, randomized, partially blinded, good-clinical-practice conform study received TES (5+5 ms biphasic pulses; 20Hz; DTL electrodes) 30 minutes per week for 6 consecutive weeks. Patients were randomly assigned to one of three groups: sham, 66%, or 150% of individual electrical phosphene threshold (EPT). All 9 visits within 17 weeks included full ophthalmological examination (visual acuity, slit-lamp, funduscopy, intraocular pressure) and assessment of the individual EPT at 3Hz, 6Hz, 9Hz, 20Hz, 40Hz, 60Hz and 80Hz. During 4 visits (1st, 5th , 9th and 17th week) visual field (VF; kinetic, static) and electroretinography (Ganzfeld, multifocal) measurements were completed additionally.
Results: TES was well tolerated. Two patients reported foreign body sensation, no other side effects were observed. Statistically significant improvements of kinetic VF area (P<0.001) and of the scotopic b-wave amplitude (P<0.027) was shown in the 150%-group. Other parameters in the 150%-group exhibited a positive tendency, however not reaching significant values. No changes were observed in the 66%-group.
Conclusions: We found TES in RP patients to be safe. After 6 sessions TES at 150% EPT significant improvements of kinetic VF area and scotopic b-wave amplitude were found. Future studies including larger sample sizes and longer duration are needed to confirm findings and to define optimal stimulation parameters.