Randomized controlled trial of electro‐stimulation therapies to modulate retinal blood flow and visual function in retinitis pigmentosa

• Published in: Acta ophthalmologica (Oxford, England) Vol. 96; no. 3; pp. e366 - e376
• Main Authors: Bittner, Ava K., Seger, Kenneth, Salveson, Rachel, Kayser, Samantha, Morrison, Natalia, Vargas, Patricia, Mendelsohn, Deborah, Han, Jorge, Bi, Hua, Dagnelie, Gislin, Benavente, Alexandra, Ramella‐Roman, Jessica
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.05.2018
• Subjects: Acuity; Acupuncture; Adult; Aged; Blood flow; Capillaries; Clinical trials; Contrast Sensitivity; Cornea; Diabetes mellitus; Diabetic retinopathy; Doppler effect; Electric Stimulation Therapy - methods; Electrical stimuli; Electroretinography; Female; Humans; Male; Middle Aged; Photopigments; Regional Blood Flow - physiology; Retina; Retinal Artery - diagnostic imaging; Retinal Artery - physiopathology; retinal blood flow; Retinitis; Retinitis pigmentosa; Retinitis Pigmentosa - physiopathology; Retinitis Pigmentosa - therapy; Retinopathy; transcorneal electrical stimulation; Treatment Outcome; Ultrasonography, Doppler, Color; Visual Acuity; Visual Fields; Visual perception; retinitis pigmentosa; acupuncture; transcorneal electrical stimulation; retinal blood flow
• ISSN: 1755-375X; 1755-3768; 1755-3768
• DOI: 10.1111/aos.13581

Purpose We examined changes in visual function and ocular and retinal blood flow (RBF) among retinitis pigmentosa (RP) participants in a randomized controlled trial of electro‐stimulation therapies. Methods Twenty‐one RP participants were randomized (1:1:1) to transcorneal electrical stimulation (TES) at 6 weekly half‐hour sessions, electro‐acupuncture or inactive laser acupuncture (sham control) at 10 half‐hour sessions over 2 weeks. Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity (VA), quick contrast sensitivity function, Goldmann visual fields, AdaptDx scotopic sensitivity, spectral flow and colour Doppler imaging of the central retinal artery (CRA), and RBF in macular capillaries were measured twice pre‐treatment, after 2 TES sessions, within a week and a month after intervention completion. Results We measured a significant improvement in retrobulbar CRA mean flow velocity for both the TES (p = 0.038) and electro‐acupuncture groups (p = 0.001) on average after 2 weeks of treatment when compared to sham controls. Transcorneal electrical simulation (TES) and electro‐acupuncture subjects had significant 55% and 34% greater increases, respectively, in RBF in the macular vessels when compared to sham controls (p < 0.001; p = 0.008) within a week of completing six TES sessions or a month after electro‐acupuncture. There was a significant difference in the proportion of eyes that had improved visual function when comparing the three intervention groups (p = 0.038): four of seven TES subjects (57%), two of seven electro‐acupuncture subjects (29%) and none of the seven control subjects (0%) had a significant visual improvement outside of typical test–retest variability at two consecutive post‐treatment visits. Conclusion Increased blood flow following electro‐stimulation therapies is an objective, physiological change that occurred in addition to visual function improvements in some RP patients.