title: Transcorneal Electrical Stimulation for Patients With Retinitis Pigmentosa: A Prospective, Randomized, Sham-Controlled Follow-up Study Over 1 Year.
abstract: After promising results of an exploratory study, this study was designed to assess the safety and efficacy of transcorneal electrical stimulation (TES) over 1 year in patients with retinitis pigmentosa (RP).
  
  
  
  We included 52 RP patients in this prospective, randomized, partially-masked study which was done in accordance with rules of good clinical practice. Transcorneal electrical stimulation by Okustim was applied monocularly for 30 minutes per week for 52 consecutive weeks. Patients were assigned randomly to the groups: sham, 150%, or 200% of individual electrical phosphene threshold (EPT). Visual acuity (retroilluminated Snellen charts), visual field (VF; Octopus 900), electroretinography (ERG), rod and cone full-field stimulus threshold, EPTs and IOP were assessed. Primary outcome measures were VF area; secondary outcome measures were development of ERG parameters.
  
  
  
  The application of TES was tolerated well. Dry eye symptoms (31 of 52 patients) were registered as the main adverse event. Throughout the study period, the VF area showed only a trend for prevention of VF loss in the 200% group (P = 0.24). A significant improvement of light-adapted single flash b-wave was noted for the 200% (P < 0.0001) and 150% (P = 0.006) groups compared to the sham group. Tendencies of improved function were observed for scotopic b-wave amplitude for the 200% group (P = 0.097). Other examination methods did not reach statistical significance.
  
  
  
  The safety and acceptable tolerability of weekly TES self-administered by patients at home was confirmed over the course of 1 year. Objectively measured improvements in retinal function with ERG provide support for the potential benefits of TES for RP patients.
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany 2Department of Ophthalmology, Klinikum Stuttgart, Stuttgart, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schatz
authors.affiliation: Department of Ophthalmology, Klinikum Stuttgart, Stuttgart, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Pach
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Mariya
authors.initials: M
authors.lastname: Gosheva
authors.affiliation: Department of Ophthalmology, Goethe University Frankfurt am Main, Frankfurt am Main, Germany.
authors.forename: Lubka
authors.initials: L
authors.lastname: Naycheva
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany 2Department of Ophthalmology, Klinikum Stuttgart, Stuttgart, Germany.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Willmann
authors.affiliation: STZ eyetrial at the Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wilhelm
authors.affiliation: STZ eyetrial at the Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Peters
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Karl Ulrich
authors.initials: KU
authors.lastname: Bartz-Schmidt
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Eberhart
authors.initials: E
authors.lastname: Zrenner
authors.affiliation: Department of Ophthalmology, Otorhinolaryngology and Head & Neck Surgery, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Messias
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany 2Department of Ophthalmology, Klinikum Stuttgart, Stuttgart, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Gekeler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea; D004558:Electric Stimulation / Q000379:methods*; D004596:Electroretinography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012160:Retina / Q000503:physiopathology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012174:Retinitis Pigmentosa / Q000503:physiopathology / Q000628:therapy*; D016037:Single-Blind Method; D016896:Treatment Outcome; D014792:Visual Acuity; D014794:Visual Fields; D055815:Young Adult