title: Efficacy of valproic acid for retinitis pigmentosa patients: a pilot study.
abstract: OBJECTIVE
  The purpose of this study was to examine the efficacy and safety of valproic acid (VPA) use in patients with retinitis pigmentosa (RP).
  
  
  METHODS
  This was a prospective, interventional, noncomparative case study. In total, 29 eyes from 29 patients with RP whose best-corrected visual acuities (BCVAs) in logarithm of the minimum angle of resolution (logMAR) ranged from 1.0 to 0.16 with visual fields (VFs) of ≤10° (measured using Goldmann perimeter with I4) were recruited. The patients received oral supplementation with 400 mg of VPA daily for 6 months and were followed for an additional 6 months. BCVAs, VFs (measured with the Humphrey field analyzer central 10-2 program), and subjective questionnaires were examined before, during, and after the cessation of VPA supplementation.
  
  
  RESULTS
  The changes in BCVA and VF showed statistically significant differences during the internal use of VPA, compared with after cessation (P=0.001). With VPA intake, BCVA in logMAR significantly improved from baseline to 6 months (P=0.006). The mean deviation value of the VF significantly improved from baseline to 1 month (P=0.001), 3 months (P=0.004), and 6 months (P=0.004). These efficacies, however, were reversed to the baseline levels after the cessation of VPA intake. There were no significant relations between the mean blood VPA concentrations of each patient and the changes in BCVA and VF. During the internal use of VPA, 15 of 29 patients answered "easier to see", whereas blurred vision was registered in 21 of 29 patients on cessation. No systemic drug-related adverse events were observed.
  
  
  CONCLUSIONS
  While in use, oral intake of VPA indicated a short-term benefit to patients with RP. It is necessary to examine the effect of a longer VPA supplementation in a controlled study design.
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto; Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iraha
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Hirami
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Ota
authors.affiliation: Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe.
authors.forename: Genshiro A
authors.initials: GA
authors.lastname: Sunagawa
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe.
authors.forename: Michiko
authors.initials: M
authors.lastname: Mandai
authors.affiliation: Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Tanihara
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital; Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto.
authors.forename: Masayo
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Ophthalmology, Institute of Biomedical Research and Innovation Hospital; Department of Ophthalmology, Kobe City Medical Center General Hospital.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kurimoto
keywords: clinical trial; retina; retinitis pigmentosa; valproic acid