Efficacy and Safety of Oral Valproic Acid for Retinitis Pigmentosa

This study is designed as a single-site, interventional, prospective, non-randomized, controlled study of 200 participants. Patients that participate in the study will be assigned to either valproic acid group or control in a 3:1 ratio.

Inclusion criteria

• Diagnosis of retinitis pigmentosa (RP) established by night blindness, visual field constriction, marked reduction of electroretinogram, and the clinical signs of RP in fundus examination
• Best corrected visual acuity of 20/200 or more on a Snellen chart in at least one eye
• Intact visual field of 5 or more as measured by the kinetic perimetry
• Understand and sign the IRB-approved informed consent document for the study
• Body weight: male (40 kg to 100 kg), female (40 kg to 80 kg)
• Must be able to swallow tablets
• Female subjects of childbearing potential must commit to practice acceptable methods of contraception

Exclusion criteria

• Pregnant women
• Lactating mothers
• Medical problems that make consistent follow-up over the treatment period unlikely (e.g., stroke, myocardiac infarction, malignancy) or severe systemic disease
• Other ocular disease: retinal disease other than RP or cystoid macular edema, glaucoma, cataract worse than +2PSC or infectious corneal disease
• Coagulation disorder or bleeding-tendency
• Liver dysfunction
• Renal dysfunction
• History of pancreatitis
• History of neurological disorders including epilepsy, history of brain injury or any organic brain disorders
• History of mental disorders including schizophrenia, bipolar disorder, or suicidality
• Currently receiving valproic acid or other anti-convulsants
• Has taken one of the following drugs at least 4 weeks prior to enrollment as these drugs are specifically known to affect the progression of RP: vitamin A, lutein, omega-3 fatty acid, or any antioxidant which affect the blood flow of retina or retinal function.