Valproic Acid Shown To Halt Vision Loss In Patients With Retinitis Pigmentosa
Posted Jul 22 2010 6:07pm
Researchers at the University of Massachusetts Medical School (UMMS) believe they may have found a new treatment for retinitis pigmentosa (RP), a severe neurodegenerative disease of the retina that ultimately results in blindness. One of the more common retinal degenerative diseases, RP is caused by the death of photoreceptor cells and affects 1 in 4,000 people in the United States. RP typically manifests in young adulthood as night blindness or a loss of peripheral vision and in many cases progresses to legal blindness by age 40.
In the July 20 online edition of the British Journal of Ophthalmology, Shalesh Kaushal, MD, PhD, chair of ophthalmology and associate professor of ophthalmology and cell biology at UMMS, and his team, describe a potential new therapeutic link between valproic acid and RP, which could have tremendous benefits for patients suffering from the disease. In a retrospective study, valproic acid—approved by the FDA to reduce seizures, treat migraines and manage bipolar disorder—appeared to have an effect in halting vision loss in patients with RP and in many cases resulted in an improved field of vision. Results from this study, in conjunction with prior in vitro data, suggest valproic acid may be an effective treatment for photoreceptor loss associated with RP.
UMass Medical School will be the coordinating site for a $2.1 million, three-year clinical trial funded by the Foundation Fighting Blindness/National Neurovision Research Institute quantifying the potential of valproic acid as a treatment for RP. The clinical trials will build upon Kaushal’s work in the retrospective study in which patients were treated off-label with doses of valproic acid ranging from 500mg to 750mg per day over the course of two to six months. Treated at a time when patients normally experience rapid vision loss as a result of RP, five of the seven patients in the study experienced improvement in their field of vision.