The effect of transcorneal electrical stimulation in visual acuity: Retinitis pigmentosa

Abstract

Transcorneal Electrical Stimulation (TES) was applied to a group of volunteer patients suffering from Retinitis Pigmentosa (RP), in order to investigate the effect of TES in Visual Acuity (VA). 28 partial blind patients with diagnosis of classic RP, Usher syndrome I and/or II were stimulated transcornealy, during a period of 52 weeks using a non conventional waveform, only in the lowest visually capable eye. The proposed waveform has been modeled from the natural response of human retina and delivered by means of an adaptive generator designed and built for tissue stimulation. Statistical results show the improvement of average VA or at least the contention of the disease natural progress. Categorized analysis of results indicates the same effect that if the age of patients, time since diagnosis and genetic disorder variation (classic RP, Usher syndrome I and/or II) are considered, in this case clinical and electrophysiological follow-up parameters were statistically analyzed in order to know the effect of TES. General results yield an improvement of 48.15% in the average of VA for stimulated eyes against an average degreasing of －8.06% in the same scale, with respect to their basal condition before the start of the experiment.