Many retinitis pigmentosa (RP) patients seek alternative therapies because of the lack of currentmanagement options beyond nutritional supplements attempting to slow disease progression. The potential fora beneficial effect on visual function in RP following electroacupuncture and/or transcorneal electricalstimulation (TES) is suggested by research on physiological changes in the eye or brain in response to thesetherapies. In addition, both our group and others have documented that the majority of RP patients treated withTES, acupuncture or electroacupuncture had improvements in visual function. While these findings areintriguing, the potential mechanisms that may play a role have not been explored in RP. We are interested in studying some of the most promising alternative therapies to determine whetherthey have a physiologically plausible basis for improving vision in RP, which would provide a scientific rationalefor and guide the design of a future randomized controlled trial. A significant increase in blood flow velocity anddecreased vascular resistance was measured in the retrobulbar arteries during needling of vision-relatedacupoints, but not for non-vision-related acupoints, in normal subjects. Thus, ocular and retinal blood flow(ORBF) could serve as an indicator of physiological changes that occur in response to electroacupuncture.
We aim to characterize the temporal relationships between changes in ORBF velocity or oxygenationand either improvements or reductions in visual function in RP. We expect to find positive correlations betweenreductions in ORBF and vision measures within- and across subjects with varying stages of RP diseaseprogression. We hypothesize that subjects with significantly larger improvements in RBF and more recentvision loss will be more likely to develop improvements in visual function in corresponding retinal areas aftereither electroacupuncture and/or TES. Specifically, we propose to: 1) Examine longitudinal, repeated measures of ORBF in RP patients with recent decline in visualfunction. We will determine the variability and reproducibility of ORBF velocity, OBF resistance and RBFoxygenation measures over 3 months. 2) Test for possible improvements in ORBF and visual function measures in RP patients receivingelectroacupuncture and TES in a crossover trial. We will determine if the magnitude and duration of the ORBFchanges post-treatment are related to RP disease severity (retinal thickness and/or sensitivity) and/or visiontest changes. We will attempt to determine the temporality (i.e. lag or correspondence) between thesephysiological and psychophysical measures. The goal of this clinical research project is to determine if evidence exists to support the hypothesesthat reductions in ORBF are associated with visual function loss across RP patients, and that their ORBF canimprove after treatment with electroacupuncture and/or TES. The results of this work could provide a rationalefor the development of potential management options targeted at improving ORBF, and consequently visualfunction, in this disease.
Retinitis pigmentosa (RP) is a slowly progressive retinal degeneration for which there is no proven treatment. Patients are interested in trying alternative therapies to try to reduce their vision loss; but only limited research evidence exists to support their use and potential benefit. The goal of this research project is to gain a better understandin of possible changes in ocular and retinal blood flow and vision measures in RP patients receiving two promising therapies; electroacupuncture and transcorneal electrical stimulation.
