Electrical Stimulation as a Means for Improving Vision

Abstract

Evolving research has provided evidence that noninvasive electrical stimulation (ES) of the eye may be a promising therapy for either preserving or restoring vision in several retinal and optic nerve diseases. In this review, we focus on minimally invasive strategies for the delivery of ES and accordingly summarize the current literature on transcorneal, transorbital, and transpalpebral ES in both animal experiments and clinical studies. Various mechanisms are believed to underlie the effects of ES, including increased production of neurotrophic agents, improved chorioretinal blood circulation, and inhibition of proinflammatory cytokines. Different animal models have demonstrated favorable effects of ES on both the retina and the optic nerve. Promising effects of ES have also been demonstrated in clinical studies; however, all current studies have a lack of randomization and/or a control group (sham). There is thus a pressing need for a deeper understanding of the underlying mechanisms that govern clinical success and optimization of stimulation parameters in animal studies. In addition, such research should be followed by large, prospective, clinical studies to explore the full potential of ES. Through this review, we aim to provide insight to guide future research on ES as a potential therapy for improving vision. (Am J Pathol 2016 http://dx

Electrical Stimulation Induces Retinal Müller Cell Proliferation and Their Progenitor Cell Potential

“…That study provided evidence that low electrical current could have positive therapeutic effects on degenerative retinal diseases, and since then, animal and human studies have reported promising results. The use of electricity in medicine is not unperceivable [6], as it is widely used in cardiology, neurology, and psychiatry, gradually emerging in orthopedics and regenerative medicine as better and faster healing of wounds and bones [7][8][9][10][11][12]. Bioelectrical signaling has been studied closely and influences the epigenetics and transcriptional cascades that control cellular migration, proliferation, differentiation, and cell death [13].…”

“…Clinical studies have shown that low current electrical stimulation improves vision and retinal function in several eye diseases [6], such as traumatic optic neuropathy (TON) [15], central or branch retinal arterial occlusion (CRAO or BRAO) [16], dry age-related macular degeneration (AMD) [12], and retinitis pigmentosa [17][18][19]. Emerging evidence suggests that low-current electricity increases the MC's release of neurotropic factors, e.g., brain-derived neurotropic factor (BDNF) [20], ciliary neurotropic factor (Cntf) [21], fibroblast growth factor 2 (FGF-2) [22], and insulin-like growth factor-1 (IGF-1) [23].…”

Transcorneal Electrical Stimulation for the Treatment of Retinitis Pigmentosa: A Multicenter Safety Study of the OkuStim® System (TESOLA-Study)

“…Week factors [14,15]. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that is thought to have a critical neuroprotective role in retinal disease as well as other central nervous system conditions such as Parkinson's disease [16] and deserves further attention.…”

Physikalische Therapie der nicht exsudativen altersabhängigen Makuladegeneration

“…Dies gab den Impuls für weitere Studien im Bereich der Elektrostimulation auch für andere retinale Erkrankungen wie der AMD. Verschiedene Applikationswege der Elektrostimulation sind in der Literatur grundsätzlich beschrieben worden wie transpalpebrale, transorbitale, transkorneale, subretinale, epiretinale, transchoroidale und die direkte Stimulation von Sehnerv oder Sehrinde [29]. Gegenwärtig ist der transpalpebrale Ansatz der am meisten verfolgte bei den laufenden und zuletzt durchgeführten AMD-Studien [30 -32].…”

“…Verschiedene Erklärungsansätze sind formuliert worden wie bspw. eine verbesserte Zellpermeabilität, eine Verbesserung der Nervenleitgeschwindigkeit, eine Erhöhung der Perfusion oder eine Reduktion von Entzündung [29].…”