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Sadrzadeh-Afsharazar F, Douplik A. A Phosphenotron Device for Sensoric Spatial Resolution of Phosphenes within the Visual Field Using Non-Invasive Transcranial Alternating Current Stimulation. SENSORS (BASEL, SWITZERLAND) 2024; 24:2512. [PMID: 38676129 PMCID: PMC11053939 DOI: 10.3390/s24082512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024]
Abstract
This study presents phosphenotron, a device for enhancing the sensory spatial resolution of phosphenes in the visual field (VF). The phosphenotron employs a non-invasive transcranial alternating current stimulation (NITACS) to modulate brain activity by applying weak electrical currents to the scalp or face. NITACS's unique application induces phosphenes, a phenomenon where light is perceived without external stimuli. Unlike previous invasive methods, NITACS offers a non-invasive approach to create these effects. The study focused on assessing the spatial resolution of NITACS-induced phosphenes, crucial for advancements in visual aid technology and neuroscience. Eight participants were subjected to NITACS using a novel electrode arrangement around the eye orbits. Results showed that NITACS could generate spatially defined phosphene patterns in the VF, varying among individuals but consistently appearing within their VF and remaining stable through multiple stimulations. The study established optimal parameters for vibrant phosphene induction without discomfort and identified electrode positions that altered phosphene locations within different VF regions. Receiver Operating characteristics analysis indicated a specificity of 70.7%, sensitivity of 73.9%, and a control trial accuracy of 98.4%. These findings suggest that NITACS is a promising, reliable method for non-invasive visual perception modulation through phosphene generation.
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Affiliation(s)
- Faraz Sadrzadeh-Afsharazar
- Photonics Group, Department of Physics, Faculty of Science, Toronto Metropolitan University (Formerly Ryerson University), Toronto, ON M5B 2K3, Canada;
| | - Alexandre Douplik
- Photonics Group, Department of Physics, Faculty of Science, Toronto Metropolitan University (Formerly Ryerson University), Toronto, ON M5B 2K3, Canada;
- Institute for Biomedical Engineering, Science and Technology (iBEST), Keenan Research Centre of the Li Ka Shing (LKS) Knowledge Institute, St. Michael Hospital, Toronto, ON M5B 1T8, Canada
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Zhou W, Huang Z, Xu K, Li Y, Li X, Li J, Jin Y, Snellingen T, Liang L. Transpalpebral electrical stimulation for the treatment of retinitis pigmentosa: study protocol for a series of N-of-1 single-blind, randomized controlled trial. Trials 2024; 25:89. [PMID: 38279157 PMCID: PMC10821291 DOI: 10.1186/s13063-024-07933-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/16/2024] [Indexed: 01/28/2024] Open
Abstract
BACKGROUND Retinitis pigmentosa (RP) is an inherited disease characterized by a progressive loss of rod photoreceptors of the eye, leading to irreversible blindness. To date, to our knowledge, no clinical prospective studies have been undertaken that could document the effect of interventions that could reverse or reduce the progression of this disease. The application of microcurrent stimulation (ES) of the eye in the treatment of chronic eye diseases such as glaucoma and age-related macular degeneration has been used over several decades and has been reported to have beneficial effects to reduce the progression of these blinding diseases and has been supported by animal studies and smaller clinical studies, but to date, no large randomized clinical trials on the use of microcurrent therapy have been published. More recent clinical reports have also shown beneficial effects of ES on slowing the progression of RP but also lacks data from robust prospective clinical outcome studies. To our knowledge, this is the first prospective randomized study to evaluate the safety and clinical effectiveness of transpalpebral electrical stimulation (TpES) on the progression of RP. METHODS Randomized prospective study using N-of-1 trial 3 single-blind, crossover comparisons. The intervention period of each comparison is divided into treatment period and control period which are randomized arranged. Twelve participants will be strictly recruited in N-of-1 trial by the researcher in accordance with the inclusion and exclusion criteria. The main outcome of interest examined after each cycle of the 8-week intervention period is the assessment of the visual field (VF). Other variables of interest are best corrected visual acuity (BCVA), retinal function using electroretinogram (ERG), and visual function using NEI VFQ-25 questionnaire. Objective assessments of retinal changes will be undertaken using optical coherence tomography (OCT) and fundus autofluorescence (FAF). DISCUSSION The trial will evaluate the efficacy and safety of microcurrent stimulation on RP and provide high-quality evidence for clinical application through N-of-1 trial. TRIAL REGISTRATION Chinese Clinical Trial Registry; ChiCTR2300067357; https://www.chictr.org.cn/showproj.html?proj=174635 . Registered on 5 January 2023.
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Affiliation(s)
- Wei Zhou
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ziyang Huang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Kai Xu
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yamin Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaoyu Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jiaxian Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yu Jin
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Torkel Snellingen
- Beijing Research Institute of Vision Science & Sekwa Eye Hospital, Beijing, China
| | - Lina Liang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
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Navarro PA, Contreras-Lopez WO, Tello A, Cardenas PL, Vargas MD, Martinez LC, Yepes-Nuñez JJ. Effectiveness and Safety of Non-Invasive Neuromodulation for Vision Restoration: A Systematic Review and Meta-Analysis. Neuroophthalmology 2023; 48:93-110. [PMID: 38487361 PMCID: PMC10936670 DOI: 10.1080/01658107.2023.2279092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/23/2023] [Indexed: 03/17/2024] Open
Abstract
We carried out a systematic review and meta-analysis to determine the effectiveness and safety of non-invasive electrical stimulation (NES) for vision restoration. We systematically searched for randomised controlled trials (RCTs) comparing NES with sham stimulation, for vision restoration between 2000 and 2022 in CENTRAL, MEDLINE, EMBASE, and LILACS. The main outcomes were as follows: visual acuity (VA); detection accuracy; foveal threshold; mean sensitivity as the parameter for the visual field; reading performance; contrast sensitivity (CS); electroencephalogram; quality of life (QoL), and safety. Two reviewers independently selected studies, extracted data, and evaluated the risk of bias using the Cochrane risk of bias 2.0 tool. The certainty in the evidence was determined using the GRADE framework. Protocol registration: CRD42022329342. Thirteen RCTs involving 441 patients with vision impairment indicate that NES may improve VA in the immediate post-intervention period (mean difference [MD] = -0.02 logMAR, 95% confidence intervals [CI] -0.08 to 0.04; low certainty), and probably increases QoL and detection accuracy (MD = 0.08, 95% CI -0.25 to 0.42 and standardised MD [SMD] = 0.09, 95% CI -0.58 to 0.77, respectively; both moderate certainty). NES likely results in little or no difference in mean sensitivity (SMD = -0.03, 95% CI -0.53 to 0.48). Compared with sham stimulation, NES increases the risk of minor adverse effects (risk ratio = 1.24, 95% CI 0.99 to 1.54; moderate certainty). The effect of NES on CS, reading performance, and electroencephalogram was uncertain. Our study suggests that although NES may slightly improve VA, detection accuracy, and QoL, the clinical relevance of these findings remains uncertain. Future research should focus on improving the available evidence's precision and consistency.
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Affiliation(s)
| | - William Omar Contreras-Lopez
- Departament of Neuromodulation, NEMOD Research Group, Bucaramanga, Colombia
- Department of Neurosurgery, Fundación Oftalmológica de Santander FOSCAL, Floridablanca, Colombia
- School of Medicine, Department of Ophthalmology, Universidad Autonoma de Bucaramanga (UNAB), Bucaramanga, Colombia
| | - Alejandro Tello
- School of Medicine, Department of Ophthalmology, Universidad Autonoma de Bucaramanga (UNAB), Bucaramanga, Colombia
- Department of Neuro-Ophthalmology, Centro Oftalmológico Virgilio Galvis, Floridablanca, Colombia
- Department of Ophthalmology, Fundación Oftalmológica de Santander FOSCAL, Floridablanca, Colombia
- School of Medicine, Department of Ophthalmology, Universidad Industrial de Santander (UIS), Bucaramanga, Colombia
| | - Pedro Luis Cardenas
- School of Medicine, Department of Ophthalmology, Universidad Autonoma de Bucaramanga (UNAB), Bucaramanga, Colombia
- Department of Neuro-Ophthalmology, Centro Oftalmológico Virgilio Galvis, Floridablanca, Colombia
- Department of Ophthalmology, Fundación Oftalmológica de Santander FOSCAL, Floridablanca, Colombia
- School of Medicine, Department of Ophthalmology, Universidad Industrial de Santander (UIS), Bucaramanga, Colombia
| | | | - Luz Catherine Martinez
- School of Medicine, Department of Ophthalmology, Universidad Autonoma de Bucaramanga (UNAB), Bucaramanga, Colombia
- Department of Ophthalmology, Fundación Oftalmológica de Santander FOSCAL, Floridablanca, Colombia
| | - Juan José Yepes-Nuñez
- School of Medicine, Universidad de los Andes, Bogotá DC, Colombia
- Department of Epidemiology, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá DC, Colombia
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Miura G, Fujiwara T, Ozawa Y, Shiko Y, Kawasaki Y, Nizawa T, Tatsumi T, Kurimoto T, Mori S, Nakamura M, Hanaoka H, Baba T, Yamamoto S. Efficacy and safety of transdermal electrical stimulation in patients with nonarteritic anterior ischemic optic neuropathy. Bioelectron Med 2023; 9:22. [PMID: 37876021 PMCID: PMC10598888 DOI: 10.1186/s42234-023-00125-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/12/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND No effective treatment for NAION with strong evidence has been established till date. The aim of this investigator-led, prospective, non-randomized, open-label, uncontrolled multi-center exploratory clinical trial is to evaluate the efficacy and safety of transdermal electrical stimulation (TdES) using skin electrodes in patients with NAION. METHODS Five patients with monocular NAION underwent TdES (10-ms biphasic pulses, 1.0 mA, 20 Hz, 30 min) of the affected eye six times at 2-week intervals. The primary endpoint was the logarithm of the mini-mum angle of resolution (logMAR) visual acuity at 12 weeks compared with 0 weeks. The secondary endpoints were changes in the best-corrected logMAR visual acuity, Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, and mean deviation (MD) of the Humphrey field analyzer (HFA) 10-2 and HFA Esterman test scores. Additionally, the safety of TdES was evaluated. RESULTS LogMAR visual acuity improved by ≥ 0.1 in two eyes, and ETDRS visual acu-ity improved by ≥ 5 characters in one eye. The mean change in logMAR visual acuity from week 0 showed an increasing trend. The mean MD of HFA 10-2 showed no obvious change, while HFA Esterman score improved in four eyes. All patients completed the study according to the protocol, and no treatment-related adverse events were observed. CONCLUSIONS TdES treatment may have improved visual acuity and visual field in some patients. Further sham-controlled study in larger cohort is needed on its effectiveness. TRIAL REGISTRATION UMIN, UMIN000036220. Registered 15 March, 2019, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000041261 .
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Affiliation(s)
- Gen Miura
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-Ku, Chiba, 260-8670, Japan.
| | - Tadami Fujiwara
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yoshihito Ozawa
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yuki Shiko
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yohei Kawasaki
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Tomohiro Nizawa
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-Ku, Chiba, 260-8670, Japan
| | - Tomoaki Tatsumi
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-Ku, Chiba, 260-8670, Japan
| | - Takuji Kurimoto
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Sotaro Mori
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Makoto Nakamura
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Hideki Hanaoka
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Takayuki Baba
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-Ku, Chiba, 260-8670, Japan
| | - Shuichi Yamamoto
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-Ku, Chiba, 260-8670, Japan
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Sharif NA. Electrical, Electromagnetic, Ultrasound Wave Therapies, and Electronic Implants for Neuronal Rejuvenation, Neuroprotection, Axonal Regeneration, and IOP Reduction. J Ocul Pharmacol Ther 2023; 39:477-498. [PMID: 36126293 DOI: 10.1089/jop.2022.0046] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The peripheral nervous system (PNS) of mammals and nervous systems of lower organisms possess significant regenerative potential. In contrast, although neural plasticity can provide some compensation, the central nervous system (CNS) neurons and nerves of adult mammals generally fail to regenerate after an injury or damage. However, use of diverse electrical, electromagnetic and sonographic energy waves are illuminating novel ways to stimulate neuronal differentiation, proliferation, neurite growth, and axonal elongation/regeneration leading to various levels of functional recovery in animals and humans afflicted with disorders of the CNS, PNS, retina, and optic nerve. Tools such as acupuncture, electroacupuncture, electroshock therapy, electrical stimulation, transcranial magnetic stimulation, red light therapy, and low-intensity pulsed ultrasound therapy are demonstrating efficacy in treating many different maladies. These include wound healing, partial recovery from motor dysfunctions, recovery from ischemic/reperfusion insults and CNS and ocular remyelination, retinal ganglion cell (RGC) rejuvenation, and RGC axonal regeneration. Neural rejuvenation and axonal growth/regeneration processes involve activation or intensifying of the intrinsic bioelectric waves (action potentials) that exist in every neuronal circuit of the body. In addition, reparative factors released at the nerve terminals and via neuronal dendrites (transmitter substances), extracellular vesicles containing microRNAs and neurotrophins, and intercellular communication occurring via nanotubes aid in reestablishing lost or damaged connections between the traumatized tissues and the PNS and CNS. Many other beneficial effects of the aforementioned treatment paradigms are mediated via gene expression alterations such as downregulation of inflammatory and death-signal genes and upregulation of neuroprotective and cytoprotective genes. These varied techniques and technologies will be described and discussed covering cell-based and animal model-based studies. Data from clinical applications and linkage to human ocular diseases will also be discussed where relevant translational research has been reported.
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Affiliation(s)
- Najam A Sharif
- Global Alliances and External Research, Ophthalmology Innovation Center, Santen Inc., Emeryville, California, USA
- Singapore Eye Research Institute (SERI), Singapore
- SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-National University of Singapore Medical School, Singapore
- Department of Surgery and Cancer, Imperial College of Science and Technology, London, United Kingdom
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, Texas, USA
- Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA
- Department of Pharmacy Sciences, Creighton University, Omaha, Nebraska, USA
- Insitute of Ophthalmology, University College London (UCL), London, United Kingdom
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Ashok A, Tai WL, Lennikov A, Chang K, Chen J, Li B, Cho KS, Utheim TP, Chen DF. Electrical stimulation alters DNA methylation and promotes neurite outgrowth. J Cell Biochem 2023; 124:1530-1545. [PMID: 37642194 DOI: 10.1002/jcb.30462] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023]
Abstract
Electrical stimulation (ES) influences neural regeneration and functionality. We here investigate whether ES regulates DNA demethylation, a critical epigenetic event known to influence nerve regeneration. Retinal ganglion cells (RGCs) have long served as a standard model for central nervous system neurons, whose growth and disease development are reportedly affected by DNA methylation. The current study focuses on the ability of ES to rescue RGCs and preserve vision by modulating DNA demethylation. To evaluate DNA demethylation pattern during development, RGCs from mice at different stages of development, were analyzed using qPCR for ten-eleven translocation (TETs) and immunostained for 5 hydroxymethylcytosine (5hmc) and 5 methylcytosine (5mc). To understand the effect of ES on neurite outgrowth and DNA demethylation, cells were subjected to ES at 75 µAmp biphasic ramp for 20 min and cultured for 5 days. ES increased TETs mediated neurite outgrowth, DNA demethylation, TET1 and growth associated protein 43 levels significantly. Immunostaining of PC12 cells following ES for histone 3 lysine 9 trimethylation showed cells attained an antiheterochromatin configuration. Cultured mouse and human retinal explants stained with β-III tubulin exhibited increased neurite growth following ES. Finally, mice subjected to optic nerve crush injury followed by ES exhibited improved RGCs function and phenotype as validated using electroretinogram and immunohistochemistry. Our results point to a possible therapeutic regulation of DNA demethylation by ES in neurons.
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Affiliation(s)
- Ajay Ashok
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Wai Lydia Tai
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Anton Lennikov
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Karen Chang
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Julie Chen
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Boyuan Li
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Kin-Sang Cho
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Tor Paaske Utheim
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Dong Feng Chen
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
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Miura G, Fujiwara T, Iwase T, Ozawa Y, Shiko Y, Kawasaki Y, Nizawa T, Tatsumi T, Baba T, Kurimoto T, Mori S, Nakamura M, Hanaoka H, Yamamoto S. Exploratory clinical trial to evaluate the efficacy and safety of transdermal electrical stimulation in patients with central retinal artery occlusion. PLoS One 2023; 18:e0282003. [PMID: 36827287 PMCID: PMC9955643 DOI: 10.1371/journal.pone.0282003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 01/30/2023] [Indexed: 02/25/2023] Open
Abstract
PURPOSE To evaluate the efficacy and safety of transdermal electrical stimulation (TdES) using skin electrodes in patients with central retinal artery occlusion (CRAO). METHODS Five eyes of five patients with CRAO underwent TdES (10-ms biphasic pulses, 20 Hz, 30 min) six times at 2-week intervals. Only the affected eye was stimulated with 1.0-mA pulses in all patients. The primary endpoint was the best-corrected logMAR visual acuity. The secondary endpoints were changes in the best-corrected logMAR visual acuity, Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, mean deviation of the Humphrey field analyzer (HFA) 10-2, and HFA Esterman test score. We also evaluated its safety. RESULTS The logMAR visual acuity at 12 weeks was improved by 0.1 or more in two patients and was maintained in two patients compared to the baseline. No obvious changes in the mean logMAR visual acuity, ETDRS visual acuity, mean deviation, and HFA Esterman score were observed at 12 weeks compared to the baseline. All five enrolled patients completed the study according to the protocol. No treatment-related adverse events were observed during this study. CONCLUSION In this study, logMAR visual acuity was slightly improved in two patients, confirming the safety of TdES. Since CRAO has no established treatment method, further research into the effects of TdES treatment in CRAO patients may be beneficial.
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Affiliation(s)
- Gen Miura
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan
- * E-mail:
| | - Tadami Fujiwara
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Takayuki Iwase
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yoshihito Ozawa
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yuki Shiko
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Yohei Kawasaki
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Tomohiro Nizawa
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Tomoaki Tatsumi
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Takayuki Baba
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Takuji Kurimoto
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Sotaro Mori
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Makoto Nakamura
- Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hideki Hanaoka
- Clinical Research Centre, Chiba University Hospital, Chiba, Japan
| | - Shuichi Yamamoto
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan
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Yang M, Lennikov A, Chang K, Ashok A, Lee C, Cho KS, Utheim TP, Dartt DA, Chen DF. Transcorneal but not transpalpebral electrical stimulation disrupts mucin homeostasis of the ocular surface. BMC Ophthalmol 2022; 22:490. [PMID: 36522696 PMCID: PMC9756492 DOI: 10.1186/s12886-022-02717-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Transcorneal electrical stimulation (TcES) is increasingly applied as a therapy for preserving and improving vision in retinal neurodegenerative and ischemic disorders. However, a common complaint about TcES is its induction of eye pain and dryness in the clinic, while the mechanisms remain unknown. METHOD TcES or transpalpebral ES (TpES) was conducted in C57BL6j mice for 14 days. The contralateral eyes were used as non-stimulated controls. Levels of intracellular [Ca2+] ([Ca2+]i) were assessed by Fura-2AM. The conductance resistances of the eye under various ES conditions were measured in vivo by an oscilloscope. RESULTS Although TcES did not affect tear production, it significantly induced damage to the ocular surface, as revealed by corneal fluorescein staining that was accompanied by significantly decreased mucin (MUC) 4 expression compared to the control. Similar effects of ES were detected in cultured primary corneal epithelium cells, showing decreased MUC4 and ZO-1 levels after the ES in vitro. In addition, TcES decreased secretion of MUC5AC from the conjunctiva in vivo, which was also corroborated in goblet cell cultures, where ES significantly attenuated carbachol-induced [Ca2+]i increase. In contrast to TcES, transpalpebral ES (TpES) did not induce corneal fluorescein staining while significantly increasing tear production. Importantly, the conductive resistance from orbital skin to the TpES was significantly smaller than that from the cornea to the retina in TcES. CONCLUSION TcES, but not TpES, induces corneal epithelial damage in mice by disrupting mucin homeostasis. TpES thus may represent a safer and more effective ES approach for treating retinal neurodegeneration clinically.
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Affiliation(s)
- Menglu Yang
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA
| | - Anton Lennikov
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA ,grid.5510.10000 0004 1936 8921Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Kirkeveien 166, Oslo, 0450 Norway
| | - Karen Chang
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA ,grid.5510.10000 0004 1936 8921Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Kirkeveien 166, Oslo, 0450 Norway
| | - Ajay Ashok
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA ,grid.5510.10000 0004 1936 8921Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Kirkeveien 166, Oslo, 0450 Norway
| | - Cherin Lee
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA
| | - Kin-Sang Cho
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA
| | - Tor Paaske Utheim
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA ,grid.5510.10000 0004 1936 8921Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Kirkeveien 166, Oslo, 0450 Norway
| | - Darlene A. Dartt
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA
| | - Dong Feng Chen
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford St, Boston, MA 02114 USA
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Lennikov A, Yang M, Chang K, Pan L, Saddala MS, Lee C, Ashok A, Cho KS, Utheim TP, Chen DF. Direct modulation of microglial function by electrical field. Front Cell Dev Biol 2022; 10:980775. [PMID: 36158207 PMCID: PMC9493490 DOI: 10.3389/fcell.2022.980775] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/03/2022] [Indexed: 12/03/2022] Open
Abstract
Non-invasive electric stimulation (ES) employing a low-intensity electric current presents a potential therapeutic modality that can be applied for treating retinal and brain neurodegenerative disorders. As neurons are known to respond directly to ES, the effects of ES on glia cells are poorly studied. A key question is if ES directly mediates microglial function or modulates their activity merely via neuron-glial signaling. Here, we demonstrated the direct effects of ES on microglia in the BV-2 cells—an immortalized murine microglial cell line. The low current ES in a biphasic ramp waveform, but not that of rectangular or sine waveforms, significantly suppressed the motility and migration of BV-2 microglia in culture without causing cytotoxicity. This was associated with diminished cytoskeleton reorganization and microvilli formation in BV-2 cultures, as demonstrated by immunostaining of cytoskeletal proteins, F-actin and β-tubulin, and scanning electron microscopy. Moreover, ES of a ramp waveform reduced microglial phagocytosis of fluorescent zymosan particles and suppressed lipopolysaccharide (LPS)-induced pro-inflammatory cytokine expression in BV-2 cells as shown by Proteome Profiler Mouse Cytokine Array. The results of quantitative PCR and immunostaining for cyclooxygenase-2, Interleukin 6, and Tumor Necrosis Factor-α corroborated the direct suppression of LPS-induced microglial responses by a ramp ES. Transcriptome profiling further demonstrated that ramp ES effectively suppressed nearly half of the LPS-induced genes, primarily relating to cellular motility, energy metabolism, and calcium signaling. Our results reveal a direct modulatory effect of ES on previously thought electrically “non-responsive” microglia and suggest a new avenue of employing ES for anti-inflammatory therapy.
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Affiliation(s)
- Anton Lennikov
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Menglu Yang
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
| | - Karen Chang
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Li Pan
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
| | - Madhu Sudhana Saddala
- Wilmer Bioinformatics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Cherin Lee
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
| | - Ajay Ashok
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Kin-Sang Cho
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
| | - Tor Paaske Utheim
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- Department of Medical Biochemistry, Oslo University Hospital, University of Oslo, Oslo, Norway
- Department of Ophthalmology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Dong Feng Chen
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, United States
- *Correspondence: Dong Feng Chen,
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10
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Lu Z, Zhou M, Guo T, Liang J, Wu W, Gao Q, Li L, Li H, Chai X. An in-silico analysis of retinal electric field distribution induced by different electrode design of trans-corneal electrical stimulation. J Neural Eng 2022; 19. [PMID: 36044887 DOI: 10.1088/1741-2552/ac8e32] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/31/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Trans-corneal electrical stimulation (TcES) produces therapeutic effects on many ophthalmic diseases non-invasively. Existing clinical TcES devices use largely variable design of electrode distribution and stimulation parameters. Better understanding of how electrode configuration paradigms and stimulation parameters influence the electric field distribution on the retina, will be beneficial to the design of next-generation TcES devices. APPROACH In this study, we constructed a realistic finite element human head model with fine eyeball structure. Commonly used DTL-Plus and ERG-Jet electrodes were simulated. We then conducted in silico investigations of retina observation surface (ROS) electric field distributions induced by different return electrode configuration paradigms and different stimulus intensities. MAIN RESULTS Our results suggested that the ROS electric field distribution could be modulated by re-designing TcES electrode settings and stimulus parameters. Under far return location (FRL) paradigms, either DTL-Plus or ERG-Jet approach could induce almost identical ROS electric field distribution regardless where the far return was located. However, compared with the ERG-Jet mode, DTL-Plus stimulation induced stronger nasal lateralization. In contrast, ERG-Jet stimulation induced relatively stronger temporal lateralization. The ROS lateralization can be further tweaked by changing the DTL-Plus electrode length. SIGNIFICANCE These results may contribute to the understanding of the characteristics of DTL-Plus and ERG-Jet electrodes based electric field distribution on the retina, providing practical implications for the therapeutic application of TcES.
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Affiliation(s)
- Zhuofan Lu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Address: 800 Dongchuan Road, Minhang District, Shanghai, Shanghai, 200240, CHINA
| | - Meixuan Zhou
- Shanghai Jiao Tong University, Shanghai 200240, Shanghai, 200240, CHINA
| | - Tianruo Guo
- GSBME, University of New South Wales, Graduate School of Biomedical Engineering, University of New South Wales, NSW 2052, Sydney, Australia, Sydney, New South Wales, 2052, AUSTRALIA
| | - Junling Liang
- Shanghai Jiao Tong University, Address: 800 Dongchuan Road, Minhang District, Shanghai Shanghai, CN 200240, Shanghai, 200240, CHINA
| | - Weilei Wu
- Shanghai Jiao Tong University, School of Biomedical Engineering Shanghai Jiao Tong University , Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai Shanghai, CN 200240, Shanghai, 200240, CHINA
| | - Qi Gao
- Shanghai Jiao Tong University, Address: 800 Dongchuan Road, Minhang District, Shanghai, Shanghai, 200240, CHINA
| | - Liming Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, Shanghai, 200240, CHINA
| | - Heng Li
- Shanghai Jiao Tong University, Address: 800 Dongchuan Road, Minhang District, Shanghai Shanghai, CN 200240, Shanghai, 200240, CHINA
| | - Xinyu Chai
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, Shanghai, 200240, CHINA
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11
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Battaglini L, Di Ponzio M, Ghiani A, Mena F, Santacesaria P, Casco C. Vision recovery with perceptual learning and non-invasive brain stimulation: Experimental set-ups and recent results, a review of the literature. Restor Neurol Neurosci 2022; 40:137-168. [PMID: 35964213 DOI: 10.3233/rnn-221261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Vision is the sense which we rely on the most to interact with the environment and its integrity is fundamental for the quality of our life. However, around the globe, more than 1 billion people are affected by debilitating vision deficits. Therefore, finding a way to treat (or mitigate) them successfully is necessary. OBJECTIVE This narrative review aims to examine options for innovative treatment of visual disorders (retinitis pigmentosa, macular degeneration, optic neuropathy, refractory disorders, hemianopia, amblyopia), especially with Perceptual Learning (PL) and Electrical Stimulation (ES). METHODS ES and PL can enhance visual abilities in clinical populations, inducing plastic changes. We describe the experimental set-ups and discuss the results of studies using ES or PL or their combination in order to suggest, based on literature, which treatment is the best option for each clinical condition. RESULTS Positive results were obtained using ES and PL to enhance visual functions. For example, repetitive transorbital Alternating Current Stimulation (rtACS) appeared as the most effective treatment for pre-chiasmatic disorders such as optic neuropathy. A combination of transcranial Direct Current Stimulation (tDCS) and visual training seems helpful for people with hemianopia, while transcranial Random Noise Stimulation (tRNS) makes visual training more efficient in people with amblyopia and mild myopia. CONCLUSIONS This narrative review highlights the effect of different ES montages and PL in the treatment of visual disorders. Furthermore, new options for treatment are suggested. It is noteworthy to mention that, in some cases, unclear results emerged and others need to be more deeply investigated.
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Affiliation(s)
- Luca Battaglini
- Department of General Psychology, University of Padova, Italy.,Centro di Ateneo dei Servizi Clinici Universitari Psicologici (SCUP), University of Padova, Padova, Italy.,Neuro.Vis.U.S, University of Padova, Padova, Italy
| | - Michele Di Ponzio
- Department of General Psychology, University of Padova, Italy.,Istituto di Neuroscienze, Florence, Italy
| | - Andrea Ghiani
- Department of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, the Netherlands
| | - Federica Mena
- Department of General Psychology, University of Padova, Italy
| | | | - Clara Casco
- Department of General Psychology, University of Padova, Italy.,Centro di Ateneo dei Servizi Clinici Universitari Psicologici (SCUP), University of Padova, Padova, Italy.,Neuro.Vis.U.S, University of Padova, Padova, Italy
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12
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Miura G, Ozawa Y, Shiko Y, Kawasaki Y, Iwase T, Fujiwara T, Baba T, Hanaoka H, Yamamoto S. Evaluating the efficacy and safety of transdermal electrical stimulation on the visual functions of patients with retinitis pigmentosa: a clinical trial protocol for a prospective, multicentre, randomised, double-masked and sham-controlled design (ePICO trial). BMJ Open 2022; 12:e057193. [PMID: 35523495 PMCID: PMC9083404 DOI: 10.1136/bmjopen-2021-057193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Previously, we conducted a clinical trial to evaluate the safety and efficacy of transdermal electrical stimulation (TdES) with skin electrodes to improve the visual functions in patients with retinitis pigmentosa (RP). No adverse events were related to the treatment during follow-up examinations, and TdES significantly improved the mean visual acuity and visual field sensitivity. METHODS AND ANALYSIS We developed a study protocol for a prospective, multicentre, randomised, double-masked and sham-controlled clinical trial, planned to commence on June 2021. We intend to compare the maintenance or improvement in best-corrected visual acuity, and safety of TdES using skin electrodes between patients with RP and the sham group. The primary endpoint comprises the superiority of the logarithm of the minimum angle of resolution (logMAR) visual acuity change at week 24 from baseline in the treatment and sham groups. Secondary endpoints involve the comparison of the treatment and sham groups at week 24 for the logMAR visual acuity, early treatment diabetic retinopathy study visual acuity, the mean deviation value of Humphrey field analyser 10-2, monocular Humphrey Esterman visual field test score, ellipsoid zone length, central foveal thickness and 25-item National Eye Institute Visual Function Questionnaire score. We intend to enrol 50 patients from three Japanese institutions within 1 year and follow them up for 1 years. ETHICS AND DISSEMINATION The protocol was approved by the institutional review board at the Chiba University Hospital and two other institutions, and was registered with the Japan Registry of Clinical Trials on 17 May 2021. The trial will be conducted in accordance with the principles of the Declaration of Helsinki, and is in accordance with Good Clinical Practice standards. The findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER JRCT2032210094.
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Affiliation(s)
- Gen Miura
- Department of Ophthalmology and Visual Science, Chiba University, Graduate School of Medicine, Chiba, Japan
| | - Yoshihito Ozawa
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Yuki Shiko
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Yohei Kawasaki
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Takayuki Iwase
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Tadami Fujiwara
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Takayuki Baba
- Department of Ophthalmology and Visual Science, Chiba University, Graduate School of Medicine, Chiba, Japan
| | - Hideki Hanaoka
- Clinical Research Center, Chiba University Hospital, Chiba, Japan
| | - Shuichi Yamamoto
- Department of Ophthalmology and Visual Science, Chiba University, Graduate School of Medicine, Chiba, Japan
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13
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Blum MC, Hunold A, Solf B, Klee S. Ocular direct current stimulation affects retinal ganglion cells. Sci Rep 2021; 11:17573. [PMID: 34475417 PMCID: PMC8413326 DOI: 10.1038/s41598-021-96401-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/09/2021] [Indexed: 11/22/2022] Open
Abstract
Ocular current stimulation (oCS) with weak current intensities (a few mA) has shown positive effects on retinal nerve cells, which indicates that neurodegenerative ocular diseases could be treated with current stimulation of the eye. During oCS, a significant polarity-independent reduction in the characteristic P50 amplitude of a pattern-reversal electroretinogram was found, while no current stimulation effect was found for a full field electroretinogram (ffERG). The ffERG data indicated a trend for a polarity-dependent influence during oCS on the photopic negative response (PhNR) wave, which represents the sum activity of the retinal ganglion cells. Therefore, an ffERG with adjusted parameters for the standardized measurement of the PhNR wave was combined with simultaneous oCS to study the potential effects of direct oCS on cumulative ganglion cell activity. Compared with that measured before oCS, the PhNR amplitude in the cathodal group increased significantly during current stimulation, while in the anodal and sham groups, no effect was visible (α = 0.05, pcathodal = 0.006*). Furthermore, repeated-measures ANOVA revealed a significant difference in PhNR amplitude between the anodal and cathodal groups as well as between the cathodal and sham groups (p* ≤ 0.0167, pcathodal − anodal = 0.002*, pcathodal − sham = 0.011*).
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Affiliation(s)
- Maren-Christina Blum
- Institute for Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany.
| | - Alexander Hunold
- Institute for Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany
| | - Benjamin Solf
- Institute for Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany
| | - Sascha Klee
- Institute for Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany.,Department of General Health Studies, Division Biostatistics and Data Science, Karl Landsteiner University of Health Sciences, Krems, Austria
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14
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Liu J, Tong K, Lin Y, Lee VWH, So KF, Shih KC, Lai JSM, Chiu K. Effectiveness of Microcurrent Stimulation in Preserving Retinal Function of Blind Leading Retinal Degeneration and Optic Neuropathy: A Systematic Review. Neuromodulation 2021; 24:992-1002. [PMID: 33984873 DOI: 10.1111/ner.13414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/29/2021] [Accepted: 04/19/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To systematically identify and summarize the effectiveness and the parameters of electrical stimulation (ES) for the preservation of visual function in major retinal degeneration and optic neuropathy. MATERIALS AND METHODS A systematic review of clinical studies, using ES therapy in patients with blind leading retinal degenerations, including retinitis pigmentosa (RP), age-related macular degeneration (AMD), glaucoma, retinal vein occlusion (RVO), retinal artery occlusion (RAO), and optic neuropathy was conducted. PubMed, EMBASE, Cochrane Library, and Web of Science were searched for relevant interventional studies including randomized controlled trials (RCTs) and observational studies. RESULTS A total of 10 RCTs and 15 observational studies were included. Transcorneal ES (TcES), transpalpebral ES (TpES), transdermal ES (TdES), and repetitive transorbital alternating current stimulation (rtACS) were used for the treatment of the patients. ES using 20 Hz biphasic pulses with current strength at 150%-200% of individual electrical phosphene threshold (EPT) for RP patients showed improved retinal function detected by visual acuity (VA), visual field (VF), or electrical retinal graphs (ERG). rtACS on patients with optic neuropathy showed significant preservation of VA and VF. Clinical studies on AMD, RAO, and glaucoma indicated promising protective effects of ES on the visual function, though the amount of evidence is limited. CONCLUSIONS ES treatment has promising therapeutic effects on RP and optic neuropathy. More large-scale RCT studies should be conducted to elucidate the potential of ES, especially on AMD, RAO, and glaucoma. A comparison of the effects by different ES methods in the same disease populations is still lacking. Parameters of the electric current and sensitive detection method should be optimized for the evaluation of ES treatment effects in future studies.
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Affiliation(s)
- Jinfeng Liu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kelvin Tong
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Youhong Lin
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Vincent W H Lee
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kwok Fai So
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China.,Guangdong HongKong Macau Institute of CNS Regeneration: Guangdong, Guangzhou, China
| | - Kendrick Co Shih
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jimmy S M Lai
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kin Chiu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China
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15
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Blum MC, Solf B, Hunold A, Klee S. Effects of Ocular Direct Current Stimulation on Full Field Electroretinogram. Front Neurosci 2021; 15:606557. [PMID: 33679299 PMCID: PMC7928396 DOI: 10.3389/fnins.2021.606557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Studies on weak current stimulation (1-2 mA) examine effects on neuronal cells for the treatment of neurological diseases, like depression. Ocular current stimulation showed positive effects on retinal nerve cells which indicate that neurodegenerative ocular diseases, e.g., glaucoma, can be treated with current stimulation of the eye. However, up to now it remains unclear which exact retinal cells can be influenced. During an ocular direct current stimulation, a significant reduction of the characteristic P50 amplitude of a pattern-reversal electroretinogram (PERG) was found for an anodal and a cathodal stimulation. This current stimulation effect could originate from the modulation of pre-ganglion cell activity or by changes in local ON and OFF responses of ganglion cells. For clarification, we investigate acute direct current stimulation effects on a full field electroretinogram (ERG), which represents the activity of pre-ganglion cells (specifically cones and bipolar cells). The ERG from 15 subjects was evaluated before (ERG 1) and during (ERG 2) an ocular direct current stimulation with 800 μA over 5 min. The current was applied through a ring rubber electrode placed around the eye and a 25 cm2 rubber electrode placed at the ipsilateral temple. For ERG measurements, sintered Ag/AgCl skin-electrodes were positioned on the lower eyelid (active), the earlobe (reference), and the forehead (ground). The volunteers were stimulated in three independent sessions, each with a different current application (randomized order): cathodal polarity, anodal polarity (referred to the electrode around the eye), or sham stimulation. The changes between the two ERG measurements of the characteristic full field ERG amplitudes, a-wave, b-wave, and b'-wave (b-wave measured from zero line) were tested with the Wilcoxon signed-rank test (α = 0.05). Comparing before to during the current stimulation for all applications, the ERG waves showed no effects on amplitudes or latencies. Furthermore, no significant difference between the cathodal, anodal, and sham stimulation could be found by a Friedman test. These results indicate an unlikely contribution of pre-ganglion cells to the previously reported stimulation effect on PERG signals.
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Affiliation(s)
- Maren-Christina Blum
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany
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16
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Yu H, Enayati S, Chang K, Cho K, Lee SW, Talib M, Zihlavnikova K, Xie J, Achour H, Fried SI, Utheim TP, Chen DF. Noninvasive Electrical Stimulation Improves Photoreceptor Survival and Retinal Function in Mice with Inherited Photoreceptor Degeneration. Invest Ophthalmol Vis Sci 2020; 61:5. [PMID: 32271885 PMCID: PMC7401948 DOI: 10.1167/iovs.61.4.5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose Neurons carry electrical signals and communicate via electrical activities. The therapeutic potential of electrical stimulation (ES) for the nervous system, including the retina, through improvement of cell survival and function has been noted. Here we investigated the neuroprotective and regenerative potential of ES in a mouse model of inherited retinal degeneration. Methods Rhodopsin-deficient (Rho−/−) mice received one or two sessions of transpalpebral ES or sham treatments for 7 consecutive days. Intraperitoneal injection of 5-ethynyl-2′-deoxyuridine was used to label proliferating cells. Weekly electroretinograms were performed to monitor retinal function. Retinal morphology, photoreceptor survival, and regeneration were evaluated in vivo using immunohistochemistry and genetic fate-mapping techniques. Müller cell (MC) cultures were employed to further define the optimal conditions of ES application. Results Noninvasive transpalpebral ES in Rho−/− mice improved photoreceptor survival and electroretinography function in vivo. ES also triggered residential retinal progenitor-like cells such as MCs to reenter the cell cycle, possibly producing new photoreceptors, as shown by immunohistochemistry and genetic fate-mapping techniques. ES directly stimulated cell proliferation and the expression of progenitor cell markers in MC cultures, at least partially through bFGF signaling. Conclusions Our study showed that transpalpebral ES improved photoreceptor survival and retinal function and induced the proliferation, probably photoreceptor regeneration, of MCs; this occurs via stimulation of the bFGF pathways. These results suggest the exciting possibility of applying noninvasive ES as a versatile tool for preventing photoreceptor loss and mobilizing endogenous progenitors for reversing vision loss in patients with photoreceptor degeneration.
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17
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Perin C, Viganò B, Piscitelli D, Matteo BM, Meroni R, Cerri CG. Non-invasive current stimulation in vision recovery: a review of the literature. Restor Neurol Neurosci 2020; 38:239-250. [PMID: 31884495 PMCID: PMC7504999 DOI: 10.3233/rnn-190948] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background: Around 253 million people worldwide suffer from irreversible visual damage. Numerous studies have been carried out in order to unveil the effects of electrical stimulation (ES) as a useful tool for rehabilitation for different visual conditions and pathologies. Objective: This systematic review aimed to 1) examine the current evidence of ES efficacy for the treatment of visual pathologies and 2) define the corresponding degree of the recommendation of different ES techniques. Methods: A systematic review was conducted in MEDLINE and Cochrane Library database to collect documents published between 2000 and 2018. For each study, Level of Evidence of Effectiveness of ES as well as the Class of Quality for the treatment of different visual pathologies were determined. Results: Thirty-eight articles were included. Studies were grouped according to the pathology treated and the type of stimulation administered. The first group included studies treating pre-chiasmatic pathologies (age-related macular degeneration, macular dystrophy, retinal artery occlusion, retinitis pigmentosa, glaucoma, optic nerve damage, and optic neuropathy) using pre-chiasmatic stimulation; the second group included studies treating both pre-chiasmatic pathologies (amblyopia, myopia) and post-chiasmatic pathologies or brain conditions (hemianopsia, brain trauma) by means of post-chiasmatic stimulation. In the first group, repetitive transorbital alternating current stimulation (rtACS) reached level A recommendation, and transcorneal electrical stimulation (tcES) reached level B. In the second group, both high-frequency random noise stimulation (hf-RNS) and transcranial direct current stimulation (tDCS) reached level C recommendation. Conclusions: Study’s findings suggest conclusive evidence for rtACS treatment. For other protocols results are promising but not conclusive since the examined studies assessed different stimulation parameters and endpoints. A comparison of the effects of different combinations of these variables still lacks in the literature. Further studies are needed to optimize existing protocols and determine if different protocols are needed for different diseases.
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Affiliation(s)
- Cecilia Perin
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy
| | | | - Daniele Piscitelli
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada
| | - Barbara Maria Matteo
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy
| | - Roberto Meroni
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy.,Current Affilation: Department of Physiotherapy, LUNEX International University of Health, Exercise and Sports. Differdange, Luxembourg
| | - Cesare Giuseppe Cerri
- Dipartimento di Medicina e Chirurgia (School of Medicine and Surgery), University of Milan-Bicocca, Milan, Italy.,Milan Center for Neuroscience (NeuroMI), University of Milan-Bicocca, Milan, Italy
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18
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Sabel BA, Thut G, Haueisen J, Henrich-Noack P, Herrmann CS, Hunold A, Kammer T, Matteo B, Sergeeva EG, Waleszczyk W, Antal A. Vision modulation, plasticity and restoration using non-invasive brain stimulation – An IFCN-sponsored review. Clin Neurophysiol 2020; 131:887-911. [DOI: 10.1016/j.clinph.2020.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/18/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
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19
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Waugh N, Loveman E, Colquitt J, Royle P, Yeong JL, Hoad G, Lois N. Treatments for dry age-related macular degeneration and Stargardt disease: a systematic review. Health Technol Assess 2019; 22:1-168. [PMID: 29846169 DOI: 10.3310/hta22270] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the leading cause of visual loss in older people. Advanced AMD takes two forms, neovascular (wet) and atrophic (dry). Stargardt disease (STGD) is the commonest form of inherited macular dystrophy. OBJECTIVE To carry out a systematic review of treatments for dry AMD and STGD, and to identify emerging treatments where future NIHR research might be commissioned. DESIGN Systematic review. METHODS We searched MEDLINE, EMBASE, Web of Science and The Cochrane Library from 2005 to 13 July 2017 for reviews, journal articles and meeting abstracts. We looked for studies of interventions that aim to preserve or restore vision in people with dry AMD or STGD. The most important outcomes are those that matter to patients: visual acuity (VA), contrast sensitivity, reading speed, ability to drive, adverse effects of treatment, quality of life, progression of disease and patient preference. However, visual loss is a late event and intermediate predictors of future decline were accepted if there was good evidence that they are strong predictors of subsequent visual outcomes. These include changes detectable by investigation, but not necessarily noticed by people with AMD or STGD. ClinicalTrials.gov, the World Health Organization search portal and the UK Clinical Trials gateway were searched for ongoing and recently completed clinical trials. RESULTS The titles and abstracts of 7948 articles were screened for inclusion. The full text of 398 articles were obtained for further screening and checking of references and 112 articles were included in the final report. Overall, there were disappointingly few good-quality studies (including of sufficient size and duration) reporting useful outcomes, particularly in STGD. However we did identify a number of promising research topics, including drug treatments, stem cells, new forms of laser treatment, and implantable intraocular lens telescopes. In many cases, research is already under way, funded by industry or governments. LIMITATIONS In AMD, the main limitation came from the poor quality of much of the evidence. Many studies used VA as their main outcome despite not having sufficient duration to observe changes. The evidence on treatments for STGD is sparse. Most studies tested interventions with no comparison group, were far too short term, and the quality of some studies was poor. FUTURE WORK We think that the topics on which the Health Technology Assessment (HTA) and Efficacy Mechanism and Evaluation (EME) programmes might consider commissioning primary research are in STGD, a HTA trial of fenretinide (ReVision Therapeutics, San Diego, CA, USA), a visual cycle inhibitor, and EME research into the value of lutein and zeaxanthin supplements, using short-term measures of retinal function. In AMD, we suggest trials of fenretinide and of a potent statin. There is epidemiological evidence from the USA that the drug, levodopa, used for treating Parkinson's disease, may reduce the incidence of AMD. We suggest that similar research should be carried out using the large general practice databases in the UK. Ideally, future research should be at earlier stages in both diseases, before vision is impaired, using sensitive measures of macular function. This may require early detection of AMD by screening. STUDY REGISTRATION This study is registered as PROSPERO CRD42016038708. FUNDING The National Institute for Health Research HTA programme.
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Affiliation(s)
- Norman Waugh
- Division of Health Sciences, University of Warwick, Coventry, UK
| | | | | | - Pamela Royle
- Division of Health Sciences, University of Warwick, Coventry, UK
| | | | | | - Noemi Lois
- Ophthalmology, Royal Victoria Hospital, Belfast, UK.,Wellcome-Wolfson Centre for Experimental Medicine, Queens University, Belfast, UK
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Pardue MT, Allen RS. Neuroprotective strategies for retinal disease. Prog Retin Eye Res 2018; 65:50-76. [PMID: 29481975 PMCID: PMC6081194 DOI: 10.1016/j.preteyeres.2018.02.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 12/20/2022]
Abstract
Diseases that affect the eye, including photoreceptor degeneration, diabetic retinopathy, and glaucoma, affect 11.8 million people in the US, resulting in vision loss and blindness. Loss of sight affects patient quality of life and puts an economic burden both on individuals and the greater healthcare system. Despite the urgent need for treatments, few effective options currently exist in the clinic. Here, we review research on promising neuroprotective strategies that promote neuronal survival with the potential to protect against vision loss and retinal cell death. Due to the large number of neuroprotective strategies, we restricted our review to approaches that we had direct experience with in the laboratory. We focus on drugs that target survival pathways, including bile acids like UDCA and TUDCA, steroid hormones like progesterone, therapies that target retinal dopamine, and neurotrophic factors. In addition, we review rehabilitative methods that increase endogenous repair mechanisms, including exercise and electrical stimulation therapies. For each approach, we provide background on the neuroprotective strategy, including history of use in other diseases; describe potential mechanisms of action; review the body of research performed in the retina thus far, both in animals and in humans; and discuss considerations when translating each treatment to the clinic and to the retina, including which therapies show the most promise for each retinal disease. Despite the high incidence of retinal diseases and the complexity of mechanisms involved, several promising neuroprotective treatments provide hope to prevent blindness. We discuss attractive candidates here with the goal of furthering retinal research in critical areas to rapidly translate neuroprotective strategies into the clinic.
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Affiliation(s)
- Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA, 30332, USA.
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
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Electrical Stimulation as a Means for Improving Vision. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 186:2783-2797. [PMID: 27643530 DOI: 10.1016/j.ajpath.2016.07.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/12/2016] [Accepted: 07/14/2016] [Indexed: 12/31/2022]
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.
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Chaikin L, Kashiwa K, Bennet M, Papastergiou G, Gregory W. Microcurrent stimulation in the treatment of dry and wet macular degeneration. Clin Ophthalmol 2015; 9:2345-53. [PMID: 26719667 PMCID: PMC4689270 DOI: 10.2147/opth.s92296] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To determine the safety and efficacy of the application of transcutaneous (transpalpebral) microcurrent stimulation to slow progression of dry and wet macular degeneration or improve vision in dry and wet macular degeneration. Methods Seventeen patients aged between 67 and 95 years with an average age of 83 years were selected to participate in the study over a period of 3 months in two eye care centers. There were 25 eyes with dry age-related macular degeneration (DAMD) and six eyes with wet age-related macular degeneration (WAMD). Frequency-specific microcurrent stimulation was applied in a transpalpebral manner, using two programmable dual channel microcurrent units delivering pulsed microcurrent at 150 µA for 35 minutes once a week. The frequency pairs selected were based on targeting tissues, which are typically affected by the disease combined with frequencies that target disease processes. Early Treatment Diabetic Retinopathy Study or Snellen visual acuity (VA) was measured before and after each treatment session. All treatment was administered in a clinical setting. Results Significant increases were seen in VA in DAMD (P=0.012, Wilcoxon one-sample test), but in WAMD, improvements did not reach statistical significance (P=0.059). In DAMD eyes, twice as many patients showed increase in VA (52%) compared to those showing deterioration (26%), with improvements being often sizeable, whereas deteriorations were usually very slight. In WAMD eyes, five of six (83%) patients showed an increase and none showed deterioration. Conclusion The substantial changes observed over this period, combined with continued improvement for patients who continued treatment once a month, are encouraging for future studies. The changes observed indicate the potential efficacy of microcurrent to delay degeneration and possibly improve age-related macular degeneration, both wet and dry. However, this study has no control arm, so results should be treated with caution. Randomized double-blind controlled studies are needed to determine long-term effects.
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Affiliation(s)
| | | | | | | | - Walter Gregory
- Clinical Trials Research Unit, Faculty of Medicine and Health, University of Leeds, Leeds, UK
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