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Khalili MR, Shadmani A, Sanie-Jahromi F. Application of electrostimulation and magnetic stimulation in patients with optic neuropathy: A mechanistic review. Dev Neurobiol 2024; 84:236-248. [PMID: 38844425 DOI: 10.1002/dneu.22949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 03/20/2024] [Accepted: 05/20/2024] [Indexed: 07/17/2024]
Abstract
Visual impairment caused by optic neuropathies is irreversible because retinal ganglion cells (RGCs), the specialized neurons of the retina, do not have the capacity for self-renewal and self-repair. Blindness caused by optic nerve neuropathies causes extensive physical, financial, and social consequences in human societies. Recent studies on different animal models and humans have established effective strategies to prevent further RGC degeneration and replace the cells that have deteriorated. In this review, we discuss the application of electrical stimulation (ES) and magnetic field stimulation (MFS) in optic neuropathies, their mechanisms of action, their advantages, and limitations. ES and MFS can be applied effectively in the field of neuroregeneration. Although stem cells are becoming a promising approach for regenerating RGCs, the inhibitory environment of the CNS and the long visual pathway from the optic nerve to the superior colliculus are critical barriers to overcome. Scientific evidence has shown that adjuvant treatments, such as the application of ES and MFS help direct thetransplanted RGCs to extend their axons and form new synapses in the central nervous system (CNS). In addition, these techniques improve CNS neuroplasticity and decrease the inhibitory effects of the CNS. Possible mechanisms mediating the effects of electrical current on biological tissues include the release of anti-inflammatory cytokines, improvement of microcirculation, stimulation of cell metabolism, and modification of stem cell function. ES and MFS have the potential to promote angiogenesis, direct axon growth toward the intended target, and enhance appropriate synaptogenesis in optic nerve regeneration.
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Affiliation(s)
- Mohammad Reza Khalili
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Athar Shadmani
- Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA
| | - Fatemeh Sanie-Jahromi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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2
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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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3
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Li J, Zhou W, Liang L, Li Y, Xu K, Li X, Huang Z, Jin Y. Noninvasive electrical stimulation as a neuroprotective strategy in retinal diseases: a systematic review of preclinical studies. J Transl Med 2024; 22:28. [PMID: 38184580 PMCID: PMC10770974 DOI: 10.1186/s12967-023-04766-4] [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: 06/09/2023] [Accepted: 11/27/2023] [Indexed: 01/08/2024] Open
Abstract
BACKGROUND Electrical activity has a crucial impact on the development and survival of neurons. Numerous recent studies have shown that noninvasive electrical stimulation (NES) has neuroprotective action in various retinal disorders. OBJECTIVE To systematically review the literature on in vivo studies and provide a comprehensive summary of the neuroprotective action and the mechanisms of NES on retinal disorders. METHODS Based on the PRISMA guideline, a systematic review was conducted in PubMed, Web of Science, Embase, Scopus and Cochrane Library to collect all relevant in vivo studies on "the role of NES on retinal diseases" published up until September 2023. Possible biases were identified with the adopted SYRCLE's tool. RESULTS Of the 791 initially gathered studies, 21 articles met inclusion/exclusion criteria for full-text review. The results revealed the neuroprotective effect of NES (involved whole-eye, transcorneal, transscleral, transpalpebral, transorbital electrical stimulation) on different retinal diseases, including retinitis pigmentosa, retinal degeneration, high-intraocular pressure injury, traumatic optic neuropathy, nonarteritic ischemic optic neuropathy. NES could effectively delay degeneration and apoptosis of retinal neurons, preserve retinal structure and visual function with high security, and its mechanism of action might be related to promoting the secretion of neurotrophins and growth factors, decreasing inflammation, inhibiting apoptosis. The quality scores of included studies ranged from 5 to 8 points (a total of 10 points), according to SYRCLE's risk of bias tool. CONCLUSION This systematic review indicated that NES exerts neuroprotective effects on retinal disease models mainly through its neurotrophic, anti-inflammatory, and anti-apoptotic capabilities. To assess the efficacy of NES in a therapeutic setting, however, well-designed clinical trials are required in the future.
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Affiliation(s)
- Jiaxian Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Wei Zhou
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Lina Liang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China.
| | - Yamin Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Kai Xu
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Xiaoyu Li
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Ziyang Huang
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
| | - Yu Jin
- Department of Eye Function Laboratory, Eye Hospital, China Academy of Chinese Medical Sciences, 33 Lugu Road, Shijingshan District, Beijing, 100040, People's Republic of China
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4
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Hernández-Sebastián N, Carpio-Verdín VM, Ambriz-Vargas F, Morales-Morales F, Benítez-Lara A, Buenrostro-Jáuregui MH, Bojorges-Valdez E, Barrientos-García B. Fabrication and Characterization of a Flexible Thin-Film-Based Array of Microelectrodes for Corneal Electrical Stimulation. MICROMACHINES 2023; 14:1999. [PMID: 38004856 PMCID: PMC10673352 DOI: 10.3390/mi14111999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 10/21/2023] [Accepted: 10/22/2023] [Indexed: 11/26/2023]
Abstract
The electric stimulation (ES) of the cornea is a novel therapeutic approach to the treatment of degenerative visual diseases. Currently, ES is delivered by placing a mono-element electrode on the surface of the cornea that uniformly stimulates the eye along the electrode site. It has been reported that a certain degree of correlation exists between the location of the stimulated retinal area and the position of the electrode. Therefore, in this study, we present the development of a sectioned surface electrode for selective electric stimulation of the human cornea. The proposed device consists of 16 independent microelectrodes, a reference electrode, and 18 contact pads. The microelectrodes have a size of 200 µm × 200 µm, are arranged in a 4 × 4 matrix, and cover a total stimulation area of 16 mm2. The proposed fabrication process, based on surface micromachining technology and flexible electronics, uses only three materials: polyimide, aluminum, and titanium, which allow us to obtain a simplified, ergonomic, and reproducible fabrication process. The fabricated prototype was validated to laboratory level by electrical and electrochemical tests, showing a relatively high electrical conductivity and average impedance from 712 kΩ to 1.4 MΩ at the clinically relevant frequency range (from 11 Hz to 30 Hz). Additionally, the biocompatibility of the electrode prototype was demonstrated by performing in vivo tests and by analyzing the polyimide films using Fourier transform infrared spectroscopy (FTIR). The resulting electrode prototype is robust, mechanically flexible, and biocompatible, with a high potential to be used for selective ES of the cornea.
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Affiliation(s)
- Natiely Hernández-Sebastián
- Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico; (V.M.C.-V.); (F.A.-V.); (F.M.-M.); (B.B.-G.)
| | - Víctor Manuel Carpio-Verdín
- Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico; (V.M.C.-V.); (F.A.-V.); (F.M.-M.); (B.B.-G.)
| | - Fabián Ambriz-Vargas
- Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico; (V.M.C.-V.); (F.A.-V.); (F.M.-M.); (B.B.-G.)
| | - Francisco Morales-Morales
- Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico; (V.M.C.-V.); (F.A.-V.); (F.M.-M.); (B.B.-G.)
| | - Alfredo Benítez-Lara
- CONAHCYT, Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico;
| | | | - Erik Bojorges-Valdez
- Departamento de Estudios en Ingeniería para la Innovación, Universidad Iberoamericana Ciudad de México, Ciudad de México 01219, Mexico;
| | - Bernardino Barrientos-García
- Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico; (V.M.C.-V.); (F.A.-V.); (F.M.-M.); (B.B.-G.)
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5
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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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6
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Zhen F, Zou T, Wang T, Zhou Y, Dong S, Zhang H. Rhodopsin-associated retinal dystrophy: Disease mechanisms and therapeutic strategies. Front Neurosci 2023; 17:1132179. [PMID: 37077319 PMCID: PMC10106759 DOI: 10.3389/fnins.2023.1132179] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/13/2023] [Indexed: 04/05/2023] Open
Abstract
Rhodopsin is a light-sensitive G protein-coupled receptor that initiates the phototransduction cascade in rod photoreceptors. Mutations in the rhodopsin-encoding gene RHO are the leading cause of autosomal dominant retinitis pigmentosa (ADRP). To date, more than 200 mutations have been identified in RHO. The high allelic heterogeneity of RHO mutations suggests complicated pathogenic mechanisms. Here, we discuss representative RHO mutations as examples to briefly summarize the mechanisms underlying rhodopsin-related retinal dystrophy, which include but are not limited to endoplasmic reticulum stress and calcium ion dysregulation resulting from protein misfolding, mistrafficking, and malfunction. Based on recent advances in our understanding of disease mechanisms, various treatment methods, including adaptation, whole-eye electrical stimulation, and small molecular compounds, have been developed. Additionally, innovative therapeutic treatment strategies, such as antisense oligonucleotide therapy, gene therapy, optogenetic therapy, and stem cell therapy, have achieved promising outcomes in preclinical disease models of rhodopsin mutations. Successful translation of these treatment strategies may effectively ameliorate, prevent or rescue vision loss related to rhodopsin mutations.
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Affiliation(s)
- Fangyuan Zhen
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Tongdan Zou
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ting Wang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yongwei Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
| | - Shuqian Dong
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
- *Correspondence: Shuqian Dong, ; Houbin Zhang,
| | - Houbin Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China
- *Correspondence: Shuqian Dong, ; Houbin Zhang,
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7
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Liu F, Zhang M, Xiong G, Han X, Lee VWH, So KF, Chiu K, Xu Y. Trans-Sclera Electrical Stimulation Improves Retinal Function in a Mouse Model of Retinitis Pigmentosa. Life (Basel) 2022; 12:1917. [PMID: 36431052 PMCID: PMC9693292 DOI: 10.3390/life12111917] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
Retinitis pigmentosa (RP) is a photoreceptor-degenerating disease with no effective treatment. Trans-corneal electrical stimulation has neuroprotective effects in degenerating retinas, but repeated applications cause corneal injury. To avoid the risk of corneal damage, here we tested whether repetitive trans-sclera electrical stimulation (TsES) protects degenerating retinas in rd10 mice, a model of RP. At postnatal day 20 (P20), the right eyes of rd10 mice were exposed to 30 min of TsES daily or every other day till P25, at the amplitude of 50 or 100 μA, with zero current as the sham. Immunostaining, multi-electrode-array (MEA) recording, and a black-and-white transition box were applied to examine the morphological and functional changes of the treated retina. Functionally, TsES modified the retinal light responses. It also reduced the high spontaneous firing of retinal ganglion cells. TsES at 100 μA but not 50 μA increased the light sensitivities of ganglion cells as well as their signal-to-noise ratios. TsES at 100 μA increased the survival of photoreceptors without improving the visual behavior of rd10 mice. Our data suggest that repetitive TsES improves the retinal function of rd10 mice at the early degenerating stage, therefore, it might be an effective long-term strategy to delay retinal degeneration in RP patients.
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Affiliation(s)
- Feng Liu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, 601 West Huangpu Ave., Guangzhou 510632, China
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Mengrong Zhang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, 601 West Huangpu Ave., Guangzhou 510632, China
| | - Guoyin Xiong
- Department of Ophthalmology, The University of Hong Kong, Hong Kong SAR, China
| | - Xiu Han
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, 601 West Huangpu Ave., Guangzhou 510632, China
| | | | - Kwok-Fai So
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, 601 West Huangpu Ave., Guangzhou 510632, China
- Department of Ophthalmology, The University of Hong Kong, Hong Kong SAR, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China
- Department of Psychology, The University of Hong Kong, Hong Kong SAR, China
| | - Kin Chiu
- Department of Ophthalmology, The University of Hong Kong, Hong Kong SAR, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China
- Department of Psychology, The University of Hong Kong, Hong Kong SAR, China
| | - Ying Xu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, 601 West Huangpu Ave., Guangzhou 510632, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China
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8
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Kuo CY, Liu CJL. Neuroprotection in Glaucoma: Basic Aspects and Clinical Relevance. J Pers Med 2022; 12:jpm12111884. [PMID: 36579616 PMCID: PMC9697907 DOI: 10.3390/jpm12111884] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/21/2022] [Accepted: 11/04/2022] [Indexed: 11/12/2022] Open
Abstract
Glaucoma is a neurodegenerative disease that affects primarily the retinal ganglion cells (RGCs). Increased intraocular pressure (IOP) is one of the major risk factors for glaucoma. The mainstay of current glaucoma therapy is limited to lowering IOP; however, controlling IOP in certain patients can be futile in slowing disease progression. The understanding of potential biomolecular processes that occur in glaucomatous degeneration allows for the development of glaucoma treatments that modulate the death of RGCs. Neuroprotection is the modification of RGCs and the microenvironment of neurons to promote neuron survival and function. Numerous studies have revealed effective neuroprotection modalities in animal models of glaucoma; nevertheless, clinical translation remains a major challenge. In this review, we select the most clinically relevant treatment strategies, summarize preclinical and clinical data as well as recent therapeutic advances in IOP-independent neuroprotection research, and discuss the feasibility and hurdles of each therapeutic approach based on possible pathogenic mechanisms. We also summarize the potential therapeutic mechanisms of various agents in neuroprotection related to glutamate excitotoxicity.
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Affiliation(s)
- Che-Yuan Kuo
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Catherine Jui-Ling Liu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Faculty of Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
- Correspondence: ; Tel.: +886-2-2875-7325
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9
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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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10
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Liu J, Ma AK, So KF, Lee VW, Chiu K. Mechanisms of electrical stimulation in eye diseases: A narrative review. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2022; 2:100060. [PMID: 37846384 PMCID: PMC10577855 DOI: 10.1016/j.aopr.2022.100060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/14/2022] [Accepted: 05/01/2022] [Indexed: 10/18/2023]
Abstract
Background In the last two decades, electrical stimulation (ES) has been tested in patients with various eye diseases and shows great treatment potential in retinitis pigmentosa and optic neuropathy. However, the clinical application of ES in ophthalmology is currently limited. On the one hand, optimization and standardization of ES protocols is still an unmet need. On the other hand, poor understanding of the underlying mechanisms has hindered clinical exploitation. Main Text Numerous experimental studies have been conducted to identify the treatment potential of ES in eye diseases and to explore the related cellular and molecular mechanisms. In this review, we summarized the in vitro and in vivo evidence related to cellular and tissue response to ES in eye diseases. We highlighted several pathways that may be utilized by ES to impose its effects on the diseased retina. Conclusions Therapeutic effect of ES in retinal degenerative diseases might through preventing neuronal apoptosis, promoting neuronal regeneration, increasing neurotrophic factors production in Müller cells, inhibiting microglial activation, enhancing retinal blood flow, and modulating brain plasticity. Future studies are suggested to analyse changes in specific retinal cells for optimizing the treatment parameters and choosing the best fit ES delivery method in target diseases.
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Affiliation(s)
- Jinfeng Liu
- Department of Ophthalmology, The University of Hong Kong, SAR, Hong Kong, China
| | | | - Kwok Fai So
- Department of Ophthalmology, The University of Hong Kong, SAR, Hong Kong, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, SAR, Hong Kong, China
- Department of Psychology, The University of Hong Kong, SAR, Hong Kong, China
- Guangdong-Hong Kong-Macau Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
| | - Vincent W.H. Lee
- Department of Ophthalmology, The University of Hong Kong, SAR, Hong Kong, China
| | - Kin Chiu
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, SAR, Hong Kong, China
- Department of Psychology, The University of Hong Kong, SAR, Hong Kong, China
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11
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Sharif NA. Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100037. [PMID: 36685768 PMCID: PMC9846481 DOI: 10.1016/j.crneur.2022.100037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 01/25/2023] Open
Abstract
Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.
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Affiliation(s)
- Najam A. Sharif
- Duke-National University of Singapore Medical School, Singapore,Singapore Eye Research Institute (SERI), Singapore,Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA,Department of Pharmaceutical Sciences, Texas Southern University, Houston, TX, USA,Department of Surgery & Cancer, Imperial College of Science and Technology, St. Mary's Campus, London, UK,Department of Pharmacy Sciences, School of School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA.
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12
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Koo B, Weiland JD. Progressive Retinal Degeneration Increases Cortical Response Latency of Light Stimulation but Not of Electric Stimulation. Transl Vis Sci Technol 2022; 11:19. [PMID: 35446408 PMCID: PMC9034728 DOI: 10.1167/tvst.11.4.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/31/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose The brain is known to change functionally and structurally in response to blindness, but less is known about the effects of restoration of cortical input on brain function. Here, we present a preliminary study to observe alterations in visual and electrical evoked cortical potentials as a function of age in a clinically relevant animal model of retinitis pigmentosa. Methods We recorded brain potentials elicited by light (visual evoked potentials [VEPs]) or corneal electrical stimulation (electrical evoked response [EER]) in retinal degenerate animal model LE-P23H-1. We used a linear mixed model to examine the effects of age on latency and amplitude of VEP and EER age groups P120, P180, and P360. Results VEP N1, P1, and N2 latency and amplitude were analyzed across animal age. For 1 Hz VEP, N1 latency increased significantly with animal age (slope = 0.053 ± 0.020 ms/day, P < 0.01). For 10 Hz VEP, N1, P1, and N2 latency increased significantly with animal age (slope = 0.104 ± 0.011, 0.135 ± 0.011, 0.087 ± 0.023 ms/day, and P < 0.001 for all VEP peaks). Conversely, EER latency did not change with age. Signal amplitude of VEP or EER did not change with age. Conclusions Cortical potentials evoked by electrical stimulation of the retina do not diminish in spite of continued retinal degeneration in P23H rats. Translational Relevance These findings suggest that retinal bioelectronic treatments of retinitis pigmentosa will activate cortex consistently despite variations in outer retinal degeneration. Clinical studies of retinal stimulation should consider varying retinitis pigmentosa genotypes as part of the experimental design.
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Affiliation(s)
- Beomseo Koo
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - James D. Weiland
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
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13
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Erb C, Eckert S, Gindorf P, Köhler M, Köhler T, Neuhann L, Neuhann T, Salzmann N, Schmickler S, Ellrich J. Electrical neurostimulation in glaucoma with progressive vision loss. Bioelectron Med 2022; 8:6. [PMID: 35361287 PMCID: PMC8969331 DOI: 10.1186/s42234-022-00089-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/22/2022] [Indexed: 02/03/2023] Open
Abstract
Abstract
Background
The retrospective study provides real-world evidence for long-term clinical efficacy of electrical optic nerve stimulation (ONS) in glaucoma with progressive vision loss.
Methods
Seventy glaucoma patients (45 to 86 y) with progressive vision loss despite therapeutic reduction of intraocular pressure (IOP) underwent electrical ONS. Closed eyes were separately stimulated by bipolar rectangular pulses with stimulus intensities up to 1.2 mA sufficient to provoke phosphenes. Ten daily stimulation sessions within 2 weeks lasted about 80 min each. Right before ONS at baseline (PRE), vision loss was documented by static threshold perimetry and compared to the same assessment approximately 1 year afterwards (POST). Mean defect (MD) was defined as primary outcome parameter. Perimetries with a reliability factor (RF) of max. 20% were considered.
Results
Perimetry follow-up of 101 eyes in 70 patients fulfilled the criterion of a max. 20% RF. Follow-up was performed on average 362.2 days after ONS. MD significantly decreased from PRE 14.0 dB (median) to POST 13.4 dB (p < 0.01). 64 eyes in 49 patients showed constant or reduced MD as compared to baseline (PRE 13.4 dB vs. POST 11.2 dB). In 37 eyes of 30 patients, MD increased from PRE 14.9 dB to POST 15.6 dB.
Conclusions
Innovative treatments that preserve visual function through mechanisms other than lowering IOP are required for glaucoma with progressive vision loss. The present long-term data document progression halt in more than 63% of affected eyes after ONS and, thus, extend existing evidence from clinical trials.
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14
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Strang CE, Amthor FR. Effects of tACS-Like Electrical Stimulation on Off- and On-Off Center Retinal Ganglion Cells: Part II. Eye Brain 2022; 14:17-33. [PMID: 35115857 PMCID: PMC8800591 DOI: 10.2147/eb.s313090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 11/30/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Transcranial alternating current stimulation (tACS) is used as a brain stimulation mechanism to enhance learning, ameliorate some psychiatric disorders, and modify behavior. This study assessed the effects of near threshold tACS-like currents on Off-center and On-Off retinal ganglion cell responsiveness in the rabbit retina eyecup preparation as a model for central nervous system effects. MATERIALS AND METHODS We made extracellular recordings in the isolated rabbit eyecup preparation using single electrodes and microelectrode arrays to measure light-evoked spike responses in different classes of Off-center and On-Off retinal ganglion cells before, during, and after brief applications of alternating currents of 1-2 microamperes, at frequencies of 10, 20, 30, and 40 Hz. RESULTS tACS application sculpted the light-evoked response profiles without directly driving spiking activity of the 20 Off-center and On-Off ganglion cells we recorded from. During tACS application, Off responses were significantly enhanced for 6 cells and significantly suppressed for 14 cells, but after tACS application, Off responses were significantly enhanced for 7 cells and suppressed for 12 cells. The Off responses of the remaining two cells returned to baseline. On responses were less affected during and after tACS. CONCLUSION tACS sculpts Off-center and On-Off retinal ganglion cell responsiveness. The dissimilarity of effects in different cells within the same class and the differential effects on the On and Off components of the light response within the same cell are consistent with the hypothesis that tACS acts at threshold on amacrine cells in the inner plexiform layer.
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Affiliation(s)
- Christianne E Strang
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA
| | - Franklin R Amthor
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA
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15
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Effects of Daily Melatonin Supplementation on Visual Loss, Circadian Rhythms, and Hepatic Oxidative Damage in a Rodent Model of Retinitis Pigmentosa. Antioxidants (Basel) 2021; 10:antiox10111853. [PMID: 34829724 PMCID: PMC8614953 DOI: 10.3390/antiox10111853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 01/02/2023] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases characterized by a progressive loss of visual function that primarily affect photoreceptors, resulting in the complete disorganization and remodeling of the retina. Progression of the disease is enhanced by increased oxidative stress in the retina, aqueous humor, plasma, and liver of RP animal models and patients. Melatonin has beneficial effects against age-related macular degeneration, glaucoma, and diabetic retinopathy, in which oxidative stress plays a key role. In the present study, we used the P23HxLE rat as an animal model of RP. Melatonin treatment (10 mg/kg b.w. daily in drinking water for 6 months) improved the parameters of visual function and decreased the rate of desynchronization of the circadian rhythm, both in P23HxLE and wild-type rats. Melatonin reduced oxidative stress and increased antioxidant defenses in P23HxLE animals. In wild-type animals, melatonin did not modify any of the oxidative stress markers analyzed and reduced the levels of total antioxidant defenses. Treatment with melatonin improved visual function, circadian synchronization, and hepatic oxidative stress in P23HxLE rats, an RP model, and had beneficial effects against age-related visual damage in wild-type rats.
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16
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Amthor FR, Strang CE. Effects of tACS-Like Electrical Stimulation on On-Center Retinal Ganglion Cells: Part I. Eye Brain 2021; 13:175-192. [PMID: 34285622 PMCID: PMC8285569 DOI: 10.2147/eb.s312402] [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: 03/23/2021] [Accepted: 06/11/2021] [Indexed: 01/30/2023] Open
Abstract
Purpose Electrical stimulation of the human central nervous system via surface electrodes has been used for both learning enhancement and the amelioration of neurodegenerative or psychiatric disorders. However, data are sparse on how such electrical stimulation affects neural circuits at the cellular level. This study assessed the effects of tACS-like currents at 10 Hz on On-center retinal ganglion cell responsiveness, using the rabbit retina eyecup preparation as a model for central nervous system effects. Methods We made extracellular recordings of light-evoked spike responses in different classes of On-center retinal ganglion cells before, during and after brief applications of 1 microampere alternating currents using single electrodes and microelectrode arrays. Results tACS-like currents (tACS) of 1 microampere produced effects on On-center ganglion cell response profiles immediately after initiation or cessation of tACS, without driving phase-locked firing in the absence of light stimuli. tACS affected the initial transient responses to light stimulation for all cells, sustained response components (if any) more strongly for sustained cells, and the center-surround balance more strongly for transient cells. Conclusion tACS sculpted light-evoked responses that lasted for one or more hours after cessation of current without, itself, directly inducing significant firing changes. Functionally, tACS effects could result in effects on contrast thresholds for both broad classes of cells, but because tACs differentially affects the center-surround balance of transient On-center cells, there may be greater effects on the spatial resolution and gain. The isolated retina appears to be a useful model to understand tACS actions at the neuronal level.
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Affiliation(s)
- Franklin R Amthor
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA
| | - Christianne E Strang
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA
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17
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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: 9] [Impact Index Per Article: 3.0] [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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18
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Żebrowska M, Dzwiniel P, Waleszczyk WJ. Removal of the Sinusoidal Transorbital Alternating Current Stimulation Artifact From Simultaneous EEG Recordings: Effects of Simple Moving Average Parameters. Front Neurosci 2020; 14:735. [PMID: 32848538 PMCID: PMC7403449 DOI: 10.3389/fnins.2020.00735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 06/22/2020] [Indexed: 02/02/2023] Open
Abstract
Alternating current stimulation is a promising method for the study and treatment of various visual neurological dysfunctions as well as progressive understanding of the healthy brain. Unfortunately, due to the current stimulation artifact, problems remain in the context of analysis of the electroencephalography (EEG) signal recorded during ongoing stimulation. To address this problem, we propose the use of a simple moving average subtraction as a method for artifact elimination. This method involves the creation of a template of the stimulation artifact from EEG signal recorded during non-invasive electrical stimulation with a sinusoidal alternating current. The present report describes results of the effects of a simple moving average filtration that varies based on averaging parameters; in particular, we varied the number of sinusoidal periods per segment of the recorded signal and the number of segments used to construct an artifact template. Given the ongoing lack of a mathematical model that allows for the prediction of the “hidden” EEG signal with the alternating current stimulation artifact, we propose performing an earlier simulation that is based on the addition of artificial stimulation artifact to the known EEG signal. This solution allows for the optimization of filtering parameters with detailed knowledge about the accuracy of artifact removal. The algorithm, designed in the MATLAB environment, has been tested on data recorded from two volunteers subjected to sinusoidal transorbital alternating current stimulation. Analysis of the percentage difference between the original and filtered signal in time and frequency domain highlights the advantage of 1-period filtration.
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Affiliation(s)
- Małgorzata Żebrowska
- Laboratory of Visual Neurobiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland.,Faculty of Physics, Warsaw University of Technology, Warsaw, Poland
| | - Piotr Dzwiniel
- Laboratory of Visual Neurobiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Wioletta Joanna Waleszczyk
- Laboratory of Visual Neurobiology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
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19
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Limoli PG, Limoli CSS, Morales MU, Vingolo EM. Mesenchymal stem cell surgery, rescue and regeneration in retinitis pigmentosa: clinical and rehabilitative prognostic aspects. Restor Neurol Neurosci 2020; 38:223-237. [PMID: 32310198 PMCID: PMC7504992 DOI: 10.3233/rnn-190970] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Purpose: To assess whether treatment with the Limoli Retinal Restoration Technique (LRRT) can be performed in patients with retinitis pigmentosa (RP), grafting the autologous cells in a deep scleral pocket above the choroid of each eye to exert their beneficial effect on the residual retinal cells. Methods: The patients were subjected to a complete ophthalmological examination, including best corrected visual acuity (BCVA), close-up visus measurements, spectral domain-optical coherence tomography (SD-OCT), microperimetry (MY), and electroretinography (ERG). Furthermore, the complete ophthalmological examination was carried out at baseline (T0) and at 6 months (T180) after surgery. The Shapiro–Wilk test was used to assess the normality of distribution of the investigated parameters. A mixed linear regression model was used to analyse the difference in all the studied parameters at T0 and T180, and to compare the mean change between the two groups. All statistical analyses were performed with STATA 14.0 (Collage Station, Texas, USA). Results: LRRT treatment was performed in 34 eyes of 25 RP patients recruited for the study. The eyes were classified in two groups on the basis of foveal thickness (FT) assessed by SD-OCT: 14 eyes in Group A (FT≤190μm) and the remaining 20 ones in Group B (FT > 190μm). Although it had not reached the statistical significance, Group B showed a better improvement in BCVA, residual close-up visus and sensitivity than Group A. Conclusions: Previous studies have described the role of LRRT in slowing down retinal degenerative diseases. Consequently, this surgical procedure could improve the clinical and rehabilitative prognostic parameters in RP patients. On the other hand, further clinical research and studies with longer follow-up will be needed to evaluate its efficacy.
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Affiliation(s)
| | | | - Marco Ulises Morales
- Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Enzo Maria Vingolo
- Department of Sense Organs, Faculty of Medicine and Odontology, Sapienza University of Rome, p.le A. Moro, Rome, Italy
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20
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Song H, Zeng Y, Sardar Pasha SPB, Bush RA, Vijayasarathy C, Qian H, Wei L, Wiley HE, Wu Z, Sieving PA. Trans-Ocular Electric Current In Vivo Enhances AAV-Mediated Retinal Transduction in Large Animal Eye After Intravitreal Vector Administration. Transl Vis Sci Technol 2020; 9:28. [PMID: 32844051 PMCID: PMC7416894 DOI: 10.1167/tvst.9.7.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/06/2020] [Indexed: 01/25/2023] Open
Abstract
Purpose Electric micro-current has been shown to enhance penetration and transduction of adeno-associated viral (AAV) vectors in mouse retina after intravitreal administration. We termed this: “electric-current vector mobility (ECVM).” The present study considered whether ECVM could augment retinal transduction efficiency of intravitreal AAV8-CMV-EGFP in normal rabbit and nonhuman primate (NHP) macaque. Potential mechanisms underlying enhanced retinal transduction by ECVM were also studied. Methods We applied an electric micro-current across the intact eye of normal rabbit and monkey in vivo for a brief period immediately after intravitreal injection of AAV8-CMV-EGFP. Retinal GFP expression was evaluated by fundus imaging in vivo. Retinal immunohistochemistry was performed to assess the distribution of retinal cells transduced by the AAV8-EGFP. Basic fibroblast growth factor (bFGF) was analyzed by quantitative RT-polymerase chain reaction (PCR). Müller glial reactivity and inner limiting membrane (ILM) were examined by the glial fibrillary acidic protein (GFAP) and vimentin staining in mouse retina, respectively. Results ECVM significantly increased the efficiency of AAV reaching and transducing the rabbit retina following intravitreal injection, with gene expression in inner nuclear layer, ganglion cells, and Müller cells. Similar trend of improvement was observed in the ECVM-treated monkey eye. The electric micro-current upregulated bFGF expression in Müller cells and vimentin showed ILM structural changes in mouse retina. Conclusions ECVM promotes the transduction efficiency of AAV8-CMV-GFP in normal rabbit and monkey retinas following intravitreal injection. Translational Relevance This work has potential translational relevance to human ocular gene therapy by increasing retinal expression of therapeutic vectors given by intravitreal administration.
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Affiliation(s)
- Hongman Song
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yong Zeng
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Ronald A Bush
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Camasamudram Vijayasarathy
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lisa Wei
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Henry E Wiley
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhijian Wu
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul A Sieving
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Ophthalmology, School of Medicine, University of California at Davis, Sacramento, CA, USA
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21
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Sinim Kahraman N, Oner A. Effect of Transcorneal Electrical Stimulation on Patients with Retinitis Pigmentosa. J Ocul Pharmacol Ther 2020; 36:609-617. [PMID: 32429728 DOI: 10.1089/jop.2020.0017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Purpose: In this study, the aim was to evaluate the safety of transcorneal electrical stimulation (TES) treatment in retinitis pigmentosa (RP) patients and to investigate the effect of TES to the visual acuity (VA), visual field (VF), and multifocal electroretinogram (mfERG) findings. Methods: Two hundred two eyes of 101 RP patients with different stages were studied. TES was applied for 30 min once a week for 8 consecutive weeks. Two hundred eyes of 100 RP patients were enrolled as control. After the 2-month TES therapy sessions, patients were followed for 4 months without treatment. Examinations were done at the baseline before TES treatment and 1 and 6 months after the treatment. Best-corrected VA (BCVA), color fundus photography, VF test, optical coherence tomography, and mfERG tests were done at each visit. Results: The mean BCVA and VF tests improved 1 month after the beginning of TES treatment and the improvements were statistically significant (P < 0.05). There was an improvement in p1 wave amplitude in rings 1, 2, and 3 at the first month. The latency of the p1 wave showed a statistically significant shortening in rings 1 and 2. These improvements partially disappeared at 6-month follow-up. There were no serious ocular side effects related to the therapy. Mild dry eye symptoms were observed, which were revealed by artificial tears. Conclusions: TES is a safe therapy without any serious advers effects. Although it can improve VA and VF of RP patients, the beneficial effects could be transient and repeated sessions can be necessary for maintaining the efficiency.
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Affiliation(s)
| | - Ayse Oner
- Department of Ophthalmology, Acıbadem Kayseri Hospital, Kayseri, Turkey
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Sabel BA, Gao Y, Antal A. Reversibility of visual field defects through induction of brain plasticity: vision restoration, recovery and rehabilitation using alternating current stimulation. Neural Regen Res 2020; 15:1799-1806. [PMID: 32246620 PMCID: PMC7513964 DOI: 10.4103/1673-5374.280302] [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: 12/26/2022] Open
Abstract
For decades visual field defects were considered irreversible because it was thought that in the visual system the regeneration potential of the neuronal tissues is low. Nevertheless, there is always some potential for partial recovery of the visual field defect that can be achieved through induction of neuroplasticity. Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy. It is maintained throughout life and just as neurological rehabilitation can improve motor coordination, visual field defects in glaucoma, diabetic retinopathy or optic neuropathy can be improved by inducing neuroplasticity. In ophthalmology many new treatment paradigms have been tested that can induce neuroplastic changes, including non-invasive alternating current stimulation. Treatment with alternating current stimulation (e.g., 30 minutes, daily for 10 days using transorbital electrodes and ~10 Hz) activates the entire retina and parts of the brain. Electroencephalography and functional magnetic resonance imaging studies revealed local activation of the visual cortex, global reorganization of functional brain networks, and enhanced blood flow, which together activate neurons and their networks. The future of low vision is optimistic because vision loss is indeed, partially reversible.
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Affiliation(s)
- Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University of Magdeburg; Center for Behavioral and Brain Sciences (CBBS); Sabel Vision Restoration Center, Magdeburg, Germany
| | - Ying Gao
- Sabel Vision Restoration Center, Magdeburg, Germany
| | - Andrea Antal
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University of Magdeburg, Magdeburg; Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
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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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Jolly J, Wagner S, Martus P, MacLaren R, Wilhelm B, Webster A, Downes S, Charbel Issa P, Kellner U, Jägle H, Rüther K, Bertelsen M, Bragadóttir R, Prener Holtan J, van den Born L, Sodi A, Virgili G, Gosheva M, Pach J, Zündorf I, Zrenner E, Gekeler F. Transcorneal Electrical Stimulation for the Treatment of Retinitis Pigmentosa: A Multicenter Safety Study of the OkuStim® System (TESOLA-Study). Ophthalmic Res 2019; 63:234-243. [DOI: 10.1159/000505001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 11/24/2019] [Indexed: 11/19/2022]
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Song H, Bush RA, Zeng Y, Qian H, Wu Z, Sieving PA. Trans-ocular Electric Current In Vivo Enhances AAV-Mediated Retinal Gene Transduction after Intravitreal Vector Administration. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 13:77-85. [PMID: 30719486 PMCID: PMC6350231 DOI: 10.1016/j.omtm.2018.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/14/2018] [Indexed: 01/31/2023]
Abstract
Adeno-associated virus (AAV) vector-mediated gene delivery is a promising approach for therapy, but implementation in the eye currently is hampered by the need for delivering the vector underneath the retina, using surgical application into the subretinal space. This limits the extent of the retina that is treated and may cause surgical injury. Vector delivery into the vitreous cavity would be preferable because it is surgically less invasive and would reach more of the retina. Unfortunately, most conventional, non-modified AAV vector serotypes penetrate the retina poorly from the vitreous; this limits efficient transduction and expression by target cells (retinal pigment epithelium and photoreceptors). We developed a method of applying a small and safe electric current across the intact eye in vivo for a brief period following intravitreal vector administration. This significantly improved AAV-mediated transduction of retinal cells in wild-type mice following intravitreal delivery, with gene expression in retinal pigment epithelium and photoreceptor cells. The low-level current had no adverse effects on retinal structure and function. This method should be generally applicable for other AAV serotypes and may have broad application in both basic research and clinical studies.
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Affiliation(s)
- Hongman Song
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA
| | - Ronald A Bush
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA
| | - Yong Zeng
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA
| | - Haohua Qian
- National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Zhijian Wu
- National Eye Institute, NIH, Bethesda, MD 20892, USA
| | - Paul A Sieving
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA.,National Eye Institute, NIH, Bethesda, MD 20892, USA
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26
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Strang CE, Ray MK, Boggiano MM, Amthor FR. Effects of tDCS-like electrical stimulation on retinal ganglion cells. Eye Brain 2018; 10:65-78. [PMID: 30214335 PMCID: PMC6118271 DOI: 10.2147/eb.s163914] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purpose Transcranial direct current stimulation (tDCS) has been studied in humans for its effects on enhancement of learning, amelioration of psychiatric disorders, and modification of other behaviors for over 50 years. Typical treatments involve injecting 2 mA current through scalp electrodes for 20 minutes, sometimes repeated weekly for two to five sessions. Little is known about the direct effects of tDCS at the neural circuit or the cellular level. This study assessed the effects of tDCS-like currents on the central nervous system by recording effects on retinal ganglion cell responsiveness using the rabbit retina eyecup preparation. Materials and methods We examined changes in firing to On and Off light stimuli during and after brief applications of a range of currents and polarity and in different classes of ganglion cells. Results The responses of Sustained cells were consistently suppressed during the first round of current application, but responses could be enhanced after subsequent rounds of stimulation. The observed first round suppression was independent of current polarity, amplitude, or number of trials. However, the light responses of Transient cells were more likely to be enhanced by negative currents and unaffected or suppressed by first round positive currents. Short-duration currents, that is, minutes, as low as 2.5 µA produced a remarkable persistency of firing changes, for up to 1.5 hours, after cessation of current. Conclusion The results are consistent with postulated tDCS alteration of central nervous system function, which outlast the tDCS session and provide evidence for the isolated retina as a useful model to understand tDCS actions at the neuronal level.
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Affiliation(s)
- Christianne E Strang
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, USA,
| | - Mary Katherine Ray
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, USA,
| | - Mary M Boggiano
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, USA,
| | - Franklin R Amthor
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, USA,
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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: 153] [Impact Index Per Article: 25.5] [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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Bittner AK, Seger K, Salveson R, Kayser S, Morrison N, Vargas P, Mendelsohn D, Han J, Bi H, Dagnelie G, Benavente A, Ramella-Roman J. Randomized controlled trial of electro-stimulation therapies to modulate retinal blood flow and visual function in retinitis pigmentosa. Acta Ophthalmol 2018; 96:e366-e376. [PMID: 29130647 DOI: 10.1111/aos.13581] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 08/05/2017] [Indexed: 11/28/2022]
Abstract
PURPOSE We examined changes in visual function and ocular and retinal blood flow (RBF) among retinitis pigmentosa (RP) participants in a randomized controlled trial of electro-stimulation therapies. METHODS Twenty-one RP participants were randomized (1:1:1) to transcorneal electrical stimulation (TES) at 6 weekly half-hour sessions, electro-acupuncture or inactive laser acupuncture (sham control) at 10 half-hour sessions over 2 weeks. Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity (VA), quick contrast sensitivity function, Goldmann visual fields, AdaptDx scotopic sensitivity, spectral flow and colour Doppler imaging of the central retinal artery (CRA), and RBF in macular capillaries were measured twice pre-treatment, after 2 TES sessions, within a week and a month after intervention completion. RESULTS We measured a significant improvement in retrobulbar CRA mean flow velocity for both the TES (p = 0.038) and electro-acupuncture groups (p = 0.001) on average after 2 weeks of treatment when compared to sham controls. Transcorneal electrical simulation (TES) and electro-acupuncture subjects had significant 55% and 34% greater increases, respectively, in RBF in the macular vessels when compared to sham controls (p < 0.001; p = 0.008) within a week of completing six TES sessions or a month after electro-acupuncture. There was a significant difference in the proportion of eyes that had improved visual function when comparing the three intervention groups (p = 0.038): four of seven TES subjects (57%), two of seven electro-acupuncture subjects (29%) and none of the seven control subjects (0%) had a significant visual improvement outside of typical test-retest variability at two consecutive post-treatment visits. CONCLUSION Increased blood flow following electro-stimulation therapies is an objective, physiological change that occurred in addition to visual function improvements in some RP patients.
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Affiliation(s)
- Ava K. Bittner
- College of Optometry; Nova Southeastern University; Fort Lauderdale FL USA
| | - Kenneth Seger
- College of Optometry; Nova Southeastern University; Fort Lauderdale FL USA
| | - Rachel Salveson
- College of Osteopathic Medicine; Nova Southeastern University; Fort Lauderdale FL USA
| | - Samantha Kayser
- College of Optometry; Nova Southeastern University; Fort Lauderdale FL USA
| | - Natalia Morrison
- Healing Blossom - Acupuncture and Holistic Medicine; Miami FL USA
| | - Patricia Vargas
- Medical Sonography Program; College of Health Care Sciences; Nova Southeastern University; Fort Lauderdale FL USA
| | - Deborah Mendelsohn
- Medical Sonography Program; College of Health Care Sciences; Nova Southeastern University; Fort Lauderdale FL USA
| | - Jorge Han
- Medical Sonography Program; College of Health Care Sciences; Nova Southeastern University; Fort Lauderdale FL USA
| | - Hua Bi
- College of Optometry; Nova Southeastern University; Fort Lauderdale FL USA
| | | | | | - Jessica Ramella-Roman
- Department of Biomedical Engineering; Florida International University; Miami FL USA
- Department of Cellular Biology and Pharmacology and Ophthalmology; Herbert Wertheim College of Medicine; Miami FL USA
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29
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LaVail MM, Nishikawa S, Steinberg RH, Naash MI, Duncan JL, Trautmann N, Matthes MT, Yasumura D, Lau-Villacorta C, Chen J, Peterson WM, Yang H, Flannery JG. Phenotypic characterization of P23H and S334ter rhodopsin transgenic rat models of inherited retinal degeneration. Exp Eye Res 2018; 167:56-90. [PMID: 29122605 PMCID: PMC5811379 DOI: 10.1016/j.exer.2017.10.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 02/07/2023]
Abstract
We produced 8 lines of transgenic (Tg) rats expressing one of two different rhodopsin mutations in albino Sprague-Dawley (SD) rats. Three lines were generated with a proline to histidine substitution at codon 23 (P23H), the most common autosomal dominant form of retinitis pigmentosa in the United States. Five lines were generated with a termination codon at position 334 (S334ter), resulting in a C-terminal truncated opsin protein lacking the last 15 amino acid residues and containing all of the phosphorylation sites involved in rhodopsin deactivation, as well as the terminal QVAPA residues important for rhodopsin deactivation and trafficking. The rates of photoreceptor (PR) degeneration in these models vary in proportion to the ratio of mutant to wild-type rhodopsin. The models have been widely studied, but many aspects of their phenotypes have not been described. Here we present a comprehensive study of the 8 Tg lines, including the time course of PR degeneration from the onset to one year of age, retinal structure by light and electron microscopy (EM), hemispheric asymmetry and gradients of rod and cone degeneration, rhodopsin content, gene dosage effect, rapid activation and invasion of the outer retina by presumptive microglia, rod outer segment disc shedding and phagocytosis by the retinal pigmented epithelium (RPE), and retinal function by the electroretinogram (ERG). The biphasic nature of PR cell death was noted, as was the lack of an injury-induced protective response in the rat models. EM analysis revealed the accumulation of submicron vesicular structures in the interphotoreceptor space during the peak period of PR outer segment degeneration in the S334ter lines. This is likely due to the elimination of the trafficking consensus domain as seen before as with other rhodopsin mutants lacking the C-terminal QVAPA. The 8 rhodopsin Tg lines have been, and will continue to be, extremely useful models for the experimental study of inherited retinal degenerations.
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Affiliation(s)
- Matthew M LaVail
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Shimpei Nishikawa
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Roy H Steinberg
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2011, Houston, TX 77204-5060, USA.
| | - Jacque L Duncan
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Nikolaus Trautmann
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Michael T Matthes
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Douglas Yasumura
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Cathy Lau-Villacorta
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Jeannie Chen
- Zilka Neurogenetic Institute, USC Keck School of Medicine, Los Angeles, CA 90089-2821, USA.
| | - Ward M Peterson
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Haidong Yang
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - John G Flannery
- School of Optometry, UC Berkeley, Berkeley, CA 94720-2020, USA.
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30
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Electrical brain stimulation induces dendritic stripping but improves survival of silent neurons after optic nerve damage. Sci Rep 2017; 7:627. [PMID: 28377608 PMCID: PMC5428431 DOI: 10.1038/s41598-017-00487-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/27/2017] [Indexed: 12/29/2022] Open
Abstract
Repetitive transorbital alternating current stimulation (rtACS) improves vision in patients with chronic visual impairments and an acute treatment increased survival of retinal neurons after optic nerve crush (ONC) in rodent models of visual system injury. However, despite this protection no functional recovery could be detected in rats, which was interpreted as evidence of “silent survivor” cells. We now analysed the mechanisms underlying this “silent survival” effect. Using in vivo microscopy of the retina we investigated the survival and morphology of fluorescent neurons before and after ONC in animals receiving rtACS or sham treatment. One week after the crush, more neurons survived in the rtACS-treated group compared to sham-treated controls. In vivo imaging further revealed that in the initial post-ONC period, rtACS induced dendritic pruning in surviving neurons. In contrast, dendrites in untreated retinae degenerated slowly after the axonal trauma and neurons died. The complete loss of visual evoked potentials supports the hypothesis that cell signalling is abolished in the surviving neurons. Despite this evidence of “silencing”, intracellular free calcium imaging showed that the cells were still viable. We propose that early after trauma, complete dendritic stripping following rtACS protects neurons from excitotoxic cell death by silencing them.
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