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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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Choi KE, Anh VTQ, Kim JT, Yun C, Cha S, Ahn J, Goo YS, Kim SW. An experimental pig model with outer retinal degeneration induced by temporary intravitreal loading of N-methyl-N-nitrosourea during vitrectomy. Sci Rep 2021; 11:258. [PMID: 33420119 PMCID: PMC7794530 DOI: 10.1038/s41598-020-79437-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/08/2020] [Indexed: 01/19/2023] Open
Abstract
We aimed to develop an outer retinal degeneration pig model induced by temporary intravitreal loading of N-methyl-N-nitrosourea (MNU) during vitrectomy. In a preliminary experiment involving 5 mini-pig cases to determine the appropriate concentration of MNU, the vitreous cavity of each eye was filled with 4, 8, 10, 12, or 16 mg/mL MNU for 10 min, which was then replaced with a balanced salt solution. Multimodal examinations including spectral-domain optical coherence tomography (OCT) images and full-field electroretinography (ffERG) were obtained at baseline and week 2, week 6, and week 12. The retinal degeneration was classified according to the amplitudes of a dark adaptive (DA) 10.0 a-wave amplitude. The degree of moderate retinal degeneration was defined as DA 10.0 a-wave amplitude ≥ 10% and < 60% of baseline amplitude. The degree of severe degeneration was defined as DA 10.0 a-wave amplitude < 10% of baseline amplitude, noise, or flat signal. Hematoxylin and eosin staining and immunohistochemistry were performed at week 12. The main experiments were conducted first with 10 cases of 5 mg/mL and later with 13 cases of 10 mg/mL. In the preliminary experiment, degree of outer retinal degeneration increased with MNU concentration. Use of 4, 8, 10, 12, and 16 mg/mL MNU showed no, moderate, severe, severe, and atrophic changes, respectively. In the main experiments, there were 9 cases of moderate retinal degeneration and 1 case of severe degeneration in 5 mg/mL MNU group. Two cases of moderate degeneration and 11 of severe degeneration were recorded in 10 mg/mL group. Mean thickness of total retina, inner nuclear layer, and outer nuclear layer decreased at week 2 in both groups. The mean amplitudes on ffERG decreased at week 2. The ffERG and OCT findings did not change from week 2 to week 6 or week 12. The results of staining supported those of ffERG and OCT. Temporal MNU loading in a vitrectomized pig-eye model induced customized outer retinal degeneration with changing the concentration of MNU.
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Affiliation(s)
- Kwang-Eon Choi
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Vu Thi Que Anh
- Department of Ophthalmology, Hanoi Medical University, Hanoi, Vietnam
| | - Jee Taek Kim
- Department of Ophthalmology, Chung-Ang University College of Medicine, Seoul, South Korea
| | - Cheolmin Yun
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Seongkwang Cha
- Department of Physiology, Chungbuk National University College of Medicine, Cheongju, South Korea
| | - Jungryul Ahn
- Department of Physiology, Chungbuk National University College of Medicine, Cheongju, South Korea
| | - Yong Sook Goo
- Department of Physiology, Chungbuk National University College of Medicine, Cheongju, South Korea.
| | - Seong-Woo Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea.
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Choi KE, Anh VTQ, Seo HW, Kim N, Kim S, Kim SW. Ab-interno surgical technique for the implantation of a wireless subretinal prosthesis in mini-pigs. Sci Rep 2020; 10:18507. [PMID: 33116246 PMCID: PMC7595207 DOI: 10.1038/s41598-020-75579-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 10/16/2020] [Indexed: 11/22/2022] Open
Abstract
We sought to describe the surgical techniques required in the ab-interno method to implant subretinal prostheses in mini-pigs and suggest tips to facilitate optimal outcomes. During vitrectomy, the use of valved trocar cannulas was essential to stabilize the detached retina and implanted chip. As a first step in retinal detachment, a 23-gauge cannula with very small amount of viscoelastic material was used to establish the retinal hole and promote retinal detachment. Then, balanced salt solution was applied to increase the retinal detachment and diathermy was used to make opening for subretinal prosthesis. For easy positioning of the subretinal prosthesis, a curved laser probe was adopted when handling the subretinal prosthesis under the retina. After surgery, the sclerotomy sites were tightly sutured to prevent silicone oil leakage. Without special equipment, such as a 41-gauge tip, retinal detachment could be induced easily, while the prosthesis was also successfully inserted and manipulated under the retina without an iatrogenic retinal tear. Two weeks after the operation, the oil fully occupied the intraocular volume without leakage. The subretinal prosthesis remained stable without complication. Understanding the principle of the ab-interno method and considering several tips for improving surgical access may help to enhance surgical success rates of subretinal prostheses implantation.
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Affiliation(s)
- Kwang-Eon Choi
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Vu Thi Que Anh
- Department of Ophthalmology, Hanoi Medical University, Hanoi, Vietnam
| | - Hee Won Seo
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Namju Kim
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Sohee Kim
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea.
| | - Seong-Woo Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea.
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Luu KY, Zhao M, Mannis MJ. The Use of Electrotherapeutics in Ophthalmology. Am J Ophthalmol 2020; 211:4-14. [PMID: 31738895 PMCID: PMC7949834 DOI: 10.1016/j.ajo.2019.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE To present a perspective on the use of electrotherapeutics in the history of ophthalmology along with the development of novel contemporary ophthalmic instrumentation. DESIGN Perspective study. METHODS We reviewed historical journals, articles, and books discussing the use of electricity and electrotherapeutics in ophthalmology. RESULTS Electrotherapeutic applications have been researched and used to treat ocular diseases as far back as the 18th century. By the 20th century, research in electrotherapeutics in ophthalmology had caught the eye of Edward Jackson, the first president of the American Academy of Ophthalmology and Otolaryngology and first editor of the present (third) series American Journal of Ophthalmology. Edward Jackson published an extensive review on this topic and reported a variety of modalities used to treat ocular diseases. CONCLUSIONS While many early therapeutic uses of electricity did not produce effective and replicable results, studies on electrical stimulation of the eye provided the foundation for the development of clinically significant vision enhancing and restoring instrumentation.
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Affiliation(s)
- Kieu-Yen Luu
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA
| | - Min Zhao
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA; Department of Dermatology, University of California, Davis, Sacramento, California, USA
| | - Mark J Mannis
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA.
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Stamp MEM, Tong W, Ganesan K, Prawer S, Ibbotson MR, Garrett DJ. 3D Diamond Electrode Array for High-Acuity Stimulation in Neural Tissue. ACS APPLIED BIO MATERIALS 2020; 3:1544-1552. [DOI: 10.1021/acsabm.9b01165] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Melanie E. M. Stamp
- School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Wei Tong
- School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
- National Vision Research Institute, Australian College of Optometry, Carlton, Victoria 3053, Australia
- Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kumaravelu Ganesan
- School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Steven Prawer
- School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Michael R. Ibbotson
- National Vision Research Institute, Australian College of Optometry, Carlton, Victoria 3053, Australia
| | - David J. Garrett
- School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
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Behavioural responses to a photovoltaic subretinal prosthesis implanted in non-human primates. Nat Biomed Eng 2019; 4:172-180. [PMID: 31792423 DOI: 10.1038/s41551-019-0484-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/23/2019] [Indexed: 11/09/2022]
Abstract
Retinal dystrophies and age-related macular degeneration related to photoreceptor degeneration can cause blindness. In blind patients, although the electrical activation of the residual retinal circuit can provide useful artificial visual perception, the resolutions of current retinal prostheses have been limited either by large electrodes or small numbers of pixels. Here we report the evaluation, in three awake non-human primates, of a previously reported near-infrared-light-sensitive photovoltaic subretinal prosthesis. We show that multipixel stimulation of the prosthesis within radiation safety limits enabled eye tracking in the animals, that they responded to stimulations directed at the implant with repeated saccades and that the implant-induced responses were present two years after device implantation. Our findings pave the way for the clinical evaluation of the prosthesis in patients affected by dry atrophic age-related macular degeneration.
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Fernandez E. Development of visual Neuroprostheses: trends and challenges. Bioelectron Med 2018; 4:12. [PMID: 32232088 PMCID: PMC7098238 DOI: 10.1186/s42234-018-0013-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/27/2018] [Indexed: 02/06/2023] Open
Abstract
Visual prostheses are implantable medical devices that are able to provide some degree of vision to individuals who are blind. This research field is a challenging subject in both ophthalmology and basic science that has progressed to a point where there are already several commercially available devices. However, at present, these devices are only able to restore a very limited vision, with relatively low spatial resolution. Furthermore, there are still many other open scientific and technical challenges that need to be solved to achieve the therapeutic benefits envisioned by these new technologies. This paper provides a brief overview of significant developments in this field and introduces some of the technical and biological challenges that still need to be overcome to optimize their therapeutic success, including long-term viability and biocompatibility of stimulating electrodes, the selection of appropriate patients for each artificial vision approach, a better understanding of brain plasticity and the development of rehabilitative strategies specifically tailored for each patient.
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Affiliation(s)
- Eduardo Fernandez
- Institute of Bioengineering, University Miguel Hernández and CIBER-BBN, Avda de la Universidad, s/n, 03202 Alicante, Elche Spain.,2John A. Moran Eye Center, University of Utah, Salt Lake City, USA
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Abbasi A, Goueytes D, Shulz DE, Ego-Stengel V, Estebanez L. A fast intracortical brain–machine interface with patterned optogenetic feedback. J Neural Eng 2018; 15:046011. [DOI: 10.1088/1741-2552/aabb80] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Barriga-Rivera A, Bareket L, Goding J, Aregueta-Robles UA, Suaning GJ. Visual Prosthesis: Interfacing Stimulating Electrodes with Retinal Neurons to Restore Vision. Front Neurosci 2017; 11:620. [PMID: 29184478 PMCID: PMC5694472 DOI: 10.3389/fnins.2017.00620] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/23/2017] [Indexed: 01/06/2023] Open
Abstract
The bypassing of degenerated photoreceptors using retinal neurostimulators is helping the blind to recover functional vision. Researchers are investigating new ways to improve visual percepts elicited by these means as the vision produced by these early devices remain rudimentary. However, several factors are hampering the progression of bionic technologies: the charge injection limits of metallic electrodes, the mechanical mismatch between excitable tissue and the stimulating elements, neural and electric crosstalk, the physical size of the implanted devices, and the inability to selectively activate different types of retinal neurons. Electrochemical and mechanical limitations are being addressed by the application of electromaterials such as conducting polymers, carbon nanotubes and nanocrystalline diamonds, among other biomaterials, to electrical neuromodulation. In addition, the use of synthetic hydrogels and cell-laden biomaterials is promising better interfaces, as it opens a door to establishing synaptic connections between the electrode material and the excitable cells. Finally, new electrostimulation approaches relying on the use of high-frequency stimulation and field overlapping techniques are being developed to better replicate the neural code of the retina. All these elements combined will bring bionic vision beyond its present state and into the realm of a viable, mainstream therapy for vision loss.
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Affiliation(s)
- Alejandro Barriga-Rivera
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
- Division of Neuroscience, University Pablo de Olavide, Sevilla, Spain
| | - Lilach Bareket
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
| | - Josef Goding
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Gregg J. Suaning
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
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Gupta PR, Huckfeldt RM. Gene therapy for inherited retinal degenerations: initial successes and future challenges. J Neural Eng 2017; 14:051002. [DOI: 10.1088/1741-2552/aa7a27] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Ahnood A, Meffin H, Garrett DJ, Fox K, Ganesan K, Stacey A, Apollo NV, Wong YT, Lichter SG, Kentler W, Kavehei O, Greferath U, Vessey KA, Ibbotson MR, Fletcher EL, Burkitt AN, Prawer S. Diamond Devices for High Acuity Prosthetic Vision. ACTA ACUST UNITED AC 2016; 1:e1600003. [DOI: 10.1002/adbi.201600003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/27/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Arman Ahnood
- School of Physics University of Melbourne Victoria 3010 Australia
| | - Hamish Meffin
- National Vision Research Institute Australian College of Optometry Victoria 3053 Australia
- ARC Centre of Excellence for Integrative Brain Function Department of Optometry and Vision Science University of Melbourne Victoria 3010 Australia
| | - David J. Garrett
- School of Physics University of Melbourne Victoria 3010 Australia
| | - Kate Fox
- School of Physics University of Melbourne Victoria 3010 Australia
- School of Engineering RMIT University Melbourne 3000 Australia
| | | | - Alastair Stacey
- School of Physics University of Melbourne Victoria 3010 Australia
| | | | - Yan T. Wong
- National Vision Research Institute Australian College of Optometry Victoria 3053 Australia
- Department of Electrical & Electronic Engineering The University of Melbourne Victoria 3010 Australia
| | | | - William Kentler
- Department of Electrical & Electronic Engineering The University of Melbourne Victoria 3010 Australia
| | - Omid Kavehei
- School of Engineering RMIT University Melbourne 3000 Australia
| | - Ursula Greferath
- Department of Anatomy and Neuroscience University of Melbourne Victoria 3010 Australia
| | - Kirstan A. Vessey
- Department of Anatomy and Neuroscience University of Melbourne Victoria 3010 Australia
| | - Michael R. Ibbotson
- National Vision Research Institute Australian College of Optometry Victoria 3053 Australia
- ARC Centre of Excellence for Integrative Brain Function Department of Optometry and Vision Science University of Melbourne Victoria 3010 Australia
| | - Erica L. Fletcher
- Department of Anatomy and Neuroscience University of Melbourne Victoria 3010 Australia
| | - Anthony N. Burkitt
- Department of Electrical & Electronic Engineering The University of Melbourne Victoria 3010 Australia
| | - Steven Prawer
- School of Physics University of Melbourne Victoria 3010 Australia
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