1
|
Gunder N, Dörig P, Witt M, Welge-Lüssen A, Menzel S, Hummel T. Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview. HNO 2023; 71:35-43. [PMID: 36734997 PMCID: PMC9897160 DOI: 10.1007/s00106-022-01249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2022] [Indexed: 02/04/2023]
Abstract
Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.
Collapse
Affiliation(s)
- N Gunder
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - P Dörig
- Universitäts-HNO Klinik Basel, Basel, Switzerland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Germany
| | | | - S Menzel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - T Hummel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| |
Collapse
|
2
|
Ali L, Kilic H, Öztüren A. From disabled tourists to impaired cyborg tourists: What would it take to transform? UNIVERSAL ACCESS IN THE INFORMATION SOCIETY 2023:1-18. [PMID: 36789138 PMCID: PMC9910771 DOI: 10.1007/s10209-023-00970-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Despite the media reports and governments promoting tourism as a fundamental right for everyone, traveling is still not accessible for disabled people. This study has highlighted the need to make tourists with disabilities accessable for inaccessible destinations. Cyborg products in the form of technological implants can make tourists with disabilities accessable for inaccessible destinations. Since tourists with a mobility disability (TMD) will be one of the primary beneficiaries of technological implants, little is known about their acceptance of technological implants during traveling.Therefore, this study assesses the willingness of TMD to use technological implants during traveling through a qualitative research approach. The results from thematic analysis identified two main themes: the use of assistive devices during traveling with four sub-themes (freedom of traveling, physical and attitudinal barriers, cost, and additional assistance and battery issues), and drivers of impaired cyborg tourists with seven sub-themes (independence, improved well-being, convenience/ease of use, social inclusion, positive emotions, motivation, and other issues). The study contributed to the literature by introducing drivers of impaired cyborg tourists along with previously identified concepts. The results also provided implications for the stakeholders of the tourism industry.
Collapse
Affiliation(s)
- Laiba Ali
- Faculty of Tourism, Eastern Mediterranean University, Famagusta, North Cyprus Turkey
| | - Hasan Kilic
- Faculty of Tourism, Eastern Mediterranean University, Famagusta, North Cyprus Turkey
| | - Ali Öztüren
- Faculty of Tourism, Eastern Mediterranean University, Famagusta, North Cyprus Turkey
| |
Collapse
|
3
|
Wang H, Ouyang W, Liu Y, Zhang M, Zhao H, Wang J, Yin Z. Visual task-related functional and structural magnetic resonance imaging for the objective quantitation of visual function in patients with advanced retinitis pigmentosa. Front Aging Neurosci 2022; 14:825204. [PMID: 36034150 PMCID: PMC9416479 DOI: 10.3389/fnagi.2022.825204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/28/2022] [Indexed: 11/22/2022] Open
Abstract
Purpose The objective quantitation of visual function in patients with advanced retinitis pigmentosa (RP) presents a difficult challenge due to the weak visual function of these patients. This study utilized magnetic resonance imaging (MRI) to assess the function and structure of the visual cortex (VC) in patients with RP and quantitatively categorize them. Materials and Methods Twenty-three patients with RP and ten healthy controls (HCs) were enrolled for MRI examinations. The patients were divided into form perception (FP) and no form perception (NFP) groups. Participants underwent structural MRI scans, and two visual task functional MRI scans were performed using stimuli, including white flash and black and white checkerboard patterns. Eight regions of interest (ROIs) were studied. In structural MRI, the gray matter volume (GMV) was compared in the ROIs. In the two visual tasks, the response intensity and functional connectivity (FC) of ROIs were also compared separately. Correlation analysis was performed to explore the correlations between the structural and functional parameters. Results In the structural analysis, the GMV in Brodmann areas 17, 18, and 19 of the FP and NFP groups was significantly lower than that of HCs. Regarding the functional data, the response intensity in the VC of both the FP and NFP groups was significantly lower than that in HCs. The response in Brodmann areas 17, 18, and 19 obtained using the pattern stimulus was significantly lower in the NFP group than in the FP group. For the FC comparison, the FP and NFP groups exhibited significantly lower values in several pathways than the HCs, and FC in the ipsilateral V1–contralateral V1 pathway in the flash task was significantly lower in the NFP group than in the FP group. A positive correlation between response intensity and GMV was observed in Brodmann areas 17, 18, and 19 in both flash and pattern visual tasks. Conclusion Magnetic resonance imaging was an effective tool to objectively and quantitatively evaluate the visual function of patients with advanced RP. Response intensity and FC were effective parameters to distinguish FP and NFP patients. A positive correlation between response intensity and GMV was observed in the VC.
Collapse
Affiliation(s)
- Hao Wang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Wangbin Ouyang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yong Liu
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Minfang Zhang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - He Zhao
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Army Medical University, Chongqing, China
- *Correspondence: Jian Wang,
| | - Zhengqin Yin
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
- Zhengqin Yin,
| |
Collapse
|
4
|
Hintzen KW, Simons C, Schaffrath K, Roessler G, Johnen S, Jakob F, Walter P, Schwaneberg U, Lohmann T. BioAdhere: tailor-made bioadhesives for epiretinal visual prostheses. Biomater Sci 2022; 10:3282-3295. [PMID: 35583519 DOI: 10.1039/d1bm01946e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Introduction: Visual prostheses, i.e. epiretinal stimulating arrays, are a promising therapy in treating retinal dystrophies and degenerations. In the wake of a new generation of devices, an innovative method for epiretinal fixation of stimulator arrays is required. We present the development of tailor-made bioadhesive peptides (peptesives) for fixating epiretinal stimulating arrays omitting the use of traumatic retinal tacks. Materials and methods: Binding motifs on the stimulating array (poly[chloro-p-xylylene] (Parylene C)) and in the extracellular matrix of the retinal surface (collagens I and IV, laminin, fibronectin) were identified. The anchor peptides cecropin A (CecA), KH1, KH2 (author's initials) and osteopontin (OPN) were genetically fused to reporter proteins to assess their binding behavior to coated microtiter plates via fluorescence-based assays. Domain Z (DZ) of staphylococcal protein A was used as a separator to generate a bioadhesive peptide. Following ISO 10993 "biological evaluation of medical materials", direct and non-direct cytotoxicity testing (L-929 and R28 retinal progenitor cells) was performed. Lastly, the fixating capabilities of the peptesives were tested in proof-of-principle experiments. Results: The generation of the bioadhesive peptide required evaluation of the N- and C-anchoring of investigated APs. The YmPh-CecA construct showed the highest activity on Parylene C in comparison with the wildtype phytase without the anchor peptide. eGFP-OPN was binding to all four investigated ECM proteins (collagen I, laminin > collagen IV, fibronectin). The strongest binding to collagen I was observed for eGFP-KH1, while the strongest binding to fibronectin was observed for eGFP-KH2. The selectivity of binding was checked by incubating eGFP-CecA and eGFP-OPN on ECM proteins and on Parylene C, respectively. Direct and non-direct cytotoxicity testing of the peptide cecropin-A-DZ-OPN using L-929 and R28 cells showed good biocompatibility properties. Proof-of-concept experiments in post-mortem rabbit eyes suggested an increased adhesion of CecA-DZ-OPN-coated stimulating arrays. Conclusion: This is the first study to prove the applicability and biocompatibility of peptesives for the fixation of macroscopic objects.
Collapse
Affiliation(s)
- Kai-Wolfgang Hintzen
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.,DWI - Leibniz-Institute for Interactive Materials, Aachen, Germany
| | - Christian Simons
- DWI - Leibniz-Institute for Interactive Materials, Aachen, Germany
| | - Kim Schaffrath
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.
| | - Gernot Roessler
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.
| | - Sandra Johnen
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.
| | - Felix Jakob
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.,DWI - Leibniz-Institute for Interactive Materials, Aachen, Germany
| | - Peter Walter
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.,DWI - Leibniz-Institute for Interactive Materials, Aachen, Germany
| | - Tibor Lohmann
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany.
| |
Collapse
|
5
|
Dörig P, Gunder N, Witt M, Welge-Lüssen A, Hummel T. [Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview]. HNO 2021; 69:623-632. [PMID: 33988723 PMCID: PMC8120256 DOI: 10.1007/s00106-021-01060-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 11/08/2022]
Abstract
Passagere oder permanente Riechstörungen können verschiedene Ursachen haben. Ganz aktuell berichtet eine Vielzahl von Patienten im Rahmen von COVID-19-Infektionen über ein fehlendes oder vermindertes Riechvermögen. In der Vergangenheit wurden vielfältige Therapieoptionen untersucht, diese variieren vom Riechtraining über Akupunktur und medikamentöse Therapien bis hin zur transkraniellen Magnetstimulation oder, z. B. bei ausgeprägten qualitativen Riechstörungen, der chirurgischen Resektion der Riechschleimhaut. Die Entwicklung einer bioelektrischen Nase, z. B. in Verbindung mit direkter elektrischer Stimulation des Bulbus olfactorius, oder die Transplantation von Riechschleimhaut oder von Stammzellen stellen Behandlungsmöglichkeiten der Zukunft dar. Die Grundlagen für diese Entwicklungen sowie der Stand des Wissens werden in der vorliegenden Arbeit erläutert.
Collapse
Affiliation(s)
- P Dörig
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz.
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Deutschland
| | - A Welge-Lüssen
- Universitäts-HNO Klinik Basel, Petersgraben 4, 4031, Basel, Schweiz
| | - T Hummel
- Universitäts-HNO Klinik Dresden, Dresden, Deutschland
| |
Collapse
|
6
|
Quantitative assessment of visual pathway function in blind retinitis pigmentosa patients. Clin Neurophysiol 2021; 132:392-403. [PMID: 33450562 DOI: 10.1016/j.clinph.2020.11.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 11/02/2020] [Accepted: 11/08/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The current methods used to assess visual function in blind retinitis pigmentosa (RP) patients are mostly subjective. We aimed to identify effective, objective methods. METHODS We enrolled patients diagnosed with blindness associated with RP; we finally selected 26 patients (51 eyes) with a visual field radius less than 10 degrees and divided them into the following 4 groups by best-corrected visual acuity (BCVA): group 1, no light perception (NLP, 4 eyes); group 2, light perception (LP, 12 eyes); group 3, hand movement or finger counting (faint form perception, FFP, 22 eyes); and group 4, BCVA from 0.1 to 0.8 (form perception, FP, 13 eyes). All patients underwent optometry, optical coherence tomography (OCT), color fundus photography, fundus autofluorescence (FAF), full field electroretinography (ffERG), pattern electroretinography (PERG), multifocal electroretinography (mf-ERG), pattern visual evoked potential (PVEP), flash visual evoked potential (FVEP), and pupillary light response (PLR) assessments. Five patients in groups 1, 2, and 3 (1, 2, and 2 subjects, respectively) underwent functional magnetic resonance imaging (fMRI) scans and were compared with five healthy subjects. RESULTS The outer plexiform layer was thinner in group 1, and the outer nuclear layer was thinner in groups 1 and 2. The ffERG, PERG, and mf-ERG findings were unrecordable in all four groups. The P2 amplitude of the FVEP was significantly lower in groups 1 and 2, while the P100 amplitude of the PVEP was higher in groups 2, 3 and 4 than in group 1. After white- and blue-light stimuli, the PLR thresholds in the patients without form perception were significantly higher. The threshold of the PLR stimulated by blue and white light was negatively correlated with the amplitudes of P2 and P100. Moreover, the fMRI findings showed that some RP patients have significant visual cortex activation in response to certain types of stimulation. However, statistical analysis was not performed because of the small number of cases. CONCLUSIONS OCT, VEP, PLR and fMRI assessments can evaluate residual visual pathway function in blind RP patients. SIGNIFICANCE Our study may have clinical significance for the potential prediction of RP patient prognoses and the effects after clinical trials.
Collapse
|
7
|
Sun SY, Mammo DA, Koozekanani DD, Montezuma SR. Hemifacial Spasm in an Argus II Retinal Prosthesis Patient. JOURNAL OF VITREORETINAL DISEASES 2020; 4:325-326. [PMID: 37009174 PMCID: PMC9976104 DOI: 10.1177/2474126419890497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
PURPOSE A 59-year-old man with retinitis pigmentosa, who received an Argus II retinal prosthesis in the left eye 3 years prior, presented with left-sided involuntary facial contractions that occurred only after turning on the Argus II device. METHODS A case report. RESULTS Given that this patient's reported and visualized lower eyelid twitching corresponds to the location of the external region of the implanted coil, we hypothesize that heat or wirelessly transmitted electrical signals from the external coil to the implanted coil may induce spasm of the facial nerve and thus play a role in hemifacial spasm onset. CONCLUSIONS To our knowledge, this is the first report of hemifacial spasm associated with Argus II use.
Collapse
Affiliation(s)
- Susan Y. Sun
- Department of Ophthalmology and Visual Neurosciences, University of
Minnesota, Minneapolis, MN, USA
| | - Danny A. Mammo
- Department of Ophthalmology and Visual Neurosciences, University of
Minnesota, Minneapolis, MN, USA
| | - Dara D. Koozekanani
- Department of Ophthalmology and Visual Neurosciences, University of
Minnesota, Minneapolis, MN, USA
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of
Minnesota, Minneapolis, MN, USA
| |
Collapse
|
8
|
Lyu Q, Lu Z, Li H, Qiu S, Guo J, Sui X, Sun P, Li L, Chai X, Lovell NH. A Three-Dimensional Microelectrode Array to Generate Virtual Electrodes for Epiretinal Prosthesis Based on a Modeling Study. Int J Neural Syst 2020; 30:2050006. [DOI: 10.1142/s0129065720500069] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Despite many advances in the development of retinal prostheses, clinical reports show that current retinal prosthesis subjects can only perceive prosthetic vision with poor visual acuity. A possible approach for improving visual acuity is to produce virtual electrodes (VEs) through electric field modulation. Generating controllable and localized VEs is a crucial factor in effectively improving the perceptive resolution of the retinal prostheses. In this paper, we aimed to design a microelectrode array (MEA) that can produce converged and controllable VEs by current steering stimulation strategies. Through computational modeling, we designed a three-dimensional concentric ring–disc MEA and evaluated its performance with different stimulation strategies. Our simulation results showed that electrode–retina distance (ERD) and inter-electrode distance (IED) can dramatically affect the distribution of electric field. Also the converged VEs could be produced when the parameters of the three-dimensional MEA were appropriately set. VE sites can be controlled by manipulating the proportion of current on each adjacent electrode in a current steering group (CSG). In addition, spatial localization of electrical stimulation can be greatly improved under quasi-monopolar (QMP) stimulation. This study may provide support for future application of VEs in epiretinal prosthesis for potentially increasing the visual acuity of prosthetic vision.
Collapse
Affiliation(s)
- Qing Lyu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Zhuofan Lu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Heng Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Shirong Qiu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jiahui Guo
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Xiaohong Sui
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Pengcheng Sun
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Liming Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Xinyu Chai
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Nigel H. Lovell
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
9
|
Rachitskaya A, Yuan A, Davidson S, Streicher M, DeBenedictis M, Rosenfeldt AB, Alberts J. Computer-Assisted Immersive Visual Rehabilitation in Argus II Retinal Prosthesis Recipients. Ophthalmol Retina 2020; 4:613-619. [PMID: 31937474 DOI: 10.1016/j.oret.2019.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE The field of retinal prostheses is expanding. However, the best approach to training and assessing the functional benefit of postoperative vision has not been established. The purpose of this single-center prospective interventional case series was to evaluate the feasibility and effectiveness of using the Computer Assisted Rehabilitation Environment (CAREN) system as a visual rehabilitation tool in Argus II patients. DESIGN Single-center prospective interventional case series (clinicaltrials.gov identifier, NCT03444961). PARTICIPANTS Four Argus II recipients (3 men and 1 woman). METHODS Eight visual rehabilitation sessions using the CAREN system (twice weekly for 4 weeks). MAIN OUTCOME MEASURES Baseline and postintervention assessments consisted of visual function, mobility, and balance tests. RESULTS All patients successfully completed training on the CAREN system. While the Argus II device was active, walking speed increased from baseline to immediately after the intervention on flat and undulating surfaces and while localizing objects by 20%, 10%, and 18%, respectively. An improved ability to complete the timed up and go test successfully was observed. CONCLUSIONS Novel methods of visual rehabilitation for retinal prostheses recipients, such the CAREN system, are feasible and may result in improved ability to use the Argus II while performing functional tasks. Immersive technology may provide a solution for the standardization of effective rehabilitation approaches to augment retinal prosthesis performance. Heterogeneity of results indicates that a larger sample size would be beneficial.
Collapse
Affiliation(s)
- Aleksandra Rachitskaya
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio.
| | - Alex Yuan
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Sara Davidson
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Matthew Streicher
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Meghan DeBenedictis
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Anson B Rosenfeldt
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Jay Alberts
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio; Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, Ohio; Office of Clinical Transformation, Cleveland Clinic Foundation, Cleveland, Ohio
| |
Collapse
|
10
|
Abstract
In outer retinal degenerative diseases such as retinitis pigmentosa, choroideremia, and geographic atrophy, 30% of the ganglion cell layer in the macula remains intact. With subretinal and epiretinal prostheses, these inner retinal cells are stimulated with controlled electrical current by either a microphotodiode placed in the subretinal area or a microelectrode array tacked to the epiretinal region. As the patient learns to interpret the resulting phosphene patterns created in the brain through special rehabilitation exercises, their orientation, mobility, and quality of life increase. Implants that stimulate the lateral geniculate nucleus or visual cortex are currently being studied for diseases in which the ganglion cells and optic nerve are completely destroyed.
Collapse
Affiliation(s)
- Emin Özmert
- Ankara University Faculty of Medicine, Department of Ophthalmology, Divisions of Medical and Surgical-Retina-Bionic Eye and Artificial Vision, Ankara, Turkey
| | | |
Collapse
|
11
|
Lunghi C, Galli-Resta L, Binda P, Cicchini GM, Placidi G, Falsini B, Morrone MC. Visual Cortical Plasticity in Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 60:2753-2763. [PMID: 31247082 PMCID: PMC6746622 DOI: 10.1167/iovs.18-25750] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose Retinitis pigmentosa is a family of genetic diseases inducing progressive photoreceptor degeneration. There is no cure for retinitis pigmentosa, but prospective therapeutic strategies are aimed at restoring or substituting retinal input. Yet, it is unclear whether the visual cortex of retinitis pigmentosa patients retains plasticity to react to the restored visual input. Methods To investigate short-term visual cortical plasticity in retinitis pigmentosa, we tested the effect of short-term (2 hours) monocular deprivation on sensory ocular dominance (measured with binocular rivalry) in a group of 14 patients diagnosed with retinitis pigmentosa with a central visual field sparing greater than 20° in diameter. Results After deprivation most patients showed a perceptual shift in ocular dominance in favor of the deprived eye (P < 0.001), as did control subjects, indicating a level of visual cortical plasticity in the normal range. The deprivation effect correlated negatively with visual acuity (r = −0.63, P = 0.015), and with the amplitude of the central 18° focal electroretinogram (r = −0.68, P = 0.015) of the deprived eye, revealing that in retinitis pigmentosa stronger visual impairment is associated with higher plasticity. Conclusions Our results provide a new tool to assess the ability of retinitis pigmentosa patients to adapt to altered visual inputs, and suggest that in retinitis pigmentosa the adult brain has sufficient short-term plasticity to benefit from prospective therapies.
Collapse
Affiliation(s)
- Claudia Lunghi
- Laboratoire des systèmes perceptifs, Département d'études Cognitives, École Normale Supérieure, PSL University, CNRS, Paris, France.,Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - Paola Binda
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.,Institute of Neuroscience CNR, Pisa, Italy
| | | | - Giorgio Placidi
- Department of Ophthalmology, Policlinico Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Benedetto Falsini
- Department of Ophthalmology, Policlinico Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Maria Concetta Morrone
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.,IRCCS Stella Maris, Calambrone (Pisa), Italy
| |
Collapse
|
12
|
Lohmann TK, Haiss F, Schaffrath K, Schnitzler AC, Waschkowski F, Barz C, van der Meer AM, Werner C, Johnen S, Laube T, Bornfeld N, Mazinani BE, Rößler G, Mokwa W, Walter P. The very large electrode array for retinal stimulation (VLARS)—A concept study. J Neural Eng 2019; 16:066031. [DOI: 10.1088/1741-2552/ab4113] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
13
|
Xu LT, Rachitskaya AV, DeBenedictis MJ, Bena J, Morrison S, Yuan A. Correlation between Argus II array-retina distance and electrical thresholds of stimulation is improved by measuring the entire array. Eur J Ophthalmol 2019; 31:194-203. [PMID: 31680546 DOI: 10.1177/1120672119885799] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To describe two methods of measuring Argus II array-retina distance and to correlate array-retina distance to electrode stimulation thresholds. METHODS This was a case series of eight patients implanted with the Argus II. Spectral domain-optical coherence tomography array-retina distance was measured by two methods and correlated to corresponding electrode thresholds: (1) array-retina distance at each array corner and the largest array-retina distance and (2) using manual optical coherence tomography segmentation, the average array-retina distance was determined for each group of four electrodes. Patients 1-5 and 6-8 were analyzed separately due to a different threshold programming software. RESULTS The Spearman's rank coefficient between array-retina distance and thresholds was -0.006 (p = 0.98) for patients 1-5, and 0.16 (p = 0.59) for patients 6-8 with the first method. The Spearman's rank coefficient was 0.25 (p < 0.001) for patients 1-5 and 0.36 (p < 0.001) for patients 6-8 with the second method. CONCLUSION There is a positive correlation between array-retina distance and threshold measurements when measuring the entire array but not when using a faster measurement method of four corners and largest array-retina distance.
Collapse
Affiliation(s)
- Lucy T Xu
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | | | - James Bena
- Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Shannon Morrison
- Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Alex Yuan
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| |
Collapse
|
14
|
Sabel BA, Flammer J, Merabet LB. Residual vision activation and the brain-eye-vascular triad: Dysregulation, plasticity and restoration in low vision and blindness - a review. Restor Neurol Neurosci 2019; 36:767-791. [PMID: 30412515 PMCID: PMC6294586 DOI: 10.3233/rnn-180880] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vision loss due to ocular diseases such as glaucoma, optic neuropathy, macular degeneration, or diabetic retinopathy, are generally considered an exclusive affair of the retina and/or optic nerve. However, the brain, through multiple indirect influences, has also a major impact on functional visual impairment. Such indirect influences include intracerebral pressure, eye movements, top-down modulation (attention, cognition), and emotionally triggered stress hormone release affecting blood vessel dysregulation. Therefore, vision loss should be viewed as the result of multiple interactions within a “brain-eye-vascular triad”, and several eye diseases may also be considered as brain diseases in disguise. While the brain is part of the problem, it can also be part of the solution. Neuronal networks of the brain can “amplify” residual vision through neuroplasticity changes of local and global functional connectivity by activating, modulating and strengthening residual visual signals. The activation of residual vision can be achieved by different means such as vision restoration training, non-invasive brain stimulation, or blood flow enhancing medications. Modulating brain functional networks and improving vascular regulation may offer new opportunities to recover or restore low vision by increasing visual field size, visual acuity and overall functional vision. Hence, neuroscience offers new insights to better understand vision loss, and modulating brain and vascular function is a promising source for new opportunities to activate residual vision to achieve restoration and recovery to improve quality of live in patients suffering from low vision.
Collapse
Affiliation(s)
- Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany
| | - Josef Flammer
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Lotfi B Merabet
- Department of Ophthalmology, The Laboratory for Visual Neuroplasticity, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, USA
| |
Collapse
|
15
|
Prochazka A. Neurophysiology and neural engineering: a review. J Neurophysiol 2017; 118:1292-1309. [PMID: 28566462 PMCID: PMC5558026 DOI: 10.1152/jn.00149.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/19/2022] Open
Abstract
Neurophysiology is the branch of physiology concerned with understanding the function of neural systems. Neural engineering (also known as neuroengineering) is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties and functions of neural systems. In most cases neural engineering involves the development of an interface between electronic devices and living neural tissue. This review describes the origins of neural engineering, the explosive development of methods and devices commencing in the late 1950s, and the present-day devices that have resulted. The barriers to interfacing electronic devices with living neural tissues are many and varied, and consequently there have been numerous stops and starts along the way. Representative examples are discussed. None of this could have happened without a basic understanding of the relevant neurophysiology. I also consider examples of how neural engineering is repaying the debt to basic neurophysiology with new knowledge and insight.
Collapse
Affiliation(s)
- Arthur Prochazka
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
16
|
Castaldi E, Cicchini GM, Cinelli L, Biagi L, Rizzo S, Morrone MC. Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis. PLoS Biol 2016; 14:e1002569. [PMID: 27780207 PMCID: PMC5079588 DOI: 10.1371/journal.pbio.1002569] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/19/2016] [Indexed: 11/19/2022] Open
Abstract
Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD) activity in V1 and the lateral geniculate nucleus (LGN) was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation.
Collapse
Affiliation(s)
- E. Castaldi
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - L. Cinelli
- Azienda Ospedaliero-Universitaria Careggi, SOD Oculistica, Florence, Italy
| | - L. Biagi
- Stella Maris Scientific Institute, Pisa, Italy
| | - S. Rizzo
- Azienda Ospedaliero-Universitaria Careggi, SOD Oculistica, Florence, Italy
| | - M. C. Morrone
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Stella Maris Scientific Institute, Pisa, Italy
- * E-mail:
| |
Collapse
|